JP2000137093A - Fixed in-pile nuclear instrumentation system of reactor, nuclear instrumentation process, power distribution calculating device and method, and power distribution monitoring system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make power distribution calculations with accuracy after a core condition (operating condition) has been changed by sampling accurate GT (γ-ray heating) signals or LPRM (neutron detection) signals into a power distribution calculating device. SOLUTION: This system has an in-pile nuclear instrumentation, assembly 32 in which a plurality of fixed LPRM detectors 37 for detecting local power distributions within a reactor 2 and the fixed GT detectors 44 of a GT assembly 35 for detecting γ-ray heating values are enclosed in a nuclear instrumentation pipe 33 with the GT detectors 44 arranged near the LPRM detectors 37, an LPRM signal processing device 40 for processing LPRM detection signals from the LPRM detectors 37, a GT signal processing device 48 for processing GT signals from the GT assembly 35, and a GT heater control device 53 controlling the current-carrying to a heater built into the GT assembly 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nuclear reactor fixed instrumentation system for a nuclear reactor such as a boiling water reactor, a nuclear instrumentation processing method, a power distribution calculating device and a calculation method, and a power distribution monitoring system and a monitoring method. .

[0002]

2. Description of the Related Art In a nuclear reactor, for example, a boiling water reactor (hereinafter referred to as BWR), as generally shown in FIGS. In the specification, a power distribution monitoring system for monitoring the power distribution of the reactor is described as "in-core power distribution", "core power distribution", "in-core power distribution", and the like.

In a BWR, as shown in FIG.
A reactor pressure vessel 2 is housed in a reactor containment vessel 1, and a reactor core 3 is housed in the reactor pressure vessel 2. As shown in FIG. 15, the core 3 is configured by loading a large number of fuel assemblies 4, control rods 5, and the like. An in-core nuclear instrumentation assembly 6 is provided in the core 3 at a position surrounded by the fuel assembly 4.

As shown in FIG. 15, four fuel assemblies 4
A nuclear instrumentation assembly 6 in the reactor is disposed in the corner water gap G formed by the above. A neutron detector 8 is discretely provided at several places in the axial direction of the core in the nuclear instrumentation pipe 7 of the nuclear instrumentation assembly 6. Placed in The neutron detectors 8 are of a so-called fixed type. In a boiling water reactor (BWR), usually four neutron detectors 8 are arranged at equal intervals in the active fuel portion in the axial direction of the core.

Further, in the nuclear instrumentation tube 7, TIP (Tra
A versing In-CoreProbe (mobile in-core instrumentation) conduit 9 is disposed, and one mobile neutron detector (TIP) 10 is provided in the TIP conduit 9 so as to be movable in the axial direction. In addition, as shown in FIG.
1. A movable neutron flux measurement system for continuously measuring the neutron flux in the axial direction by the TIP drive device 12, the TIP control / neutron flux signal processing device 13, and the like is also provided. Reference numeral 14 denotes a penetration part, 15 denotes a valve mechanism, 16
Is a shielding container. These neutron detectors 8 and 10,
Signal processing device 1 (described later) of each neutron detector 8, 10
The reactor nuclear instrumentation system 18 includes the control devices 3, 17 and the like.

On the other hand, fixed neutron detectors (LPRM detectors) 8 arranged in the furnace are divided into several groups to generate an average signal (APRM signal) for each group. The power level in the power region of the core 3 is monitored based on the signal. That is, LPR
The M detector 8 detects the above-mentioned transient event / accident in response to an APRM signal when an abnormal transient event or an accident occurs such as a neutron flux rising rapidly, to prevent fuel damage or core damage. It is configured as a part of a reactor safety protection system for rapidly scram-operating a reactor shutdown system (not shown) such as a control rod drive mechanism.

Incidentally, the neutron detector 8 fixed in the furnace is used.
, The sensitivity changes individually due to neutron irradiation and the like. Therefore, in order to calibrate the sensitivity of each neutron detector 8 at regular intervals during operation, the TIP (mobile neutron detector) 10 is operated to obtain a continuous power distribution in the core axis direction,
The change in sensitivity of each neutron detector 8 is determined by a neutron detector (LPR).
M) Correction is performed by the gain adjustment function of the signal processing device 17. Detection signal S2 detected by neutron detector 8
Is subjected to signal processing via the signal processing device 17 and transmitted to a process computer 20 described later.

A normal process control computer 20 is installed in the BWR for monitoring the operating state and power distribution of the nuclear power plant. This process control computer 20
Is a nuclear instrumentation controller 21 for monitoring and controlling the nuclear instrumentation system 18, an output distribution calculator 22 having a physical model of a three-dimensional nuclear thermal hydraulic calculation code, and an input / output device 23.
It has. The reactor power distribution calculating device 22 is built in one or more of the process control computers 20 as a program. Reactor power distribution calculator 22
Includes an output distribution calculation module 24 and an output distribution learning module 25.

The T of the nuclear reactor instrumentation system 18
The neutron flux signal obtained by the IP 10 is processed by the TIP neutron flux signal processing device 13 of the nuclear reactor instrumentation system 18 as a nuclear instrumentation signal corresponding to the core axial position. Nuclear instrumentation control device 2
1 is read into the output distribution calculation device 22 as a reference output distribution at the time of three-dimensional nuclear thermal hydraulic calculation.

On the other hand, control rod patterns as various operating parameters representing the operating state of the reactor obtained from the reactor core data measuring device 26 as the reactor core data measuring means, core coolant flow rate, reactor pressure vessel Core current state data S3 (process amount) such as internal pressure, feedwater flow rate, feedwater temperature (or core inlet coolant temperature), etc.
The data is read into the data processor 7 and subjected to data processing to calculate the thermal power of the reactor. Then, the reactor status data S3 including the calculated reactor heat output is sent to the reactor power distribution calculator 22 via the nuclear instrumentation controller 21 of the process control computer 20.

The reactor core status data measuring device 26 is actually composed of a plurality of monitoring devices. Further, the reactor core current data measuring device 26 is a generic name of a device for collecting process data of various operating parameters of the nuclear reactor, but is illustrated as one measuring device in FIG. 14 for simplification. Further, the current data processing device 27 may be configured as a part of the function of the process control computer 20.

The detection signal S2 and the current core data S3 transmitted in this manner are stored in the process control computer 20.
Is sent to the output distribution calculating device 22. The power distribution calculating device 22 calculates the core power distribution based on the sent core current state data S3 and the three-dimensional nuclear thermal hydraulic calculation code of the power distribution calculating module 24. Further, the power distribution calculating device 22 learns a reference power distribution of the core nuclear instrumentation data by a learning function of the power distribution learning module 25, and corrects a calculation result (core power distribution) with reference to the reference power distribution. As a result, the reactor power distribution can be accurately calculated in the subsequent power distribution prediction calculation.

Further, in the conventional core instrumentation assembly 6, instead of the mobile neutron detector 10, as shown in a partially cutaway perspective view of FIG. In some cases, the γ-ray flux is continuously measured in the core axis direction by moving the γ-ray flux in the core direction. Since γ-rays are generated in proportion to the amount of fission in the reactor core 3, by measuring the γ-ray flux, the amount of fission in the vicinity can be measured.

Mobile neutron detector 10 and gamma ray detector 1
By using 0A, it is possible to calibrate the variation in the detection accuracy of each of the plurality of neutron detectors 8 arranged in the core axis direction, and to continuously measure the power distribution in the core axis direction.

As described above, in the conventional nuclear reactor instrumentation system 18, the continuous axial power distribution of the reactor core 3 is measured by the mobile neutron detector 10 and the movable neutron detector 10 constituting the movable nuclear reactor core instrumentation apparatus. It relied on the formula γ-ray detector 10A.

On the other hand, a mobile (movable) neutron detector 1
The 0 or γ-ray detector 10A is configured to connect at least one neutron detector 10 or γ-ray detector 10A from outside the reactor pressure vessel 2 to the entire length of the core 3 (length in the axial direction of the core) in the TIP conduit 9. Since the measurement is performed while moving up and down, the mechanical drive operating device that moves and operates the neutron detector 10 and the γ-ray detector 10A becomes large, and the structure is complicated, and the moving operation and maintenance become complicated. was there. In particular, a detector driving device 12 for moving and operating the neutron detector 10 and the γ-ray detector 10A, and an indexing device 1 for selecting the TIP conduit 9
1. It is necessary to maintain and manage mechanical drive operating devices such as a valve mechanism 15, a shielding container 16, and the like.
Since 0A has been activated, the maintenance management work is a work involving the possibility of exposure.

From this point of view, there is a need for a method of monitoring the operating state of the reactor and the power distribution in the axial direction of the core without using a mobile measurement (nuclear instrumentation) device in the nuclear reactor instrumentation system.

The in-core nuclear instrumentation assembly 6 used in the conventional nuclear reactor instrumentation system usually includes four fixed neutron detectors 8 and one mobile neutron detector (TIP) 10 or mobile γ. A hollow conduit (TIP conduit 9) which movably accommodates the X-ray detector 10A and the mobile neutron detector (mobile γ-ray detector) is provided. Instead of the TIP 10, a fixed γ-ray heat detector is provided. Neutron detector 8
It is being considered to arrange them in the same way.

However, when a plurality of, for example, four fixed gamma ray heat detectors are arranged in the core axis direction, the output at the upper and lower portions of the core 3 cannot be measured. Also 4
When the measurement data of the upper part and the lower part of the core 3 is extrapolated from the measurement data of
Since the power distribution changes differently between the respective portions in the core axis direction, a large measurement error occurs and the accuracy deteriorates.

If the reactor nuclear instrumentation system is provided with only a small number of fixed type measurement (nuclear instrumentation) devices in the axial direction, the measurement error of the power distribution in the axial direction of the reactor core becomes large. It is necessary to provide a large margin in advance for the operation restriction condition (operation restriction value). As a result, the margin of the reactor operation is reduced, which may adversely affect the operation rate and the like.

Further, in order to improve the measurement accuracy of the power distribution in the core axis direction, it is conceivable to arrange a large number of fixed γ-ray heat generation detectors in the core axis direction. However, in this case, the number of detector signal lines increases and the number of detector connection cables that can pass through the nuclear instrumentation pipe 7 of the in-core nuclear instrumentation assembly 6 limits the number of γ-ray heat detectors. There are limits to placing

Further, as described in JP-A-6-289182, a large number of gamma ray heat detectors (GT, GT
A nuclear reactor instrumentation system having a detector (also called a detector) has been devised. However, in this nuclear reactor instrumentation system, the analysis of the γ-ray heating contribution range and the knowledge of γ-ray heating are not sufficient. Since at least one of the upper and lower γ-ray heat detectors is located within 15 cm from the upper and lower ends of the active fuel portion in the core axial direction, the γ-ray heat generation at the upper and lower ends of the active fuel portion can be accurately and accurately detected. It was difficult to do.

When the power distribution in the reactor is measured using a large number of fixed γ-ray heat detectors (GT detectors), a part of the large number of GT detectors is arranged close to the LPRM detector. In this way, the sensitivity and gain of the LPRM detector can be adjusted with the GT detector because of the characteristics of the GT detector with a small bias change, and the mobile neutron detector or the mobile gamma ray detector can be used as the core axial power distribution measuring means. Instead of a vessel,
It has been proposed to replace the GT detector with a GT aggregate having a plurality of axially arranged GT detectors.

[0024]

The gamma ray heat generation detector (GT detector) used in the conventional nuclear reactor instrumentation system is:
Since a differential type thermocouple is used as a method for detecting the temperature of γ-ray heat generation, there is little change over time, but with the passage of time on a weekly or monthly basis, a decrease in the voltage output of the thermocouple with respect to the gamma heat generation, A saturation phenomenon after a certain core residence time (core loading time) has been reported. Therefore, by using a heater incorporated in a gamma thermometer (GT) assembly composed of a plurality of GT exothermic detectors, the sensitivity of each GT detector ｛the sensitivity constant; the thermocouple output of each GT detector periodically Voltage and γ-ray calorific value per unit weight (unit: W
/ G) is measured, and the value of the measured sensitivity is checked. If there is a change of a certain level or more, a new sensitivity constant is used to derive the γ-ray of the GT detector from the thermocouple output voltage signal. It is necessary to calculate the calorific value.

In this specification, the sensitivity of each GT detector is measured by using the above-described processing, that is, using a heater. The process of setting a new sensitivity constant for correcting (calibrating) the change is referred to as “sensitivity calibration process”.

The GT signal output from the GT detector during the sensitivity calibration processing is bypassed and is not used for the output distribution measurement processing. It should be noted that the GT detector or the GT assembly which is not used for the sensitivity distribution obtaining process as described above or which is used for the output distribution measuring process of the detector showing abnormal sensitivity determined to be faulty is bypassed. Called a GT detector or GT aggregate.

The GT assembly is integrally incorporated in the same nuclear instrumentation tube as the LPRM detector assembly, which is a thermal neutron detector. The sensitivity of the LPRM detector to thermal neutrons is determined by the fission type detection. U23 applied to the inner surface of the container
When the sensitivity of the LPRM detector to thermal neutrons falls below a certain value, the sensitivity of each of the reactor core instrumentation assemblies, that is, the sensitivity has dropped to below a certain value, is determined by the change in the concentration of 5 and U234 depending on the irradiation dose in the furnace. The reactor core instrumentation tube including the LPRM detector and the GT assembly is replaced together. Therefore, in actual operation, the gamma thermometer (G
T) The elapsed time of the furnace interior load of the assembly differs for each individual core instrumentation assembly.

Further, the actual sensitivity of the GT detector in the output voltage sensitivity calibration processing by the built-in heater of the GT assembly is obtained from the following equation (2) based on the increase in the voltage signal of the thermocouple due to the additional heating amount of the GT detector. Measured.

For this reason, in the thermal equilibrium state in which the additional heating by the built-in heater has been sufficiently completed, it is necessary to obtain an average value from a large number of time series data of one GT detector signal.
A GT signal (output voltage signal) collection time of about 30 to 60 seconds per T aggregate is required.

In an ABWR (improved boiling water reactor) of 1.35 million kWe class, there are 52 reactor core instrumentation tubes containing such a GT assembly in the core. Therefore, when calibrating the GT assembly with the built-in heater, the GT
When the heater calibration of the assembly is performed, it depends on the number of the power supply circuit of the heater and the number of the heating amount measuring circuits of the heater.
Minutes.

Further, the core loading life of the GT assembly (about 7
During the year, performing heater calibration of the GT assembly by heating the heater potentially raises the possibility of heater disconnection. Therefore, it is desirable to avoid unnecessary calibration by heater heating and shorten the time required for calibration by heater heating so as to minimize the time during which the power distribution of the entire core cannot be measured by the GT signal.

On the other hand, during calibration of the GT assembly by heating the heater and measurement of the power distribution in the furnace using the calibrated GT assembly, the power of the core and the power distribution in the furnace are longer than a certain time (the gamma decay series is substantially balanced). It is necessary from the principle of measuring gamma-ray heating that it is steady (about 1 hour or more to be in a state).

In the BWR, the process control computer sends BWR3
Built-in 3D simulator, calculates core power distribution regularly or as needed using parameters of core current data such as reactor pressure, core thermal output, core coolant flow rate, control rod pattern, etc. Make sure the fuel meets the restrictions.

When the power distribution in the reactor changes relatively short time (within about one hour) before the time of calculation of the core power distribution on a regular basis, for example, due to a change in the control rod pattern or a large change in the core coolant flow rate. , LPRM detector can immediately output a neutron flux signal corresponding to the change in output distribution. However, the signal of the GT detector (GT signal) does not reach a more accurate signal level until a required time, for example, one hour or more, because the delayed component of the gamma ray source slowly changes.

Therefore, the power distribution learning correction process or the LPRM detector sensitivity / gain adjustment process based on the GT signal cannot be performed until the GT signal reaches an accurate signal level. LPRM
The detector sensitivity / gain adjustment processing could not be performed periodically (every time) or at any time.

The present invention has been made in consideration of the above-described circumstances, and accurately performs heater heating calibration management of a gamma thermometer assembly (GT assembly) to realize a GT detector, and more particularly, an LPRM detector. A nuclear reactor fixed instrumentation system and a nuclear instrumentation processing method, a power distribution calculation apparatus and a calculation method, and a power distribution monitoring system capable of accurately performing sensitivity or gain calibration and performing accurate power distribution calculation. It is to provide a monitoring method.

Another object of the present invention is to reduce the heater heating calibration time of a gamma thermometer assembly, reduce the probability of heater damage, and, in turn, provide a reactor that can accurately calibrate the sensitivity or gain of an LPRM detector. An object of the present invention is to provide a fixed in-core nuclear instrumentation system, a nuclear instrumentation processing method, a power distribution calculation device and a calculation method, and a power distribution monitoring system and a monitoring method.

Another object of the present invention is to accurately perform heater heating calibration management of a gamma thermometer assembly on the basis of a difference in furnace interior loading time or in-furnace irradiation burnup of the gamma thermometer assembly, thereby improving sensitivity. A nuclear reactor fixed instrumentation system, a nuclear instrumentation processing method, a power distribution calculation apparatus, and a calculation that prevent useless sensitivity calibration of a gamma thermometer assembly in a stable period and reduce the burden on operators. A method and a power distribution monitoring system and method are provided.

Still another object of the present invention is to accurately perform heater heating calibration management of a gamma thermometer assembly,
A fixed nuclear reactor instrumentation system, a nuclear instrumentation processing method, and an output of a reactor in which the sensitivity or gain adjustment accuracy of the LPRM detector and the calculation accuracy of the reactor power distribution are improved when the GT signal level of the T detector is in an equilibrium state. An object of the present invention is to provide a distribution calculation device and a calculation method, and an output distribution monitoring system and a monitoring method.

Still another object of the present invention is to accurately manage the heater heating calibration of the gamma thermometer, and to realize the LPRM even when the GT signal level of the GT detector is not balanced.
An atom that can adjust the sensitivity or gain of the detector periodically or as needed and can accurately calculate the power distribution in the furnace by using the calibration value of the LPRM signal or the equilibrium value predicted value of the GT detector. It is an object of the present invention to provide a fixed in-core nuclear instrumentation system of a nuclear reactor, a nuclear instrumentation processing method, a power distribution calculation device and a calculation method, and a power distribution monitoring system and a monitoring method.

Another object of the present invention is to fix a reactor capable of accurately calculating a power distribution after a change in a core state (operating state) by taking an accurate GT signal or LPRM signal into a power distribution calculating apparatus. It is an object of the present invention to provide a nuclear instrumentation system in a nuclear reactor, a nuclear instrumentation processing method, a power distribution calculation device and a calculation method, and a power distribution monitoring system and a monitoring method.

[0042]

According to a first aspect of the present invention, there is provided a fixed nuclear reactor instrumentation system for a nuclear reactor according to the present invention. A plurality of fixed neutron detectors (LPRM detectors) for detecting local power distribution and a fixed γ-ray heat detector of a gamma thermometer assembly for detecting γ-ray heat generation are housed in a nuclear instrumentation tube, An in-core nuclear instrumentation assembly in which the linear heat detectors are arranged at least in the vicinity of the LPRM detector, and an L for processing a neutron flux detection signal from the LPRM detector.
A PRM signal processor, a gamma thermometer signal processor for processing a gamma thermometer signal from the gamma thermometer assembly, and a gamma thermometer heater for controlling energization of a heater built in the gamma thermometer assembly The gamma thermometer heater control device controls the amount of electric current applied to the built-in heater of the gamma thermometer assembly, and the heater heating controls the output voltage sensitivity of each detector of the gamma thermometer assembly. It is set to perform calibration.

According to a second aspect of the present invention, there is provided a nuclear instrumentation control device as a monitoring control module for monitoring and controlling the gamma thermometer heater control device and the gamma thermometer signal processing device. The gamma thermometer heater control device and the gamma thermometer signal processing device for calibrating the output sensitivity voltage of each detector are controlled.

According to a third aspect of the present invention, in order to solve the above-mentioned problem, while the heater wire built in the gamma thermometer assembly has a known heater resistance value, the fixed type gamma ray The heat generation detector has a detector unit with a built-in differential thermocouple, the mass of the detection unit is known, and the gamma thermometer is assembled by controlling the power supply from the gamma thermometer heater controller during reactor operation. Performs heating control of the built-in heater of the body, and measures changes in the output voltage signal of the fixed γ-ray heat detector and the heating voltage and current to the built-in heater by the gamma thermometer signal processing device or the nuclear instrumentation control device due to the heating of the heater And fixed γ based on the measurement result
This is for calibrating the thermocouple output voltage sensitivity per unit heating value (W / g) of the linear heating detector.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, the nuclear instrumentation control device calculates a reactor operating time (reactor interior loading time) after loading each gamma thermometer assembly inside the reactor. The gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled using the furnace interior loading time of each gamma thermometer assembly as a parameter, and the unit of the fixed type γ-ray heat detector is provided. When calibrating the output voltage sensitivity per heating value (W / g), one of a plurality of predetermined time intervals predetermined according to the furnace interior loading time is selected, and the heater is heated at the selected predetermined time interval. The calibration of the output voltage sensitivity of the fixed type γ-ray heat detector of each gamma thermometer assembly according to the above.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problem, the nuclear instrumentation control device includes an output voltage sensitivity calibration time interval of a fixed type γ-ray heating detector of each gamma thermometer assembly by heater heating. At the time of changing to another (new) predetermined time interval, information or an alarm is output to the outside of the operator or the like.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device performs the calibration of the output voltage sensitivity of the fixed type γ-ray heat detector by heating the heater, and the furnace of the gamma thermometer assembly. The irradiation amount in the furnace is used as a parameter instead of the interior loading time.

According to a seventh aspect of the present invention, in order to solve the above-described problems, the nuclear instrumentation control device stores the furnace interior loading time or the irradiation amount in the furnace of each gamma thermometer assembly, and stores the stored data. Evaluation is performed to control the output voltage sensitivity calibration by heating the heater of each fixed type γ-ray heat detector of the gamma thermometer assembly.

According to an eighth aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device includes a core power level, a core coolant flow rate, a control rod pattern and the like from a reactor core current data measuring device. While detecting the core state change by inputting the current state data, the elapse of a predetermined time after the core state change detection is determined to judge whether or not the heater heating calibration is appropriate. It controls the output voltage sensitivity calibration by heating the heater of each fixed γ-ray heat detector of the thermometer assembly.

In order to solve the above-described problems, the nuclear instrumentation processing method for a nuclear reactor according to the present invention includes a method for detecting a local power distribution in an output region in a nuclear reactor. A nuclear instrumentation assembly in a reactor having at least a fixed neutron detector (LPRM detector) and a fixed γ-ray heating detector of a gamma thermometer assembly disposed near each of the above neutron detectors was loaded into the reactor. Thereafter, the heater incorporated in the gamma thermometer assembly is energized and controlled by the gamma thermometer heater control device to perform the internal heater heating, and the fixed gamma ray heat generation detector of the gamma thermometer assembly accompanying the heating of the heater. This is a method of measuring the output voltage change from the heater and the heater heating voltage / current, and calibrating the output voltage sensitivity of the fixed γ-ray heat generation detector based on the measurement result.

According to a tenth aspect of the present invention, in order to solve the above-mentioned problem, the output voltage change and the heater heating voltage /
The step of measuring the current is performed by heating the built-in heater of the gamma thermometer assembly through the gamma thermometer heater control device while the reactor is operating, and fixing the gamma thermometer assembly accompanying the heating of the heater. It is a step of measuring the output voltage change from the formula γ-ray heat detector and the heater heating voltage / current, and when performing the output voltage sensitivity calibration step, the furnace interior loading time of the gamma thermometer assembly as a parameter, One of a plurality of predetermined time intervals predetermined according to the furnace interior loading time is selected, and at the selected predetermined time intervals, the fixed type γ-ray heat detector of each gamma thermometer assembly by heater heating is selected. This is the step of performing output voltage sensitivity calibration.

According to an eleventh aspect of the present invention, in order to solve the above-mentioned problem, the nuclear reactor operation time (reactor internal loading time) after the reactor internal loading of each gamma thermometer assembly is calculated by the nuclear instrumentation control device. The nuclear instrumentation control device selects the gamma thermometer assembly to be calibrated for the heater and controls the operation of the corresponding gamma thermometer heater control device and gamma thermometer signal processing device while storing the furnace interior loading time. is there.

According to a twelfth aspect of the present invention, in order to solve the above-mentioned problem, the calibration of the output voltage sensitivity of the fixed type γ-ray heat detector by heating the heater is performed in place of the furnace interior loading time of the gamma thermometer assembly. This is a method in which the irradiation amount in the furnace is used as a parameter.

Further, in order to solve the above-mentioned problems, the fixed nuclear reactor instrumentation system for a nuclear reactor according to the present invention, as described in claim 13, determines the local power distribution in the power region in the nuclear reactor. Multiple fixed neutron detectors (LPR
M detector) and a fixed γ-ray heating detector of a gamma thermometer assembly for detecting γ-ray heating value are housed in a nuclear instrumentation tube, and the γ-ray heating detector is arranged at least near the LPRM detector. An in-core nuclear instrumentation assembly, an LPRM signal processor for processing a neutron flux detection signal from the LPRM detector, and a gamma thermometer signal processor for processing a gamma thermometer signal from the gamma thermometer assembly, A gamma thermometer heater control device that controls energization of a heater built in the gamma thermometer assembly, a nuclear instrumentation control device that calculates and stores a furnace interior loading time or a furnace irradiation amount of the gamma thermometer, The nuclear instrumentation control device controls the operation of a gamma thermometer heater control device and a gamma thermometer signal processing device, The gamma thermometer controller controls the amount of heating applied to the built-in heater of the gamma thermometer assembly, and performs calibration of the output voltage increase sensitivity of the fixed type γ-ray heat detector by heater heating at required time intervals. is there.

According to a fourteenth aspect of the present invention, in order to solve the above-mentioned problems, the gamma thermometer signal processing device or the nuclear instrumentation control device includes an output from each fixed type γ-ray heat detector of the gamma thermometer assembly. On the other hand, while calculating the voltage increase sensitivity data, the nuclear instrumentation control device stores a plurality of time interval data prepared in advance for heater calibration (for example, from the shorter time interval to the first time interval, The second time interval, the third time interval,...), The output voltage sensitivity calibration is performed at the first shortest predetermined time interval at the beginning of the furnace interior loading of the gamma thermometer assembly, and the gamma thermometer assembly is performed. The output voltage increase sensitivity data is stored and stored as time-series data each time the sensitivity is calibrated, and the time-series data of the output voltage sensitivity of the fixed type γ-ray heat detector is used to store the data at the nearest two or more points. The output voltage sensitivity change curve is estimated by taking series data points, and if the output voltage sensitivity change curve does not exceed the allowable sensitivity change determination value set for a predetermined future time, the fixed type γ-ray heat generation detector is The heater heating calibration is performed at a second predetermined time interval longer than the first predetermined time, and if the allowable sensitivity change determination value is exceeded, the heater heating calibration is performed at a predetermined time interval selected at the present time. In the case where the sensitivity calibration is performed and stored at the time interval of 2, the output voltage sensitivity change curve is created by taking two or more points nearest from the present time using the stored output sensitivity time-series data. If the voltage sensitivity change curve does not exceed the allowable sensitivity change determination value set for the predetermined future time,
The heater heating calibration of the fixed gamma ray heat detector is performed at a third predetermined time interval longer than the selected second predetermined time, and if it exceeds, the fixed gamma ray heat detector is set to the second time.
By performing heater heating calibration at predetermined time intervals,
Gamma thermometer heater control device and gamma thermometer signal processing so as to automatically determine whether the next prepared sensitivity calibration time interval can be changed for the currently selected time interval. The operation of the device is controlled.

According to a fifteenth aspect of the present invention, in order to solve the above-mentioned problems, the gamma thermometer signal processing device or the nuclear instrumentation control device includes an output from each fixed type γ-ray heat detector of the gamma thermometer assembly. While the voltage increase sensitivity is calculated and the time series data is stored and stored, the nuclear instrumentation control device stores a plurality of time interval data for heater calibration prepared in advance (for example, the first time interval data is stored in the first order from the shorter time interval). Each of the time intervals, the second time interval, the third time interval,
...), The output voltage sensitivity data of each detector of each gamma thermometer assembly is stored at each selected heater calibration time interval each time the sensitivity of the gamma thermometer assembly is calibrated, and each fixed gamma-ray heat detector is stored. The output voltage sensitivity change curve is estimated by taking two or more nearest time-series data points from the present time using the output voltage sensitivity time-series data, and the output voltage sensitivity change curve is set for a predetermined future time. If the allowable sensitivity change determination value is exceeded, the maximum predetermined time interval that can be selected from the predetermined calibration time intervals that can satisfy the determination result for the fixed-type γ-ray heat generation detector, or has been selected so far. The gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled so that the heater heating calibration is performed at the next shorter time interval than the specified time interval. .

According to a sixteenth aspect of the present invention, in order to solve the above-mentioned problem, the nuclear instrumentation control device includes a heater heating calibration time interval of a heater heating calibration time interval of a fixed type γ-ray heating detector of a gamma thermometer assembly. When a change is made from the calibration time interval, information or an alarm is output to an operator or the like.

According to a seventeenth aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device stores the furnace interior loading time of the gamma thermometer assembly or the irradiation amount in the furnace, and evaluates the stored data. Then, the calibration of the output voltage increase sensitivity due to the heater heating of each fixed gamma ray heat detector of the gamma thermometer assembly is controlled.

According to an eighteenth aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device is provided with a nuclear power level, a core coolant flow rate, a control rod pattern, etc., from a reactor core status data measuring device. While detecting the core state change by inputting the reactor current state data, the elapse of a predetermined time after the core state change detection is determined to determine whether or not the heater heating calibration of the gamma thermometer assembly is appropriate. While outputting to the display device, it controls the sensitivity calibration of the output voltage increase due to heater heating of each fixed γ-ray heat detector of the gamma thermometer assembly.

According to a nineteenth aspect of the present invention, in order to solve the above-described problem, the nuclear instrumentation control device includes a plurality of time intervals (for example, time intervals) prepared in advance according to the loading time of the gamma thermometer assembly inside the furnace. , The first time interval, the second time interval, the third time interval,...) Are selected in order from the shorter one in correspondence with the furnace interior loading time of the gamma thermometer assembly. At a time interval (for example, a third time interval), the gamma thermometer heater control device and the gamma thermometer signal processing device are operated so as to calibrate the output voltage sensitivity by heating the fixed gamma-ray heat detector. Control, and the nuclear instrumentation control device stores the time-series data of the output voltage sensitivity of each fixed γ-ray heating detector of the gamma thermometer assembly, and uses this time-series data from the present time. The output voltage sensitivity change curve is estimated by taking the nearest two or more time-series data points, and if the output voltage sensitivity change curve exceeds the allowable sensitivity change determination value set for a predetermined future time, the above selection is performed. Prior to the given time interval (eg, the third time interval) or the next shortest predetermined time interval (eg, the second time interval) or the maximum of a plurality of previously prepared time intervals that satisfy the permissible sensitivity change determination value. A predetermined time interval is set, and the output voltage sensitivity calibration by the heater heating is performed at the newly selected and set time interval.

According to a twentieth aspect of the present invention, in order to solve the above-mentioned problem, the nuclear instrumentation control device is provided with an output voltage increase sensitivity calibration time due to heater heating of each fixed γ-ray heat detector of the gamma thermometer assembly. When the interval (heater heating calibration time interval) is changed from the previous calibration time interval, information or an alarm is output to an operator or the like.

According to a twenty-first aspect of the present invention, in order to solve the above-mentioned problem, the nuclear instrumentation control device sets the heater heating calibration time interval of each fixed γ-ray heating detector of the gamma thermometer assembly to the furnace interior load. The irradiation amount in the furnace is set as a parameter instead of time.

According to a twenty-second aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device stores the furnace interior loading time of the gamma thermometer assembly or the irradiation amount in the furnace, and evaluates the stored data. Then, the calibration of the output voltage increase sensitivity due to the heater heating of each fixed γ-ray heat detector of the gamma thermometer assembly is controlled.

