JP2016080585A - Plant state analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant state analysis device that enables an estimation of a future plant state even when a lost of detection signal from a part of sensors in a nuclear plant makes it difficult to estimate an accident event, or makes it hard to simulate the accident event.SOLUTION: A plant state analysis device comprises: a plant simulator 4 that analyzes a future plant state of a nuclear plant on the basis of a detection signal of a plurality of sensors and an accident event estimated by an accident event estimation device 3; and an analysis result database 9 in which an analysis result of a pre-analyzed future plant state based on input information set corresponding to each of a plurality of predetermined accident events is stored. The analysis result to be output as the future plant state of the nuclear plant is changed over to any of the analysis result of the plant simulator 4 and the analysis result retrieved from the analysis result database 9.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plant state analysis apparatus that analyzes an operation state of a nuclear power plant.

  When an accident or abnormality occurs in a nuclear power plant, the operator estimates an accident event based on various sensor values and performs operation based on the operation procedure place at the time of the accident. However, when an accident occurs, a large number of warnings are issued and a large number of sensor values need to be checked, so the burden on the operator is very large, and the estimation of accident events occurring in the plant and the plant It is difficult to accurately grasp the state.

  For example, Patent Document 1 (Japanese Patent Application Laid-Open No. Hei 6-222191) discloses, as a technique related to grasping of a plant state and prediction of progress at the time of an accident of a nuclear power plant, real time that simulates the operation state of the plant at the present time. It includes at least a simulator, a prediction simulator that simulates the operation state of the plant in the future, and a diagnostic device that diagnoses an abnormal state based on collected actual plant data, and includes boundary conditions such as an abnormal state and manual operation In the plant state prediction device that sets the initial value, operates the real-time simulator and the prediction simulator, and informs the driver of plant operation support information, an abnormal state occurs in the actual plant, and the abnormal state is determined by the diagnostic device. After this, when there is a forecast re-operation request from the operator to the forecast simulator, The internal data of the prediction simulator during re driving request to reconfigure as the initial value of the predictive simulator, which operated again this prediction simulator is disclosed.

  In addition, as another technique relating to grasping the plant state and predicting the progress, for example, in Patent Document 2 (Japanese Patent Laid-Open No. 6-103481), diagnosis of an abnormality occurring in the plant is performed from plant data input from the actual plant. A plant abnormality diagnosis unit to be performed, an important process amount determination unit that is activated after abnormality diagnosis by the plant abnormality diagnosis unit, determines the process amount most affected by the cause of the abnormality, and the process amount to be monitored at the time of recovery operation; and the plant An operation amount determination unit that inputs operation guide information from the abnormality diagnosis unit and selects the quantitativeness of the operation guide, and a model selection that selects and determines the optimum physical model according to the abnormality occurring in the plant A determination unit, a boundary condition file storing boundary conditions given to the selected physical model, and the model selection A prediction simulation unit that predicts how the abnormality will progress when the selected operation is performed using the physical model selected by the fixed unit and the boundary condition from the boundary condition file In the plant operation monitoring system, a load request-related signal is input from the plant during normal operation when no abnormality has occurred in the plant to the prediction simulation unit, and the same model as the prediction model is input during the normal operation. That have the function of periodically calculating the initial value for the prediction model is disclosed.

JP-A-6-222191 JP-A-6-103481

  By the way, when accidents or abnormalities occur in the nuclear power plant or when they progress, it is considered that a part of the detection signal from the sensor arranged in the nuclear power plant is lost. In this case, a parameter necessary as a condition for analyzing the future plant state is lost. In the prior art described in Patent Documents 1 and 2, not only the estimation of the accident event but also the future plant state There is a problem that it becomes difficult to analyze and predict.

  The present invention has been made in view of the above, and even if detection signals from some sensors in a nuclear power plant are lost and it becomes difficult to estimate an accident event or simulation becomes difficult, An object of the present invention is to provide a plant state analyzing apparatus capable of predicting the plant state of the plant.