According to a twenty-third aspect of the present invention, in order to solve the above-described problems, the nuclear instrumentation control device includes a core power level, a core coolant flow rate, a control rod pattern, and the like measured by a reactor core current data measuring device. While the reactor status change is detected by inputting the reactor status data indicating the core status of the above, after the detection of the core status change, the elapse of a predetermined time is determined to determine whether or not the heater heating calibration of the gamma thermometer assembly is appropriate. While the determination result is output to the display device, the calibration of the output voltage sensitivity by heating the heater of each fixed γ-ray heat detector of the gamma thermometer assembly is controlled.

In order to solve the above-mentioned problems, the nuclear instrumentation processing method for a nuclear reactor according to the present invention includes a method for detecting a local power distribution in an output region in a nuclear reactor. A nuclear reactor instrumentation assembly having at least a fixed neutron detector (LPRM detector) and a fixed γ-ray exothermic detector of a gamma thermometer assembly disposed in the vicinity of each of the above LPRM detectors was loaded into the reactor. After that, the nuclear instrumentation control device stores the time series data of the output voltage sensitivity of each fixed type γ-ray heat detector of the gamma thermometer assembly and controls the operation of the gamma thermometer heater control device and the gamma thermometer signal processing device. And a method of controlling the amount of current supplied to the built-in heater of the gamma thermometer assembly to calibrate the output voltage sensitivity of the fixed γ-ray heat detector by heating the heater at required time intervals.

According to a twenty-fifth aspect of the present invention, there is provided a gamma thermometer assembly having a fixed gamma thermometer assembly.
When calibrating the output voltage sensitivity of the X-ray heating detector, the output sensitivity calibration of the fixed γ-ray heating detector is initially performed by the nuclear instrumentation control unit for a plurality of sensitivity calibration times stored in advance, when the gamma thermometer assembly is loaded inside the furnace. The sensitivity calibration is performed and stored at the shortest first time interval in the interval, and stored as time-series data. Using the stored output sensitivity time-series data, two or more nearest points from the present time are determined. An output voltage sensitivity change curve is created, and when the output voltage sensitivity change curve does not exceed the allowable sensitivity change determination value set for a predetermined future time, the fixed type γ-ray heat detector is selected. The heater heating calibration is performed at a second predetermined time interval longer than the first predetermined time, and if it exceeds, the fixed type γ-ray heat detector is heated at the first predetermined time interval, and the heater heating calibration is similarly performed. Feeling at 2 time intervals A calibration is performed and stored, and an output voltage sensitivity change curve is created by taking two or more points closest to the present time using the stored output sensitivity time-series data, and the output voltage sensitivity change curve is set to a predetermined future time. If the allowable sensitivity change determination value does not exceed the set value, the heater heating calibration is performed on the fixed type γ-ray heat detector at a third predetermined time interval next longer than the selected second predetermined time, If it exceeds, change the next longer sensitivity calibration time interval prepared for the currently selected time interval so that the fixed γ-ray heat detector performs heater heating calibration at the second predetermined time interval. This is a method of automatically determining and calculating whether or not it is permissible.

Further, a nuclear instrumentation processing method for a nuclear reactor according to the present invention is intended to solve the above-mentioned problem.
As described in No. 6, a plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in the reactor and a fixed γ of a gamma thermometer assembly in the vicinity of each of the LPRM detectors. After loading the in-core nuclear instrumentation assembly in which at least the line heating detector is disposed in the reactor, the nuclear instrumentation control device stores time-series data of the reactor interior loading time and output voltage sensitivity of the gamma thermometer assembly. The nuclear instrumentation control device, from a plurality of time intervals prepared in advance according to the furnace interior loading time of the gamma thermometer assembly,
At a predetermined time interval selected according to the furnace interior loading time of the gamma thermometer assembly, the fixed type γ-ray heat detector performs output voltage increase sensitivity calibration by heater heating, and further includes the nuclear instrumentation. The control device estimates and calculates a time-series data sensitivity change curve based on the stored output voltage sensitivity time-series data, and the output voltage sensitivity change curve sets an allowable output voltage sensitivity change determination value set for a predetermined future time. , In preference to the selected time interval,
This is a method of controlling the gamma thermometer heater control device and the gamma thermometer signal processing device such that the gamma thermometer heater control device and the gamma thermometer signal processing device are set at a short predetermined time interval and perform output voltage sensitivity calibration by heater heating.

According to a twenty-seventh aspect of the present invention, in order to solve the above-described problem, the nuclear instrumentation control device is configured to control the output voltage sensitivities of two or more points closest to the present time based on the stored time-series data of the output voltage sensitivities. The output voltage sensitivity change curve is estimated and calculated from the time-series data, and if the output voltage sensitivity exceeds the allowable output voltage sensitivity change determination value set for a predetermined future time, a plurality of curves are prepared before satisfying the allowable sensitivity change determination value. In this method, the maximum value is set to a predetermined time interval in the set time intervals, and the output voltage sensitivity calibration by heating the gamma thermometer assembly by the heater is forcibly and preferentially performed.

According to a twenty-eighth aspect of the present invention, in order to solve the above-mentioned problem, the time interval of the output voltage increase sensitivity calibration due to the heater heating of the gamma thermometer assembly is changed from the previous output voltage sensitivity time interval. When this happens, the nuclear instrumentation control device is outputting information or an alarm signal to the outside (operator etc.).

According to a twenty-ninth aspect of the present invention, in order to solve the above-described problem, the irradiation time in the furnace is changed by replacing the time interval of the calibration of the output voltage increase sensitivity by heating the gamma thermometer assembly with the heater interior loading time. This is a method using parameters.

According to a thirty-first aspect of the present invention, in order to solve the above-mentioned problems, the present reactor data such as a reactor power level, a reactor coolant flow rate, and a control rod pattern from a reactor core data analyzer are controlled by nuclear instrumentation. The core state change is detected by inputting to the device, and after detecting the core state change, the nuclear instrumentation control device determines the elapse of a predetermined time and determines whether or not the heater heating calibration of the gamma thermometer assembly is appropriate, and determines the determination result. This is a method of performing output voltage increase sensitivity calibration by heating the gamma thermometer assembly while displaying it on the display device.

Further, in order to solve the above-mentioned problems, a fixed nuclear reactor instrumentation system for a nuclear reactor or a power distribution monitoring system for a nuclear reactor according to the present invention has the following features. Fixed neutron detectors (LPRM detectors) for detecting the local power distribution in the output region of
A gamma thermometer assembly for detecting the amount of x-ray heat generated is housed in a nuclear instrumentation tube with a fixed γ-ray heat detector, and the above-mentioned γ-ray heat detector is arranged at least in the vicinity of the LPRM detector. A LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and a built-in gamma thermometer A gamma thermometer heater control device that controls the energization of the heater, and a nuclear instrumentation control device that controls the operation of the gamma thermometer heater control device and the gamma thermometer signal processing device. Core data to measure core conditions such as reactor power level, core coolant flow rate, control rod pattern, etc. While receiving a signal from the measuring instrument and judging that a predetermined time has elapsed since detecting a change in the core state, the judgment is made, the judgment result is displayed outside, and the gamma thermometer assembly The signal or the gamma calorific value calculated from the signal is taken into a furnace power distribution calculation device.

Further, in order to solve the above-mentioned problem, a fixed nuclear reactor instrumentation system or a power distribution monitoring system of a nuclear reactor according to the present invention has a power range in a nuclear reactor. A plurality of fixed neutron detectors (LPRM detectors) for detecting the local power distribution of the laser and a fixed γ-ray heat detector of a gamma thermometer assembly for detecting the γ-ray heating value are housed in a nuclear instrumentation tube. an in-core nuclear instrumentation assembly in which a γ-ray heat detector is arranged at least in the vicinity of the LPRM detector, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, and a gamma thermometer assembly. A gamma thermometer signal processing device for processing a gamma thermometer signal, and a gamma thermometer device for controlling energization of a heater built in the gamma thermometer assembly A gamma thermometer heater control device and a gamma thermometer signal processing device for controlling the nuclear instrumentation control device, wherein the nuclear instrumentation control device has a reactor core power level, a core coolant flow rate. A signal is received from a reactor current state data measuring device for measuring a core state such as a control rod pattern, and it is determined that a predetermined time has elapsed since a change in the core state is detected. The results are displayed externally, and the sensitivity of the LPRM detector is determined by using the gamma ray heating value calculated from the signal of the fixed γ-ray heating detector at the same axial position as the LPRM detector of the instrumentation pipe in the same furnace. Alternatively, it is set so as to perform gain calibration.

Further, in order to solve the above-mentioned problems, a fixed nuclear reactor instrumentation system for a nuclear reactor or a power distribution monitoring system for a nuclear reactor according to the present invention has the following features. A plurality of fixed neutron detectors (LPRM detectors) that detect the local power distribution of the output area in the chamber and a fixed γ-ray heat detector of a gamma thermometer assembly that detects the γ-ray calorific value are installed in the nuclear instrumentation tube. An in-core nuclear instrumentation assembly containing the γ-ray heat detector disposed at least near the LPRM detector, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, and the gamma thermometer A gamma thermometer signal processing device for processing a gamma thermometer signal from the aggregate, and a gamma thermometer for controlling energization of a heater built in the gamma thermometer aggregate A nuclear instrumentation control system including a gamma thermometer heater control device and a nuclear instrumentation control device for controlling operation of the gamma thermometer signal processing device, wherein the nuclear instrumentation control device includes a nuclear reactor core. A predetermined time has elapsed since the core status change was detected according to the reactor status data including the reactor power level, reactor coolant flow rate, control rod pattern, etc., measured by the current status data measurement device. And outputs the determination result to the input / output device, while calculating the in-furnace power distribution using the detection signal of the fixed γ-ray heat detector or the gamma heating value calculated from the detection signal as input. The furnace power distribution calculating apparatus further includes an input detection signal of the fixed γ-ray heat detector,
Alternatively, the core power distribution is learned and calculated using the gamma calorific value and the three-dimensional nuclear thermal hydraulic calculation model, the predicted detection value of each LPRM detector is calculated from the core power distribution, and the calculated predicted detection value and the current detection value are calculated. The sensitivity or gain calibration of the LPRM detector is performed in comparison with the actually measured value.

According to a thirty-fourth aspect of the present invention, in order to solve the above-mentioned problem, the LPRM signal processing device calibrates a large number of fixed neutron detectors (LPRM detectors) by dividing them into a plurality of APRM channels or LPRM groups. LPRM detector calibration means, wherein the LPRM detector calibration means comprises:
LP included in each APRM channel or LPRM group
The sensitivity or gain of the LPRM detector is adjusted within the range of the maximum allowable number of bypasses of the RM detector.

The invention according to claim 35 is made in order to solve the above-mentioned situation, and the LPRM signal processing apparatus comprises a plurality of fixed neutron detectors (LPRM detectors) each having a plurality of APRM channels or LPRM groups. LPRM detector calibrating means for calibrating the APRM channel divided by the APRM channel or LPRM group within the maximum allowable number of bypasses.
The sensitivity or gain of the LPRM detector is adjusted for each LPRM detector group included in the channel or LPRM group.

In order to solve the above-mentioned problems, a nuclear instrumentation processing method for a nuclear reactor or a power distribution monitoring method for a nuclear reactor according to the present invention has the following features. Fixed neutron detectors (LPRM detectors) for detecting the local power distribution of
A nuclear instrumentation assembly with a fixed gamma-ray heating detector of a gamma thermometer placed near the M detector is loaded into the reactor, and the reactor core power level, core coolant flow rate, control rod pattern, etc. Reactor status data including the above is measured by a reactor core status data measuring device to detect the change in the core state, and the nuclear instrumentation control device has passed a predetermined time after detecting the change in the core state. Is determined, and the result of the determination is displayed to the operator, while the output signal of the gamma thermometer assembly or the gamma calorific value calculated from the signal is taken into the in-furnace power distribution calculation device on a regular or occasional basis.

Further, the nuclear instrumentation method for a nuclear reactor or the power distribution monitoring method for a nuclear reactor according to the present invention, as set forth in claim 37, solves the above-mentioned problem. A plurality of fixed neutron detectors (LPRM detectors) for detecting local power distribution and at least the LPRMs
A nuclear instrumentation assembly with a fixed gamma-ray heating detector of a gamma thermometer assembly placed near the detector is loaded into the reactor, and the reactor core power level, core coolant flow rate, control rod pattern Reactor status data including such as is measured by a reactor core status data measuring device to detect the core state, and the nuclear instrumentation control device determines that a predetermined time has elapsed after detecting the change in the core state. Then, while displaying the determination result to the operator, using the γ-ray heating value calculated from the signal of the fixed γ-ray heating detector at the same core axial direction position as the LPRM detector in the same core instrumentation pipe, This is a method for calibrating the sensitivity or gain of the LPRM detector.

Further, a nuclear instrumentation processing method of a nuclear reactor or a power distribution monitoring method of a nuclear reactor according to the present invention has the following features.
A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor and a fixed γ-ray heating detector of a gamma thermometer assembly at least near the fixed neutron detectors The installed core instrumentation assembly is loaded into the reactor, and the current reactor data, including the reactor core power level, core coolant flow rate, control rod pattern, etc., is detected by the core current data measurement device and nuclear instrumentation is performed. Outputs to the control device, determines that a predetermined time has elapsed since the nuclear instrumentation control device detects a change in the core state according to the output reactor current data, and displays the determination result to the operator On the other hand, the in-furnace power distribution calculation device that takes in the in-furnace power distribution calculation device the output signal of the gamma thermometer assembly or the γ-ray calorific value calculated from the output signal on a regular or occasional basis is the fixed-type γ-ray heat detection device. The core power distribution is learned and calculated using the gamma heating value calculated from the signal of the reactor and the three-dimensional nuclear thermal hydraulic calculation model, and each of the LPRM detections calculated by the core power distribution calculating device from the learned core power distribution is calculated. Comparing the predicted detection value of the detector with the current actual measurement value,
This is a method for calibrating the sensitivity or gain of the M detector.

According to a thirty-ninth aspect of the present invention, in order to solve the above problems, a large number of fixed neutron detectors (LPRMs) are provided.
Detector) is divided into a plurality of APRM channels or LPRM groups, and the maximum allowable bypass number of LPRM detectors included in each APRM channel or LPRM group is L
This is a method for adjusting the sensitivity or gain of the PRM detector.

In order to solve the above-mentioned problem, the invention according to claim 40 provides a large number of fixed neutron detectors (LPRMs).
Detectors) are divided into a plurality of APRM channels or LPRM groups, and the sensitivity of the LPRM detectors in units of LPRM detector groups included in the bypassed APRM channels or LPRM groups within the allowable bypass number of each APRM channel or LPRM group. Alternatively, the gain is adjusted.

According to the present invention, there is provided a reactor power distribution calculating apparatus or a reactor power distribution monitoring system according to claim 41, wherein the core power level, the core coolant flow rate, and the power consumption of the reactor are calculated. A core state parameter signal, which is the above measurement result, is input from a reactor core state data measuring device for measuring a core state parameter representing a core state (operating state) such as a control rod pattern. An in-core power distribution calculating device for calculating an in-core power distribution using a thermometer signal and an LPRM signal, and determining the elapse of a predetermined time after detecting the core state change by inputting the core state parameter signal and determining The nuclear instrumentation control device displays the determination result on the display device, and if the required condition is not satisfied, the gamma sensor While the LPRM signal is input to the in-core power distribution calculating device instead of the momometer signal, the in-core power distribution calculating device uses the core state parameter signal and the learning correction amount obtained by the gamma thermometer signal at the nearest time. Power distribution calculation based on the current core state is performed based on the above, and the correction ratio based on the comparison between the LPRM signal calculated value and the LPRM signal actual measurement value calculated from the result is interpolated and extrapolated in the axial direction to correct the correction ratio of all nodes in the axial direction. The output distribution can be evaluated even when the gamma thermometer signal changes and the gamma ray heat detector is in an unbalanced transient state, and then when the equilibrium state is reached and learning correction by the gamma ray heat detector can be performed. The additional learning correction amount by LPRM is cleared to zero again, and the learning correction amount based on the gamma thermometer signal is obtained and stored again.

In order to solve the above-mentioned problems, the method for calculating the power distribution of a nuclear reactor or the method for monitoring the power distribution according to the present invention has the following features. The core state parameters representing the core state (operating state) such as the control rod pattern are measured, and the measured core state parameter signal is input to the in-core power distribution calculation device, while the gamma thermometer signal and the The reactor power distribution is calculated using the LPRM signal, the core state change is detected from the input of the core state parameter signal, and it is determined by the nuclear instrumentation control device that a predetermined time has elapsed since the detection, and the determination result is obtained. Is displayed on the display device. If the required condition is not satisfied, the LPRM signal is used instead of the gamma thermometer signal to calculate the power distribution in the furnace. On the other hand, the in-core power distribution calculation device calculates the power distribution in accordance with the current core state based on the core state parameter signal and the learning correction amount obtained from the gamma thermometer signal, and obtains the power distribution at the current time. And L calculated according to the estimated output distribution
The correction ratio based on the comparison between the PRM signal calculated value and the LPRM signal actual measurement value is extrapolated in the axial direction to obtain the correction ratio for all nodes in the axial direction. Then, when the learning correction by the gamma ray heat detector can be newly performed in the equilibrium state, the LPR is renewed.
In this method, the M additional learning correction amount is cleared to zero, and the learning correction amount based on the gamma thermometer signal is obtained and stored again.

On the other hand, the reactor power distribution calculating device or the power distribution monitoring system according to the present invention provides a core power level, a core coolant flow rate, While the core state parameter signal is input from a reactor core current state data measuring device for measuring a parameter signal of a core state (operation state) such as a control rod pattern, a gamma thermometer signal and an LPRM signal are used at regular intervals or as needed. An in-core power distribution calculating device for calculating the in-core power distribution, and a nuclear instrumentation control device for inputting the core state parameter signal and detecting a core state change to determine whether a predetermined time has elapsed. ,
The above-mentioned nuclear instrumentation control device displays the determination result on the display device. If the required condition is not satisfied, the nuclear instrumentation control device inputs the LPRM signal instead of the gamma thermometer signal to the in-core power distribution calculation device, and The internal power distribution calculating device calculates the power distribution in accordance with the current operation (core) state based on the core state parameter signal and the learning correction amount obtained by the gamma thermometer signal at the nearest time, and And the gamma thermometer signal is calculated in accordance with the estimated power distribution, while using the change in the control rod state of the fuel node around the LPRM from the nearest time to the current time and the change in the void ratio in the channel. LP expected by calculation from the nearest point
The amount of change of the RM signal is obtained, and the pseudo-RPM signal obtained by correcting the actually measured LPRM signal based on the difference between the amount of change of the LPRM signal and the amount of change of the gamma thermometer signal in an equilibrium state expected by calculation is calculated. A gamma thermometer signal and a gamma thermometer signal calculated from the output distribution by the current calculation are interpolated and extrapolated in the axial direction to obtain a correction ratio for all nodes in the axial direction. The pseudo-gamma thermometer based on the LPRM signal is used when the reactor power distribution can be evaluated even in the transient state where the gamma ray heat detector changes and the gamma ray heat detector is unbalanced. Additional learning correction by calculating gamma thermometer signal from signal and output distribution calculation Clears the correction amount to zero and learns again based on gamma thermometer signal It is obtained so as to store Newsletter Seiryo.

Further, in order to solve the above-mentioned problems, the method for calculating the power distribution of a nuclear reactor or the method for monitoring the power distribution according to the present invention has the following features. A core state parameter representing a core state (operating state) such as a control rod pattern is measured, and a parameter signal of the measured core state is input to the in-core power distribution calculating device, while a gamma thermometer signal and a The reactor power distribution is calculated using the LPRM signal, the core state change is detected from the input of the core state parameter signal, and whether or not a predetermined time has elapsed since the detection is determined by the nuclear instrumentation control device. Is displayed on the display device. If the required conditions are not satisfied, the LPRM signal is used instead of the gamma thermometer signal to calculate the power distribution in the furnace. The in-core power distribution calculation device calculates the power distribution in accordance with the current operating state (core state) based on the learning correction amount obtained from the gamma thermometer signal at the nearest point in time. Is estimated using the gamma thermometer signal equilibrium value calculated according to the estimated output distribution, the change in the control rod state of the fuel node around the LPRM from the nearest time to the current time, and the change in the void ratio in the channel. The amount of change in the LPRM signal expected from the nearest point in time is calculated, and based on the difference in response between the amount of change in the LPRM signal and the amount of change in the gamma thermometer signal in the equilibrium state expected in the calculation. The pseudo-gamma thermometer signal value obtained by correcting the measured LPRM signal and the gamma calculated from the output distribution by the calculation at the present time. The correction ratio based on the comparison with the equilibrium signal is interpolated and extrapolated in the axial direction to obtain the correction ratio for all nodes in the axial direction. When the learning correction by the gamma thermometer can be performed in the next equilibrium state, the additional learning correction amount due to the pseudo-gamma thermometer signal based on the LPRM signal and the gamma thermometer signal calculation from the output distribution calculation is cleared to zero again and the gamma thermometer is again performed. This is a method of obtaining and storing a learning correction amount based on a signal.

On the other hand, the power distribution calculating device or the power distribution monitoring system for a nuclear reactor according to the present invention has a core power level, a core coolant flow rate, While the above core state parameter signal is input from a reactor core current state data measuring device for measuring a core state parameter signal representing a core state (operating state) such as a control rod pattern, a gamma thermometer signal is used at regular intervals or as needed. An in-core power distribution calculating device that calculates the in-core power distribution, and a nuclear instrumentation control device that determines whether a predetermined time has elapsed since the core state parameter signal was input and the core state change was detected, The nuclear instrumentation control device displays the determination result on a display device,
The fixed in-core nuclear instrumentation system has a gamma thermometer signal processing device that processes the gamma thermometer signal,
If the required condition for the core state change is not satisfied, the gamma thermometer signal processor or the nuclear instrumentation controller predicts and calculates the equilibrium signal level of the gamma ray heat detector after a predetermined time has elapsed, and further includes The power distribution calculation device calculates the power distribution in accordance with the current operating state, and calculates the correction ratio by comparing the gamma thermometer signal value calculated from the result with the predicted gamma thermometer signal value in the axial direction. The correction ratio of all nodes in the axial direction of the fuel assembly is obtained by inserting the gamma-ray heat detector so that the output distribution can be evaluated even when the gamma-ray heat detector is in an unbalanced transient state.

According to a forty-sixth aspect of the present invention, in order to solve the above-described problem, the nuclear instrumentation control device or the gamma thermometer signal processing device predicts and calculates the equilibrium signal level of the gamma ray heat detector after the required time has elapsed. On the other hand, while the prediction function operation instruction for performing the prediction calculation is issued, the W / g level signal of the γ-ray heat detector at each new time is read, the oldest data is rejected, and the gamma thermometer using the least squares fitting is rejected. Updates the calculated predicted value of the meter signal, sends the updated calculated predicted value of the gamma thermometer signal from the gamma thermometer signal processing device or the nuclear instrumentation control device to the power distribution calculation device in the furnace, and calculates the calculated predicted value of the gamma thermometer signal. It is set to display on the display device that it is in the mode in which the in-furnace power distribution calculation is performed.

Further, in order to solve the above problems, the method for calculating the power distribution of a nuclear reactor or the method for monitoring the power distribution according to the present invention has the following features. A core state parameter signal representing a core state (operating state) such as a control rod pattern is detected,
While the detected core state parameter signal is input to the in-core power distribution calculation device, the in-core power distribution is calculated using a gamma thermometer signal at regular intervals or as needed, and the core state is determined from the input of the core state parameter signal. Detect the change, determine whether the predetermined time has elapsed from this detection in the nuclear instrumentation control device, while displaying the determination result on the display device, if the required conditions are not satisfied,
A nuclear instrumentation control device or a gamma thermometer signal processing device captures a plurality of gamma thermometer signals that change at predetermined time intervals, and predicts and calculates an equilibrium signal level of a γ-ray heat detector after a lapse of a required time. The internal power distribution calculation device performs power distribution calculation in accordance with the current operating state, and calculates a correction ratio in the axial direction by comparing the gamma thermometer signal value calculated from the result with the predicted gamma thermometer signal value. This is a method to obtain the correction ratio of all nodes in the axial direction of the fuel assembly by interpolation and extrapolation, and to evaluate the power distribution in the reactor even when the gamma thermometer detector in which the gamma thermometer signal is changing is in an unbalanced transient state. .

According to a forty-eighth aspect of the present invention, in order to solve the above-mentioned problems, the nuclear instrumentation control device or the gamma thermometer signal processing device predicts and calculates the equilibrium signal level of the γ-ray heat detector after the required time has elapsed. On the other hand, while the prediction function operation instruction for performing the prediction calculation is issued from the display device, the W / g level signal of the γ-ray heat detector at each new time is read, the oldest data is discarded, and the least squares operation is performed. Gamma thermometer signal prediction calculation value by fitting is updated, and the updated gamma thermometer signal prediction calculation value is sent from the gamma thermometer signal processing device or the nuclear instrumentation control device to the reactor power distribution calculation device, and the gamma thermometer signal is calculated. This is a method of displaying on the display device that the mode is set to perform the in-furnace power distribution calculation using the predicted calculation value.

On the other hand, the power distribution monitoring system for a nuclear reactor according to the present invention is intended to solve the above-mentioned problems.
As described in 9, a plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a reactor and a fixed γ-ray of a gamma thermometer assembly for detecting a γ-ray heating value An in-core nuclear instrumentation assembly having a heat generation detector housed in a nuclear instrumentation tube and a gamma-ray heat generation detector arranged at least in the vicinity of the LPRM detector; and an LP from the LPRM detector.
An LPRM signal processing device for processing an RM signal, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and energization control to a heater built in the gamma thermometer assembly. A gamma thermometer heater control device, a nuclear instrumentation control device that calculates and stores the furnace interior loading time or in-furnace irradiation burnup of the gamma thermometer, and a core power level, a core coolant flow rate, a control rod pattern, and the like. A gamma thermometer signal processing device, comprising: a furnace power distribution calculating device for calculating a furnace power distribution by using a gamma thermometer signal and an LPRM signal while receiving a parameter signal of a core state, or on a regular or occasional basis. Alternatively, the nuclear instrumentation control device acquires a plurality of gamma thermometer signals that change every predetermined time, and Predicts and calculates the equilibrium signal level of the γ-ray heat detector after the required time has elapsed, reads the new gamma thermometer signal at each new time, discards the oldest data, and calculates the predicted gamma thermometer signal value by least squares fitting And sends the updated gamma thermometer signal prediction calculation value to the in-furnace power distribution calculation device, while the in-furnace power distribution calculation device periodically or whenever necessary predicts and calculates the equilibrium gamma thermometer. Using the signal value, the output distribution is learned and corrected, and the fixed gamma thermometer signal at the same core axial position as the fixed neutron detector of the same core instrumentation tube is used for the fixed neutron detector. A fixed neutron detector that performs sensitivity or gain calibration, or is calculated by the in-core power distribution calculator from the core power distribution corrected for learning. Comparing the predicted signal value of the fixed neutron detector with the current measured value, and calibrating the sensitivity or gain of each fixed neutron detector to match the calculated predicted signal value of the fixed neutron detector. It is.

On the other hand, the method for monitoring the power distribution of a nuclear reactor according to the present invention, as described in claim 50, comprises a plurality of fixed neutron detectors (LPRM detection) for detecting a local power distribution in a power region in the reactor. ) And at least a core gamma thermometer assembly in which a fixed gamma-ray heating detector of a gamma thermometer assembly is disposed in the vicinity of each of the above LPRM detectors. The nuclear instrumentation control device takes in a plurality of gamma thermometer signals that change every predetermined time, predicts and calculates the equilibrium signal level of the γ-ray heat detector after the lapse of the predetermined time, and outputs the signal of the γ-ray heat detector at each new time. And reject the oldest data, update the gamma thermometer prediction calculation value by least squares fitting, and use the updated gamma thermometer signal prediction calculation value in the furnace. While feeding the force distribution calculation device,
The in-core power distribution calculation device uses the equilibrium gamma thermometer signal value periodically or as needed to learn and correct the power distribution, and has the same core axial position as the LPRM detector of the same in-core nuclear instrumentation tube. The sensitivity or gain of the LPRM detector using the balanced gamma thermometer signal, or the predicted signal value of the LPRM detector calculated by the in-core power distribution calculation device from the learned and corrected core power distribution Is compared with the current actual measurement value, and each LPR is calculated so as to match the calculated predicted signal value of each LPRM detector.
This is a method for calibrating the sensitivity or gain of the M detector.

[0092]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a nuclear reactor instrumentation system, a nuclear instrumentation processing method, a power distribution calculation apparatus and a calculation method, and a power distribution monitoring system and a monitoring method according to the present invention. It will be described with reference to FIG.

[First Embodiment] FIG. 1 is a block diagram showing a reactor power distribution monitoring system of a boiling water reactor (BWR) according to the present invention. In the output distribution monitoring system shown in FIG. 1, the same components as those of the BWR output distribution monitoring system shown in FIGS. 14 to 16 will be described using the same reference numerals.

As shown in FIG. 1, a reactor power distribution monitoring system 29 of a boiling water reactor includes a fixed in-core nuclear instrumentation system 30 having a detector and a signal processing device, a reactor operating state and a reactor core. A process control computer 20A for monitoring performance;

The process control computer 20A is, for example, a CP
It is a computer including a U, a memory, an input console, a display device, and the like, and a part of its processing functions is configured as a reactor power distribution calculation device 31 for calculating a core power distribution. The in-furnace power distribution calculating device 31 calculates the furnace power distribution and monitors the core performance.

On the other hand, in the boiling water reactor, a reactor pressure vessel 2 is housed in a reactor containment vessel 1, and a reactor core 3 is housed in the reactor pressure vessel 2. The core 3 is cooled by a coolant that also serves as a moderator. Core 3
Are loaded with a large number of fuel assemblies 4 as shown in FIGS. A large number of fuel assemblies 4 are each configured as a set of four fuel assemblies.
A control rod 5 having a cross-shaped cross section is mounted between the lower part and the lower part so that the control rod 5 can be taken in and out from below.

A plurality of, for example, 52 in-core nuclear instrumentation assemblies 32 constituting a detector of a nuclear reactor instrumentation system are provided in a core 3 constituted by loading a plurality of fuel assemblies 4 in a set of four bodies. Provided. The in-core nuclear instrumentation assembly 32 is arranged at a position different from the arrangement position of the control rods 5, and as shown in FIG. 2 and FIG. 3, is located in a corner water gap G formed between the four fuel assemblies 4. Be placed.

That is, the in-core nuclear instrumentation assembly 32 comprises a long and narrow tubular nuclear instrumentation tube 33 and a neutron detector assembly as fixed neutron detection means (LPRM) housed in the nuclear instrumentation tube 33, respectively. Body (LPRM detector assembly) 34
And a γ-ray heat detector aggregate (GT aggregate) 35 as fixed γ-ray detection means (gamma thermometer).

The LPRM detector assembly 34 is composed of LPRM detectors 37 as fixed neutron detectors arranged discretely or dispersedly at equal intervals in the core axis of the nuclear instrumentation tube 33 at several locations in the core axis direction. Be composed. In the boiling water reactor, the four LPRM detectors 37 are usually dispersed and arranged at equal intervals in the axial direction of the core in the active fuel portion of the core 3. Each of the LPRM detectors 37 is electrically connected to an LPRM signal processor 40 through a penetration section 39 by a signal cable 38, and is connected to an output area neutron flux measurement system 41.
Is configured. This LPRM signal processing device 40
The LPRM signal S2 sent from the PRM detector 37 is subjected to, for example, A / D conversion processing, gain calculation, and the like, converted into a digital LPRM signal (LPRM data) D2, and transmitted to the process control computer 20A. It is supposed to.

On the other hand, the GT assembly 35 has a plurality of fixed γ
The line heating detectors 44 are arranged discretely in the core axis direction, and each gamma-ray heating detector 44 measures a gamma-ray heating value. The γ-ray heat detector 44 has the same number or more, for example, eight, in the core axis direction as the number of LPRM detectors 37 in the core axis direction, and an aggregate of γ-ray heat detectors is a gamma thermometer assembly ( GT aggregate) 35. The γ-ray heat detectors (GT detectors) 44 are respectively arranged at least in the vicinity of the LPRM detector 37. Each γ-ray heat detector 44 of the GT assembly 35 is connected to the penetration section 4 by a signal cable 45.
9 and is electrically connected to a gamma thermometer signal processing device 48 to provide a gamma thermometer output distribution measuring system 5.
0 is configured.

The gamma thermometer signal processing device 48 (hereinafter simply referred to as a GT signal processing device 48) is a computer including, for example, a CPU, a memory, an operation panel, a display panel, and the like. γ per unit weight based on the output signal (GT signal) S1 from the γ-ray heat detector 44 and the sensitivity S ₀ of each γ-ray heat detector 44
A digital γ-ray heat measurement signal (GT signal D1; hereinafter, also referred to as GT data D1) representing the linear heat generation (W / g) is obtained, and the obtained GT data D1 is transmitted to the process control computer 20A. Has become.

That is, the fixed in-core nuclear instrumentation system 30
Has a power range neutron measurement system 41 and a gamma thermometer power distribution measurement system 50, and includes an in-core nuclear instrumentation assembly (LPRM) including the detector groups 37 and 44 of the fixed in-core nuclear instrumentation system 30. The detector assembly 34 and the GT assembly 35) 32 transmit detection signals from the detectors 37 and 44 and signal processing from the signal processing devices 40 and 48 at fixed measurement points set in the core 3 in advance. ,
The neutron flux and γ-ray calorific value in the core 3 are measured as core nuclear instrumentation data (GT data D1 and LPRM data D2).

Further, the GT assembly 35 has a built-in heater wire, and the fixed in-core nuclear instrumentation system 30 is electrically connected to the built-in heater (described later) to supply power to the built-in heater. And a gamma thermometer heater control device (hereinafter also referred to as a GT heater control device) 53 for controlling the power supply amount.

The GT heater control device 53 includes, for example,
A power supply device that includes a power supply circuit, current measurement circuit, voltage measurement circuit, voltage control circuit (microcomputer), energization switching circuit, etc.
GT assembly 3 selected via the power cable 54
A voltage is applied to the built-in heater 5 to heat the heater.

The fixed nuclear reactor instrumentation system 3 of this reactor
According to 0, a mobile neutron detector and a mobile γ-ray detector are not required, so that a mechanical drive operating device provided in a conventional nuclear reactor instrumentation system can be omitted. Therefore,
While the structure of the fixed in-core nuclear instrumentation system 30 can be simplified, the nuclear instrumentation system 30 does not require any moving parts, and can be maintenance-free, and does not require or greatly reduce the exposure of workers. Can be reduced.

In the reactor pressure vessel 2 or in a primary piping (not shown), various operating parameters for operating the reactor, such as the core coolant flow rate (or approximate recirculation flow rate) and the core pressure ( Measure the reactor core current process data (process signal) S3 such as pressure inside the pressure vessel, feedwater flow rate, feedwater temperature (or core inlet coolant temperature), and control rod position (control rod pattern) in the control rod drive. A core current state data measuring device 55 is installed.

In FIG. 1, core current status data measuring device 55 is
It is simplified and represented by a measuring instrument in the PCV like a single measuring instrument, but in actuality, a plurality of measurement data for measuring or monitoring multiple core status data (process data) inside and outside the PCV It is a core current data measurement means composed of equipment.

[0108] Some of the core current data measuring devices 55 are connected to a current data processing device 58 via a signal cable 57 penetrating the penetration portion 56, and the other is connected to a current data measuring device 55 outside the containment vessel. A process data measurement system 59 is configured by being connected to a current data processing device 58 via a signal cable 57.

The current status data processing device 58 receives the current core process data S3 (analog or digital signal) measured by the current core data measuring device 55, and executes data processing based on the received current core process data S3. To calculate the reactor heat output, core inlet coolant temperature, etc., convert the core current process data S3 including the calculated reactor heat output into digital core current data D3, and send the digital core current data D3 to the process control computer 20A. It has become.

The current data processing device 58 of the process data measurement system 59 may be configured as a part of the processing function of the process control computer 20A instead of a dedicated independent device.
In this sense, the process data measuring system 59 is a process control computer 20 including the in-furnace power distribution calculating device 31.
A may be configured as a part of the processing function of A, and the power distribution calculation device of the nuclear reactor is also a part of the processing function. The process data measurement system 59 may be configured as a part of the fixed nuclear reactor instrumentation system 30 from the concept of a detector and a signal processing device.

Further, the current data processing device 58 of the process data measurement system 59 and the L of the output area neutron flux measurement system 41
The PRM signal processing device 40, the gamma thermometer heater control device 53 of the gamma thermometer heater control system, and the GT signal processing device 48 of the gamma thermometer output distribution measurement system 50 are each electrically connected to the process control computer 20A. .

The data group processed by each of the processing devices 40, 48, and 58, ie, core nuclear instrumentation data (GT data D
1 and LPRM data D2) and core status data D
Numeral 3 is a nuclear instrumentation control device (nuclear instrumentation control module) 60 having an interface function of the process control computer 20A.
Is input to the in-furnace power distribution calculating device 31 via the.

The nuclear instrumentation control device 60, that is, the nuclear instrumentation control module 60 of the process control computer 20A is configured as a part of the components of the in-core nuclear instrumentation system 30. LPRM signal processor 40, GT signal processor 48, and gamma thermometer heater controller 53 of instrumentation system 30
Has the function of controlling each of them.

The in-core power distribution calculator 31 of the process control computer 20A uses a built-in physical model (three-dimensional nuclear thermal hydraulic calculation code) to calculate the neutron flux distribution,
A processing function (output distribution calculation module) 61 for calculating the power distribution, a margin for the thermal operation limit value, and the like, and a calculation result from the power distribution calculation module 61 are input and corrected to reflect the measured core nuclear instrumentation data. And a processing function (power distribution learning module) 62 for obtaining a core power distribution. In addition, the process control computer 20A can input various commands such as a power distribution calculation instruction command and a GT calibration instruction command via the operator, and also provides the operator with core performance calculation results (for example, power distribution, operation restriction). And a display operation device 63 including a display function capable of outputting display information such as an alarm display.

The in-furnace power distribution calculating device 31 of the process control computer 20A includes a physical model (BWR three-dimensional simulator model; three-dimensional nuclear thermohydraulic) of the power distribution calculating module 61 stored in advance in (the memory of) the process control computer 20A. Calculation code), and input GT data D1,
The core power distribution and the like are calculated based on the LPRM data D2 and the core state data D3.

That is, the power distribution calculation module 61 of the in-reactor power distribution calculation device 31 outputs the input core current state data D3 and the physical model (three-dimensional nuclear thermal hydraulic calculation code).
Calculation based on the neutron flux distribution in the core,
The core power distribution, the margin for the thermal operation limit value, and the like are calculated.

The output distribution learning module 62 of the in-core power distribution calculation device 31 calculates the result (the neutron flux distribution and the power distribution in the core) calculated by the power distribution calculation module (three-dimensional nuclear thermal hydraulic power calculation module) 61. To the input GT data D1, or GT data D1 and LPR
The correction is made with reference to the M data D2, and the result is returned to the power distribution calculation module 61. The module 61 has a highly reliable core power distribution reflecting the measured core nuclear instrumentation data (GT data D1, LPRM data D2) and thermal operation limitation. A margin for the value is obtained.

Here, each module 60, 61, 62
Is a module representing the processing function of the process control computer 20A, that is, a program module built in the memory of the process computer 20A, and a process control computer 20A (the CP
The processing in U) is realized, and the in-furnace power distribution calculation module 31 and the power distribution learning module 62 constitute the in-furnace power distribution calculation device 31. The monitoring control module of the in-core nuclear instrumentation system 30 constitutes the nuclear instrumentation control device 60.

The in-core nuclear instrumentation assembly 32 is shown in FIG.
As shown in FIG. 3, a part of the in-core nuclear instrumentation system 30 of the nuclear reactor is configured, and a large number, for example, 52, are arranged in the reactor core 3. The in-core nuclear instrumentation assembly 32 is disposed at a corner water gap G surrounded by four fuel assemblies 4.

The in-core nuclear instrumentation assembly 32 includes a nuclear instrumentation pipe 33.
A neutron detector assembly (LPRM detector assembly) 34 as fixed neutron detection means, and a γ-ray heat detector assembly (GT assembly) 35 as fixed gamma ray detection means (gamma thermometer) 35 The LPRM detector assembly 34 and the GT assembly 35 are combined and arranged integrally in the nuclear instrumentation tube 33.

The LPRM detector assembly 34 constitutes a local power region monitoring system (LPRM) as a fission ionization chamber, and has N (N ≧ 4) within the active fuel length in the core axial direction.
For example, four LPRM detectors 37 are provided discretely or dispersedly at equal intervals (interval L). GT aggregate 35
Is inserted into the nuclear instrumentation tube 33 together with the LPRM detector assembly 34.

The number of GT aggregates 35 is, for example, eight or nine.
Gamma (γ) ray heat detectors 44 are discretely provided in the axial direction. Each neutron detector 3 of the LPRM detector assembly 34
7 and each gamma ray heat detector 44 of the GT assembly 35
Is housed in the nuclear instrumentation pipe 33 while the nuclear instrumentation pipe 3
3 is guided so that the coolant flows upward from below.

FIGS. 2 and 3 show an example of a GT assembly 35 in which eight γ-ray heat detectors 44 are arranged in a fuel effective portion H in the core axis direction. In addition, the fuel effective part H is
As shown in FIG. 3, in each fuel element of the fuel assembly (nuclear fuel filled in the fuel pipe), it represents a region where the nuclear fuel is effectively filled along the core axis direction. The fuel effective portion H along the direction is also referred to as a fuel effective length.

The arrangement interval of each γ-ray heat detector 44 in the core axis direction is determined in consideration of the arrangement interval of each neutron detector 37 of the LPRM detector assembly 34 in the core axis direction.

Specifically, assuming that the axial distance between the LPRM detectors 37 is L, the gamma thermometer assembly (GT assembly) 35
Are located at the same axial position as the LPRM detector 37, and three are located at intermediate positions of the LPRM detectors 37 at L / 2 intervals. The respective axial centers are arranged downward in the active fuel section at a distance of L / 4 to L / 2 and 15 cm or more from the lower end of the active fuel section. When the γ-ray heat detector 44 is installed above the uppermost LPRM detector 37, the γ-ray heat detector 44 is positioned above the uppermost neutron detector 37 by a distance of L / 4 to L / 2. It is located at a distance and within the active fuel section 15 cm or more below the upper end of the active fuel section. The reason that the γ-ray heat detector 44 is arranged to be inward by 15 cm or more from the upper and lower ends of the fuel effective portion is as follows.
This is because the analysis of the γ-ray heat generation contribution range allows the γ-ray contribution range to be newly found and the γ-ray heat generation amount at the upper and lower ends of the fuel effective portion to be detected accurately and accurately.

Since the lowermost γ-ray heat detector 44 is required to be disposed as close to the lower end as possible within the active fuel length H, the active fuel length (currently about 371 cm) H is set, for example, in the axial direction of the core. If it is divided into 24 nodes, 2 from the bottom
It is preferable to dispose the lowermost γ-ray heat detector 44 such that the center position of the lowermost γ-ray heat detector 44 is located substantially at the axial center of the second core axial node. With this arrangement, the γ-ray heat generation detector 44 at the lowermost end of the GT assembly 35 can also detect γ-ray heat generation at the lower end side of the core.
The linear heat generation can be measured from a region as wide as possible in the core axial direction along the active fuel length H, and can also be measured in a region on the lower end side of the core.

This is because the output of the lowermost node is originally low due to neutron leakage, the sensitivity of the γ-ray heat detector 44 is low, and the contribution range of the gamma ray to the γ-ray heat detector 44 is 15 cm or more. It is 15 from the lower effective fuel length
By separating them by at least cm, the γ-ray heat detector 44 can equally detect the amount of γ-ray heat generated in the vertical direction. Also, 15c
If not more than m apart, the γ-ray heat detectors 44 at other core axial positions measure the heating effect of γ-rays from above and below in the axial direction, while the lowermost γ-ray heat detector 44 This is because only the contribution of γ-ray heat generation is detected, thereby losing the balance of γ-ray heat generation measurement and avoiding different correlation formulas for output measurement.

In the recent design of the fuel assembly 4 in the axial direction, the lowermost node often uses a natural uranium blanket. This is because the output signal of the aggregate 35 is extremely low and there is no point in extrapolating the output distribution below the lowermost LPRM detector 37.

Incidentally, a gamma thermometer assembly (GT assembly) 35 combined with a fixed type γ-ray heat generation detector 44
Has an elongated rod-like structure shown in FIGS.

Gamma thermometer assembly (GT assembly)
Reference numeral 35 denotes a long and narrow rod-shaped sensor assembly having a diameter of, for example, about 8 mmφ, and a fuel effective length in a core axis direction, for example, from 3.7 m (370 cm) to 4 m (400 c).
m) has a length substantially covering the extent.

The GT assembly 35 has a cover tube 65 made of, for example, stainless steel as a metal jacket.
And a metal long rod-shaped core tube 66 housed in the cover tube 65. The cover tube 65 is caulked to the core tube 66 and fixed to each other by shrink fitting or cold fitting. Between the cover tube 65 and the core tube 66, a sleeve-like or annular gap portion 67 constituting a heat insulating portion is formed,
A plurality of the annular void portions 67 are spaced apart in the axial direction,
For example, at least four, specifically seven to nine discretely are arranged.

The annular space 67 is formed by cutting the outer surface of the core tube 66 along the circumferential direction, and a gas having low heat conductivity, for example, Ar gas is sealed in the annular space 67. The annular gap 67 may be formed on the cover tube 65 side which is a jacket tube. Examples of the gas having low heat conductivity include an inert gas such as an Ar gas and a nitrogen gas.

The position of the annular gap 67 is the position of the fixed-type γ-ray heat detector (GT detector) 44, and constitutes the sensor section of the gamma thermometer assembly 35. The core tube 66 has an inner hole 68 penetrating the center part in the axial direction, and a cable sensor assembly 70 formed into an MI cable is fixed to the inner hole 68 by brazing or caulking.

The cable sensor assembly 70 has a built-in heater 71 as a rod-shaped heating element which is a heater wire for calibrating the gamma thermometer assembly 35 in the center, and a plurality of differential sensors as temperature sensors around the heater 71. Type thermocouple (thermocouple) 72. The gap between the built-in heater 71 and each thermocouple 72 is solidified with an electric insulating layer or a metal / metal alloy filler 73 if necessary, and
The metal cladding tube 74 is tightly attached to both the outer surface and the inner surface. The built-in heater 71 of the gamma thermometer assembly 35 is formed of, for example, a sheathed heater, and the heater wire 75 is covered with a metal coating tube 77 via an electric insulating layer 76 and is integrated. Similarly, each thermocouple 72 has a thermocouple element wire 78 covered with a metal cladding tube 80 via an electric insulating layer 79 to be integrated.

The differential thermocouple 72 located in the inner hole 68 of the core tube 66 has a low-temperature side contact and a high-temperature side contact respectively arranged corresponding to the annular gap 67, and the sensor section of the gamma thermometer assembly 35. Gamma ray heat detector 44
Is composed. Each thermocouple 72, as shown in FIG.
The high-temperature side contact 81a is set at the axial center of the sensor portion formed by the annular gap 67, that is, the heat insulating portion, and the low-temperature side contact 81b is set at a position slightly below the heat insulating portion (the low-temperature side contact 81b is It may be located slightly above the heat insulating part). The thermocouples 72 are inserted concentrically around the built-in heater 71 by the number of the γ-ray heat detectors 44.

The fixed type γ-ray heat detector 44 constitutes a gamma thermo-assembly 35 for detecting the power distribution in the furnace.
The principle of measuring the power distribution in the furnace is shown in FIGS. 6 (A) and 6 (B).

In a nuclear reactor such as a boiling water reactor, gamma rays are generated in proportion to the fission amount of nuclear fuel loaded in the reactor core 3 in the reactor pressure vessel 2, and a gamma thermometer assembly is generated by the generated gamma ray flux. The structure 35, for example, the core tube 66 is heated. This heating amount is proportional to the γ-ray flux, and the γ-ray flux is proportional to the amount of fission in the vicinity. At the portion of the annular gap 67 of each γ-ray heat detector 44 constituting the gamma thermometer assembly 35, the heat removal by the radial coolant 82 is poor due to its heat insulating property, and the axial direction as shown by the arrow A is poor. A heat flux that bypasses the airflow is generated, causing a temperature difference. Thus, when the high-temperature side contact 81a and the low-temperature side contact 81b of the differential thermocouple 72 are arranged as shown in FIG. 5, this temperature difference can be detected by a voltage signal. Since this temperature difference is proportional to the γ-ray heating value, the γ-ray heating value proportional to the local fission amount can be obtained from the voltage signal of the differential thermocouple 72. This is the measurement principle of a gamma thermometer.

On the other hand, in the fuel assembly 4, as shown in FIGS. 2 and 3, a large number of fuel rods (not shown) are housed in a rectangular cylindrical channel box 83. Each fuel rod has a zirconium alloy fuel cladding filled with uranium oxide sintered pellets or uranium-plutonium mixed oxide sintered pellets, and the upper and lower ends are welded and sealed with end plugs. A large number of fuel rods are collected and bundled, and a plurality of fuel spacers are arranged at intervals in the axial direction in order to secure a predetermined distance between the fuel rods.

An upper tie plate and a lower tie plate are disposed at the upper and lower ends of the fuel assembly 4, respectively, so as to engage with the lower core structure and the upper core structure. In the fuel assembly 4 of the boiling water reactor (BWR), the channel box 83 further surrounds the outside of the fuel bundle, and forms a coolant passage for each fuel assembly 4.

The distribution of power in the reactor of a reactor in which a large number of such fuel assemblies 4 are provided in the core 3 and the operation limit values of the core fuel (maximum linear power density (kW / m) and minimum limit power ratio)
Is calculated by the so-called three-dimensional nuclear thermal hydraulic simulation calculation in the in-core power distribution calculation device 31 of the process control computer 20A. The in-furnace power distribution calculation device 31 calculates a margin or the like with respect to the core fuel operation limit value {maximum linear power density (kW / m) and minimum limit power ratio)}, and the calculation result is displayed by the display operation device 63. The operator is informed.

Next, regarding the reactor power distribution monitoring process and the reactor power distribution monitoring method of the reactor power distribution monitoring system 29 of the present embodiment, in particular, the detection sensitivity calibration process of the fixed nuclear reactor instrumentation system 30 and the GT The method of calibrating the detection sensitivity of the detector 44 will be mainly described.

According to the reactor power distribution monitoring system 29 of this embodiment, the fuel state and the reactor operation state of the core 3 of the boiling water reactor (BWR) are controlled by the process control computer 20A.
Monitored by

That is, various process data (control rod pattern, core coolant flow rate, core flow rate, etc.) as the reactor current data measured by the reactor current data measuring device 55 of the boiling water reactor.
Reactor dome pressure, feedwater flow rate, feedwater temperature, (core inlet coolant temperature, etc.) are input to the current data processor 58,
The core current state data measuring device 55 performs data collection processing and calculates the reactor heat output and the like.

The current data processing device 58 may be configured as a part of the process control computer 20A. In this case, the data collection processing of the core current data is performed by the process control computer 20A.

The core current data D3 including the reactor heat output, which has been subjected to the data collection processing and the calculation processing by the current data processing device 58, is transmitted to the reactor via the signal interface function of the nuclear instrumentation control device 60 of the process control computer 20A. It is transferred to the internal output distribution calculating device 31.

On the other hand, the LPRM of each in-core nuclear instrumentation assembly 32
The neutron flux in the core 3 detected by the detector assembly 34 is converted into LPRM data D2 via the LPRM signal processing device 40, and is converted into a reactor through the signal interface function of the nuclear instrumentation control device 60 of the process control computer 20A. It is transferred to the internal output distribution calculating device 31.

Similarly, the thermocouple output signal (GT signal) measured by the γ-ray heat detector 44 of each in-core nuclear instrumentation assembly 32 is calculated based on the sensitivity S ₀ of the γ-ray heat detector 44.
The T signal processor 48 converts the data into GT data D1 representing the γ-ray heat generation per unit weight (W / g), and calculates the in-furnace power distribution via the signal interface function of the nuclear instrumentation controller 60 of the process control computer 20A. The data is transferred to the device 31.

The in-furnace power distribution calculating device 31 transfers the transferred GT data D1, LPRM data D2, core current condition data D3, and data stored in the process control computer 20A.
The arithmetic processing is executed based on the two-dimensional nuclear thermal hydraulic calculation code, and the core power distribution, the core neutron flux distribution, the margin for the thermal operation limit value, and the like are calculated. Data such as the calculated core neutron flux distribution, core power distribution, calculated value of the GT signal reading, and margin for the thermal operation limit value are as follows:
It is stored in the memory as needed.

That is, the power distribution calculation module 61 calculates the core neutron flux distribution, the core power distribution, and the GT based on the core current data D3 and the three-dimensional nuclear thermal hydraulic calculation code.
The calculated value of the signal reading (corresponding to the measured GT data D1), the margin for the operation limit value, and the like are calculated. This GT
In the simulation calculation of the signal reading, the memory of the process control computer 20A stores parameters of a correlation equation for expressing the correlation between the fuel assembly node output value and the GT data value D1 based on the GT signal {for example, fuel type,
Node burnup, presence of control rod, historical relative water density (historical void ratio), instantaneous relative water density (instantaneous void ratio) 内 based on fitting formula data (data set),
Alternatively, look-up table data (data set) of the interpolation / extrapolation method based on the correlation equation parameter is stored, and the GT reading value is calculated using the parameter value calculated by the output distribution calculation module 61.

The calculated core power distribution and the like are based on core nuclear instrumentation data (GT data D) actually measured from core 3.
Learning correction is performed based on 1) and the three-dimensional nuclear thermal hydraulic calculation code.

At this time, the GT aggregate 35 has the axial power distribution of the core 3 smaller than 24 nodes and the fixed LP
N same as RM detector 37, for example, 4 or 4
It has more than one fixed GT detector 44 and each G
The power distribution is calculated by the output distribution calculation module 61 based on the core nuclear instrumentation data (GT data D1) corresponding to the GT signal measured by each GT detector 44 of the T assembly 35 and the three-dimensional nuclear thermal hydraulic calculation code. The core power distribution and the like are learned and corrected (the power distribution learning correction based on the GT signal data D1 will be described in more detail in the description of FIG. 9 of the sixth embodiment of the present specification).

That is, the thermocouple output signal (GT signal) S1 from the actual GT assembly 35 is supplied to the GT signal processor 4
8, the voltage signal is converted from the voltage signal into GT data D1 corresponding to the gamma ray heating value (W / g), and the process control computer 20A
Is input to the output distribution calculating device 31.

At this time, in the output distribution learning module 62 of the output distribution calculation device 31, the output distribution calculation module 6
From the reactor power distribution calculated based on the three-dimensional nuclear thermal hydraulic calculation model of 1, the γ-ray heating value of each GT assembly for each axial node is obtained by simulation calculation and temporarily stored in a memory. The simulation calculation value and the actual measurement value (GT
The difference from the value of the data D1) is obtained in the form of a ratio for the node where the GT detector actually exists.

In the power distribution learning module 62, the measured values of the actual γ-ray heating value (the value of the GT data D1) and the γ-ray heating value are limited for each GT assembly 35 in the core axis direction. (Γ-ray heating value difference correction amount data) representing the difference (ratio form) from the simulation calculation value of the above is extrapolated to each node in the core axis direction, and the γ-ray heating value difference correction amount data for all axial nodes Is required. In addition,
In addition to the extrapolation in the axial direction, it is also possible to extrapolate the γ-ray calorific value difference correction amount (correction ratio; correction coefficient) along the core radial direction to the radial position where the GT aggregate does not exist. is there.

The output distribution learning module 62 determines that the value of the γ-ray heat generation difference correction amount data for each node of each GT aggregate thus obtained is “1.0”,
By correcting the reactor power distribution calculated by the power distribution calculation module 61 so that the value of the GT data D1 at each node in the axial direction of the assembly and the simulation calculation value of the γ-ray heating value match, the accuracy is improved. Higher reactor power distribution (or neutron flux distribution) and margins for operational limits are required.

As described above, the process control computer 20A for monitoring the operating state of the reactor and for monitoring the core power distribution.
Receives the core status data D3 continuously and constantly, and updates the latest operation parameters (for example, once an hour) or at any time in response to a calculation request command input by the input / output device operation of the operator. The core power distribution calculation (three-dimensional nuclear thermal hydraulic simulation calculation) is performed by the in-core power distribution calculator 31 based on the core current state data D3) and the three-dimensional nuclear thermal hydraulic power code.

That is, the power distribution learning module 62 corrects the reactor power distribution calculated by the power distribution calculation module 61 based on the GT data D1 (W / g) based on the GT signal S1 at that time. High accuracy, margin for reactor power distribution and operation limit value,
(And also the neutron flux distribution) can be calculated.

On the other hand, the nuclear instrumentation control device 60 configured as a part of the processing function of the process control
A function of calculating a reactor operation time after the T-assembly 35 is loaded into the reactor (hereinafter, defined as a reactor interior loading time), and a process control of the reactor interior loading time of each GT assembly 35. It has a function of updating and storing in a memory of the computer 20A and a function of storing and retaining a plurality of heater calibration time intervals, which will be described later, set in advance in the memory.

Further, the nuclear instrumentation control device 60 normally operates each GT assembly 35 in a state where there is no change in the operating parameters (reactor power, core coolant flow rate, current core process amount S3 such as control rod pattern). Output voltage sensitivity measurement processing (calculation processing) by built-in heater 71 of fixed GT detector 44
Is transmitted to the GT heater control device 53 at predetermined time intervals. The built-in heater 71
The sensitivity of the thermocouple output voltage of the GT detector 44 (thermocouple output voltage and γ-ray heat generation per unit weight (unit: W /
The process of measuring (calculating) that determines the relationship with g) is also referred to as a heater calibration process.

The nuclear instrumentation controller 60 has a function of storing the time (calibration processing start time) at the time of transmitting the output voltage measurement processing execution command (heater calibration command) in the memory for each corresponding GT assembly 35. It has.

At this time, the nuclear instrumentation control device 60
The transmission interval of the heater calibration command to the assembly 35 (hereinafter, referred to as the transmission interval)
The heater calibration time interval is set differently according to the furnace interior loading time of the GT assembly 35.

That is, the process control computer 20A (memory) stores the reactor operation time 50 after loading the GT assembly.
48 hours as a heater calibration time interval for a GT assembly within 0 hours (within 500 hours of furnace interior loading time), 168 hours as a heater calibration time interval for a GT assembly with a furnace interior loading time of 500 hours to 1000 hours. 336 hours are stored as a heater calibration time interval for a GT assembly having a loading time of 1000 hours to 2000 hours, and 1 month (or 1000 hours) is stored as a heater calibration time interval for a GT assembly having a furnace interior loading time exceeding 2000 hours. The nuclear instrumentation control device 60 refers to the memory to determine the elapsed time from the previous calibration processing time of each GT assembly 35 to the present time and the calculated current furnace interior loading time of each GT assembly 35. The heater calibration target is selected from all the GT aggregates 35 based on the heater calibration time interval corresponding to Determine the GT aggregate extracts made.

Next, the nuclear instrumentation control device 60 registers, in the memory, the heater calibration time interval corresponding to the furnace interior loading time corresponding to each GT assembly 35 at the time of the discrimination for each discrimination process. A heater calibration time interval corresponding to the corresponding furnace interior loading time of each GT assembly 35 is transmitted to the display / operation device 63, and a corresponding heater calibration time interval registration screen representing the heater calibration time interval of each GT assembly 35 is displayed. It is displayed via the display operation device 63.

Further, the nuclear instrumentation control device 60 automatically issues the extracted heater calibration processing execution command (including the address (position address) of the heater calibration target GT assembly 35) to the GT assembly 35 to be heated calibration. Heater control device 5
3 and the GT signal processor 48, respectively.
Alternatively, G for the GT assembly 35 to be calibrated for the heater
A T calibration instruction command transmission request is transmitted to the display operation device 63, and a display is output to the operator via the display operation device 63. At this time, the operator operates the display operation device 63 in response to the GT calibration instruction command transmission request displayed by the display operation device 63, thereby transmitting the GT calibration instruction command to the GT assembly 35 to be heated. I do. The nuclear instrumentation control device 60 automatically transmits the heater calibration process execution command to the GT heater control device 53 and the GT signal processing device 48 in response to the transmitted GT calibration instruction command.

At this time, the GT heater control device 53 operates the built-in heater 71 of one or more GT assemblies 35 corresponding to the position address of the transmitted heater calibration process execution command.
Is supplied (voltage is applied) to the internal heater 71.
The heater voltage to be applied is controlled so that the current value flowing through the heater becomes a predetermined value.

Next, the GT heater control device 53 measures a voltage value applied to the built-in heater of each GT assembly and a current value flowing through the built-in heater 71, and transmits the measured value to the GT signal processing device 48.

On the other hand, the GT signal processing device 48 receives the heater calibration process execution command (position address) transmitted from the nuclear instrumentation control device 60, and in accordance with the reception timing,
A thermocouple output voltage signal (mV) of each GT detector 44 in a non-heated state of the heater of the GT assembly 35 having the corresponding position address is simultaneously measured in parallel along the core axis direction, and the GT heater control is performed. The heater application voltage and the current measurement value transmitted from the device 53 are received, and the GT assembly 3 at the time of heater heating is received according to the reception timing.
5, the thermocouple output voltage signals (mV) of the respective GT detectors 44 are simultaneously measured in parallel along the axial direction.

Then, the GT signal processing device 48 outputs the measured state of no heater heating in each GT detector 44 of the GT assembly 35 for heater calibration and the output voltage signal at the time of heater heating for each GT detector 44, respectively. Remember. This heater calibration processing execution command is continued by changing the position address of the GT aggregate until the end of the target GT aggregate requiring heater calibration is completed.

Next, the GT signal processing device 48 determines the current G signal based on the heater non-heating state of each of the GT detectors 44 to be calibrated and the output voltage signal at the time of heater heating.
The sensitivity S ₀ of the T detector 44 {the value that determines the relationship between the thermocouple output voltage of the GT detector 44 and the γ-ray calorific value per unit weight (W / g)} is measured.

Hereinafter, the sensitivity measurement processing by the GT signal processing device 48 will be described.

The thermocouple output voltage signal U _{γ of the} GT detector 44
And the gamma ray heating value W per unit weight of the GT detector 44
_The following equation (1) holds as a relational expression with _γ .

[0172]

(Equation 1) The nonlinear coefficient α is a fixed value calculated in consideration of the temperature dependence of the physical property values of the structural materials of the GT detector 44.

The output voltage sensitivity S ₀ of the GT detector 44
Can be calculated by the following equation (2) using the measured state of no heater heating and the output voltage signal during heater heating.

[0174]

(Equation 2)

That is, for example, when it is confirmed by the operator that the core state is constant and stable,
Heating value P _H by internal heater 71 shown in FIGS. 4 and 5
The addition of, for thermocouple output signal change corresponding to the heating value P _H (difference between U and U ') is generated, which is previously measured GT
Mass (weight) of the detector 44, heater resistance value and (2)
The sensitivity S ₀ of the GT detector 44 can be calculated using the equation. Here, it is desirable that the built-in heater 71 of the GT assembly 35 be manufactured so that its resistance value is constant in the axial direction regardless of each GT detector. since manufacturing errors are considered in the direction distribution, reflecting the manufacturing data, seeking additional heating value P _H of the internal heater 71 based on the resistance value of the detector portion of the supply current and the individual heaters 71.