  To achieve the above object, the present invention provides an accident event estimation device for estimating an accident event of a nuclear power plant based on detection signals from a plurality of sensors arranged in the nuclear power plant, and detection signals from the plurality of sensors. And an accident event estimated by the accident event estimation device, a plant simulator for analyzing a future plant state of the nuclear power plant, and a plurality of accident events assumed in advance are set. The analysis result database storing the analysis result of the future plant state analyzed in advance based on the input information and the analysis result stored in the analysis result database are searched based on the detection signals from the plurality of sensors. Based on the analysis result search device and detection signals from the plurality of sensors, it is determined whether or not the state of the plurality of sensors is normal. A sensor state determination device to be determined, and an analysis result output as a future plant state of the nuclear power plant, either an analysis result of the plant simulator or an analysis result retrieved from the analysis result database by the analysis result retrieval device And an analysis result switching device for switching to.

  Even if detection signals from some sensors in the nuclear power plant are lost and it becomes difficult to estimate an accident event or simulation becomes difficult, the future plant state can be predicted.

1 is a diagram schematically showing an overall configuration of a plant state analysis system according to an embodiment of the present invention. It is a figure which shows an example of the detection signal of the sensor group obtained via a sensor signal input device in time series. It is a figure which shows an example of the estimation criteria of the accident event in an accident event estimation apparatus. It is a figure which shows the measured value of the main steam flow detected by the flow sensor of the main steam among the several sensors installed in the nuclear power plant as an example. It is a figure which shows an example of the analysis result output screen displayed by the analysis result output device. It is a flowchart which shows the plant state analysis process which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing an overall configuration of a plant state analysis system according to an embodiment of the present invention.

  In FIG. 1, the plant state analysis system diagnoses an accident event or the like occurring in a nuclear power plant, analyzes and estimates the progress of the subsequent plant state, and includes a plurality of sensors arranged in the nuclear power plant. A sensor signal input device 2 to which a detection signal (measured value) from the sensor group 1 is input, and an accident that estimates an accident event of a nuclear power plant based on a detection signal (measured value) obtained via the sensor signal input device 2 Based on the event estimation device 2, the detection signal (measured value) from the sensor group 1 obtained via the sensor signal input device 2, and the accident event estimated by the accident event estimation device, the future plant state of the nuclear power plant Based on the plant simulator 3 for analyzing the above and input information (initial values) set in advance corresponding to each of a plurality of accident events assumed in advance. Based on the analysis result database 9 in which the analysis result of the analyzed future plant state is stored and the detection signal (measured value) from the sensor group 1 obtained via the sensor signal input device 2, the analysis result database 9 Based on the analysis result search device 8 that searches the stored analysis results and the detection signal (measured value) from the sensor group 1 obtained via the sensor signal input device 2, the state of each sensor in the sensor group 1 is determined. An analysis result retrieved from the analysis result database by the analysis result of the plant simulator 4 and the analysis result search device 8 is output as the sensor state determination device 5 for determining whether or not it is normal and the analysis result output as the future plant state of the nuclear power plant. Based on the determination result from the analysis result switching device 6 and the analysis result switching device 6 that switches by determining which of the results to adopt. , The analysis result from the plant simulator 4, or, is schematically configured from the analysis result output device 7 for outputting one of the analysis result from the analysis result retrieval device 8 to the display device or the like.

  The sensor group 1 is composed of a plurality of sensors arranged in the nuclear power plant, and includes a plurality of types of sensors such as a temperature sensor, a pressure sensor, a water level sensor, a flow rate sensor, and a radiation sensor.

  The sensor signal input device 2 receives a detection signal (measured value) of each sensor of the sensor group 1 and inputs it to a computer such as a process computer.

  FIG. 2 is a diagram illustrating an example of detection signals of the sensor group acquired via the sensor signal input device in time series.