[0176] Incidentally, the output voltage sensitivity _{S 0} and GT detector 44 output voltage signal (mV signal) U gamma heating value W per unit weight of GT detector 44 from _γ of GT detector 44 thus determined _γ is the following equation (3)

W _γ = U _γ / (S ₀ (1 + αU _γ )) (3)

As described above, based on the built-in heater 71 control process (heater calibration process) of the GT assembly 35 to be calibrated by the GT heater control device 53, the GT signal processing device 48 The sensitivity S ₀ of all GT detectors 44 can be calculated. And
The GT signal processing device 48 controls each of the calculated GT detectors 44.
The sensitivity S ₀ stored in the processing device (the memory),
And transmitting the sensitivity _{S 0} of the respective GT detector 44 nuclear calculation control unit 60 of the process control computer 20A.

The sensitivity measurement process of the GT heater control device 53 and the GT signal processing device 48 based on the above-described heater calibration process execution command is performed in a predetermined sequence until the processes for all the GT assemblies 35 to be calibrated are completed. Is repeatedly executed. Also, as described above, each GT
The sensitivity measurement process of each GT detector 44 of the assembly 35 is repeatedly executed at each corresponding heater calibration time interval according to the heater calibration process execution command transmitted by the determination process of the nuclear calculation control device 60.

As described above, the sensitivity S ₀ of each GT detector 44 of each GT assembly 35 is determined by the GT signal processor 48 according to the heater calibration interval determined based on the furnace interior loading time of the GT assembly 35. The sensitivity S of each GT detector 44 of each GT assembly 35 that is periodically measured (calculated) and measured.
₀ is transmitted to the nuclear instrumentation control device 60, respectively.

The nuclear instrumentation controller 60 determines the sensitivity S ₀ of each GT detector 44 of each GT assembly 35 transmitted periodically according to the heater calibration time interval, that is, the sensitivity S ₀ of each GT detector 44. The time change data of ₀ for each GT detector 4
4 is stored in the memory. Then, the nuclear instrumentation control device 60
Are the GTs newly transmitted to the nuclear instrumentation controller 60.
The sensitivity S ₀ ′ of the detector 44 is compared with several points of sensitivity S ₀ data (sensitivity change data) stored in the memory and traced back to the past from the transmission time of the sensitivity S ₀ ′, and the comparison result is displayed on the display device 63.
And a process of displaying a time-dependent change trend (graph) of the sensitivity including the sensitivity S ₀ ′ via the display device 63 based on the time-dependent change data of the sensitivity stored in the memory. Do either. For example, as an example of the temporal change trend display processing function, G
Least-squares fitting (least-squares approximation) using all the sensitivity S ₀ data of the T detector 44 or the nearest several sensitivity S ₀ data retroactive from the present time.

Equation 4] ^{_{S 0 = a + b · e}} -λt ...... (4) the function of calculating for each individual GT detector 44 may be incorporated in the nuclear instrumentation control unit (nuclear instrumentation control module) 60.

Here, λ can be obtained by fitting based on the sensitivity S ₀ data, or past actual data values can be used as representative values.

Here, the GT detector 44 of the GT assembly 35 associated with the operation or operation of the reactor based on the above equation (4)
Shows the example of the temporal change trend graph sensitivity S ₀ in Fig. Here, the symbol X indicates the measured GT detector sensitivity S ₀ , and the symbol Y is the actually measured sensitivity S ₀ represented by the symbol X.
5 shows an approximate curve represented by the prediction fitting equation “S ₀ = a + be · ^−λt ” of the above equation (4) obtained by using the equation (4).

The operator is displayed on the display device 63,
The result of comparison between the newly transmitted sensitivity S ₀ ′ and the sensitivity change data or the trend graph of sensitivity change with time (see FIG. 7) is monitored, and as a result of this monitoring, the newly transmitted sensitivity S ₀ ′ is monitored. _{0 'is} a constant value stored in the memory predetermined {first determination value (abnormality judgment value; acceptable sensitivity change determination value, for example, 10% sensitivity S _0)} when it is determined to have changed over the , The operator operates the corresponding GT detector 44
The bypass command is transmitted to the process control computer 20A via the input / output device 63, with the sensitivity S ₀ ′ of as an abnormal value.

When the newly transmitted sensitivity S ₀ ′ does not exceed the first determination value, the operator sets the sensitivity of the GT detector 44 of the corresponding GT assembly 35 to the sensitivity S 0.
A sensitivity update command for updating to ₀ ′ is transmitted to the nuclear instrumentation control device 60 of the process control computer 20A via the input / output device 63.

When the operator determines that any of the sensitivities of the plurality of GT detectors 44 of the plurality of GT aggregates 35 is a change in the range expected without abnormality, for example, the operator selects a corresponding one of the plurality of GT detectors. It is also possible to transmit a sensitivity update command for collectively updating the sensitivities of the plurality of GT detectors 44 in the aggregate 35, and also for each GT aggregate 35 and G
A sensitivity update command for individually updating each T detector 44 can also be issued.

The nuclear instrumentation controller 60 of the process control computer 20A replaces the sensitivity S ₀ of the GT detector 44 of the GT assembly 35 corresponding to the sensitivity update command transmitted from the input device 63 with the new sensitivity S ₀ ′. Is transmitted to the GT signal processing device 48.

[0187] GT signal processing device 48 based on the transmission sensitivity update command, the sensitivity _{S 0} of GT detector 44 of the corresponding GT assembly 35 to change to the new sensitivity _{S 0} ', the new sensitivity S updating _{Using 0} ′, the output voltage signal from the GT detector 44 is converted to GT data D1.

Note that the nuclear instrumentation control device 60 of the process control computer 20A uses a second allowable sensitivity change judgment value (a judgment value smaller than the first judgment value in the assumed change range) stored in the memory in advance. ; for example, 0.2% sensitivity _{S 0),}
And the newly transmitted sensitivity S ₀ ′ exceeds the second allowable sensitivity change determination value based on the comparison result of the obtained sensitivity S ₀ ′ and the sensitivity change data or the sensitivity time-dependent change trend graph. Automatically determines whether or not the value does not exceed the first determination value. As a result of this determination, the newly transmitted sensitivity S ₀ ′ exceeds the second allowable sensitivity change determination value and the first sensitivity value changes. When it is determined that the difference does not exceed the determination value, it is determined that the change is not an abnormal change but a normal change and a significant change, and the sensitivity S ₀ of the GT detector 44 of the corresponding GT assembly 35 is changed to the new sensitivity S ₀ ′. G to update sensitivity automatically to automatically update
It is also possible to transmit to the T signal processing device 48. Further, when it is determined that the newly transmitted sensitivity S ₀ ′ does not exceed the second allowable sensitivity change determination value, the nuclear instrumentation control device 60 determines that there is no need to update the sensitivity, Do not perform sensitivity update processing.

Then, the nuclear instrumentation control device 60 determines that the newly transmitted sensitivity S ₀ ′ is equal to the first determination value (for example,
When changed to 10%) or more of the sensitivity S ₀ is automatically determined to be abnormal in GT detector 44 of the corresponding GT assembly 35 occurs, GT detector 4 the abnormality change has occurred
4 and an alarm display including the address of the GT assembly 35 is output directly to the outside or to the operator via the display device 63. As a result, the operator detects, based on the output alarm display, the GT detector 44 in which the abnormal change has occurred.
Alternatively, the GT assembly 35 including the GT detector 44 is determined to be faulty, and the GT detector 44 or the GT
5 can be registered as a fault bypass.

Further, the nuclear instrumentation control device 60 of the process control computer 20A stores each GT which is sequentially updated and recorded in the memory.
The furnace interior loading time of the assembly 35 is periodically evaluated, and the GT heater calibration time interval set at the present time (furnace interior loading time range) according to the progress of the furnace interior loading time of each GT assembly 35. Is switched to the heater calibration time interval set in the next furnace interior loading time range, the display mode of the display symbol of the corresponding GT assembly 35 on the heater calibration time interval registration screen of the display device 63. (For example, by blinking a display symbol), the operator is notified of the switching of the heater calibration time interval.

As described above, according to the present embodiment,
The nuclear instrumentation control device 60, the GT heater control device 53, and the built-in heater 7 are set in accordance with the heater calibration interval set according to the furnace interior loading time of each GT assembly 35 (GT detector 44).
1, the sensitivity of each GT detector 44 is measured, the sensitivity of each GT detector 44 is updated based on the measured temporal change data of the sensitivity S ₀ , and the GT for the gamma ray heat generation amount is updated.
A decrease in the output voltage of the detector 44 and a saturation phenomenon can be corrected, and a very accurate γ-ray heat generation (GT data D1) can be obtained. Therefore, the accuracy of the power distribution correction processing using the GT data can be further improved, and a more reliable core power distribution and the like can be obtained.

In particular, in the reactor operating or operating state of the nuclear reactor, the sensitivity S ₀ of each GT detector 44 of each GT assembly 35 changes slowly with time as shown by the broken line Y in FIG. Since the equilibrium state is reached, the nuclear instrumentation assembly 32, which has been loaded into the reactor core 3 and has just been put into operation, has a shorter reactor interior loading time, changes rapidly during the operation cycle, while the previous operation cycle or the The sensitivity S ₀ of the GT detector 44 is substantially stable in the previously loaded nuclear instrumentation assembly 32, that is, in the nuclear instrumentation assembly 32 having a longer furnace interior loading time.

[0193] Thus, GT assembly 35 furnace loading time sensitivity S ₀ of the long GT detector 44 is stable, so good to the extent that checks whether there is no abnormality, the heater calibration interval above By setting the time to, for example, 1000 hours or more, unnecessary GT heater calibration processing can be performed to prevent an unnecessary in-operation state (bypass state) of the GT signal from becoming longer, and the furnace interior loading time can be reduced. By performing heater calibration only on the relatively short GT assembly 35 at a relatively short heater calibration interval (for example, 48 hours), it is possible to perform an efficient short-time GT heater calibration. Further, the probability of heater disconnection during the operational life of the GT assembly 35 can be reduced.

Further, since the heater calibration time interval of each GT assembly (each GT detector) can be displayed as a heater calibration time interval registration screen on the display device 63, the heater calibration frequency management of the GT assembly 35 can be performed. In addition, the presence or absence of the calibration target GT assembly 35 can be easily identified.

[0195] Incidentally, the process of calculating the sensitivity _{S 0} of GT detector 44 in this embodiment is configured so as performed in GT signal processing unit 48, an output voltage signal of GT detector 44 (m
V) The nuclear instrumentation controller 60 of the process control computer 20A
And the calculation of the sensitivity S ₀ of the GT detector 44 may be performed by the processing of the nuclear instrumentation control device 60. That is, the calculation process of the sensitivity S ₀ of GT detector 44, the problem of whether carried out by sharing in any computer of CPU is not an essential problem.

In the above-described embodiment, the sensitivity calibration time interval of the GT assembly 35 stored in the memory of the process control computer 20A has been described as four steps in accordance with the history of furnace interior loading time. Is not limited to this, and may be a plurality of other steps, for example, three steps or two steps for simplicity. This time interval is the actual G
Referring to the degree of sensitivity change due to the individual furnace interior loading time of the T signal detector, for example, a sensitivity change diagram as shown in FIG. 7, the change is large in the early stage of loading and becomes saturated with time. Because of having the characteristic, based on this time interval characteristic, for example, the deviation from the sensitivity at the time of heater calibration predicted from the time-series sensitivity data, or the change from the measurement result sensitivity at the previous sensitivity calibration When the allowable sensitivity change determination value of No. 3 is set as a relatively small value (for example, 1% of the sensitivity), it is desirable to have multiple levels such as four levels as described above.

Instead of the furnace interior loading time, the neutron irradiation amount in the furnace of the sensor unit of each GT detector may be used as a parameter. In this case, the in-furnace power distribution calculating device 31 accurately calculates the in-furnace neutron irradiation amount for each GT detector 44 and stores it in the memory of the process control computer 20A instead of the furnace interior loading time. The calibration time interval may be set according to the range of the neutron irradiation amount in the furnace and stored in the memory. The neutron irradiation amount in the furnace does not need to be calculated accurately, and may be replaced with a parameter substantially proportional to the neutron irradiation amount. For example, the average burnup of the fuel node surrounding the GT detector 44 may be employed as a parameter.

When the reactor core fixed nuclear instrumentation system 30 shown in the first embodiment is arranged, a plurality of LPRM detectors 3 for detecting the local power distribution in the power region in the reactor are provided.
7 and a gamma thermometer assembly 3 for detecting γ-ray heating value
5 is accommodated in the nuclear instrumentation tube 33, and the GT detector 44 is at least installed in the LPRM detector 3.
, An in-core nuclear instrumentation assembly 32 disposed in the vicinity of
LP for processing LPRM signal S2 from RM detector 37
RM signal processing device 40 and GT signal processing device 4 that processes output voltage signal (GT signal) S1 from GT aggregate 35
8 and a GT heater control device 53 for controlling the energization of the heater 71 incorporated in the GT assembly 35.

On the other hand, the fixed in-core nuclear instrumentation system 30 of the nuclear reactor is monitored and controlled by the nuclear instrumentation control device 60 provided in the process control computer 20A. Nuclear instrumentation control device 60
Constitutes a monitoring control module, and controls the operation of the GT heater control device 53 and the GT signal processing device 48. The GT heater control device 53 includes the GT aggregate 3
5, the power supply to the built-in heater 71 is controlled, and the output voltage sensitivity of each GT detector 44 is calibrated by heating the heater.

Further, the GT assembly 35 is energized and heated to the built-in heater 71 during the operation of the reactor, so that the output voltage of each GT detector 44 is increased by heating the heater (additional heating amount) and the heating voltage to the built-in heater 71 is increased. The current is measured by the GT signal processor 48, and the thermocouple of the GT detector 44 per unit calorific value (W / g) by gamma rays is obtained by using the measured heater resistance and the mass of the fixed GT detector 44 in advance. Output voltage sensitivity calibration is performed. The time interval at which the output voltage sensitivity calibration is performed uses the furnace interior loading time of the gamma thermometer assembly 35 as a parameter. The furnace interior loading time of the gamma thermometer assembly 35 is calculated and stored by the nuclear instrumentation controller 60.

According to the furnace interior loading time of the GT assembly 35,
For example, a first time interval, a second time interval, a third time interval,... And a heater calibration time interval are prepared in advance from the shortest one, and automatically correspond to the calculated furnace interior loading time. A time interval is selected, and output voltage sensitivity measurement by heater heating is performed at predetermined time intervals.

Further, the nuclear instrumentation control device 60 issues an alarm signal when the heater calibration time interval of the output voltage sensitivity due to the heater heating of the fixed GT detector 44 of the GT assembly 35 is changed from the previous time interval. Is output to the output device 63,
The operator is notified of the change in the calibration time interval.

[Second Embodiment] A second embodiment of a nuclear reactor fixed instrumentation system and a nuclear instrumentation processing method, a power distribution calculation device and a calculation method, and a power distribution monitoring system and a monitoring method according to the present invention. The form will be described.

The basic configuration, operation, operation, power distribution monitoring method, and nuclear instrumentation processing method of the reactor power distribution monitoring system 29, the in-core nuclear instrumentation system 30, and the power distribution calculation device 31 in the second embodiment. Since the output distribution calculation method is not different from that shown in the first embodiment of the present invention (see FIGS. 1 to 7), the same components are denoted by the same reference numerals and description thereof will be omitted. .

The nuclear instrumentation system 30 and the power distribution calculator 31 of the nuclear reactor of the second embodiment are different from those shown in the first embodiment of the present invention in that the fixed type GT detector 44 is heated by a heater. The gamma thermometer assembly 35 that performs the output voltage sensitivity calibration according to the above is basically different in the determination process.

The process control computer 20A is provided with a nuclear instrumentation control device 60.
Has a function of calculating the reactor operating time (reactor interior loading time) after the GT assembly 35 is loaded inside the reactor and a function of storing the reactor operating time (reactor interior loading time). The nuclear instrumentation control device 60 constitutes a nuclear instrumentation control module which is a part of the function of the process control computer 20A.

Further, the nuclear instrumentation control device 60 converts the temporal change data (time series data of the output voltage sensitivity) of the output voltage sensitivity S ₀ of each GT detector 44 into the furnace interior loading time of the GT assembly 35. Each time the sensitivity calibration of the GT assembly 35 is performed at a predetermined time interval selected according to the function, the function is stored in the memory of the plant monitoring and control device 20A in association with the furnace interior loading time. , The output voltage sensitivity time series data of the GT detector 44 is stored as a table for the furnace interior loading time.

The nuclear instrumentation control device 60 uses the time series data of the sensitivity S ₀ of the GT detector 44 to take at least two or more nearest time series data points from the current time, and based on these time series data points. Estimating and calculating the output voltage sensitivity change curve by linear extrapolation or quadratic curve extrapolation, or by using a linear or quadratic curve fitting equation or the above “a +
The output voltage sensitivity change curve in the future is estimated and calculated by fitting the curve represented by be · e− ^λt ”to the least squares fitting equation.

Here, when estimating the output sensitivity change curve using “a + be · ^−λt ”, t is the furnace interior loading time, and
a, b, and λ are constants to be fitted (here, λ may be a value typically selected from sensitivity characteristics of a past GT detector).

Then, the nuclear instrumentation control device 60 determines the GT detector 44 at a predetermined future time from the output voltage sensitivity change curve.
The value of the sensitivity S ₀ is estimated, and after a predetermined period from the last heater heating calibration time, the currently selected time interval (for example, 4
The estimated value is calculated after a longer time interval (e.g., 168 hours) than the current time that is scheduled to be selected next to (8 hours).

[0211] change in the output voltage sensitivity S ₀ is a predetermined value, i.e. if more than the third allowable sensitivity change determination value set for the future time, for example, the third tolerance sensitivity change determination value) of 1% If the amount of change in the output voltage sensitivity S ₀ is estimated to vary more than 1% from the last heater heating the calibration point, predetermined short time interval (e.g., a current time interval, the current time interval If the time is 48 hours, the time interval is set as a heater calibration time interval and registered in the memory so that the next heater heating calibration is performed at that time (48 hours), and the third allowable sensitivity change determination value ( If the change does not exceed 1% of the sensitivity, for example, the change amount is 1% or less, the next heater calibration time interval is set to the next predetermined time interval (for example, 168 hours) longer than the current time interval (for example, 48 hours). Set to It has a function to be registered in the memory. The nuclear instrumentation control device 60 controls the sensitivity change amount within a predetermined sensitivity change width (within the allowable sensitivity change determination value) according to the sensitivity change estimated by the above-described estimation calculation. It is also possible to automatically calculate the heater calibration time interval within a fixed minimum heater time calibration time interval and a maximum heater calibration time interval limit.

Heater calibration of the GT detector 44 in the axial direction of one gamma thermometer assembly 35 (except for those which are comprehensively judged to be faulty and registered in the nuclear instrumentation control device 60 by bypass) Based on the time interval registration value or the heater calibration time interval evaluation result, the nuclear instrumentation control device 60
Referring to the memory, all GTs in the axial direction of the GT aggregate
The heater calibration time interval of the detector 44 is searched, and each GT is determined based on the heater calibration time interval having the shortest heater calibration time interval among all the GT detectors 44 along the axial direction of the GT assembly 35. The heater calibration command of the detector 44 is transmitted to the GT signal processing device 48 and the GT heater control device 53, respectively.

This function and the heater calibration method are necessary when the neutron irradiation amount of the GT detector 44 is used instead of the furnace interior loading time of the GT assembly 35 as a heater calibration parameter.

According to the second embodiment, as the output voltage sensitivity S ₀ of the GT detector 44 of the GT assembly 35 newly loaded in the regular inspection work before the operation cycle, only the data at the time of shipment from the out-of-pile test is used. or for only the initial data are registered, by detecting the initial sensitivity S ₀ of the GT detector 44, when the turbine provisional the incorporation of startup, partial output point and a rated output after the turbine the the incorporation When the core state at the earliest possible time after the arrival is selected, the core state is selected to be constant. By the above-described operation processing of the nuclear instrumentation control device 60, the GT signal processing device 48, and the GT heater control device 53, for example, three to four times the GT A heater heating calibration process is performed.

For example, the output voltage sensitivity S ₀ data of the GT detector 44 of the GT assembly 35 having four or more sensitivity S ₀ data of the GT detector 44 by, for example, four or more heater heating calibration processes is as follows. using the time-series data of the sensitivity S ₀ of the nearest least two points or more GT detectors 44 from the present time, given the currently selected time intervals (say where the second predetermined time interval) after GT the value of the sensitivity S ₀ of the detector 44, and (if the third predetermined time interval here) long predetermined time interval than the next second predetermined time interval sensitivity S ₀ of GT detector 44 after The value is estimated by linear extrapolation or quadratic extrapolation, respectively, or 1
It is estimated by a quadratic or quadratic curve fitting or a + be · ^λt curve fitting.

[0216] Results of this estimation process, in the case where the amount of change in the sensitivity S ₀ of GT detector 44 after a second predetermined time interval has been estimated to exceed 1% tolerance sensitivity change determination value, the next heater calibration time As the interval, a first calibration time interval shorter than the second predetermined time interval is registered in the memory, and the amount of change in the sensitivity S ₀ of the GT detector 44 after the third predetermined time interval is equal to the allowable sensitivity change determination value 1 %, It is registered in the memory as a next heater calibration time interval, a third predetermined time interval longer than the second predetermined time interval.

If the estimated change in the sensitivity S ₀ after the second predetermined time interval does not exceed 1%, but the estimated change after the third predetermined time interval exceeds 1%, the next time The second predetermined time interval is directly registered in the memory as the heater calibration time interval.

Thereafter, automatic search processing of each heater calibration time interval registered in the memory of the GT detectors 44 distributed in the axial direction of the same GT assembly 35 is performed, and the GT detectors 44 that are not registered in the bypass are processed. If at least one GT heater calibration time interval of a short time interval is registered, the heater calibration time interval of all the GT detectors 44 of the corresponding GT assembly 35 is automatically stored in the memory at the short heater calibration time interval. Corrected registration.

When the finally registered GT heater calibration time interval is changed from the previous heater calibration time interval to a new heater calibration time interval, the G
As for the T-assembly 35, the nuclear instrumentation control device 60 has a function of alerting the operator by flashing and displaying the corresponding heater calibration time interval data on the heater calibration time interval registration screen of the display device 63. And the operator
Or check the reference heater calibration time interval which is blinking by the trend graph of the output voltage sensitivity S ₀ of GT detector 44 that is displayed on the display device 63, it is compared with the previous output voltage sensitivity S ₀ Can be.

In this way, the GT registered in the memory
The final registration result of the heater calibration time interval is displayed to the operator on the display device 63 by the processing of the nuclear instrumentation control device 60.

That is, when the predetermined heater calibration time corresponding to the predetermined heater calibration time interval of the GT assembly 35 is reached, the nuclear instrumentation control device 60 prompts the operator via the display device 63 to perform the GT heater heating calibration process. The execution is warned, and the target GT aggregate 35 is displayed based on the registration result described above.
The GT heater calibration timing differs for each GT assembly. However, before the start-up of the LPRM detector sensitivity by the GT signal at the cycle start-up (low output) or near the rated reactor output after the start-up, be sure to complete GT detector 44
Is performed, the starting point of the heater calibration time timing of each GT assembly 35 can be unified throughout the cycle.

[0222] GT heater calibration process, the same procedure as the first embodiment, is performed by an instruction of a process control computer 20A, the output voltage sensitivity S ₀ is the process control computer 20A of the newly obtained GT detector 44 Sent to. The subsequent operation of the operator is the same as in the first embodiment.

[0223] In the present embodiment, the output voltage sensitivity _{S 0} of GT detector 44, at least two points or more sensitivity _{S 0} of the nearest GT detector 44, for example extrapolation from the three points,
Linear or quadratic fitting or a + be
^Although the case where the estimation is performed using the ^-λt- type fitting has been described, the present invention is not limited to this, and the estimation may be performed from four points by a cubic fitting or a fitting using a least-square fitting of another function form.

As described above, according to the present embodiment,
For the current sensitivity S ₀ of the GT detector 44, the nearest S
_{From the 0} trend data, the amount of change in the sensitivity S ₀ of the GT detector 44 at a predetermined future time is predicted and estimated, and if the rate of change of the estimated value is larger than the allowable sensitivity change determination value, G
Since a short time interval can be registered as the T heater calibration time interval, it is possible to flexibly cope with an unexpected change in output voltage sensitivity of the GT aggregate 35, and to prevent deterioration of the output distribution measurement accuracy due to the GT aggregate 35. . In addition, when the GT heater calibration time interval is changed from before, the change can be notified via the display device 63.
The operator can be alerted to the inspection whether there is any abnormality, and the processing efficiency for maintaining the reliability of the nuclear instrumentation in the nuclear reactor can be improved.

It is to be noted that, within a predetermined sensitivity change width (within the range of the allowable sensitivity change determination value) according to the estimated change in sensitivity.
It is also possible to automatically calculate the heater calibration time interval within a fixed minimum heater time calibration time interval and a maximum heater calibration time interval limit so that the amount of change in sensitivity is limited.

When the nuclear reactor core instrumentation system 30 of the second embodiment is arranged, a plurality of fixed neutron detectors (LPRM detectors) 37 for detecting the local power distribution in the power region in the reactor are provided. The fixed GT detector 44 of the gamma thermometer assembly 35 for detecting the calorific value of the γ-ray is accommodated in the nuclear instrumentation pipe 33, and the GT detector 44 is arranged at least in the vicinity of the fixed LPRM detector 37. The reactor core instrumentation assembly 32 and the LPR from the LPRM detector 37
An LPRM signal processing device 40 that processes the M signal S2, a GT signal processing device 48 that processes the output voltage signal S1 from the gamma thermometer assembly 35, and an energization control to the heater 71 built in the GT assembly 35 And a nuclear instrumentation control unit 60 for calculating and storing the furnace interior loading time of the GT assembly 35 or the irradiation amount (or burnup) in the furnace, and the nuclear instrumentation control unit 60 includes a GT heater. The operation of the control device 53 and the GT signal processing device 48 is controlled.

The heater wire of the built-in heater 71 is energized and heated by the GT heater control device 53 during the operation of the reactor, and the thermocouple output voltage of the fixed GT detector 44 of the GT assembly 35 with respect to heater heating (additional heating amount). The increase sensitivity is measured by the GT signal processor 48 based on the heating voltage / current of the built-in heater (heater wire). Then, the GT signal processing device 48
Thus, the output voltage sensitivity per unit heat value (W / g) by gamma rays is calibrated based on the measured (known) heater resistance value and the mass (heat conversion mass) of the fixed GT detector 44 measured in advance.

As a time interval for calibrating the output voltage sensitivity of the GT assembly 35, the nuclear instrumentation control device 60 converts the sensitivity time-series data of each GT detector 44 calculated by the GT signal processing device 48 into a table with respect to the furnace interior loading time. At the beginning, the furnace interior loading is stored for a predetermined shortest time interval (first time interval), and a change curve of the output voltage sensitivity is estimated and calculated from time series data at two or more points closest to the present time, The change in the output voltage sensitivity is compared with an allowable sensitivity change determination value set for a predetermined future time, that is, the future time after the first time interval, and the future time after the second time interval. If the allowable sensitivity change determination value is not exceeded even after the time interval, the heater heating calibration of each GT detector 44 is performed at a predetermined second long time interval.

[0229] Further, with the elapse of the loading time, in a state where the heater calibration time interval of the GT assembly 35 which is longer, for example, the third time interval is set, the time series data of the nearest two or more points from the present time are set. Estimate and calculate the change curve of the output voltage sensitivity from the output voltage sensitivity change is a predetermined future time,
That is, the allowable sensitivity change determination values set for the future time after the third time interval and the future time after the fourth time interval are compared, and 1) when the determination value does not exceed the determination value even after the long fourth time interval At each predetermined fourth long time interval, each GT detector 44
And 2) when the determination value does not exceed the determination value at the predetermined third time interval but exceeds the determination value after the long fourth time interval, the predetermined third long time interval 3) If the GT value exceeds the determination value even at the third predetermined time interval, the GT detector 44 is calibrated with the heater as it is. The nuclear instrumentation control unit 60 performs the heater heating calibration of each GT detector 44 at the maximum value (in this case, either the first or second time interval) of the predetermined time intervals to be satisfied. Gamma thermometer heater control device 5
3 and an output sensitivity calibration process for controlling the gamma thermometer signal processing device 48.

Further, the nuclear instrumentation control device 60 outputs an alarm signal to the display device 63 when the heater heating calibration time interval of the GT assembly 35 is changed from the previous time interval,
The operator is notified of the change in the heater calibration time interval.

[Third Embodiment] A third embodiment of the in-core nuclear instrumentation system, power distribution calculation device, and power distribution monitoring system of the reactor according to the present invention will be described.

The basic configuration, operation (action) of the reactor power distribution monitoring system 29, the nuclear reactor instrumentation system 30, and the power distribution calculating device 31 in the third embodiment are as follows.
Since the power distribution monitoring method, the nuclear instrumentation processing method, and the power distribution calculation method are not different from those shown in the first and second embodiments of the present invention, the same components are denoted by the same reference numerals. The description is omitted.

The nuclear instrumentation system 30 and the power distribution calculating device 31 of the nuclear reactor of the third embodiment are different from those shown in the first and second embodiments of the present invention in that The determination process of the gamma thermometer assembly 35 for calibrating the output voltage sensitivity by heating the heater of the heater 44 is basically different. That is, the third embodiment is a combination of the first embodiment and the second embodiment of the present invention.

The process control computer 20A is provided with a nuclear instrumentation control unit 60. The nuclear instrumentation control unit 60 has a function of calculating the reactor operating time after loading the GT assembly 35 inside the reactor, It has a function to store the operation time.

[0235] The nuclear instrumentation control device 60 controls the time (load power) after loading into the furnace in a state where the normal operation parameters (reactor power, core coolant flow rate, core current state data such as control rod pattern) do not change. As described in the first embodiment, the elapsed time from the previous calibration processing time of each GT assembly 35 to the present time is referred to as the first embodiment in accordance with the elapse of the elapsed time in the furnace in the operating state). Each GT calculated
Based on the heater calibration time interval corresponding to the current furnace interior loading time of the assembly 35, all GTs
The GT aggregate to be calibrated for the heater is automatically determined and extracted from the aggregate 35.

The nuclear instrumentation control device 60 performs a re-determination process for each GT heater process, registers a heater calibration time interval corresponding to the furnace interior loading time corresponding to each GT assembly 35 in a memory, and A heater calibration time interval corresponding to the registered furnace interior loading time of each GT assembly 35 is transmitted to the display operation device 63, and a heater calibration time interval registration screen representing the heater calibration time interval of each GT assembly 35 is displayed. Is displayed via the display operation device 63.

Further, the nuclear instrumentation control device 60 automatically issues the heater calibration process execution command to the extracted GT assembly 35 to be subjected to heater calibration, to the GT heater control devices 53 and G.
Respectively to the T signal processor 48, or
A GT calibration instruction command transmission request for the GT assembly 35 to be subjected to the heater calibration is transmitted to the display / operation device 63, and the display is output to the operator via the display / operation device 63.

The GT assembly 35 requiring the heater calibration displayed on the display device 63 is controlled by the nuclear instrumentation control device 60 of the process control computer 20A (automatically or manually).
The heaters are calibrated in a predetermined sequence by the processes of the GT signal processor 48 and the GT heater controller 53.

That is, the GT heater control device 53 supplies power (applies voltage) to the built-in heater 71 of the GT assembly 35 corresponding to the position address of the transmitted heater calibration process execution command, and The heater voltage to be applied is controlled so that the current value flowing through the heater becomes a predetermined value.

Next, the GT heater control device 53 measures the applied voltage value and the current value flowing through the built-in heater 71,
The measurement value is transmitted to the GT signal processing device 48.

On the other hand, the GT signal processing device 48 receives the heater calibration process execution command (position address) transmitted from the nuclear instrumentation control device 60, and according to the reception timing,
The thermocouple output voltage signal (mV) of each GT detector 44 of the GT assembly 35 having the corresponding position address and not being heated is measured simultaneously and in parallel along the core axis direction, and the GT heater control is performed. The heater application voltage and the current measurement value transmitted from the device 53 are received, and the GT assembly 3 at the time of heater heating is received according to the reception timing.
5, the thermocouple output voltage signals (mV) of the respective GT detectors 44 are simultaneously measured in parallel along the axial direction.

Then, the GT signal processing device 48 outputs the measured state of no heater heating and the output voltage signal at the time of heater heating in each GT detector 44 of the GT assembly 35 for heater calibration in the processing device 48 (the memory thereof). ) Is stored for each GT detector 44. This heater calibration execution process is continued by changing the position address of the GT assembly until the target GT assembly requiring heater calibration is completed.

Each GT detector 4 stored in this way is
8 based on the heater unheated state and the output voltage signal at the time of heating the heater, the GT signal processing device 48 performs the same processing as in the first embodiment, and performs the same processing as in the first embodiment. A sensitivity S ₀ of 44 can be calculated. Then, the GT signal processing device 48 stores the calculated sensitivity S ₀ of each GT detector 44 in the processing device (the memory thereof), and stores the sensitivity S ₀ of each GT detector 44 in the process control computer 20A. Is transmitted to the nuclear calculation control device 60.

The sensitivity measurement process of the GT heater control device 53 and the GT signal processing device 48 based on the above-described heater calibration process execution command is performed in a predetermined sequence until the process for all the GT assemblies 35 to be calibrated is completed. Is repeatedly executed.

In addition, the nuclear instrumentation control device 60 uses the G
The GT signal processing device 4
8 has a function of storing, in a memory, temporal change data of the sensitivity S ₀ of each GT detector 44 transmitted from the GT detector 44.
From the two or more data points closest to the present time in the time series data of the sensitivity S ₀ of the detector 44, a linear extrapolation or 2
The output voltage sensitivity change curve is estimated and calculated by extrapolation of a quadratic curve, or a linear or quadratic curve fitting equation, a least squares fitting equation or a cubic fitting equation of the curve represented by the above “a + be · ^λt ” To estimate the future output voltage sensitivity change curve.

Then, the nuclear instrumentation control device 60 calculates the estimated value of the sensitivity change amount after a predetermined time interval to be automatically selected from the furnace internal loading time at the present time from the last heater calibration time (that is, the future time). calculate.

If the calculated sensitivity change estimated value is equal to or more than the allowable sensitivity change determination value (for example, 1%), the nuclear instrumentation control device 60 sets the next scheduled heater determined by the furnace interior loading time stored in the memory. Regardless of the calibration time interval, a plurality of heaters stored in advance in memory such that a predetermined time interval one step shorter than the currently selected time interval or a sensitivity change amount falls within a range of an allowable sensitivity change determination value. Update registration in the memory so that the next heater calibration is performed at the maximum time interval among the calibration time intervals.

If the sensitivity change amount is equal to or less than the allowable sensitivity change determination value (for example, 1%), the nuclear instrumentation control device 60
Is to register the next heater calibration time interval as a predetermined time interval determined from the furnace interior loading time (for example, the next scheduled heater calibration time interval determined from the furnace interior loading time stored in the memory).

Then, the heater calibration time interval of the GT detector 44 in the axial direction of the GT assembly 35 is searched, and the heater calibration time interval of any one of the detectors is determined (however, it is determined that a failure has been comprehensively determined. Except for detectors that are bypass registered with the nuclear instrumentation controller 60), if they are registered in the memory at shorter time intervals, the nuclear instrumentation controller 60 determines which heater has the shortest heater calibration time interval. Based on the calibration time interval, a heater calibration command for each GT detector 44 is transmitted to the GT signal processor 48 and the GT heater controller 53, respectively.

According to the third embodiment, at the beginning of the furnace interior loading,
GT detector sensitivity S at a predetermined short first time interval₀But he
After calibrated and the specified furnace loading time has elapsed, the furnace
To a predetermined long second heater calibration time interval corresponding to time
Registered for renewal, and after that the furnace interior loading time has passed
Automatically selects a longer heater calibration time interval
Are selected and sequentially updated and registered.
T detector sensitivity S₀Data trends (temporal change data
After the future time estimated from the
GT heater calibration time interval selected from time)
GT detector sensitivity S ₀Is the allowable sensitivity change judgment value
(For example, 1%) or more, temporarily, short time interval
Is registered.

Thereafter, automatic search processing of each heater calibration time interval registered in the memory of the GT detectors 44 distributed in the axial direction of the same GT assembly 35 is performed. If at least one GT heater calibration time interval of a short time interval is registered, the heater calibration time interval of all the GT detectors 44 of the corresponding GT assembly 35 is automatically stored in the memory at the short heater calibration time interval. Corrected registration.

When the finally registered GT heater calibration time interval is changed from the previous heater calibration time interval to a new heater calibration time interval, the G
As for the T-assembly 35, the nuclear instrumentation control device 60 has a function of alerting the operator by flashing and displaying the corresponding heater calibration time interval data on the heater calibration time interval registration screen of the display device 63. And the operator
Or check the reference heater calibration time interval which is blinking by the trend graph of the output voltage sensitivity S ₀ of GT detector 44 that is displayed on the display device 63, it is compared with the previous output voltage sensitivity S ₀ Can be.

As described above, the GT registered in the memory
The final registration result of the heater calibration time interval is displayed to the operator on the display device 63 by the processing of the nuclear instrumentation control device 60.

That is, when the predetermined heater calibration time corresponding to the predetermined heater calibration time interval of the GT assembly 35 is reached, the nuclear instrumentation control device 60 prompts the operator via the display device 63 to perform the GT heater heating calibration process. The execution is warned, and the target GT aggregate 35 is displayed based on the registration result described above.

The GT assembly 35 changed to a time interval until the next calibration shorter than the heater calibration time interval selected from the furnace interior loading time is determined by the core loading time at that time after the next heater calibration. Estimate the sensitivity change amount until the next heater calibration calibration, and if the change amount satisfies the allowable sensitivity change determination value, the heater calibration time interval determined by the core loading time is restored, but if it is not satisfied again , The next heater calibration is performed again at short time intervals.

[0256] GT heater calibration process, the same procedure as the first embodiment, is performed by an instruction of a process control computer 20A, the output voltage sensitivity S ₀ is the process control computer 20A of the newly obtained GT detector 44 Sent to. The subsequent operation of the operator is the same as in the first embodiment.

As described above, according to the present embodiment,
For the current sensitivity S ₀ of the GT detector 44, the nearest S
_{From the 0} trend data, the amount of change in the sensitivity S ₀ of the GT detector 44 at a predetermined future time is predicted and estimated, and if the rate of change of the estimated value is larger than the allowable sensitivity change determination value, G
Since a short time interval can be registered as the T heater calibration time interval, it is possible to flexibly cope with an unexpected change in output voltage sensitivity of the GT aggregate 35, and to prevent deterioration of the output distribution measurement accuracy due to the GT aggregate 35. . In addition, when the GT heater calibration time interval is changed from before, the change can be notified via the display device 63.
The operator can be alerted to the inspection whether there is any abnormality, and the processing efficiency for maintaining the reliability of the nuclear instrumentation in the nuclear reactor can be improved.

When the nuclear reactor core fixed instrumentation system 30 of the third embodiment is arranged, a plurality of fixed neutron detectors (LPs) for detecting the local power distribution in the power region in the reactor are provided.
RM detector) 37 and GT assembly 3 for detecting γ-ray calorific value
5 is accommodated in the nuclear instrumentation tube 33, and the GT detector 44 is at least installed in the LPRM detector 3.
, An in-core nuclear instrumentation assembly 32 disposed in the vicinity of
LP for processing LPRM signal S2 from RM detector 37
An RM signal processing device 40, a GT signal processing device 48 that processes the output voltage signal S1 from the GT assembly 35, a GT heater control device 53 that controls energization of a heater 71 built in the GT assembly 35, A nuclear instrumentation control device 60 that calculates and stores the furnace interior loading time of the GT assembly 35,
The nuclear instrumentation control device 60 controls the operation of the GT heater control device 53 and the GT signal processing device 48 according to the furnace interior loading time of the GT assembly 35.

The heater wire of the built-in heater 71 is energized and heated by the GT heater control device 53 during operation of the reactor, and the thermocouple output voltage of the fixed GT detector 44 of the GT assembly 35 with respect to heater heating (additional heating amount). The increase sensitivity is measured by the GT signal processor 48 based on the heating voltage / current of the built-in heater (heater wire). Then, the GT signal processing device 48
Thus, the output voltage sensitivity per unit heat value (W / g) by gamma rays is calibrated based on the measured (known) heater resistance value and the mass (heat conversion mass) of the fixed GT detector 44 measured in advance.

When calibrating the output voltage sensitivity of the GT assembly 35, the nuclear instrumentation control device 60 previously stores in the memory the furnace interior loading time of the GT assembly 35 (or the irradiation amount in the furnace) as a parameter. The heater calibration time interval is selected in accordance with a plurality of heater calibration time interval data to be selected according to the furnace interior loading time, and the selected heater calibration time interval is set via the GT signal processing device 48 and the GT heater control device 53 at the selected heater calibration time interval. Calibration by heater heating.

Further, the nuclear instrumentation control device 60 stores the sensitivity time series data of each GT detector 44 calculated by the GT signal processing device 48, and changes the sensitivity change curve from the time series data at two or more points closest to the present time. If the sensitivity change exceeds the allowable sensitivity change determination value set for a predetermined future time determined from the furnace interior loading time, the calibration time interval is switched to a short time interval, and the GT heater control device is changed. 5
3 and controlling the GT signal processor 48,
A heater calibration process is performed.

[Fourth Embodiment] A fourth embodiment of a fixed nuclear reactor instrumentation system, a power distribution calculating device and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

The power distribution monitoring system 29 of the reactor, the in-core nuclear instrumentation system 30, and the power distribution monitoring device 31 in the fourth embodiment have the same basic structure and operation as those shown in the first embodiment of the present invention. Since the power distribution monitoring method, the nuclear instrumentation processing method and the power distribution calculation method are not different from those shown in the first and second embodiments of the present invention, the same components are denoted by the same reference numerals. The description is omitted.

The in-core nuclear instrumentation system 30 and the power distribution monitoring system 31 of the nuclear reactor of the fourth embodiment are modifications of the first, second and third embodiments of the present invention. In the first, second and third embodiments of the present invention, the GT heater calibration processing of the sensitivity S ₀ of the GT detector 44 is performed by the GT assembly 3.
The reactor output operation elapsed time (reactor interior loading time) after loading the reactor interior of the reactor No. 5 was used as a parameter.

The process control computer 20A according to the fourth embodiment has a function of calculating the neutron irradiation dose in the in-core nuclear instrumentation assembly 32. The neutron irradiation amount calculated instead of the furnace interior loading time of the assembly 32 is used as a parameter.

The calculation of the in-furnace neutron irradiation dose is executed by the in-furnace power distribution calculating device 31 in the process control computer 20A. Specifically, the in-furnace power distribution calculation device 31 includes:
The in-reactor neutron dose is calculated using the three-dimensional nuclear thermal hydraulic calculation code of the power distribution calculation module 61, which is a BWR three-dimensional simulator module. The power distribution calculation module 61 uses the core nuclear instrumentation assembly 3
The parameter takes into account not only the loading time inside the furnace 2 but also the effect of aging of the thermocouple with time due to neutron irradiation. Here, the calculation of the neutron irradiation dose is not performed accurately, and the parameter is substantially proportional to the average burnup of the fuel node surrounding the GT detector 44. Cumulative burnup increments may be used.

With the in-furnace power distribution calculating device 31 of the process control computer 20A, it is possible to more accurately reflect the sensitivity change of the GT detector 44 which changes due to the in-furnace neutron irradiation.

The fourth embodiment is a modification of the first to third embodiments. The fixed in-core nuclear instrumentation system of the reactor according to the fourth embodiment includes a nuclear instrument control device. 60
Stores the furnace interior loading time of the GT detector 44 of the gamma thermometer assembly 35 or the irradiation amount in the furnace in a memory, and evaluates the data by the nuclear instrumentation control device 60 to control the heater heating calibration of the GT detector 44. Is what you do.

[Fifth Embodiment] A fifth embodiment of a fixed nuclear reactor instrumentation system, a power distribution calculating device and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

The fifth embodiment is a modification of the first to fourth embodiments of the present invention. The reactor power distribution monitoring system 29, the fixed nuclear reactor instrumentation system 30, and the power distribution calculation device 31 in the fifth embodiment are basically the same as those shown in the first embodiment of the present invention.
Since the power distribution monitoring method, the nuclear instrumentation processing method, and the power distribution calculation method are the same, the same components are denoted by the same reference numerals and description thereof will be omitted.

In the first to fourth embodiments of the present invention, at the time of performing the GT heater calibration, the operating state parameters of the reactor (reactor current data S3 such as reactor power, core flow rate, and control rod pattern) are constant. For example, the operator confirms that there is, and the GT heater calibration process is performed when the core current state data S3 is constant.

However, in fact, the response characteristic of the GT aggregate 35 is that the GT aggregate 35 measures gamma ray heat generation. Therefore, accurate fission is required unless the decay chain of the nuclide of the gamma ray source has reached an equilibrium state. Rate, a GT signal level proportional to the local power in the furnace. Therefore, even if the operation state of the reactor is constant, an accurate GT signal level cannot be output unless it continues for a predetermined time.

In the fifth embodiment, the reactor core status data measuring device 55 detects core state changes such as core power, core flow rate, control rod pattern, etc., and a predetermined time has elapsed since the core state change was detected. Whether or not it is determined by the nuclear instrumentation control device 60 of the process control computer 20A based on the transmitted core state data D3.

That is, the nuclear instrumentation control device 60 stores the time when the core state (parameter) has changed in the memory, and determines that the scheduled time for the GT heater calibration is obtained by the same processing as in the first to fourth embodiments. At this stage, it is automatically determined whether or not a predetermined required time has elapsed since the core state (parameter) has changed, based on the core current state data D3. The operator confirms that the heater calibration of the GT assembly 35 can be properly performed, and manually starts the GT heater calibration process, or automatically starts the GT heater calibration process after waiting for a predetermined necessary time.

With this, in a state where the GT signal level is unbalanced and in a transient state, the sensitivity S ₀ of the GT detector 44 is calibrated by additional heating by the built-in heater 71, and the output voltage mV by the gamma thermo thereafter. Inaccurate conversion of the unit heat value (W / g) of gamma heat from the signal can be prevented.

[Sixth Embodiment] A sixth embodiment of a fixed nuclear reactor instrumentation system, a power distribution calculating device, and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

Basic Configuration, Operation, Power Distribution Monitoring Method, Nuclear Instrumentation Method, and Power Distribution Calculation Method of the Power Distribution Monitoring System 29, Reactor Nuclear Instrumentation System 30, and Power Distribution Monitoring Device 31 of the Sixth Embodiment Are not different from those shown in the first embodiment of the present invention, and the same components are denoted by the same reference numerals and description thereof will be omitted.

The block configuration of the reactor power distribution monitoring system 29 according to the present embodiment is substantially the same as or different from the block configuration of the reactor power distribution monitoring system shown in FIG.

That is, as shown in FIG. 1, the reactor pressure vessel 2 is stored in the reactor containment vessel 1, and the reactor core 3 is accommodated in the reactor pressure vessel 2. As shown in FIGS. 2 and 3, the core 3 is configured by loading a large number of fuel assemblies 4 and control rods 5.

In the reactor pressure vessel 2, the in-core nuclear instrumentation assembly 32 of the fixed in-core in-core instrumentation system 30 has four fuel assemblies 4.
Between the fuel gaps G. The fixed in-core nuclear instrumentation assembly 32 includes a nuclear instrumentation pipe 33 and this nuclear instrumentation pipe 33.
A plurality (N) of fixed neutron detectors (LPRN detectors) 37 constituting the neutron detector assembly 34 housed in the inside
And a plurality of (≧ N) fixed γ-ray heat detectors (GT detectors) 44 constituting a γ-ray heat detector aggregate (GT aggregate) 35.

On the other hand, the fixed in-core nuclear instrumentation system 30
It has an output area neutron flux measurement device 41 which is an output area neutron flux measurement system and a gamma thermometer output distribution measurement system 50 which is a gamma thermometer output distribution measurement system. The output area neutron flux measurement system 41 includes a plurality of fixed LPRM detectors 37 loaded in the core 3 and a signal processing device 40 thereof, and a gamma thermometer output distribution measurement system 50.
Is composed of a GT aggregate 35 having a plurality (≧ N) of GT detectors 44 and a GT signal processing device 48.

Thus, the fixed in-core nuclear instrumentation assembly 32
Accommodates a group of detectors of the fixed-type in-core nuclear instrumentation system 30, and includes an in-core nuclear-instrumentation assembly 3 containing the fixed-type detectors.
Numeral 2 measures the neutron flux and γ-ray calorific value at predetermined measurement points in the core 3.

Further, the fixed in-core nuclear instrumentation system 30 includes a gamma thermometer heater control device 53 for supplying power to the built-in heater 71 of the GT assembly 35. The GT heater control device 53 includes a power cable 54
, The built-in heater 71 of the GT assembly 35 is energized and the heater heating amount is adjusted and controlled.

Although not shown in detail in the reactor pressure vessel 2 or the piping of the primary system, various operating parameters for operating the reactor, such as the coolant core flow rate (or approximate recirculation Flow rate), core pressure (pressure in the pressure vessel), feedwater flow rate, feedwater temperature (or core inlet coolant temperature), and control rod position (control rod pattern) in the control rod drive, etc. Signal) A core current data measuring device 55 for measuring S3 is installed. Although the core current state data measuring device 55 is simplified by being represented by a measuring device inside the containment vessel like one measuring apparatus in FIG. 1, actually, a plurality of core current state data inside and outside the containment vessel (core state , Operating conditions) are collectively referred to as a plurality of measuring devices for measuring or monitoring.

Further, GT data D1 (W / g signal) obtained by signal processing of the GT signal processing device 48 based on the GT signal S1 detected by the GT detector 44, and LP
The LPRM data D2 obtained by the signal processing of the LPRM signal processor 40 based on the LPRM signal S2 detected by the RM detector 37 and the core current state data measuring device 55
The core current data D3 obtained by the signal processing of the current data processing device 58 based on the core current data signal S3 measured by the above is input to calculate the reactor power distribution and the like.
A process control computer 20A for monitoring and controlling the in-core nuclear instrumentation system 30 is provided.

The process control computer 20A receives the input core current state data D3 and uses the physical model (three-dimensional nuclear hydrothermal calculation code) stored in the memory of the computer 20A to perform three-dimensional nuclear thermal hydraulic An in-core power distribution calculation module 61 is provided for calculating a neutron flux distribution, a power distribution, a margin for a thermal operation limit value, and the like in the core 3 by calculation.

Further, the process control computer 20A further calculates the GT data D1 together with the calculation result of the output distribution calculation module (three-dimensional nuclear thermal hydraulic calculation module) 61.
(W / g signal) or the LPRM data D2, the power distribution learning module 62 for correcting the power distribution calculation result of the physical model to obtain a highly reliable core power distribution reflecting actual measurement data, A core instrumentation monitoring and control module 60 for monitoring and controlling the instrumentation system 30 and an input / output device (display device) 63 having a display function are provided.

[0288] The fixed nuclear reactor instrumentation system 3 of the present embodiment.
The structure of the GT aggregate 35 incorporated in the GT assembly 0 is the GT aggregate structure shown in FIGS. 2 to 5 as described in the first embodiment.

By the way, the calculation of the power distribution in the reactor in which a large number of fuel assemblies 4 are provided in the reactor core 3 is performed by a so-called three-dimensional nuclear thermal hydraulic simulation calculation by the power distribution calculating device 31 of the process control computer 20A. Done. The reactor power distribution calculation device 31 shows the operator with information such as the reactor power distribution and the margin for the operation limit values {the maximum linear power density (kW / m) and the minimum limit power ratio} of the core fuel via the display device 63. It is.

In the sixth embodiment, the core status data signal S3 representing the current core status obtained from the reactor core status data measuring device 55 in the reactor core 3 is provided by the current status data processing device (the process control computer 20A may be used). Yes) 58
Reactor heat output, core inlet coolant temperature, etc. are calculated, and the core current state data D3 including the calculation results of the reactor heat output, etc., is sent to the in-core power distribution calculator 31 in the process control computer 20A. The data is transferred via the signal interface function of the nuclear instrumentation control device 60 of the process control computer 20A.

The process control computer 20A for monitoring the reactor operation state and monitoring the core power distribution receives the core current state data D3 (core state parameter data) constantly and continuously, and periodically (for example, once every hour) or The latest operating parameters (core state data D) are arbitrarily set according to the calculation request command input by the operator's input / output device operation.
The core power distribution calculation (three-dimensional nuclear thermohydraulic simulation calculation) is performed by the in-core power distribution calculator 31 based on 3) and the three-dimensional nuclear thermohydraulic code.

Then, the process control computer 20A corrects the reactor power distribution obtained by the three-dimensional nuclear thermal hydraulic simulation calculation based on the GT data D1 (W / g signal) at the time of calculating the core power distribution. Accordingly, it is possible to calculate a highly accurate reactor power distribution, a margin for an operation limit value, and the like.

Further, in the present embodiment, the number of GT detectors 44 (for example, the same as the LPRM detector 37 or four or more) is smaller than 24 nodes (for example, there are 12 nodes and 26 nodes). GT converted by the GT signal processor 48 based on the detected GT signal
By using the data (W / g) and the three-dimensional nuclear thermal hydraulic calculation code, the axial output distribution can be learned and corrected.

That is, in the output learning module 62 of the process control computer 20A, the γ for each axial node of the GT aggregate obtained from the output distribution calculated by the output distribution calculation (three-dimensional nuclear thermal hydraulic calculation) module 61 The simulation calculation value and the actual measurement value (GT data D1
Is obtained in the form of a ratio for the node where the GT detector actually exists.

In the output distribution learning module 62, the measured values of the actual γ-ray calorific value (the value of the GT data D1) and the γ-ray calorific value, the number of which is limited in the core axis direction, are calculated for each GT assembly 35. (Γ-ray heating value difference correction amount data) representing the difference (ratio form) from the simulation calculation value of the above is extrapolated to each node in the core axis direction, and the γ-ray heating value difference correction amount data for all axial nodes It is said. In addition, it is also possible to extrapolate the γ-ray calorific value difference correction amount (correction ratio) along the core radial direction with respect to the radial position where the GT aggregate does not exist.

At the time of performing the output distribution learning correction processing, the nuclear instrumentation control device 60 of the process control computer 20A
Converts the GT data (W / g) calculated by the GT signal processor 48 based on the GT signal S1 into the furnace power distribution calculator 3
1 (power distribution learning module 62), it is determined whether or not a predetermined time, for example, one hour or more, has elapsed since the change of the parameter (core current data) representing the core state based on the core current data D3. Deciding.

As a result of the above judgment, if the predetermined time has not elapsed, the process control computer 20A (nuclear instrumentation control device 60)
Outputs an alarm indicating that the predetermined time has not elapsed to the display device 63 and notifies the operator via the display device 63.

On the other hand, regardless of whether the predetermined time has elapsed or the predetermined time has not elapsed, the process control computer 2
0A calculates the in-core power distribution by performing a three-dimensional nuclear thermal hydraulic simulation calculation by the power distribution calculation module 61 of the in-core power distribution calculation device 31, and the GT based on the GT signal S1 by the power distribution learning module 62. Using the data D1, the calculated furnace power distribution is corrected by learning.

At this time, the process control computer 20A
When the learning power is corrected by the GT data D1 based on the GT signal S1 measured in the state where the predetermined time has not elapsed, that is, the GT data D1 based on the GT signal in the unbalanced state, the power distribution in the furnace is obtained. An alarm indicating the result of the output distribution learning correction based on the GT signal in the equilibrium state is displayed and output to the operator via the display device 63.

The power distribution learning method by the in-furnace power distribution calculating device 31 (power distribution learning module 62) of the process control computer 20A is described in Japanese Patent Application No. 10-6732 of the prior application.
The contents are substantially the same as those described in the specification and drawings of No. 4. Here, FIG. 9 shows an outline of the flow of the power distribution learning correction by the in-furnace power distribution calculation device 31 (power distribution learning module 62).

That is, according to FIG. 9, the output distribution calculation module 61 of the process control computer 20A executes the three-dimensional nuclear hot water simulation calculation based on the current core data D3 and the three-dimensional nuclear hot water code, thereby Pn (I, J, K) is calculated (step S1).
The suffixes (I, J, K) indicate the position of each node of the fuel assembly, and n indicates the currently (currently) calculated core power distribution.

Next, the power distribution calculation module 61 calculates the node core power distribution P _n (I, J,
K) and the previous (n-1) node core power distribution P
_It is determined whether the difference from _n-1 (I, J, K) is smaller than a certain value (step S2). If the determination in step S2 is YES, the operation limit value (minimum limit output value: MC)
PR, the maximum linear output density: MLHGR), a margin based on the operation limit value, and the like are calculated and displayed and output via the display device 63 (step S3). Further, step S
If the judgment of No. 2 → NO (normally, the initial step of the repetitive calculation passes through this branch), the simulation value (W _c ) of the γ-ray heating value is calculated by the power distribution calculation module 61 based on the calculated core power distribution. (I, J, K)) is obtained (step S4).

On the other hand, as described above, in the GT signal processing device 48, as described in the first embodiment, the GT detector 4
4, the thermocouple output voltage signal U _γ (I, J,
K) is read (step S5), and the read output voltage signal U _γ (I, J, K) is converted to the gamma ray heating value W _m (I,
J, K) (corresponding to GT data D1) (step S6).

At this time, the output distribution learning module 62 simulates the calculated γ-ray heating value W
_c (I, J, K) and gamma ray heating value W _m (I, J,
K) difference data (γ-ray calorific value difference correction amount data) is calculated, and this difference data is extrapolated to each node in the core axis direction, and γ-ray calorific value difference correction amount data BCF _IJK for all axial nodes is obtained. Is obtained (step S7).

In the output distribution learning module 62, the γ-ray heating value difference correction amount data (correction coefficient) BCF _IJK for all the axial nodes is “1.0”, that is,
Simulation Calculated γ-ray heating value at each node _{W c (I, J, K} ) and gamma ray heating value _W m (I, J,
K) so that the output distribution calculation module 61
The power distribution Pn (I, J, K) calculated by the following equation is corrected, and ｛Pn (I, J, K) → P′n (I, J,
K) {, and the correction ratio {output distribution correction amount (learning correction amount)} for each fuel assembly node at this time is stored in the memory within the process control computer 20A (step S8).

The output distribution learning correction module 62
Then, the gamma ray heating value W _m based on the actually measured GT signal
P ′ corrected by (I, J, K) (GT data value)
The adjustment factor of the three-dimensional nuclear thermohydraulic code (physical model) is estimated according to n (I, J, K) (step S9), and the process returns to step S1 of the output distribution calculation module 61 to return to the three-dimensional nuclear hot water. Repeat the output distribution calculation using the force code. Finally, the determination in step S2 converges with YES, and a learning-corrected result is obtained (step S3).

[0307] In this way, the adjustment factor correction of the correction learning repetition calculation is executed by the three-dimensional nuclear thermal hydraulic code (physical model), and the output distribution calculation module 61 executes the next (n)
(+1) (step S)
1), when the convergence is achieved in step S2, a highly accurate output distribution is obtained.

As another method of learning correction,
FIG. 9 may be modified as follows. That is, the output distribution calculation module 61 of the process control computer 20A
As a result, the repetitive calculation of the three-dimensional nuclear hot water simulation based on the current core data D3 and the three-dimensional nuclear hot water code is executed, and the core power distribution Pn (I, J, K) is calculated (step S1; see FIG. 10). ). Iterative calculation
The node core power distribution P _n (I, J, K) of the current (n) and the node core power distribution P _n-1 (I,
J, K) is determined whether or not the difference is smaller than a predetermined value (step S2).
If you go through this branch at the beginning of the repeated calculation),
Returning to step S1, the next cycle (n +
The three-dimensional nuclear thermal hydraulic calculation of 1) is performed, and the determination in step S2 → in the case of YES, the output distribution calculation module 61
A simulation calculation value (W _c (I, J, K)) of the γ-ray calorific value is obtained based on the calculated core power distribution result (step S4).

On the other hand, as described above, in the GT signal processor 48, as described in the first embodiment, the GT detector 4
4, the thermocouple output voltage signal U _γ (I, J,
K) is read (step S5), and the read output voltage signal U _γ (I, J, K) is converted to the gamma ray heating value W _m (I,
J, K) (corresponding to GT data D1) (step S6).

At this time, in the output distribution learning module 62, the simulation calculation value W of the obtained γ-ray heating value is obtained.
_c (I, J, K) and gamma ray heating value W _m (I, J,
K) difference data (γ-ray calorific value difference correction amount data) is calculated, and this difference data is extrapolated to each node in the core axis direction, and γ-ray calorific value difference correction amount data BCF _IJK for all axial nodes is obtained. Is obtained (step S7).

In the output distribution learning module 62, the γ-ray heating value difference correction amount data (correction coefficient) BCF _IJK for all axial nodes is “1.0”, that is,
Simulation Calculated γ-ray heating value at each node _{W c (I, J, K} ) and gamma ray heating value _W m (I, J,
K) so that the output distribution calculation module 61
The power distribution P (I, J, K) calculated by the above equation is corrected {P (I, J, K) → P ′ (I, J, K)}, and for each fuel assembly node at this time. The correction ratio {output distribution correction amount (learning correction amount)} is stored in a memory in the process control computer 20A (step S8).

[0312] The process returns from step S8 to step S3 of the output distribution calculation module 61, and the operation limit value calculation result based on the learned and corrected output distribution is obtained, and the process is terminated (step S3).

When the convergence is achieved in step S2, a highly accurate output distribution is obtained.

In this modification, the output distribution after learning correction is
The result is inconsistent with the neutron flux distribution, but it is a method of learning correction.

FIG. 11 is an explanatory diagram for extrapolating the ratio between the calculated GT signal level at the position where the GT detector 44 is present and the measured GT signal level to 24 nodes in the axial direction. In this example, straight line interpolation is performed, and both ends are GT detectors 44 at the upper and lower ends.
Is extrapolated with the ratio at. There is essentially no difference if the interpolation and extrapolation are quadratic.

Further, the process control computer 20A confirms that a predetermined time, for example, one hour or more, has elapsed since the detection of the change in the core state, and that the process control computer 20A has a fixed time (fixed cycle) or an input / output device In response to an operation instruction through 63,
Gamma ray heating value W _m (I, J, K) (G
T data value), the command to execute the sensitivity or gain adjustment of the LPRM detector 37 is transmitted to the L
The signal is transmitted to the PRM signal processing device 40.

[0317] The LPRM signal processing device 40 responds to the transmitted sensitivity / gain adjustment execution instruction by each of the LPRM detectors 4.
Of the gamma ray heating value W at the same node position
_m Set to a value that matches (I, J, K) (unit: W / g) or a value that is proportional.

On the other hand, if the predetermined time has not elapsed since the detection of the change in the core state, the process control computer 20A does not perform the LPRM detector sensitivity / gain adjustment at that time, and proceeds to the next fixed time. It waits until (fixed period) adjustment (or transmission of an adjustment command by the next operator) or after the lapse of the predetermined time (for example, one hour). In the case of the standby, the process control computer 20A outputs an alarm indicating the standby state through the display device 63 to notify the operator.

As described above, according to the present embodiment,
Output distribution learning based on the GT detection signal obtained when the output signal level of the GT detector 44 of the GT assembly 35 does not accurately reach the equilibrium state of the gamma decay chain corresponding to the core power distribution state (unbalanced state). The error generated by the operator is not used for monitoring the operation limit value without the operator's knowledge, and the reliability of the reactor power monitoring system 29 and the fixed in-core nuclear instrumentation system 30 can be improved. Also, the LP signal is obtained using the unbalanced GT signal.
Performing sensitivity or gain calibration of the RM detector 37 can be prevented, and the reliability of the reactor power monitoring system 29 and the fixed in-core nuclear instrumentation system 30 can be further improved.