  As shown in FIG. 2, the time-series data 20 of the detection signals (measured values) of the sensors constituting the sensor group 1 is, for example, the measured value 22 (main steam flow rate A (%)) of the flow sensor or the temperature sensor. Measurement value 23 (container temperature A (° C.)), pressure sensor measurement value 24 (container pressure A (kPa)), radiation sensor measurement value 25 (container radiation dose (Gy / hr)), etc. Are acquired corresponding to time 21.

  The accident event estimation device 3 estimates an accident event that has occurred in the nuclear power plant based on the detection signals (measured values) of the sensors input via the sensor signal input device 2. For example, the accident event estimation device 3 preliminarily defines the relationship between the detection signal of each sensor of the sensor group 1 and the accident event, and estimates the accident event from the detection signal (measured value) of each sensor using the relationship. To do.

  FIG. 3 is a diagram illustrating an example of an accident event estimation criterion in the accident event estimation apparatus.

  As shown in FIG. 3, the accident event estimation reference 30 in the accident event estimation device is represented by the relationship between the accident event to be estimated and the detection signal of each sensor. In FIG. 3, as an example of the accident event 31, accident events such as main steam pipe breakage, loss of water supply, and scram are shown. The main steam flow rate 32, the containment vessel temperature 33, the containment vessel pressure 34, and the containment, respectively. An accident event is estimated based on detection signals (measured values) of each sensor such as the radiation dose 35 in the container. For example, the main steam flow rate 32 (the average value of the measured values of the plurality of sensors that detect the main steam flow rate) is reduced by 10% or more, and the containment vessel temperature 33 (the measured values of the plurality of sensors that detect the containment vessel temperature) The average value) is 60 ° C. or higher, the pressure in the containment vessel 34 (the average value of the measured values of the plurality of sensors for detecting the pressure in the containment vessel) is 100 kPa or more, and the radiation dose in the containment vessel 35 (radiation in the containment vessel) When the average value of the measured values of a plurality of sensors that detect the amount is 0.1 Gy / hr, it is estimated that the accident event is a main steam pipe breakage. For example, when each sensor detection signal (measured value) of the sensor group 1 as shown in FIG. 2 is obtained, the main steam pipe break condition is satisfied at time 00:20. Presumed that a fracture occurred.

  In FIG. 3, the items of measurement values of each sensor used to estimate an accident event are not applicable to all items (that is, only partially applicable to the items). Accident events may be estimated by setting the accuracy according to the ratio of items to be performed. For example, when only 3 items out of 4 measured values for estimating main steam pipe breakage as an accident event are estimated, it is estimated with an accuracy of 75% that a main steam pipe breakage has occurred as an accident event.

  The plant simulator 4 analyzes the future plant state based on the detection signal (measured value) of each sensor input via the sensor signal input device 2 and the accident event estimated by the accident event estimation device 3. . For example, the estimated accident event is analyzed using the reactor water level, main steam flow rate, main steam temperature, feed water flow rate, and feed water temperature at time 00:20 in FIG. 2 as initial values. For example, when a main steam pipe break is estimated as an accident event, an analysis is performed when the main steam pipe is broken. The analysis result (future plant state) obtained by the plant simulator 4 is represented by time series data in the same manner as the detection signal of the sensor shown in FIG.

  The sensor state determination device 5 determines whether or not the value of the detection signal of each sensor is valid based on the detection signal (measurement value) of each sensor input via the sensor signal input device 2. For example, a plurality of measured values (for example, main steam flow rates A to D in FIG. 4) detected by a plurality of main steam flow sensors installed in a nuclear power plant for the purpose of redundancy or the like are usually Changes with correlation. Therefore, the Euclidean distance between these sensors is calculated, and when the Euclidean distance is greater than or equal to a certain value, it is determined that there is an abnormality.

  FIG. 4 is a diagram illustrating, as an example, measured values of the main steam flow rate detected by the main steam flow rate sensor among a plurality of sensors installed in the nuclear power plant.

  In FIG. 4, the time series data 40 of the detection signals (measured values) of the plurality of flow sensors acquired by the sensor state determination device 5 are acquired for, for example, main steam flows A to D (main steam flows 42 to 45). Shows the case.