The reactor core nuclear instrumentation system 30 of the sixth embodiment, when arranged, comprises a plurality of fixed neutron detectors (LPRM detectors) 37 for detecting the local power distribution in the power region in the reactor. And a fixed type GT detector 44 of a GT assembly 35 for detecting the calorific value of the γ-ray are accommodated in a nuclear instrumentation tube 33, and the GT detector 44 is arranged at least in the vicinity of the LPRM detector 37. An aggregate 32, an LPRM signal processor 40 for processing a neutron flux detection signal from the LPRM detector 37, a GT signal processor 48 for processing a GT signal from the GT aggregate 35,
A GT heater control unit 53 for controlling power supply to a heater 71 incorporated in the T-assembly 35, and core current state data indicating a core state such as a reactor core power level, a core coolant flow rate, and a control rod pattern are detected. It has a reactor core status data measuring device 55, and a nuclear instrumentation control device 60 for controlling the operation of the GT heater control device 53 and the GT signal processing device 48. While it is determined whether a predetermined time has elapsed since the detection of the state change, the result of the determination is output to the display device 63 and displayed as an alarm to notify the operator.

The nuclear instrumentation control device 60 has an interface function of the process control computer 20A, and distributes GT data D1 (W / g signal) based on the GT signal S1 output from the GT assembly 35 in the reactor power distribution. The power distribution calculation device 31 calculates the reactor power distribution using the GT data D1, corrects the power distribution calculation result based on the physical model, and increases the core power distribution reflecting the actually measured data. It is designed to gain reliability.

Further, the nuclear instrumentation control device 60 transmits a sensitivity / gain adjustment execution command to the GT signal processing device 48, and the GT detector at the same core axial position as the LPRM detector 37 in the same core instrumentation tube 33. Using the GT data D1 (γ-ray heating value; W / g signal) based on the GT signal S1 from the GT 44, the LPRM detector 3 via the GT signal processor 48.
7 is performed.

[Seventh Embodiment] A seventh embodiment of a fixed nuclear reactor instrumentation system, a power distribution calculating device and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

In the seventh embodiment, the reactor power distribution monitoring system 29 and its monitoring method, the in-core nuclear instrumentation system 30 and its nuclear instrumentation processing method, and the power distribution calculator 31 and the power distribution monitoring system 29 shown in the sixth embodiment are described. This shows a modification of the calculation method. In the sixth embodiment, the LPR
The sensitivity and gain of the M detector 37 are adjusted by the LPRM detector 37.
GT data (W / g) of the GT detector 44 at the same position as
(Detection signal).

On the other hand, in the present embodiment, the LPRM detector 37 is previously stored in the memory of the process control computer 20A.
Equation data representing the correlation between the reading (calculated value) of and the output of the fuel node around the LPRM ｛fuel type (enrichment distribution of horizontal section, type of Gd distribution design), control rod insertion state, node combustion度 which has the degree, the node void rate history, the instantaneous node void rate, and the like are stored, and the process control computer 20A sets the GT aggregate 35
The GT data (W / g signal) based on the GT signal S1 detected by each of the GT detectors 44 is learned by the in-core power distribution calculating device 31, and the three-dimensional power distribution in the core 3 is calculated. And the above correlation equation data,
The response value of the LPRM detector 37 is calculated from the output of the fuel around the LPRM detector 37. Then, the process control computer 20A compares the response calculation value of the LPRM detector 37 with the LPRM detector signal D2 when it is determined that the GT signal is in an equilibrium state based on the core current state data,
The sensitivity or gain (RG) of the LPRM detector 37 is set so that the actual detection value (the value of the actually measured LPRM data D2) of the LPRM detector 37 matches the calculated value of the LPRM detector response.
AF ^L ) is calculated, and the sensitivity or gain adjustment execution command of the LPRM detector 37 is sent to the LP through the nuclear instrumentation control device 60.
This is transmitted to the RM signal processing device 40.

The LPRM signal processing device 40 uses the measured LPR
The gain adjustment factor (RGAF) transmitted to the value of the M data D2
^L , where L indicates the address of the LPRM detector) or the measured LPRM signal S
Adjustment is made by multiplying 2 by an integral gain adjustment factor.

[0327] integral gain adjustment factor ^GAF _{L n} to be multiplied to the measured LPRM signal S2 is determined as follows.

That is,

(Equation 5) Here, GAF ^L _(n−1) is a conventional integration gain adjustment factor, and GAF ^L _n is a new integration gain adjustment factor.

As described above, by multiplying the RGAF ^L each time by multiplying the integrated GAF ^L _n gain adjustment factor by then, the signal S2 not gain-adjusted is multiplied by the signal D2.
2 can be defined. The LPRM signal S2 is added to this LPRM signal S2.
In this specification, the integral gain adjustment factor multiplied by
The first gain adjustment factor is referred to as the aforementioned gain adjustment factor (RG
AF ^L ) is referred to as a second gain adjustment factor.

This first gain adjustment factor is stored in the memory of the LPRM signal processor 40, and may be transferred to the process control computer 20A. LPRM detector 37
Since the correlation equation parameters used in the response calculation of the above are known techniques, detailed description will be omitted.

In the sixth and seventh embodiments, when it is not determined that the GT detection signal S2 (GT data D2) has reached the equilibrium signal level, that is, the nuclear instrumentation control device 60 sets the core state parameter ( A predetermined time (for example, 1 hour or more) after the core current state data D3) changes
When it is confirmed that the elapsed time has not elapsed, an unbalanced alarm of the GT detection signal is displayed on the display device 63, and the output distribution learning calculation is performed based on the GT detection signal.

At this time, the process control computer 20A
Although the correction processing of the reactor power distribution was performed by executing the learning calculation based on the GT data D2 in the unbalanced state, the learning calculation was performed using the LPRM signal as described in ninth and tenth embodiments described later. And a correction process of the reactor power distribution can be performed. Further, a learning calculation is performed by using a GT signal predicted by a GT signal prediction function as described in an eleventh embodiment to be described later to perform a reactor calculation. It is also possible to perform output distribution correction processing, and the process control computer 20A can select which correction calculation processing to execute.

In the sensitivity or gain adjustment of the LPRM signal, if the periodic (regular) high frequency adjustment (for example, once every hour in principle when the core state does not change for one hour or more) is performed, Control computer 2
The data D1 to D3 captured via the nuclear instrumentation control device 60 of 0A are transferred to the output distribution calculation device 31 by the interface processing of the nuclear instrumentation control device 60.

At this time, the output distribution calculating device 31
A second gain adjustment factor (RGAF ^L ) to be multiplied by the LPRM data D2 sent from the RM signal processing device 40 is calculated and stored in the memory of the process control computer 20A.
This value is not transferred to the LPRM signal processor 40.
Therefore, the LPRM signal processing device 40 does not perform the sensitivity or gain adjustment process using the new first gain adjustment factor, and the output distribution calculation device 31 performs the sensitivity or gain adjustment process based on the second gain adjustment factor. .

After a significant fluctuation in the core power distribution has occurred (for example, after one hour or more), the LPRM signal response calculation value and LP calculated by the three-dimensional nuclear thermal hydraulic simulation calculation
Only when the actual measurement value of the LPRM data D2 processed by the RM signal processing device 40 deviates by a predetermined ratio (for example, 20%) or more, or when a predetermined time, for example, 1000 hours or more elapses, the process control computer 20A outputs 2 is sent to the LPRM signal processor 40,
LPRM signal processing device 40 performs sensitivity or gain adjustment processing using the new first gain adjustment factor obtained by multiplying by the second gain adjustment factor transmitted, and performs sensitivity or gain adjustment processing using the first gain adjustment factor. At the time of execution, the aforementioned second gain adjustment factor is set to 1.0 (L
A method of zeroing the PRM data D2 to zero) is also conceivable.

By doing so, the frequency of the gain adjustment processing in the LPRM signal processor 40 can be reduced, the bypass time of the LPRM detector assembly 34 which is a part of the security protection system can be reduced, and the adjustment of the security protection system can be performed. It has the advantage that it can be under the full supervision and control of the operator.

The reactor core nuclear instrumentation system 30 of the seventh embodiment, when arranged, comprises a plurality of fixed neutron detectors (LPRM detectors) 37 for detecting the local power distribution in the power region in the reactor. And a fixed GT detector 44 of a gamma thermometer assembly 35 for detecting a γ-ray calorific value are housed in a nuclear instrumentation tube 33, and the GT core 44 is arranged at least in the vicinity of the LPRM detector 37. An instrumentation assembly 32, an LPRM signal processor 40 for processing a neutron flux detection signal from the LPRM detector 37, and the GT
A GT signal processing device 48 for processing a GT signal from the aggregate 35, a GT heater control device 53 for controlling power supply to a heater built in the GT aggregate 35, the GT heater control device 53 and the GT signal processing. A nuclear instrumentation system 30 having a nuclear instrumentation control device 60 for controlling the operation of the device 48 is provided. The nuclear instrumentation control device 60 receives the core status data such as the reactor core power level, the core coolant flow rate, and the control rod pattern output from the core status data measuring device 55 and subjected to data processing by the status data processor 58, and It is determined whether a predetermined time has elapsed since the state change was detected.

[0338] The nuclear instrumentation control device 60 notifies the operator by outputting the result of the determination to the display device 63 for display. Further, the in-furnace power distribution calculating device 31 includes:
A core power distribution is learned and calculated from GT data (gamma heating value) calculated based on the GT signal detected by the fixed GT detector 44 and a three-dimensional nuclear thermal hydraulic calculation model, and each LPRM is calculated from the core power distribution. The reading (calculated value) of the detector 37 is calculated, and the sensitivity or gain of each LPRM detector 37 is calibrated by comparing it with the current actual reading (actual detected value).

Note that the LPRM detector signal D2 is converted to the conventional T
When used as an auxiliary means of a power distribution monitoring device as in the case of a system using IP, a GT signal (data) D
1 is different from the correlation between the fuel output around the GT detector and the LPRM detector signal (data) D2 and the fuel output around the LPRM detector. In particular, the LPRM detector signal D2 is different from the nuclear instrumentation of the fuel assembly 4. It has been found that the output of the fuel rod at the corner on the side of the tube 33 depends more strongly than the GT signal D1. Therefore, the operation of the control rod 5 causes the nuclear instrumentation pipe 33 to operate.
If the output distribution of the fuel assembly 4 adjacent to the fuel assembly 4 changes greatly on the control rod side and the nuclear instrumentation tube side, the GT signal change and the LPRM signal change are not in a proportional relationship.

In the sixth and seventh embodiments, the movement of the LPRM detection signal (detection signal) is proportional to the thermal neutron flux in the actual LPRM detector, and the response is focused on the advantage that it is extremely fast. Therefore, the output distribution after the operation of the control rod is changed even before the GT signal (detection signal) reaches the equilibrium state.
The M measurement signal always corresponds to the thermal neutron flux level at the nuclear instrumentation tube location. Therefore, when the output distribution correction learning calculation is performed based on the LPRM signal, there is an advantage that there is no delay in response to a change in local output. This example is described in detail in the ninth and tenth embodiments.

[Eighth Embodiment] An eighth embodiment of an in-core nuclear instrumentation system, a power distribution calculating device, and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

In this embodiment, the power distribution monitoring system 29 of the reactor and its monitoring method, the nuclear instrumentation system 30 in the reactor and its nuclear instrumentation processing method, and the power distribution calculation device 31 and its calculation method are described in the sixth and seventh embodiments. This is a modified example of the embodiment, and differs from the sixth and seventh embodiments in the method of adjusting the sensitivity or gain of the LPRM detector 37, and the other configurations are substantially the same. Is omitted.

The LPRM signal processing device 40
It has a function of adjusting (calibrating) the sensitivity or gain of the detector 37. There are two types of adjustment methods based on the adjustment function of the LPRM detector 37, a first adjustment method and a second adjustment method.

A first adjustment method by the LPRM signal processor 40 when adjusting the sensitivity or gain of the LPRM detector 37 is to divide a large number of LPRM detectors 37 into a plurality of APRM channels or LPRM groups (depending on the design, AP
Some LPRM detectors are not taken into the RM channel), and each of the LPRM detectors 37 belonging to each APRM channel or LPRM group has a nuclear instrumentation control device according to the maximum bypass number condition of the LPRM detector which is operationally permitted among them. A predetermined LPRM is automatically selected from each APRM channel or LPRM group by an instruction signal from
Detector 37 is selected to bypass (bypass mode)
To adjust the sensitivity or gain of the LPRM detector 37 in the bypass state, and adjust the LP in the bypass mode after the adjustment.
This is a method of returning the RM detector 37 to the normal mode.

Therefore, the sensitivity or gain of the LPRM detector 37 can be adjusted according to a command from the nuclear instrumentation control device 60 by “{number of APRM channels (or LPRM groups)} × (maximum allowable LPRM detector bypass number). )) Are performed almost simultaneously by the LPRM signal processor 40,
In addition, the operation can be performed without bypassing the APRM channel or the LPRM group itself. This LPRM adjustment is applied to all LPR
It is necessary to make sure that the gain of each APRM is adjusted after making the adjustment to the M detector 37.
The process control computer 20A automatically performs a comparison calculation of the heat output calculated from the RM signal instruction and the heat balance of the nuclear power plant. If the difference by the comparison calculation is larger than the set value, the process control computer 20A displays the display device 63
A warning is issued to the operator.

As a result, APRM during LPRM gain adjustment
Bypassing the channel or LPRM group itself is eliminated and the sensitivity or gain of the LPRM detector is adjusted in a short time.

The second adjustment method by the LPRM signal processor 40 when adjusting the sensitivity or gain of the LPRM detector 37 is as follows. Each of the APRM channels or LPRM groups (depending on the design, the LPRM that is not taken in the APRM channels).
M detectors are also considered, and one APRM channel (L
PRM group) is selected and bypassed, and all LPRM detectors 37 belonging to the APRM channel (LPRM group) are selected.
Is switched to a bypass state (bypass mode) to adjust the gain or sensitivity of each LPRM detector 37 in the bypass mode.

Therefore, the calibration of the gain or sensitivity of the LPRM detector 37 can be performed almost simultaneously by the number of LPRM detectors included in one or the maximum number of APRM channels or LPRM groups in which bypass is allowed.
Is adjusted by the LPRM signal processing device 40 in accordance with the instruction from. When the sensitivity or gain adjustment processing of the LRPM detector 37 is completed, the LPRM detector 37 in the bypass mode and its APRM channel (LPRM group) are
Return to normal mode.

At the same time when returning from the normal mode, each APRM
It is necessary to adjust the gain or the sensitivity of the power supply, but a comparison between the APRM signal instruction and the heat output calculated from the heat balance of the nuclear power plant is automatically performed by the process control computer 20A for confirmation. At this time, if the result of the comparison calculation is large and is equal to or larger than a predetermined amount, the display device 6
An alarm is issued at 3 to notify the operator. All LPRs that make up one APRM channel or one LPRM group
When the sensitivity / gain adjustment processing of the M detector is completed, the LPRM signal processing device 4 receives a command from the nuclear instrumentation control device 60.
0 is another APRM channel (or another LPRM
Group) adjustment.

As a result, during LPRM sensitivity or gain adjustment, one or the maximum number of APs allowed by-pass
Although the RM channel (or LPRM group) is bypassed at the same time, even if a failure occurs in the nuclear instrumentation control device 60, the bypass state of the APRM and the bypass state of the LPRM detector 37, which are the safety protection systems, are permitted to be bypassed in a specific manner. Only the APRM channel (or a specific LPRM group), and the reliability of the security system is higher than that of the first calibration method.

LPRM detector 3 belonging to one APRM
Reference numeral 7 denotes four LPRM detectors 37 having different core coordinates, varying in the core axis direction, and present in a specific nuclear instrumentation pipe 33.
Belong to substantially different APRM channels. Therefore, automatically selecting and adjusting the LPRM detector 37 belonging to one APRM channel from the plurality of LPRM detectors independently of the manual selection by the operator can prevent mistakes at the time of manual selection, and is convenient. Is good.

The introduction of the gamma thermometer makes it possible to adjust the gain or sensitivity of the LPRM detector at a high frequency. When such adjustment is performed, it is necessary to consider such automation and safety.

[Ninth Embodiment] A ninth embodiment of an in-core nuclear instrumentation system, a power distribution calculating device, and a power distribution monitoring system of a nuclear reactor according to the present invention will be described.

The basic configuration of the reactor power distribution monitoring system 29 and its monitoring method, the in-core nuclear instrumentation system 30 and its nuclear instrumentation method, and the power distribution calculation device 31 and its calculation method in the ninth embodiment are as follows. The description is omitted because it is not substantially different from that shown in the first embodiment.

According to the reactor power distribution monitoring system 29 and the in-core nuclear instrumentation system 30 shown in the ninth embodiment, the core power level detected by the reactor core current data measuring device 55, the core coolant flow rate, Reactor core status data S representing parameters of the reactor core state (operating state) such as control rod patterns
3 is input as digital core current status data D3 to the nuclear instrumentation control device 60 of the process control computer 20A via the current status data processing device 58.

The nuclear instrumentation control device 60 determines whether or not a predetermined time has elapsed after detecting a change in the core state according to the input core current state data D3, and displays the determination result on the display device 63. And inform the operator.

When the operator determines that the operating state does not satisfy the required conditions based on the determination result displayed on the display device 63, the operator operates the display device (input / output device) 63. The calculation command is output to the in-core power distribution calculation device 31 via the nuclear instrumentation control device 60.

At this time, the in-furnace power distribution calculating device 31
Learning correction of the three-dimensional power distribution is performed based on the latest nuclear instrumentation information (core current state data; core state, operating state) obtained from the core 3.

In the embodiments described above, when the core state is a steady state and the steady core state continues for a sufficiently long time, the three-dimensional simulator model and the GT
Although the case where the core power distribution calculation processing or the like is performed by the learning calculation processing using the GT data of the aggregate has been described, in the ninth embodiment, immediately after the parameter indicating the operating state such as the power distribution or the power level changes. An alternative of the processing means and processing method for calculating and monitoring the core power distribution will be described.

Immediately after the above-mentioned operating state parameters such as the power distribution or the power level change, when it is determined that the GT signal of the GT assembly 35 has not reached the equilibrium state, the core nuclear instrumentation assembly 32 is moved The output distribution obtained by the calculation processing based on the three-dimensional simulation is learned and corrected by using the LPRM detector aggregate 34 having the fast response among the GT aggregate 35 and the LPRM detector aggregate 34 that constitute the GT aggregate 35 and the LPRM detector aggregate 34. The first learning correction process will be described.

That is, in the first learning correction processing method, the correlation between the fuel assembly node output value and the LPRM signal reading value (calculated value corresponding to D2 of the actually measured data) is stored in the memory of the process control computer 20A. Parameters of the correlation equation to represent ｛e.g. fuel type, nodal burnup,
Fitting data (data set) of interpolation method based on presence / absence of control rod, history relative water density (history void rate), instantaneous relative water density (instant void rate)｝, or look of interpolation method based on the above correlation equation parameters Up table data (data set) is stored.

In the first learning correction processing method, for example, the GT signal processor 48 or the nuclear instrumentation controller 60 of the process control computer 20A determines that the GT signal of the GT assembly 35 has not reached the equilibrium state. When the learning correction process is executed in the state thus performed, the output distribution calculating device 31 (output distribution learning module) 62 outputs a state (equilibrium) in which the nearest steady state, which is retroactive from the learning correction process execution time (current time), has been continued. In the state), the GT aggregate 35
Core power distribution data obtained by learning correction processing based on the GT signal S1 output from the
The learning correction amount data from the calculated predicted value for each fuel assembly node based on the T data D1 and the increase in the average core burnup from the time when the power distribution is calculated in the equilibrium state to the present time (the time when the learning correction processing is executed), and the nearest time Core power at the present time based on change data of operating parameters (core data D3) representing the core state (operating state) such as control rod pattern, core coolant flow rate, core power, core entrance enthalpy, core pressure, etc. Simulate the distribution.

The in-furnace power distribution calculating device 31 calculates the above-mentioned correlation equation parameters determined based on the power distribution obtained by the simulation calculation: fuel type, nodal burnup, presence or absence of control rods, history relative water density (history void rate) ), The instantaneous relative water density (instantaneous void ratio), etc., and a fitting equation (look-up table) stored in the memory to obtain an LPRM data prediction value corresponding to the output distribution as a simulation calculation result.

On the other hand, the LPRM signal adjusted by the LPRM signal processor 40 by the method described in the seventh embodiment.
The data D2 is incorporated in the in-furnace power distribution calculating device 31 (power distribution learning module) 62 of the process control computer 20A, and the in-furnace power distribution calculating device 31 predicts the LPRM data based on the simulation calculation result at the present time. The value is compared with the value of the actually measured LPRM data D2, and the correction ratio representing the difference between the predicted value of the LPRM data obtained by the comparison and the value of the actually measured LPRM data D2 is interpolated and extrapolated in the axial direction of the reactor core in all directions. A correction ratio (additional learning correction amount; relative learning correction amount) for the node is obtained.

The power distribution calculating device 31 corrects the in-core power distribution for each fuel assembly node, which is the simulation calculation result at the present time, based on the obtained additional learning correction amount for all axial nodes. , The maximum linear power density (MLHGR) and the minimum limit power ratio (MCP) at the current time (at the time of executing the learning correction process) based on the corrected power distribution in the furnace.
R) is calculated.

The output distribution calculating device 31 calculates the additional learning correction amount for each of all the axial nodes based on the above-described LPRM data D2 by using the G for each of the axial nodes stored in the memory.
It is stored in the memory separately from the learning correction amount based on the T data D1.

As described above, when performing the power distribution learning correction process in the GT signal unbalanced state, the simulation-calculated in-core power distribution at the time of the execution of the power distribution learning correction process is used to calculate the in-core power distribution when the GT data D1 is balanced. By performing the learning correction based on the learning correction amount and the additional learning correction amount based on the LPRM signal, a highly accurate output distribution can be generated.

When the GT signal processing device 48 or the nuclear instrumentation control device 60 determines that the GT data D1 has reached an equilibrium state, the output distribution calculation device 31
(Output distribution learning module) 62 resets the additional learning correction amount based on the LPRM data D2 stored in the memory to zero and returns the additional relative learning correction ratio (correction coefficient) based on the LPRM data D2 to 1.0. Meaning, as shown in FIG. 9 described above, the GT data D1 in the equilibrium state again
Is obtained and stored in a memory, and an output distribution learning correction process is performed based on the learning correction amount.

As a result, the GT from the GT aggregate 35
Even when the signal is unbalanced and changing, the in-core power distribution calculation device 31 can perform the power distribution learning correction calculation based on the in-core nuclear instrumentation, so that the GT data D1 reaches the equilibrium state in the unbalanced state. The furnace power distribution learning correction process can be performed without waiting until the process is completed, and the furnace power distribution learning correction process can be performed periodically or as needed.

In this embodiment, at the time of the power distribution learning correction in the unbalanced state, four LPs along the core axis direction are set.
Although the output distribution learning correction calculation is performed using the additional learning correction amount for interpolation and extrapolation obtained based on the LPRM data D2 detected by the RM detector 37, when the GT signal equilibrium state is reached, At the timing of the output distribution learning correction processing based on the GT signal, the additional relative learning correction amount that is likely to include an interpolation error is cleared to zero, and detected by the GT detector 35 having a large number along the axial direction. Output distribution learning correction processing based on the GT data D1 in an equilibrium state can be performed. Therefore, the error of the LPRM assembly 34 does not affect the core power distribution calculation over a long period of time, and depends only on the error of the GT assembly 35, and the maximum linear power density (MLHGR) and the minimum The evaluation accuracy of the output ratio (MCPR) can be maintained as high as possible.

[Tenth Embodiment] The basic configurations of a nuclear instrumentation system, a power distribution calculation device, and a power distribution monitoring system of a nuclear reactor of a tenth embodiment are the same as those shown in the first embodiment. The description is omitted because it is not substantially different.

In the reactor power distribution monitoring system 29, the in-core nuclear instrumentation system 30, and the power distribution calculating device 31 shown in the tenth embodiment, as in the configuration shown in the ninth embodiment, the GT set When it is determined that the GT signal of the body 35 has not reached the equilibrium state, a quick response is provided between the GT assembly 35 and the LPRM detector assembly 34 constituting the core nuclear instrumentation assembly 32. Using the LPRM detector assembly 34, the second correction of the output distribution obtained by the calculation process based on the three-dimensional simulation is performed.
Will be described.

The second learning correction processing method uses the LP data by using the gamma heat converted GT data D1 (W / g) based on the GT signal S1 of the GT aggregate 35 described in the sixth embodiment.
This is based on a processing method in which the gain of the LPRM signal S2 detected by the M detector 37 is directly adjusted.

According to the second learning correction processing method, the LPR
At any point after the direct gain adjustment process using the GT data D1 by the LPRM signal processor 40 is completed for the LPRM signal S2 of the M detector 37, the output distribution calculator 31 (output distribution learning module) 62 Are the core power distribution data obtained by the learning correction process based on the GT signal data D1 output from the GT assembly 35 and stored in the memory, and the fuel assemblies based on the GT data D1, Based on the learning correction amount data from the node output calculation predicted value for each node and the change data of the operating parameter (core current state data D3) representing the core state (operating state) from the calculation of the power distribution in the equilibrium state to the present time. Simulation calculation of core power distribution at present.

Here, the difference from the calculation process of the in-furnace power distribution calculating device 31 described in the ninth embodiment is that, in this embodiment, when the GT signal is excessive, the LPRM signal is
The point is that it is considered as moving by the same proportional amount as the T signal.
That is, if the LPRM signal is adjusted relatively frequently, for example, once a day or once an hour, or to match the W / g signal level of the GT data D1, local or overall core Changes in the fuel assembly nodes due to combustion are very small even if there is a
The change in the output peaking due to the combustion of the fuel rod at the corner of the nuclear instrumentation tube which strongly affects the detection signal level of the M detector 37 is extremely small and can be ignored.

Therefore, the change in the output of the fuel assembly node average is directly applied to the GT signal level detected by the GT detector 44 as well as the L signal detected by the LPRM detector 37.
The PRM signal level is also reflected at the same change rate.

However, when a change in the state of the control rod such as insertion or withdrawal of the control rod 5 or a change in the void ratio in the fuel channel occurs and the GT signal level changes to an excessive state, the response of the GT signal There is a large difference between the change and the response change of the LPRM signal.

As described in the first embodiment, the memory of the process control computer 20A of the present embodiment stores the GT data value D2 based on the fuel assembly node output value and the GT signal.
And extrapolation based on the parameters of the correlation equation for expressing the correlation with {for example, fuel type, nodal burnup, presence / absence of control rods, historical relative water density (history void rate), instantaneous relative water density (instantaneous void rate)} The fitting type data (data set) of the method or the lookup table data (data set) of the interpolation method based on the correlation equation parameters are stored.

[0379] From such a background, the memory of the process control computer 20A of the present embodiment stores the parameters of the correlation equation for expressing the correlation between the fuel assembly node output value and the LPRM data value D2 based on the LPRM signal. In addition to the first fitting expression data (lookup table data) of the interpolation method based on the above, only the second fitting expression data (lookup table data) of the interpolation method for the LPRM signal data shown below is provided. ing.

The second fitting expression data (look-up table data) is the LRM of the LPRM detector 37.
The PRM signal S2 is converted by the LPRM signal processor 40 into a GT.
In the case where adjustment is frequently performed using the data D1, when an instantaneous or rapid transient phenomenon of the LPRM data D2 occurs due to a change in the control rod state or a change in the void ratio in the channel, the LPRM detector is used. 37 LPRMs
In order to calculate a different ratio between the response change amount of the data D2 and the response change amount of the GT data D1 of the GT detector 44 (the change amount when the GT data D1 assumes an equilibrium value instantaneously), Parameters of a correlation equation for expressing the correlation between the first response change amount of the LPRM signal and the second response change amount of the signal of the GT detector 44 {for example, fuel type, nodal burnup, control rod presence / absence, Fitting equation data (data set) based on the historical relative water density (history void rate), instantaneous relative water density (instantaneous void rate)｝, or lookup table data based on the interpolation equation based on the above correlation equation parameters (data set) (Data set).

That is, the second fitting equation data (lookup table data) for the LPRM detector is used in the in-furnace power distribution calculating device 31 as follows. The in-furnace power distribution calculating device 31 is, for example, G
T signal processing device 48 or process control computer 20
In the state where the GT signal of the GT assembly 35 is determined to be changing in an excessive state by the nuclear instrumentation control device 60 of A, the operator's output distribution learning mode selection command command or the automatic output distribution learning mode The GT command is unbalanced by the switching command command, but the LPRM signal is settled and the power distribution learning calculation is instructed. As described above, the core power distribution data in the nearest GT signal equilibrium state, the learning correction amount data, and the change data of the core current state data D3 from the above-mentioned equilibrium state to the present time are executed, and the power distribution calculation result is obtained. Further, L at the moment
The PRM data D2 is taken into the in-furnace power distribution calculating device 31, and the second fitting equation data (lookup table data) of the LPRM detector is obtained from the obtained power distribution.
The LPRM data D2 is converted from the first response change amount of the LPRM signal data to a second change amount corresponding to the GT signal equilibrium value, and the converted four LPRMs are reduced in the axial direction. The data is replaced as the pseudo GT data D1 that has reached the equilibrium at the present time.

Then, the in-furnace power distribution calculating device 31 calculates the value of the pseudo GT data D1 and the value (calculated value) of the equilibrium GT data for 24 nodes obtained from the above-described power distribution calculated by simulation at the present time. The comparison is made only at the node position where the LPRM detector exists, and the pseudo GT data value and the equilibrium GT data value (calculated value) obtained by this comparison are obtained.
The correction ratio (additional learning correction amount; relative learning correction amount) for all axial nodes is obtained by extrapolating the correction ratio representing the difference from the above in the core axis direction.

The output distribution calculating device 31 calculates the in-core power output for each fuel assembly node, which is the current simulation calculation result, based on the additional learning correction amount for each of all the axial nodes obtained by the above-described processing. The distribution is corrected, and the maximum linear power density (MLHGR) and the minimum critical power ratio (MCPR) at the present time are calculated based on the corrected power distribution in the furnace.

The output distribution calculating device 31 calculates the additional learning correction amount for each of all the axial nodes based on the pseudo GT data described above and the learning correction amount based on the GT data for each of the all axial nodes stored in the memory. Are stored separately in memory.

As described above, in the GT signal unbalanced state,
When performing the power distribution learning correction process in a state where the signal level has reached the transient state, the simulation-calculated in-core power distribution at the time of the execution of the power distribution learning correction process is used as the learning correction amount when the GT data D1 is balanced. , And LPR
By performing the learning correction based on the additional learning correction amount based on the pseudo GT data estimated as the transient state equilibrium value obtained from the M signal, a highly accurate output distribution can be generated.

When the GT signal processing device 48 or the nuclear instrumentation control device 60 determines that the GT data D1 has reached an equilibrium state, the output distribution calculation device 31
(Output distribution learning module) 62 resets the additional learning correction amount based on the LPRM signal S2 stored in the memory to zero and returns the additional relative learning correction ratio (correction coefficient) based on the LPRM signal S2 to 1.0. Means｝, Fig. 9 above.
As shown in (1), a learning correction amount based on the GT data D1 in the equilibrium state is obtained again, stored in the memory, and the output distribution learning correction process is performed based on the learning correction amount.

Thus, the GT from the GT aggregate 35
Even when the signal is unbalanced and changing, the in-core power distribution calculation device 31 can perform the power distribution learning correction calculation based on the in-core nuclear instrumentation, so that the GT data D1 reaches the equilibrium state in the unbalanced state. The furnace power distribution learning correction process can be performed without waiting until the process is completed, and the furnace power distribution learning correction process can be performed periodically or as needed.

In this embodiment, at the time of the power distribution learning correction in the unbalanced state, four LPs along the core axis direction are set.
Although the output distribution learning correction calculation is performed using the additional learning correction amount of the interpolation and extrapolation calculated based on the LPRM signal S2 detected by the RM detector 37, when the GT signal equilibrium state is reached, At the timing of the output distribution learning correction processing based on the GT signal, the additional relative learning correction amount that is likely to include an interpolation error is cleared to zero, and detected by the GT detector 35 having a large number along the axial direction. Output distribution learning correction processing based on the GT data D1 in an equilibrium state can be performed. Therefore, LPRM aggregate 3
4 is no longer influencing the core power distribution calculation over a long period of time, and depends only on the error of the GT assembly 35, the maximum linear power density (MLHGR) and the minimum power ratio (MCPR) Can be maintained as high as possible.

In the ninth and tenth embodiments, G
The core power distribution was calculated using the LPRM signal when the T signal was in an unbalanced state.
If the LPRM detector 37 fails and is bypassed, the LPRM of the bypassed LPRM detector 37
It is also possible to disregard the signal and give priority to the simulation calculation value, or substitute the LPRM signal of the nuclear instrumentation tube position where the symmetry is guaranteed from the core fuel loading, the control rod pattern, and the like.

[Eleventh Embodiment] An eleventh embodiment of the reactor core instrumentation system, power distribution calculation device, and power distribution monitoring system of the reactor according to the present invention will be described.

The basic configuration of the reactor power distribution monitoring system 29, reactor core instrumentation system 30, and power distribution calculation device 31 in the eleventh embodiment is substantially different from that shown in the first embodiment. The description is omitted because it is not necessary.

The reactor power distribution monitoring system 29 and the nuclear instrumentation system 30 of the reactor shown in the eleventh embodiment
Does not lose the advantage that the number of GT detectors 44 in the axial direction is greater than that of the LPRM detector 37. Even when the GT signal S1 output from the GT detector 44 is in a transient state, the output distribution is obtained only with the GT data D1. This makes it possible to perform the learning correction.

That is, according to the reactor power distribution monitoring system 29 shown in the ninth and tenth embodiments,
The state in which the GT data D1 output from the T detector 44 has not reached the equilibrium level of gamma decay, that is, after the operating parameters (core state current data) such as the core power, the core coolant flow rate, and the control rod pattern have changed. For example, in a short time within one hour, the level of the GT data D1 (W / g) based on the GT signal S1 changes in a predetermined time, for example, on the order of minutes, and the furnace power distribution calculation device 31 outputs the power based on the GT data D1. When the distribution is learned and corrected, the local output is overestimated (when the local output is reduced) or underestimated (when the local output is increased) by the amount of the unbalanced GT data D1.

For this reason, even if the learning is corrected by the power distribution learning module 62 of the in-furnace power distribution calculating device 31, an error is included, and the response of the LPRM detector 37, which has a fast response, is used as an auxiliary means. (9th and 10th
See the embodiment).

However, since only four LPRM detectors 37 are provided in the axial direction, the accuracy may be inferior in terms of learning correction of the axial output distribution.

Therefore, in the reactor power distribution monitoring system 29, the fixed reactor core instrumentation system 30, and the reactor power distribution calculator 31 in the eleventh embodiment, the core output from the reactor current data processor 58 is used. Core state parameter signals (core state data D3) such as the power level, the core coolant flow rate, and the control rod pattern are input to the in-core power distribution calculation device 31 via the nuclear instrumentation control device 60 of the process control computer 20A. Internal output distribution calculator 31
Is the core status data D3 and GT data D
1, the power distribution in the furnace is calculated regularly (every time) or as needed.

That is, the nuclear instrumentation control unit 60 detects a change in the core state based on the core state data D3 such as the core power level, the core coolant flow rate, and the control rod pattern transmitted from the reactor state data processing unit 58. Then, it is determined whether a predetermined time has elapsed after the detection.

The power distribution calculating device 31 determines that a predetermined time has elapsed after detecting the core state change, and that the nuclear instrumentation control device 60
Is determined by the process control computer 20A
Of the output distribution calculating device 31 displays the determination result on the display device 6
3 to inform the operator via a display device (input / output device) 63.

The operator confirms the result of the judgment displayed on the input / output device confirmation command via the device 63, and operates the input / output device 63 to transmit the confirmation command to the nuclear instrumentation control device 60.

[0400] The nuclear instrumentation control device 60 determines that the condition is not satisfied (the GT signal has not reached the equilibrium state) in response to the confirmation command from the operator or automatically based on the above determination result. , A GT signal prediction calculation command is transmitted to the GT signal processing device 48.

The GT signal processing device 48 transmits the transmitted GT
The GT data D1 (W / g signal level) generated based on the changing GT signal S1 is changed every predetermined time, for example, every several tens of seconds (20 to 30 seconds) or every minute according to the signal prediction calculation command. By capturing a predetermined number of data points, for example, several points or about 10 points,

(Equation 6) Perform least-squares fitting on the equation. Where a,
b is a constant to be fitted, and t is the elapsed time (seconds, minutes). λ is the process control computer 2
For example, a nuclear time constant is set for each node based on the time constant library stored in the memory of 0A (see Table 1).

The GT signal processor 48 obtains a constant (coefficient) by fitting the GT data D1 to the above equation (6), and calculates a constant (coefficient) based on the obtained coefficient according to the equation (6) after a required time, for example, one hour or more has elapsed. The balanced signal level of GT data is predicted and calculated based on the GT signal S1 actually measured by the GT detector 44, and the predicted and calculated first GT data (equivalent to the balanced value) is calculated in the furnace power distribution calculating device 31 of the process control computer 20A. Send to Note that the GT data equilibrium level prediction calculation process based on the least squares fitting may be executed by the nuclear instrumentation control device 60 of the process control computer 20A.

On the other hand, the in-core power distribution calculating device 31 matches the operating state of the reactor based on the core current state data D3 representing the current operating state (core power, core coolant flow rate, control rod pattern, etc.). The power distribution in the furnace is calculated by simulation, and the second GT data is calculated from the simulation calculation result.

Next, the in-furnace power distribution calculating device 31 calculates the difference between the second predicted GT data (equivalent to the equilibrium value) calculated from the simulation calculation and the first GT data predicted and calculated from the actually measured GT signal S1. Data representing a difference (form of ratio) is obtained, and the difference data is extrapolated to each node in the core axis direction to generate correction amount data (correction ratio data) for all axial nodes, thereby obtaining a correction amount data for all axial nodes. The learning correction amount based on the GT signal can be obtained.

The in-core power distribution calculating device 31 corrects the in-core power distribution for each fuel assembly node, which is the simulation calculation result at the present time, based on the obtained learning correction amount for all axial nodes. Then, based on the corrected furnace power distribution, the maximum linear power density (MLHGR) and the minimum critical power ratio (MCP) at the current time (at the time of executing the learning correction process)
R) is calculated.

As a result, even in a so-called reactor transient state where the GT signal output from the GT detector 44 is changing, it is possible to monitor and evaluate the power distribution of the reactor.

At this time, the prediction calculation performed by the GT signal processing device 48 (or the nuclear instrumentation control device 60) for predicting the equilibrium signal level of the GT detector 44 after the required time, for example, one hour or more has elapsed is as follows. From the output device 63 through the nuclear instrumentation control device 60, the prediction function mode (G
The output distribution learning mode based on T data prediction) is automatically and sequentially performed at each new time (for example, every 20 to 30 seconds or every minute) while the selection instruction information is being transmitted.

That is, when the GT signal processing device 48 (or the nuclear instrumentation control device 60) fetches the GT data D1 (W / g level signal) based on the new GT signal S1, the GT data processing device 48 (or the nuclear instrumentation control device 60) Discard and new GT data D
The estimated GT data value (equilibrium value) is updated from the time series GT data group including several or ten points including 1 by the least square fitting based on the above equation (5), and the updated GT data value (equilibrium value) is calculated. Is transmitted to the in-furnace power distribution calculating device 31.
Performs a furnace power distribution learning correction calculation based on the updated GT data prediction calculation value. Then, the output distribution calculating device 31 displays information indicating that the mode is in the mode of performing the learning correction of the output distribution using the equilibrium prediction value of the GT data (output distribution learning mode by GT data prediction). The information is output to the display unit 63 to inform the operator via the display device 63.

The thermal time constant of the GT detector 44 is on the order of seconds, and the gamma source that contributes to the heat generation of the GT detector 44 emits gamma rays almost simultaneously with fission or in a short time on the order of seconds. It has a wide distribution of time constants from those with minute, hour and day order time constants.

The weight of the component of each time constant depends on the gamma source contained in the fuel, and this gamma source is a fission nuclide (for example, U235, Pu2
39 etc.), and also depending on the elapsed time since fission.

[0411] Strictly treating the nuclide concentration with a three-dimensional BWR simulator to obtain the component of the nuclear time constant for each node of the fuel assembly requires a large data library of nuclear time constants to be stored in the memory. Not practical.

Therefore, in this embodiment, the time constant of the gamma source is limited to a time constant dominant to the required time, for example, about one hour after the elapse of a minute order,
When the number of data points is limited to, for example, 10 or less or about 10, the following equation (7)

(Equation 7) Least-squares fitting to fit a, bi
A coefficient (i = 1 to a maximum of about 10) is obtained, and a required time, for example, an equilibrium GT data value after about one hour is estimated and calculated from the time series data of the GT data. The value of λi in the above equation was obtained from a nuclear constant library,

[Table 1] The time constant (sec ⁻¹ ) of the JNDC fitting equation of ( ¹ ) can be considered as a candidate, but this is an example, and another time constant may be used depending on editing. 10 data points
The reduction to less than the number is a method of having a longer time constant (half-life) and omitting the one having a weak gamma source intensity. For example, a time constant of a level of 10 ⁻⁵ (sec ⁻¹ ) is set. It can be ignored.

[0413] According to this method, the GT data processing device 4
8 (or the nuclear instrumentation control device 60) chronologically converts GT data D1 (W / g signal) based on the GT signal S1 output from the GT detector 44 every predetermined time, for example, every 30 seconds or every minute. Stored in dozens of memories, erased old GT data and updated and stored new GT data sequentially, for example, every 30 seconds or 1 minute

(Equation 8) By repeatedly executing the least-squares fitting of, and updating the GT prediction data value after a required time, for example, about one hour each time, even when the GT signal S1 is in an unbalanced state,
Simultaneously, GT every predetermined time, for example, every 30 seconds or every minute
A GT data value at the time of equilibrium based on the GT signal S1 output from the detector 44 can be generated. About 5 to 15 minutes after the output fluctuation, the GT signal output from the GT detector 44 is generated. A predicted equilibrium GT data value can be obtained.

Note that the time series data collection interval is GT
It is practically selected according to the operation speed of the signal processing device 48 and the process control computer 20A, and is not limited to 30 seconds or 1 minute. Here, as an example, a well-chosen time interval is selected.
Seconds or one minute, but one per sample
It is also conceivable to employ a sampling method in which several to ten samples having a frequency of times per second are continuously sampled and signal fluctuation or noise is filtered. This gives a better approximation of the least squares fitting. Also, the number of data points stored in time series and subjected to the least squares fitting is not limited to about 10 points. Even if the number of data points is reduced to a smaller number of points, for example, about 5 points in balance between prediction accuracy and time required for prediction. good. The point is to obtain the predicted value as fast as possible without reducing the prediction accuracy very much.

With reference to FIGS. 12 and 13, the operation of the nuclear instrumentation system and the power distribution calculation device of the nuclear reactor of the present embodiment will be described. FIG. 12 is a graph showing actual measured GT data values and predicted GT data values with respect to elapsed time (minutes) when the output of the fuel portion around the sensor unit of the GT detector 44 increases, and FIG. Measured GT data and G for elapsed time (minutes)
It is a graph which shows a T data predicted value.

In FIG. 12 and FIG. 13, the solid line P indicates the actual change in the core local power, and the dot point O indicates the measured GT.
The data (W / g signal) value and the broken line q indicate the predicted value of the GT data. In any case, the sum of the polynomial of the exponential function and the constant term obtained by taking in a time series of GT signals having data points of, for example, about 10 immediately after the change and performing least square fitting (formula (6) to
(8)), the equilibrium value can be calculated with high accuracy. In particular, selecting the decay time constant of the gamma source that contributes between about one minute and one hour and reducing the number of polynomials is extremely effective in reducing the calculation time.

In the least-squares fitting calculation, in order to speed up convergence, it is preferable to prepare separate sets of initial guesses a and bi for a case where the furnace power is increased and a case where the furnace power is decreased.

As a result, by the simple method described above, the history before the time when a transient change such as the change in the local power and the change in the power of the entire core, and the distribution of the gamma source at that time are calculated. The gamma exotherm (GT equilibrium data value) at the time of equilibrium of gamma decay can be easily predicted without performing complicated processing such as finding gamma exotherm after output change.

The display device 63 indicates that the output distribution monitoring system 29 is operated in a mode in which such gamma heat (GT data value) is obtained by prediction calculation (output distribution learning mode based on GT data prediction). Then, by alerting the operator, it is possible to alert the operator that the error due to the prediction calculation is included in the output distribution calculation result after the LPRM adjustment and the learning correction.

In this embodiment, the function for calculating the equilibrium prediction of the GT data value is used when the GT signal is in an unbalanced state, and it is standard that the GT signal is not always used. However, the present invention is not limited to this. Not something.

As a modification of the present embodiment, the GT signal processing device 48 always uses the GT data (W / g signal) obtained as a result of using the prediction calculation function except when calibrating the heater of the GT detector 44 to process control computer 20A. (Output distribution calculation device 3
1), the process control computer 20A always takes in the transmitted predicted GT data value, and uses it for learning correction of the output distribution, or uses the L in the LPRM signal processor 48.
It can also be used for PRM sensitivity / gain adjustment.

Note that the sensitivity / gain adjustment of the LPRM in this modification includes (1) a method of adjusting the sensitivity or gain of the LPRM detector so as to directly match the calculated value of GT balance data, and (2) The furnace power distribution is learned and calculated by the furnace power distribution calculator 31 using the calculated GT equilibrium data, and the LPRM signal (LPRM) calculated using the result is calculated.
And adjusting the sensitivity or gain of the LPRM detector to match the data.

The sensitivity or gain adjustment of the LPRM detector 37 is executed by the operator's operation command from the display device 63 through the nuclear instrumentation controller 60.

[0424] Thus, the operator can automatically perform the output distribution learning calculation processing and the LPRM based on the GT data value of the equilibrium level without worrying about whether the GT data level is in an unbalanced state or an equilibrium state. Since the gain / sensitivity adjustment process is executed, the operation of the in-furnace power distribution monitoring system becomes easier, and the burden on the operator is reduced.

In this case, however, the fitting accuracy based on the least squares is always monitored by the GT signal processor 48 or the process control computer 20A, and when the fitting accuracy falls below a predetermined accuracy, an alarm is issued to the process control computer. By outputting to the display device 63 by the processing of 20A to notify the operator, the operator can manually perform the output distribution learning calculation process using the GT equilibrium data value or the LPRM sensitivity /
It is preferable to configure so that the gain adjustment processing can be controlled.
With this configuration, when the fitting accuracy is below a predetermined accuracy, the output distribution learning calculation process or the LPRM sensitivity / gain adjustment process using the GT equilibrium data value is stopped, and the operator's manual command is issued. Since it is possible to switch to output distribution learning calculation processing or LPRM sensitivity / gain adjustment processing based on the above, the reliability of the output distribution monitoring system can be maintained at a high level.

As described above, in the eleventh embodiment, even if the GT signal detected by the GT detector has not reached the signal level of the equilibrium state of the gamma decay chain, the GT detector 44 can be easily operated. Correct response 3
A dimensional output distribution learning process can be performed. Therefore, using only the GT detector signal in a simple fixed in-core nuclear instrumentation system 30, the minimum critical power ratio (MCPR),
Monitoring of thermal limits during operation, such as maximum linear power density (MLHGR), can be performed at any point within a practically timed delay.

[0427]

As described above, according to the nuclear reactor fixed instrumentation system and the nuclear instrumentation processing method, the power distribution calculation apparatus and the calculation method, and the power distribution monitoring system and the monitoring method according to the present invention, as described above. , The heater heating calibration management of the gamma thermometer assembly can be accurately performed, and the sensitivity calibration (adjustment) of the GT detector can be accurately and accurately performed based on the heater heating calibration of the gamma thermometer assembly. Therefore, it is possible to accurately calculate the power distribution in the furnace.

Further, according to the fixed nuclear reactor instrumentation system and the nuclear instrumentation processing method, the power distribution calculation device and the calculation method, and the power distribution monitoring system and the monitoring method of the present invention, a gamma thermometer assembly is provided. Can shorten the heater heating calibration time, reduce the probability of damage to the heater, and accurately perform the sensitivity calibration of the GT detector. Therefore, useless sensitivity calibration of the gamma thermometer assembly in the sensitivity stable period Can be prevented beforehand, and the burden on the operator can be reduced.

Further, according to the fixed nuclear reactor instrumentation system of the nuclear reactor, the nuclear instrumentation processing method, the power distribution calculation device and the calculation method, and the power distribution monitoring system and the monitoring method according to the present invention, the gamma thermometer assembly Can accurately control the heater heating of the gamma thermometer assembly due to the difference in the furnace interior loading time or the amount of irradiation in the furnace. In addition, when the GT signal level is in equilibrium, the sensitivity or gain calibration of the LPRM detector and the furnace Since the output distribution can be calculated, the sensitivity / gain calibration accuracy can be improved and the burden on the operator can be reduced. On the other hand, when the GT signal level is not in a balanced state, the LPRM signal is used or the GT detector is used. By using the equilibrium value predicted value, it is possible to calculate the power distribution in the furnace with high accuracy.

Further, according to the fixed nuclear reactor instrumentation system and the nuclear instrumentation processing method of the nuclear reactor according to the present invention, and the power distribution monitoring system and the monitoring method, the initial stage of the GT assembly, for example, 6 months The automatic or semi-automatic GT heater heating calibration procedure appropriate for the characteristic sensitivity change of the GT detector during the period is performed using the furnace interior loading time of the GT assembly or the in-furnace irradiation amount as a parameter, and the new G
It is possible to provide the operator with a correct GT heater heating calibration operation in a core loaded state in which the T-assembly and the continuous-use GT-assembly are mixed. Can be prevented, and an abnormal change in sensitivity can be efficiently detected and displayed to the operator.

Further, according to the fixed nuclear reactor instrumentation system and the nuclear instrumentation processing method of the nuclear reactor according to the present invention, and the power distribution monitoring system and the monitoring method, a predetermined time after the reactor power state is reached, For example, if the GT signal does not reach about one hour or more, the GT signal does not reach a signal level proportional to the average output of the fuel node around the GT detector. Prevent the GT signal from being taken into the device or use LPR
By preventing the sensitivity or gain adjustment of the M detector, the reliability of the calculation of the power distribution in the furnace and the calculation of the thermal operation limit value parameter can be maintained.

Further, according to the fixed nuclear reactor instrumentation system and the nuclear instrumentation processing method of the nuclear reactor according to the present invention, and the power distribution monitoring system and the monitoring method, even if the GT signal is in an unbalanced transient state, GT when in equilibrium
Using the LPRM signal calibrated based on the signal, the core power distribution calculation and the calculation of the thermal operation limit value parameter can be performed at regular intervals or at any time.

Further, according to the fixed nuclear reactor instrumentation system and the nuclear instrumentation processing method of the nuclear reactor according to the present invention, and the power distribution monitoring system and the monitoring method, even if the GT signal is in an unbalanced transient state. The GT signal level in the equilibrium state is predicted and calculated from the signal at the time of non-equilibrium, and the predicted GT signal is used to perform the LPRM gain adjustment or the core power distribution calculation and the calculation of the thermal operation limit value parameter on a regular basis. It can be performed every or at any time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an in-core nuclear instrumentation system, a power distribution calculation device, and a reactor power distribution monitoring system according to the present invention.

FIG. 2 is a partially cutaway perspective view showing a detector arrangement relationship of a GT power distribution measuring device in a first embodiment of a nuclear power instrumentation system, a power distribution calculating device, and a reactor power distribution monitoring system according to the present invention. FIG.

FIG. 3 is a partially cutaway front view showing a detector arrangement relationship of the GT output distribution measuring device in FIG. 2;

FIG. 4 is a perspective view showing an example of the structure of a gamma thermometer assembly with a partial cutout.

FIG. 5 is a diagram showing a principle of measuring a γ-ray calorific value of a gamma thermometer detector.

FIG. 6A is a diagram illustrating the principle of measuring gamma heat generation of a gamma thermometer detector, and FIG. 6B is a diagram illustrating a flow of heat when (A) is partially enlarged.

FIG. 7 is a diagram for explaining a change in the sensitivity of the GT detection unit depending on the loading time inside the furnace.

FIG. 8 is a view for explaining the principle of calibrating the sensitivity of the GT detection unit using a built-in heater.

FIG. 9 is a schematic flowchart showing an example of a flow of output distribution calculation and learning of an output distribution calculation module and an output distribution learning correction module of the three-dimensional simulator.

FIG. 10 is a schematic flowchart showing a modification of the flow of output distribution calculation and learning of the output distribution calculation module and the output distribution learning correction module of the three-dimensional simulator.

FIG. 11 is an explanatory diagram of a method of obtaining a correction ratio of all nodes in the fuel assembly axial direction from a difference between an actual GT signal value and a GT signal reading value calculated by a three-dimensional nuclear thermal hydraulic simulation code of BWR.

FIG. 12 is an explanatory operation diagram of a behavior of a GT signal when an output of a fuel part around a GT detection unit increases, and a method of calculating an equilibrium value from time series data of an initial change thereof.

FIG. 13 is an explanatory action diagram of a behavior of a GT signal when an output of a fuel portion around a GT detection unit is reduced, and a method of calculating an equilibrium value from time-series data of an initial change thereof.

FIG. 14 is a block diagram of a conventional reactor power distribution monitoring device, a power distribution calculating device, and a reactor power distribution monitoring system.

FIG. 15 is a view showing a detector arrangement relationship of a conventional power distribution measuring device, and is a diagram showing a movable neutron detector and a fixed neutron detector.

FIG. 16 is a view showing a detector arrangement relationship of a conventional power distribution measuring apparatus, and is a diagram showing a combination of a mobile γ-ray detector and a fixed neutron detector.

[Description of Signs] 1 Reactor containment vessel 2 Reactor pressure vessel 3 Reactor core 4 Fuel assembly 5 Control rod 20, 20A Process control computer 30 Fixed in-core nuclear instrumentation system 31 In-core power distribution calculation device 32 In-core nuclear instrumentation Assembly 33 Nuclear instrumentation tube 34 Neutron detector assembly (fixed neutron detection means, L
PRM detector aggregate) 35 γ-ray heat detector aggregate (fixed γ-ray heat detector, GT aggregate, gamma thermometer aggregate) 37 Fixed neutron detector (LPRM detector) 38 Signal cable 39 Penetration unit Reference Signs List 40 LPRM signal processing device 41 Output region neutron flux measurement system (output region neutron flux measurement device) 44 Fixed gamma ray heat generation detector (GT detector) 45 Signal cable 48 Gamma thermometer signal processing device 49 Penetration unit 50 Gamma thermometer Power distribution measurement system (gamma thermometer output distribution measurement device) 53 gamma thermometer heater control device 54 power cable 55 core current data measurement device 56 penetration unit 57 signal cable 58 current data processing device 59 process data measurement system 60 nuclear instrumentation control device (In-core nuclear instrumentation system Module 61) Power distribution calculation module (3D nuclear thermal hydraulic power calculation module) 62 Output distribution learning module 63 Display operation device (display device) 65 Cover tube 66 Core tube 67 Void portion 68 Inner hole 70 Cable sensor assembly (MI cable) 71 Built-in heater (heater wire) 72 Differential thermocouple 73 Filler 74 Metal cladding tube 75 Heater wire 76 Electrical insulation layer 77 Metal cladding tube 78 Thermocouple wire 79 Electrical insulation layer 80 Metal cladding tube

Claims (50)