  For example, when the Euclidean distance 46 between the main steam flow rate D and the average value of the main steam flow rates A to C is 10 or more (see, for example, time 00:50), the sensor state determination device 5 performs the main steam flow rate. The determination result 47 of the sensor that detects D is determined to be abnormal. Note that the calculation of the Euclidean distance 46 is not limited to one type of redundant sensor. For example, the main steam flow rate measured by the flow rate sensor and the feed water flow rate measured by the feed water sensor can be used for sensors that change with correlation. A combination of detection signals (measured values) may be used.

  The analysis result database 9 stores the result of analyzing the future plant state for a plurality of accident states assumed in advance. The analysis of the accident event is performed based on input information (initial value) set in advance corresponding to each accident event by a simulator such as the plant simulator 4, for example. The analysis result stored in the analysis result database 6 is time-series data similar to the example of the detection signal of the sensor shown in FIG.

  The analysis result search device 8 stores the analysis result database 9 in the analysis result database 9 based on the detection signal (measured value) of the sensor input via the sensor signal input device 2 when the determination result by the sensor state determination device 5 is abnormal. Search the stored analysis results. For example, the analysis result search device 8 uses the input information (initial value) most similar to the detection signals (measurement values) from a plurality of sensors arranged in the nuclear power plant among the analysis results stored in the analysis result database 9. The analysis result obtained based on this is searched. As the determination of similarity, for example, the detection signal (measured value) of the sensor and the Euclidean distance of each analysis result are calculated, and the analysis result having the smallest Euclidean distance is used as the search result. In the search of the analysis result, the signal of the sensor determined to be abnormal is not used.

  Based on at least one of the accident event estimated by the accident event estimation device 3 and the determination result by the sensor state determination device 5, the analysis result switching device 6 outputs a plant result as an analysis result to be output as a future plant state of the nuclear power plant. Switching between the analysis result of the simulator 4 and the analysis result retrieved from the analysis result database 9 by the analysis result search device 8 is determined and the determination result is input to the analysis result output device 7.

  For example, when the sensor state determination device 5 determines that all the sensors are normal, the analysis result of the plant simulator 4 is adopted as the future plant state of the nuclear power plant and is input to the plant simulator 4 as an initial condition. When any of the sensor signals of the reactor water level, main steam flow rate, main steam temperature, feed water flow rate, and feed water temperature is lost, the analysis result retrieved from the analysis result database 6 by the analysis result retrieval device 8 is adopted. . In addition, when the sensor signal here is lost, in the example of the main steam flow rate, the sensor signal itself cannot be measured for any of the redundant main steam flow rates A to D, or Even if it can be measured, it means a case where the sensor state determination device 5 determines that there is an abnormality.

  As another example, when all the sensors are determined to be normal by the sensor state determination device 5, the analysis result of the plant simulator 4 is adopted as the future plant state of the nuclear power plant, and the accident event estimation is performed. When the accident event is not specified by the device 3 or when the accuracy of the estimated accident event is lower than a predetermined standard, the analysis result retrieved from the analysis result database 9 by the analysis result retrieval device 8 may be adopted. . That is, when the estimated accuracy of the accident event is less than a predetermined standard (for example, 80%), it is determined that a sufficiently accurate analysis cannot be expected by a simulation by the plant simulator 4, and the analysis result database 8 is analyzed by the analysis result search device 8. The analysis result retrieved from 9 is adopted.

  The analysis result switching device 6 displays the analysis result of the plant simulator 4 and the analysis result searched from the analysis result database 9 by the analysis result search device 8 as a candidate on a display or the like, and confirms or judges the operator etc. A function of switching by selecting an analysis result to be output as a future plant state of the plant and inputting the selection result to the analysis result output device 7 may be provided.

  The analysis result output device 7 displays the analysis result adopted by the analysis result switching device 6 among the analysis result of the plant simulator 4 and the analysis result searched from the analysis result database 9 by the analysis result search device 8 on a display or the like. .