[Claims] 1. A fixed-type neutron detector for a plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor and a gamma thermometer assembly for detecting a γ-ray heating value. And a gamma-ray heating detector arranged at least in the vicinity of the LPRM detector, and an LPRM signal for processing a neutron flux detection signal from the LPRM detector. A gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and a gamma thermometer heater control device for controlling energization of a heater built in the gamma thermometer assembly The gamma thermometer heater control device controls the amount of energization heating to the built-in heater of the gamma thermometer assembly, A fixed nuclear reactor instrumentation system for a nuclear reactor, wherein the output voltage sensitivity of each detector of the gamma thermometer assembly is calibrated by heating. 2. A nuclear instrumentation control device is provided as a monitoring control module for monitoring and controlling the gamma thermometer heater control device and the gamma thermometer signal processing device, and the nuclear instrumentation control device outputs an output of each detector of the gamma thermometer assembly. 2. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 1, wherein operation control of a gamma thermometer heater control device and a gamma thermometer signal processing device for calibrating a sensitivity voltage is performed. 3. The heater wire contained in the gamma thermometer assembly has a known heater resistance value, while the fixed gamma ray heat detector is a detector in which a differential thermocouple is incorporated. The mass of the detection unit is known, and the heating control of the built-in heater of the gamma thermometer assembly is performed by controlling the power supply from the gamma thermometer heater control device during the operation of the reactor. The change of the output voltage signal of the γ-ray heat detector and the heating voltage / current to the built-in heater are measured by a gamma thermometer signal processing device or a nuclear instrumentation control device, and based on the measurement result, a fixed γ
3. The nuclear reactor fixed instrumentation system according to claim 1, wherein the thermocouple output voltage sensitivity per unit heating value (W / g) of the linear heating detector is calibrated. 4. The nuclear instrumentation control device has a function of calculating and recording a reactor operation time (reactor interior loading time) after loading each gamma thermometer assembly inside the reactor, while each gamma thermometer assembly has The gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled using the furnace interior loading time as a parameter to calibrate the output voltage sensitivity per unit calorific value (W / g) of the fixed gamma ray heat detector. , One of a plurality of predetermined time intervals determined in advance according to the furnace interior loading time, and a fixed γ-ray heat detector of each gamma thermometer assembly by heater heating at the selected predetermined time interval. 4. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 2, wherein the output voltage sensitivity calibration is performed. 5. A nuclear instrumentation control device according to claim 1, wherein the time interval when the output voltage sensitivity calibration time interval of the fixed gamma heat generation detector of each gamma thermometer assembly due to heater heating is changed to another (new) predetermined time interval. 5. The fixed in-core nuclear instrumentation system for a nuclear reactor according to claim 4, wherein information or an alarm is output to an outside of an operator or the like. 6. The nuclear instrumentation control device performs calibration of the output voltage sensitivity of the fixed type γ-ray heat detector by heating the heater by using the irradiation amount in the furnace as a parameter instead of the furnace interior loading time of the gamma thermometer assembly. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 4 or 5, wherein: 7. The nuclear instrumentation control device stores the furnace interior loading time of each gamma thermometer assembly or the amount of irradiation in the furnace, evaluates the stored data and evaluates each fixed gamma ray of the gamma thermometer assembly. 7. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 2, wherein the calibration of the output voltage sensitivity by heating the heater of the heat generation detector is controlled. 8. The nuclear instrumentation control device detects reactor core state changes by inputting reactor current data such as a core power level, a core coolant flow rate, and a control rod pattern from a reactor core current data measuring device, After the detection of the core state change, the elapse of a predetermined time is determined to determine whether the heater heating calibration is appropriate, and the above determination result is output to the display device, while the fixed gamma-ray heat detector of the gamma thermometer assembly is The fixed nuclear reactor instrumentation system for a nuclear reactor according to any one of claims 2 to 7, which controls output voltage sensitivity calibration by heating the heater. 9. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a reactor, and a fixed γ-ray heat source of a gamma thermometer assembly near each of the neutron detectors. After loading the in-core nuclear instrumentation assembly in which at least the detector is disposed in the reactor, the heater incorporated in the gamma thermometer assembly is energized by the gamma thermometer heater control device to perform built-in heater heating,
The change in output voltage from the fixed-type gamma-ray heat detector and the heater heating voltage / current of the gamma thermometer assembly accompanying the heater heating are measured, and the output voltage sensitivity of the fixed-type gamma-ray heat detector is measured based on the measurement result. And a nuclear instrumentation processing method for a nuclear reactor. 10. The output voltage change and heater heating voltage
In the step of measuring the current, the built-in heater of the gamma thermometer assembly is heated by controlling the energization through the gamma thermometer heater control device during the operation of the reactor, and the gamma thermometer assembly accompanying the heating of the heater is fixed. It is a step of measuring the output voltage change from the formula γ-ray heat detector and the heater heating voltage / current, and when performing the output voltage sensitivity calibration step, using the furnace interior loading time of the gamma thermometer assembly as a parameter, One of a plurality of predetermined time intervals predetermined according to the furnace interior loading time is selected, and at the selected predetermined time interval, the fixed type γ-ray heat detector of each gamma thermometer assembly by heater heating is selected. The nuclear instrumentation processing method for a nuclear reactor according to claim 9, wherein the output voltage sensitivity calibration is performed. 11. A nuclear instrumentation controller calculates a reactor operation time (reactor interior loading time) after loading each gamma thermometer assembly inside the reactor and stores the reactor interior loading time. 11. The nuclear instrumentation processing method for a nuclear reactor according to claim 10, wherein a gamma thermometer assembly to be calibrated for the heater is selected to control operation of the corresponding gamma thermometer heater control device and gamma thermometer signal processing device. 12. The method according to claim 10, wherein the calibration of the output voltage sensitivity of the fixed type γ-ray heat detector by heating the heater is performed using the irradiation amount in the furnace as a parameter instead of the loading time inside the furnace of the gamma thermometer assembly. Nuclear instrumentation method for nuclear reactors. 13. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
And a fixed gamma-ray heat detector of a gamma thermometer assembly for detecting a gamma-ray calorific value is housed in a nuclear instrumentation pipe, and the in-core nuclear instrumentation in which the gamma-ray heat detector is arranged at least near the LPRM detector An assembly, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and the gamma thermometer A gamma thermometer heater control device that controls energization of a heater built into the assembly, and a nuclear instrumentation control device that calculates and stores the furnace interior loading time or the irradiation amount in the furnace of the gamma thermometer, The nuclear instrumentation control device operates and controls a gamma thermometer heater control device and a gamma thermometer signal processing device, and controls the gamma thermometer. The heater control unit controls the amount of heating applied to the built-in heater of the gamma thermometer assembly, and performs calibration of the output voltage increase sensitivity of the fixed type γ-ray heat detector by heater heating at required time intervals. Characterized in-core nuclear instrumentation system of nuclear reactor. 14. A gamma thermometer signal processing device or a nuclear instrumentation control device calculates output voltage increase sensitivity data from each fixed γ-ray heat detector of the gamma thermometer assembly, while the nuclear instrumentation control device comprises: A plurality of time interval data for heater calibration prepared in advance are stored (for example, each of the first time intervals and the second
, A third time interval,...), The output voltage sensitivity calibration is performed at the first shortest predetermined time interval at the beginning of the furnace interior loading of the gamma thermometer assembly. Each time the sensitivity calibration is performed, the output voltage increase sensitivity data is stored and stored as time-series data, and the time-series data of two or more points closest to the present point in time using the time-series data of the output voltage sensitivity of the fixed type γ-ray heat detector. The output voltage sensitivity change curve is estimated by taking a point.If the output voltage sensitivity change curve does not exceed the allowable sensitivity change determination value set for a predetermined future time, the fixed γ-ray heat generation detector is First
The heater heating calibration is performed at a second predetermined time interval longer than the predetermined time, and when the allowable sensitivity change determination value is exceeded, the heater heating calibration is performed at a predetermined time interval selected at the present time. When the sensitivity calibration is performed and stored at intervals, the output voltage sensitivity change curve is created by taking two or more points closest to the current point using the stored output sensitivity time-series data, If the curve does not exceed the allowable sensitivity change determination value set for the predetermined future time, the fixed γ-ray heat detector is activated at a third predetermined time interval that is longer than the selected second predetermined time. The heater heating calibration is performed, and if it exceeds, the fixed type γ-ray heat detector is subjected to the heater heating calibration at the second predetermined time interval. Long sensitivity comparison 14. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 13, wherein the gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled to automatically determine and calculate whether the time interval can be changed. . 15. The gamma thermometer signal processing device or the nuclear instrumentation control device calculates the output voltage increase sensitivity from each fixed γ-ray heat detector of the gamma thermometer assembly, and stores and stores the time series data. The nuclear instrumentation control device stores a plurality of time interval data for heater calibration prepared in advance (for example, each of the first time interval, the second time interval, and the third Time interval,...), The output voltage sensitivity data of each detector of each gamma thermometer assembly is stored at the selected heater calibration time interval each time the sensitivity of the gamma thermometer assembly is calibrated, and each fixed type is stored. Using the time-series data of the output voltage sensitivity of the γ-ray heat detector, the nearest two or more time-series data points are taken from the present time to estimate the output voltage sensitivity change curve, and the output voltage sensitivity change curve is determined by a predetermined value. If the allowable sensitivity change determination value set for the future time is exceeded, the maximum predetermined time interval that can be selected from the predetermined calibration time intervals that the determination result can satisfy the fixed type γ-ray heat generation detector, 15. The reactor according to claim 13, wherein the gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled so as to perform heater heating calibration at a time interval shorter than the time interval selected so far. In-core nuclear instrumentation system. 16. The nuclear instrumentation control device informs an operator or the like when the heater heating calibration time interval of the fixed gamma ray heat detector of the gamma thermometer assembly is changed from the previous heater heating calibration time interval. 16. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 13, 14 or 15, wherein an alarm is output. 17. The nuclear instrumentation control device stores the furnace interior loading time of the gamma thermometer assembly or the irradiation dose in the furnace, evaluates the stored data, and evaluates each fixed gamma-ray heating of the gamma thermometer assembly. 3. The method according to claim 1, further comprising controlling an output voltage increase sensitivity calibration by heating the detector.
7. A fixed nuclear reactor instrumentation system for a nuclear reactor according to any one of 6. 18. The nuclear instrumentation control device detects reactor core state changes by inputting reactor current data such as a core power level, a core coolant flow rate, and a control rod pattern from a reactor core current data measuring device, After the detection of the core state change, the elapse of a predetermined time is determined to judge the suitability of the heater heating calibration of the gamma thermometer assembly, and the above determination result is output to the display device, while the gamma thermometer assembly is fixed. 18. The fixed in-core nuclear instrumentation system for a nuclear reactor according to claim 13, wherein calibration of output voltage increase sensitivity calibration by heating of the γ-ray heat detector is controlled. 19. The nuclear instrumentation control device may include a plurality of time intervals (for example, a first time interval, a second time interval, a second time interval, Time interval, third time interval, ...)
At a predetermined time interval (for example, a third time interval) selected corresponding to the furnace interior loading time of the gamma thermometer assembly, the output of the fixed-type γ-ray heat generation detector by heating the heater. The gamma thermometer heater control device and the gamma thermometer signal processing device are operated and controlled to perform the voltage sensitivity calibration, and the nuclear instrumentation control device further includes:
The time series data of the output voltage sensitivity of each fixed γ-ray heat detector of the gamma thermometer assembly is stored, and the time series data points at two or more points closest to the present time are taken from this time series data and the output voltage is obtained. A sensitivity change curve is estimated, and if the output voltage sensitivity change curve exceeds an allowable sensitivity change determination value set for a predetermined future time, priority is given to the selected (for example, third time interval) time interval. Then, the next predetermined time interval (for example, the second time interval) or the maximum predetermined time interval among a plurality of time intervals prepared beforehand which satisfies the permissible sensitivity change determination value is set. 14. The fixed nuclear reactor instrumentation system for a nuclear reactor according to claim 13, wherein the output voltage sensitivity calibration by heating the heater is performed at time intervals. 20. The nuclear instrumentation control device according to claim 1, wherein a calibration time interval of an output voltage increase sensitivity (heater heating time interval) due to heater heating of each fixed γ-ray heating detector of the gamma thermometer assembly is different from a previous calibration time interval. 20. The fixed in-core nuclear instrumentation system for a nuclear reactor according to claim 19, wherein information or an alarm is output to an operator or the like when the change is made. 21. The nuclear instrumentation control device, wherein a heater heating calibration time interval of each fixed type γ-ray heat detector of the gamma thermometer assembly is set in the furnace irradiation amount as a parameter instead of the furnace interior loading time. 21. The fixed nuclear reactor instrumentation system for a nuclear reactor according to any one of 19 and 20. 22. The nuclear instrumentation control device stores the furnace interior loading time of the gamma thermometer assembly or the irradiation amount in the furnace, evaluates the stored data, and evaluates each fixed gamma ray heating of the gamma thermometer assembly. 20. The apparatus according to claim 19, further comprising controlling an output voltage increase sensitivity calibration by heating the detector.
2. A fixed nuclear reactor instrumentation system for a nuclear reactor according to any one of the preceding claims. 23. The nuclear instrumentation control device inputs the reactor current state data indicating the core state such as the core power level, the core coolant flow rate, and the control rod pattern measured by the reactor core state data measuring device, and On the other hand, after detecting the change in the core state, the elapse of a predetermined time is determined to determine whether or not the heater heating calibration of the gamma thermometer assembly is appropriate, and the determination result is output to the display device, while the gamma thermometer is output. The fixed nuclear reactor instrumentation system for a nuclear reactor according to any one of claims 19 to 22, wherein calibration of output voltage sensitivity by heating of each fixed γ-ray heat detector of the assembly is controlled. 24. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
After loading the core nuclear instrumentation assembly in which at least the fixed gamma-ray heat detector of the gamma thermometer assembly is arranged in the vicinity of each of the above LPRM detectors, the nuclear instrumentation control device sets the gamma thermometer assembly The gamma thermometer heater control device and the gamma thermometer signal processing device are operated to control the gamma thermometer heater control device and the gamma thermometer signal processing device by storing time-series data of the output voltage sensitivity of each fixed gamma ray heat generation detector of the body, and the gamma thermometer assembly has a built-in heater. A nuclear instrumentation processing method for a nuclear reactor, comprising: calibrating an output voltage sensitivity of a fixed-type γ-ray heat detector by heating a heater at required time intervals by controlling a heating amount. 25. A fixed γ of a gamma thermometer assembly
When calibrating the output voltage sensitivity of the X-ray heating detector, the output sensitivity calibration of the fixed γ-ray heating detector is initially performed by the nuclear instrumentation control unit for a plurality of sensitivity calibration times stored in advance, when the gamma thermometer assembly is loaded inside the furnace. Implement and store at the first time interval which is the shortest in the interval, save as time-series data, and use this stored output sensitivity time-series data to take two or more points closest to the current point and output A voltage sensitivity change curve is created, and if the output voltage sensitivity change curve does not exceed the allowable sensitivity change determination value set for a predetermined future time, the fixed type γ-ray heat detector is set to the first selected one. The heater heating calibration is performed at a second predetermined time interval longer than the predetermined time, and if it exceeds, the fixed type γ-ray heat detector is heated at the first predetermined time interval, and the heater heating calibration is performed similarly. Perform sensitivity calibration at intervals・ Using the stored output sensitivity time-series data, the output voltage sensitivity change curve is created by taking two or more points closest to the current time point, and this output voltage sensitivity change curve is determined for a predetermined future time. If the set allowable sensitivity change determination value is not exceeded, the heater heating calibration of the fixed type γ-ray heat detector is performed at a third predetermined time interval that is longer than the selected second predetermined time, and if it is exceeded, In order to perform the heater heating calibration of the fixed γ-ray heat detector at the second predetermined time interval, it is possible to change the next prepared sensitivity calibration time interval from the currently selected time interval. 25. The nuclear instrumentation processing method for a nuclear reactor according to claim 24, wherein the determination is automatically made as to whether it is good. 26. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
And a nuclear instrumentation assembly in which at least a fixed gamma-ray heat detector of a gamma thermometer assembly is disposed in the vicinity of each of the LPRM detectors, is loaded into a reactor, and then the furnace interior of the gamma thermometer assembly is loaded. The nuclear instrumentation control device stores the time series data of the loading time and the output voltage sensitivity, and the nuclear instrumentation control device selects a plurality of time intervals prepared in advance according to the furnace interior loading time of the gamma thermometer assembly. Calibrating the output voltage increase sensitivity by heating the fixed γ-ray heat detector at predetermined time intervals selected according to the furnace interior loading time of the gamma thermometer assembly, The device control device estimates and calculates a time-series data sensitivity change curve based on the stored output voltage sensitivity time-series data, and sets the output voltage sensitivity change curve for a predetermined future time. If the allowable output voltage sensitivity change determination value is exceeded, the gamma thermometer heater is set to the next shorter predetermined time interval in preference to the selected time interval, and performs output voltage sensitivity calibration by heater heating. A nuclear instrumentation processing method for a nuclear reactor, comprising controlling a controller and a gamma thermometer signal processor. 27. The nuclear instrumentation control device estimates and calculates an output voltage sensitivity change curve from the time series data of two or more output voltage sensitivities nearest to the present time based on the stored time series data of the output voltage sensitivity. If the output voltage sensitivity exceeds the allowable output voltage sensitivity change determination value set for a predetermined future time, the output voltage sensitivity is set to a predetermined time interval of the maximum value of a plurality of time intervals prepared in advance before satisfying the allowable sensitivity change determination value. 27. The nuclear instrumentation processing method for a nuclear reactor according to claim 26, wherein the output voltage sensitivity calibration by heating the gamma thermometer assembly by the heater is forcibly and preferentially performed. 28. When the time interval of the sensitivity calibration of the output voltage increase due to the heating of the gamma thermometer assembly is changed from the previous output voltage sensitivity time interval, the nuclear instrumentation control device is externally (operator etc.). 28. The nuclear instrumentation processing method for a nuclear reactor according to claim 26, wherein the information or the alarm signal is output to the nuclear reactor. 29. The atom according to claim 26, wherein the time interval of the output voltage increase sensitivity calibration by heating the gamma thermometer assembly by the heater is replaced with the furnace interior loading time and the irradiation amount in the furnace is used as a parameter. Nuclear instrumentation processing method of furnace. 30. Reactor core status data such as a reactor power level, a core coolant flow rate, and a control rod pattern from a reactor core status data measuring device are input to a nuclear instrumentation controller to detect a core state change, and After detecting the state change, the nuclear instrumentation control device determines the elapse of a predetermined time to determine whether or not the heater heating calibration of the gamma thermometer assembly is appropriate, and displays the determination result on the display device, while displaying the determination result on the heater of the gamma thermometer assembly. 27. An output voltage increase sensitivity calibration by heating is performed.
30. The nuclear instrumentation processing method for a nuclear reactor according to any one of claims to 29. 31. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a fixed gamma-ray heat detector of a gamma thermometer assembly for detecting a gamma-ray calorific value is housed in a nuclear instrumentation pipe, and the in-core nuclear instrumentation in which the gamma-ray heat detector is arranged at least near the LPRM detector An assembly, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and the gamma thermometer A gamma thermometer heater control device for controlling energization of a heater incorporated in the gamma thermometer, and a nuclear instrumentation control device for controlling the gamma thermometer heater control device and the gamma thermometer signal processing device. The equipment includes the reactor core power level,
Receives a signal from the reactor core current state data measuring device that measures the core state such as core coolant flow rate, control rod pattern, etc., and judges that a predetermined time has elapsed after detecting a change in the core state. On the other hand, the determination result is displayed externally, and the signal from the gamma thermometer assembly or the gamma calorific value calculated from the signal is taken into the in-core power distribution calculation device. Fixed core nuclear instrumentation system or reactor power distribution monitoring system. 32. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a fixed gamma-ray heat detector of a gamma thermometer assembly for detecting a gamma-ray calorific value is housed in a nuclear instrumentation pipe, and the in-core nuclear instrumentation in which the gamma-ray heat detector is arranged at least near the LPRM detector An assembly, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and the gamma thermometer A gamma thermometer heater control device for controlling energization of a heater incorporated in the assembly; and a nuclear instrumentation control device for controlling operation of the gamma thermometer heater control device and the gamma thermometer signal processing device. The core control unit measures the core state, such as the reactor core power level, core coolant flow rate, control rod pattern, etc. While receiving the signal from the state data measuring instrument and judging that a predetermined time has elapsed since the detection of the change in the core state, the judgment is made, the judgment result is displayed externally, and the instrumentation pipe in the same furnace is displayed. The sensitivity or gain of the LPRM detector is set to be calibrated using the gamma ray heating value calculated from the signal of the fixed type gamma ray heating detector at the same core axial direction position as the LPRM detector. Reactor fixed core nuclear instrumentation system or reactor power distribution monitoring system. 33. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a fixed gamma-ray heat detector of a gamma thermometer assembly for detecting a gamma-ray calorific value is housed in a nuclear instrumentation pipe, and the in-core nuclear instrumentation in which the gamma-ray heat detector is arranged at least near the LPRM detector An assembly, an LPRM signal processing device for processing a neutron flux detection signal from the LPRM detector, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and the gamma thermometer A gamma thermometer heater control device for controlling energization of a heater built in the assembly, and a nuclear instrumentation control device for controlling the gamma thermometer heater control device and the gamma thermometer signal processing device The nuclear instrumentation control device is measured by a reactor core status data measuring device,
The core power level of the reactor, the core coolant flow rate, the control rod pattern, etc., and determines whether or not a predetermined time has elapsed since the detection of the core state change according to the reactor current state data indicating the reactor state including the control rod pattern. The apparatus further includes an in-furnace power distribution calculating device that outputs a determination result to the input / output device and receives a detection signal of the fixed γ-ray heat detector or a gamma heating value calculated from the detection signal as an input. The distribution calculation device detects the input detection signal of the fixed γ-ray heat detector,
Alternatively, the core power distribution is learned and calculated using the gamma calorific value and the three-dimensional nuclear thermal hydraulic calculation model, the predicted detection value of each LPRM detector is calculated from the core power distribution, and the calculated predicted detection value and the current detection value are calculated. A fixed nuclear reactor instrumentation system for a nuclear reactor or a power distribution monitoring system for a nuclear reactor, wherein calibration of the sensitivity or gain of an LPRM detector is performed in comparison with an actually measured value. 34. An LPRM signal processing apparatus, comprising: LPRM detector calibration means for calibrating a large number of fixed neutron detectors (LPRM detectors) by dividing them into a plurality of APRM channels or LPRM groups. Is
LP included in each APRM channel or LPRM group
33. The sensitivity or gain of the LPRM detector is adjusted within the range of the maximum allowable number of bypasses of the RM detector.
Or a fixed nuclear reactor instrumentation system for a nuclear reactor or a power distribution monitoring system for a nuclear reactor. 35. An LPRM signal processing apparatus, comprising: an LPRM detector calibrating means for calibrating a plurality of fixed neutron detectors (LPRM detectors) by dividing them into a plurality of APRM channels or groups of LPRMs. Is
LPR in units of LPRM detector group included in the bypassed APRM channel or LPRM group within the maximum allowable number of bypasses of the APRM channel or LPRM group
The fixed nuclear reactor instrumentation system for a nuclear reactor or the power distribution monitoring system for a nuclear reactor according to claim 32 or 33, wherein sensitivity or gain of the M detector is adjusted. 36. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a nuclear instrumentation assembly in which a fixed gamma-ray heat detector of a gamma thermometer is arranged at least in the vicinity of the LPRM detector, and loaded into the reactor, and the reactor core power level, core coolant flow rate, and control Reactor current data including a rod pattern and the like is measured by a reactor core current data measuring instrument to detect a change in the core state, and the nuclear instrumentation control device detects a change in the core state and a predetermined time has elapsed after detecting the change in the core state. The gamma thermometer assembly output signal or the gamma calorific value calculated from the signal is taken into the furnace power distribution calculation device on a regular or occasional basis. A nuclear instrumentation processing method for a nuclear reactor or a power distribution monitoring method for a nuclear reactor. 37. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
And a nuclear instrumentation assembly in which a fixed gamma-ray heating detector of a gamma thermometer assembly is arranged at least in the vicinity of the LPRM detector, loaded into the reactor, the reactor core power level and the core coolant flow rate. Reactor current data including a control rod pattern, etc. is measured with a reactor core current data measuring device to detect the core state, and the nuclear instrumentation control device detects a change in the core state and a predetermined time has elapsed after detecting the change in the core state. Judge that
The result of the determination is displayed to the operator, and the LPRM is calculated using the γ-ray heating value calculated from the signal of the fixed γ-ray heating detector at the same axial position as the LPRM detector in the same core instrumentation tube. A nuclear instrumentation processing method or a power distribution monitoring method for a nuclear reactor, comprising performing a sensitivity or gain calibration of a detector. 38. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor.
And a nuclear instrumentation assembly in which a fixed γ-ray heating detector of a gamma thermometer assembly is arranged at least in the vicinity of the fixed neutron detector, loaded into the reactor, and the reactor core power level and core cooling. Reactor status data including material flow rate, control rod pattern, etc. is detected by the core status data measuring device and output to the nuclear instrumentation control device, and the nuclear instrumentation control device changes the core state according to the output reactor status data. It is determined that a predetermined time has passed since the detection of the gamma thermometer, and the determination result is displayed to the operator, while the output signal of the gamma thermometer assembly or the γ-ray heating value calculated from the output signal is output in the furnace. The in-core power distribution calculation device, which is taken into the distribution calculation device on a regular or occasional basis, is a core power distribution using a gamma calorific value calculated from the signal of the fixed γ-ray heat detector and a three-dimensional nuclear thermal hydraulic calculation model. Learning calculation, comparing the predicted detection value of each LPRM detector calculated by the core power distribution calculation device and the current actually measured value from the core calculation power distribution calculated by learning, to calibrate the sensitivity or gain of the LPRM detector. A nuclear instrumentation processing method for a nuclear reactor or a power distribution monitoring method for a nuclear reactor. 39. A multiple stationary neutron detector (LPRM)
Detector) is divided into a plurality of APRM channels or LPRM groups, and the maximum allowable bypass number of LPRM detectors included in each APRM channel or LPRM group is L
38. Adjusting the sensitivity or gain of the PRM detector.
Or a nuclear instrumentation method for a nuclear reactor or a power distribution monitoring method for a nuclear reactor. 40. A multiple fixed neutron detector (LPRM)
Detectors) are divided into a plurality of APRM channels or LPRM groups, and the sensitivity of the LPRM detectors in units of LPRM detector groups included in the bypassed APRM channels or LPRM groups within the allowable bypass number of each APRM channel or LPRM group. Or performing gain adjustment.
39. The nuclear instrumentation processing method for a nuclear reactor or the power distribution monitoring method for a nuclear reactor according to 7 or 38. 41. A reactor core status data measuring device for measuring core status parameters indicating a core status (operating status) such as a core power level, a core coolant flow rate, a control rod pattern, etc. While inputting the parameter signal, the in-core power distribution calculating device for calculating the in-core power distribution using the gamma thermometer signal and the LPRM signal at regular intervals or as needed, and inputting the core state parameter signal to determine the core state change A nuclear instrumentation control device for judging the elapse of a predetermined time from the detection, and making a judgment.The nuclear instrumentation control device displays the judgment result on a display device. While the LPRM signal is input to the in-core power distribution calculator instead of the meter signal, the in-core power distribution calculator calculates the core state parameter signal and the Based on the learning correction amount obtained from the gamma thermometer signal at the nearest time, a power distribution calculation in accordance with the current core state is performed, and the calculated LPRM signal value calculated from the result is compared with the measured LPRM signal value. The correction ratio is interpolated and extrapolated in the axial direction to obtain the correction ratio for all nodes in the axial direction, and the output distribution can be evaluated even when the gamma thermometer signal changes and the gamma ray heat detector is in an unbalanced transient state. When the equilibrium state is reached and the learning correction by the gamma ray heat generation detector can be performed, LPRM is renewed.
A power distribution calculating device for a nuclear reactor or a power distribution monitoring system for a nuclear reactor, wherein a learning correction amount based on a gamma thermometer signal is obtained and stored again after the additional learning correction amount is cleared to zero. 42. A core state parameter indicating a core state (operating state) such as a core power level, a core coolant flow rate, a control rod pattern, etc., is measured, and a parameter signal of the measured core state is sent to an in-core power distribution calculating device. Gamma thermometer signal and LPRM
The core power distribution is calculated using the signal, the core state change is detected from the input of the core state parameter signal, and it is determined by the nuclear instrumentation control device that a predetermined time has elapsed since the detection, and the determination result is obtained. On the other hand, when the required condition is not satisfied, the LPRM signal is taken into the in-core power distribution calculator instead of the gamma thermometer signal while the in-core power distribution calculator calculates the core state parameter signal. A power distribution calculation based on the current core state is performed based on the learning correction amount obtained from the gamma thermometer signal and the current power distribution is estimated, and an LPRM signal calculation calculated according to the estimated power distribution is performed. Value and LP
The correction ratio by comparison with the measured RM signal value is extrapolated in the axial direction to obtain the correction ratio of all nodes in the axial direction, and the output distribution can be evaluated even when the gamma ray heat detector is in an unbalanced transient state.
Next, when the learning correction by the gamma ray heat detector can be newly performed in the equilibrium state, the LPRM additional learning correction amount is reset to zero again, and the learning correction amount based on the gamma thermometer signal is obtained and stored again. Power distribution calculation method or reactor power distribution monitoring method. 43. While the core state parameter signal is input from a reactor core status data measuring device for measuring core state (operating state) parameter signals such as a core power level, a core coolant flow rate, a control rod pattern and the like, A furnace power distribution calculating device that calculates a furnace power distribution using a gamma thermometer signal and an LPRM signal at regular or as needed times,
A nuclear instrumentation control device that determines whether a predetermined time has elapsed since the core state parameter signal was input and the core state change was detected, and the nuclear instrumentation control device displays the determination result on a display device. On the other hand, if the required condition is not satisfied, LP instead of the gamma thermometer signal
While the RM signal is input to the in-core power distribution calculation device, the in-core power distribution calculation device calculates the current value based on the core state parameter signal and the learning correction amount obtained from the gamma thermometer signal at the nearest time. A power distribution is calculated in accordance with the operating (core) state to estimate a current power distribution, and a gamma thermometer signal is calculated according to the estimated power distribution. On the other hand, a fuel node around the LPRM from the nearest time to the current time is calculated. The change amount of the LPRM signal expected in the calculation from the nearest time point is obtained using the change in the control rod state and the change in the void ratio in the channel, and the change amount of the LPRM signal and the gamma of the equilibrium state expected in the calculation are calculated. The pseudo-gamma thermometer signal obtained by correcting the actually measured LPRM signal based on the difference between the amount of change of the thermometer signal and the response The correction ratio by comparison with the gamma thermometer signal calculated from the output distribution by the current calculation is interpolated in the axial direction to obtain the correction ratio of all nodes in the axial direction, and the gamma thermometer signal changes to generate gamma ray heat. Even if the detector is in a non-equilibrium transient state, the reactor power distribution can be evaluated, and the learning correction can be performed by the gamma-ray heating detector in the next equilibrium state. The power distribution calculation device or the reactor of the nuclear reactor characterized in that the additional learning correction amount based on the gamma thermometer signal calculation is cleared to zero and the learning correction amount based on the gamma thermometer signal is obtained and stored again. Output distribution monitoring system. 44. A core state parameter indicating a core state (operating state) such as a core power level, a core coolant flow rate, a control rod pattern, etc., is measured, and a parameter signal of the measured core state is sent to an in-core power distribution calculating device. Gamma thermometer signal and LPRM
The core power distribution is calculated using the signals, and the core state change is detected from the input of the core state parameter signal.
The nuclear instrumentation control device determines whether a predetermined time has elapsed from this detection, and displays the determination result on a display device.
If the required conditions are not satisfied, the LPRM signal is taken into the in-furnace power distribution calculator instead of the gamma thermometer signal, and the in-furnace power distribution calculator calculates the learning obtained by the gamma thermometer signal at the nearest time. Based on the correction amount, the power distribution is calculated in accordance with the current operating state (core state) to estimate the current power distribution, and the gamma thermometer signal equilibrium value calculated according to the estimated power distribution and the nearest From the time point to the current time point, the change amount of the LPRM signal expected by the calculation from the nearest time point is obtained using the change in the control rod state of the fuel node around the LPRM and the change in the void ratio in the channel. LP measured based on the difference between the amount of change in the gamma thermometer signal in the equilibrium state expected by calculation and the amount of response
The correction ratio obtained by comparing the pseudo-gamma thermometer signal value obtained by correcting the RM signal with the gamma thermometer signal equilibrium value calculated from the output distribution by the current calculation is interpolated and extrapolated in the axial direction to obtain the total value in the axial direction. Get the correction ratio of the node,
Even if the gamma-ray heat detector is in an unbalanced transient state, the power distribution of the reactor can be evaluated, and when the learning correction by the gamma thermometer can be performed in the next equilibrium state, LPRM is renewed.
A reactor characterized in that a learning correction amount based on a gamma thermometer signal based on a pseudo-gamma thermometer signal based on a signal and a power distribution calculation is cleared to zero and a learning correction amount based on a gamma thermometer signal is obtained and stored again. Output distribution calculation method or output distribution monitoring method. 45. The core state parameter signal is input from a reactor core state data measuring device for measuring a core state parameter signal representing a core state (operating state) such as a core power level, a core coolant flow rate, and a control rod pattern. On the other hand, an in-core power distribution calculating device that calculates the in-core power distribution using a gamma thermometer signal at regular intervals or as needed, and a predetermined time after detecting the core state change by inputting the core state parameter signal. A nuclear instrumentation control device for determining whether or not the gamma thermometer signal processing device processes the gamma thermometer signal while displaying the determination result on a display device. If the core instrumentation system does not satisfy the required conditions for the core state change, a gamma thermometer signal processor or Predicts and calculates the equilibrium signal level of the gamma-ray heat detector after a predetermined time elapses in the nuclear instrumentation controller,
Further, the in-furnace power distribution calculating device performs a power distribution calculation in accordance with the current operation state, and calculates a correction ratio by comparing the gamma thermometer signal value calculated from the result with the predicted gamma thermometer signal value. The reactor is characterized in that the correction ratio of all the nodes in the axial direction of the fuel assembly is obtained by extrapolating in the axial direction and the power distribution can be evaluated even when the gamma ray heat detector is in an unbalanced transient state. Power distribution calculator or reactor power distribution monitoring system. 46. The nuclear instrumentation control device or the gamma thermometer signal processing device predicts and calculates the equilibrium signal level of the gamma ray heat detector after the required time has elapsed, and has issued a prediction function operation instruction for performing the prediction calculation. , Read the W / g level signal of the γ-ray heat detector at each new time,
The oldest data is discarded, and the gamma thermometer signal prediction calculation value by the least squares fitting is updated, and the updated gamma thermometer signal prediction calculation value is transferred from the gamma thermometer signal processing device or the nuclear instrumentation control device to the inside of the furnace. 46. The apparatus according to claim 45, wherein the setting is made so as to be sent to a power distribution calculating device, and to display on a display device that a mode is set in which a furnace power distribution calculation is performed using a predicted gamma thermometer signal calculated value. Reactor power distribution calculator or reactor power distribution monitoring system. 47. A core state parameter signal indicating a core state (operating state) such as a core power level, a core coolant flow rate, a control rod pattern, etc., is detected, and the detected core state parameter signal is sent to an in-core power distribution calculating device. While inputting, calculate the power distribution in the furnace using the gamma thermometer signal at regular intervals or as needed, detect core state changes from input of core state parameter signals, and determine whether a predetermined time has elapsed since this detection. Is determined by the nuclear instrumentation controller,
While the judgment result is displayed on the display device, if the required condition is not satisfied, the nuclear instrumentation control device or the gamma thermometer signal processing device fetches a plurality of gamma thermometer signals that change every predetermined time, and Predicting and calculating the equilibrium signal level of the γ-ray heat detector after a lapse of time, and further, the in-furnace power distribution calculating device performs a power distribution calculation in accordance with the current operating state, and calculates the gamma thermometer calculated from the result The correction ratio based on the comparison between the signal value and the predicted calculated gamma thermometer signal value is interpolated and extrapolated in the axial direction to obtain the correction ratio of all nodes in the fuel assembly axial direction, and the gamma thermometer signal is changing. A power distribution calculation method or a power distribution monitoring method for a nuclear reactor, wherein the power distribution in the reactor is evaluated even when the heat generation detector is in an unbalanced transient state. 48. The nuclear instrumentation control device or the gamma thermometer signal processing device predicts and calculates the equilibrium signal level of the γ-ray heat detector after the required time has elapsed, and the prediction function operation instruction for performing the prediction calculation is displayed on the display device. While out of the
Read the W / g level signal of the γ-ray heat detector at each new time, discard the oldest data, update the gamma thermometer signal prediction calculation value by the least squares fitting, and update the updated gamma thermometer signal The predicted calculation value is sent from the gamma thermometer signal processing device or the nuclear instrumentation control device to the in-core power distribution calculation device, indicating that the mode is set in which the in-core power distribution is calculated using the gamma thermometer signal predicted calculation value. 48. The method for calculating power distribution of a nuclear reactor or the method for monitoring power distribution of a nuclear reactor according to claim 47, wherein the method is displayed on an apparatus. 49. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a gamma thermometer assembly for detecting a γ-ray heating value and a fixed γ-ray heating detector housed in a nuclear instrumentation tube, and a nucleus instrumentation assembly in which a γ-ray heating detector is arranged at least near an LPRM detector. Body and LPRM from said LPRM detector
An LPRM signal processing device for processing signals, a gamma thermometer signal processing device for processing a gamma thermometer signal from the gamma thermometer assembly, and energization control to a heater built in the gamma thermometer assembly A gamma thermometer heater control device, a nuclear instrumentation control device that calculates and stores the furnace interior loading time or in-furnace irradiation burnup of the gamma thermometer, a core power level,
A core power distribution calculation device that calculates a core power distribution using a gamma thermometer signal and an LPRM signal while inputting a core state parameter signal such as a core coolant flow rate and a control rod pattern. The gamma thermometer signal processing device or the nuclear instrumentation control device captures a plurality of gamma thermometer signals that change at predetermined time intervals, and predicts and calculates the equilibrium signal level of the γ-ray heating detector after the required time has elapsed. Read the gamma thermometer signal for each new time, discard the oldest data,
While updating the gamma thermometer signal prediction calculation value by the least squares fitting and sending the updated gamma thermometer signal prediction calculation value to the in-furnace power distribution calculation device, the in-furnace power distribution calculation device may perform the The balanced gamma thermometer at the same core axial position as the fixed neutron detector of the core instrumentation tube in the same reactor, wherein the output distribution is learned and corrected at any time using the predicted and calculated balanced gamma thermometer signal value. Using the signal, or the sensitivity or gain calibration of the fixed neutron detector, or the predicted signal value of the fixed neutron detector calculated by the in-core power distribution calculation device from the learned corrected core power distribution and the core power distribution By comparing with the actual measured value, the sensitivity or the use of each fixed neutron detector is adjusted to match the calculated signal value of the fixed neutron detector. Power distribution monitoring system of a nuclear reactor, characterized in that to perform the calibration. 50. A plurality of fixed neutron detectors (LPRM detectors) for detecting a local power distribution in a power region in a nuclear reactor
And a nuclear instrumentation assembly in which a fixed gamma-ray heat detector of a gamma thermometer assembly is arranged at least in the vicinity of each of the above LPRM detectors, and then loaded into the reactor, and then a gamma thermometer signal processing device or nuclear instrumentation. The controller takes in multiple gamma thermometer signals that change every predetermined time, predicts and calculates the equilibrium signal level of the γ-ray heat detector after the lapse of the predetermined time, and reads the signal of the γ-ray heat detector at each new time , Reject the oldest data, update the gamma thermometer prediction calculation value by the least squares fitting, and send the updated gamma thermometer signal prediction calculation value to the furnace power distribution calculation device, while calculating the furnace power distribution. The apparatus uses the equilibrium gamma thermometer signal value on a regular or occasional basis to learn and correct its power distribution, and to adjust the LP of the nuclear instrumentation tube in the same reactor. The sensitivity or gain of the LPRM detector is calibrated using the balanced gamma thermometer signal at the same core axial position as the M detector, or calculated by the in-core power distribution calculation device from the learned corrected core power distribution. Comparing the calculated predicted signal value of the LPRM detector with the current actually measured value, and performing sensitivity or gain calibration of each LPRM detector so as to match the calculated predicted signal value of each LPRM detector. Characteristic method of monitoring power distribution of reactor.