  FIG. 5 is a diagram illustrating an example of an analysis result output screen displayed by the analysis result output device.

  In FIG. 5, the analysis result output screen 50 is provided with a display unit 51 for the current time, a display unit 52 for the estimated accident event, and a display unit 53 for the plant state. The example of FIG. 5 shows a case where the reactor water level is displayed as an example of the plant state when the main steam pipe breakage occurs as an accident event. In FIG. 5, until the current time 00:30, the measured value of the reactor water level by each sensor of the sensor group 1 arranged in the nuclear power plant is displayed, and the reactor water level at the time thereafter is related to the present invention. The value of the analysis result by the plant state analyzer (that is, the future plant state of the nuclear power plant) is shown.

  Here, the plant state analysis process in the plant state analysis apparatus according to the present embodiment will be described.

  FIG. 6 is a flowchart showing the plant state analysis processing of the present embodiment.

  In FIG. 6, when the plant state analysis process is executed, first, the plant state analysis apparatus receives a sensor signal (measured value) via the sensor signal input device 2 (step S60). Subsequently, the accident event estimation device 3 estimates an accident event based on the sensor signal (measured value) input via the sensor signal input device 2 (step S61), and the sensor state determination device 5 detects the sensor signal ( Whether or not the state of each sensor in the sensor group 1 is normal is determined based on the measured value) (step S62).

  Here, the analysis result switching device 6 confirms whether or not it is determined that the sensor signal has been lost in the determination result by the sensor state determination device 5 (step S63). If the determination result is NO, the accident event estimation is performed. It is determined whether or not the accuracy of the accident event estimated by the device 3 is smaller than a predetermined criterion (step S64). If the determination result in step S64 is NO, the analysis result switching device 6 determines to adopt the analysis result in the plant simulator 4 as the analysis result of the future plant state (step S65), and outputs the analysis result The device 7 outputs the analysis result in the plant simulator 4 as the future plant state of the nuclear power plant based on the determination result of the analysis result switching device 6 (step S66), and ends the process.

  If the determination result in step S63 is YES or if the determination result in step S64 is YES, the analysis result switching device 6 uses the analysis result search device 8 as an analysis result of the future plant state. It is determined that the analysis result searched from the analysis result database 9 is adopted (step S67), and the analysis result output device 7 is analyzed by the analysis result search device 8 based on the determination result of the analysis result switching device 6. Is output as the future plant state of the nuclear power plant (step S68), and the process is terminated.

  The procedure of steps S60 to S62 is performed every time a sensor signal is input (for example, every second), and the procedure of steps S63 to S68 is configured to be performed when an accident event or a sensor state changes. Also good.

  The effect in this Embodiment comprised as mentioned above is demonstrated.

  When accidents or abnormalities occur in a nuclear plant, or when they develop, some of the detection signals from sensors installed in the nuclear plant may be lost. Parameters necessary as conditions for analyzing plant conditions will be lost, and in the conventional technology, it is difficult not only to estimate accident events but also to analyze and predict future plant conditions. There was a point.

  In contrast, in the present embodiment, the accident event estimation device 3 that estimates the accident event of the nuclear power plant based on the detection signals from the plurality of sensors arranged in the nuclear power plant, and the detection signals from the plurality of sensors Based on the accident event estimated by the accident event estimation device 3, a plant simulator 4 for analyzing the future plant state of the nuclear power plant, and input information set in correspondence with each of a plurality of accident events assumed in advance. The analysis result database 9 storing the analysis result of the future plant state analyzed in advance based on the above, and the analysis result for searching the analysis result stored in the analysis result database 9 based on the detection signals from the plurality of sensors Based on the search device 8 and detection signals from the plurality of sensors, a sensor state for determining whether or not the states of the plurality of sensors are normal An analysis result that is output from the analysis result database 9 as an analysis result of the plant simulator 4 and an analysis result search device 8. Since it is determined which of the results is to be adopted and the analysis result output by the analysis result output device 7 is switched, detection signals from some sensors of the nuclear power plant are lost, making it difficult to estimate the accident event Even if it becomes or when simulation becomes difficult, the future plant state can be predicted.

  That is, when an analysis with sufficient accuracy can be expected by simulation by the plant simulator 4, the sensor signal (measured value) input via the sensor signal input device 2 may be reflected at the time when the accident event occurs. In addition, since the occurrence time and interval of the accident event can be reflected, it is possible to output the analysis result with higher accuracy than when the analysis result stored in the analysis result database 9 is used.

  In addition, when the simulation by the plant simulator 4 cannot be expected with sufficient accuracy, it is limited to the accident event assumed in advance, but even under severe accident conditions in which some sensor signals are lost. It is possible to output the most similar (most effective) analysis result using the sensor signal effective at the time.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Moreover, you may implement | achieve part or all of said each structure, function, etc., for example by designing with an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. For example, the accident event estimation device 3, the plant simulator 4, the sensor state determination device 5, the analysis result search device 8, and the analysis result switching device 6 may be implemented as a computer program. Further, the analysis result database 9 may be included in the computer.

1 Sensor group (multiple sensors)
2 Sensor signal input device 3 Accident event estimation device 4 Plant simulator 5 Sensor state determination device 6 Analysis result switching device 7 Analysis result output device 8 Analysis result search device 9 Analysis result database 50 Analysis result output screen

Claims (7)

An accident event estimation device that estimates an accident event of a nuclear plant based on detection signals from a plurality of sensors arranged in the nuclear plant;
A plant simulator for analyzing a future plant state of the nuclear power plant based on detection signals from the plurality of sensors and an accident event estimated by the accident event estimation device;
An analysis result database storing analysis results of future plant states analyzed in advance based on input information set corresponding to each of a plurality of accident events assumed in advance;
Based on detection signals from the plurality of sensors, an analysis result search device that searches for analysis results stored in the analysis result database;
A sensor state determination device for determining whether or not the state of the plurality of sensors is normal based on detection signals from the plurality of sensors;
An analysis result switching device for switching an analysis result to be output as a future plant state of the nuclear power plant to either an analysis result of the plant simulator or an analysis result searched from the analysis result database by the analysis result search device; A plant state analysis apparatus characterized by comprising. In the plant state analysis apparatus according to claim 1,
The analysis result switching device, based on at least one of the accident event estimated by the accident event estimation device and the determination result of the sensor state determination device, the analysis result to be output as the future plant state of the nuclear power plant, A plant state analysis apparatus that switches between an analysis result of the plant simulator and an analysis result retrieved from the analysis result database by the analysis result retrieval apparatus. In the plant state analysis apparatus according to claim 1,
The analysis result switching device is a candidate of an analysis result to be output as a future plant state of the nuclear power plant based on at least one of the accident event estimated by the accident event estimation device and the determination result of the sensor state determination device. And switching between the analysis result of the plant simulator and the analysis result retrieved from the analysis result database by the analysis result retrieval device based on the analysis result selected by the operator from the plurality of candidates A plant state analyzing apparatus characterized by that. In the plant state analysis apparatus according to claim 1,
The analysis result search device is an analysis result obtained based on the input information most similar to detection signals from the plurality of sensors arranged in the nuclear power plant among the analysis results stored in the analysis result database. A plant state analysis device characterized by searching for In the plant state analysis apparatus according to claim 1,
The plant state analysis apparatus, wherein the plurality of sensors include any of a temperature sensor, a pressure sensor, a water level sensor, a flow rate sensor, and a radiation sensor. In the plant state analysis apparatus according to claim 1,
The analysis result switching device is configured to switch to an analysis result searched from the analysis result database by the analysis result search device when the sensor state determination device determines that the detection signals of the plurality of sensors are abnormal. A plant state analysis device. In the plant state analysis apparatus according to claim 1,
The analysis result switching device switches to an analysis result retrieved from the analysis result database by the analysis result retrieval device when it is difficult to estimate an accident event in the accident event estimation device. Analysis device.

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