JP3825447B2 - How to create data for calibration of internal and external nuclear instrumentation - Google Patents

Description

  The present invention relates to the creation of in-core / outer nuclear instrumentation calibration data.

  In order to monitor and control the operation status of the reactor, a nuclear instrument (neutron detector) is placed outside the reactor and the output of the reactor is measured. It is necessary to calibrate the reactor so that the power distribution in the axial direction of the core and the value of the axial offset (AO) indicated by the nuclear instrumentation located outside the reactor indicate an accurate value at the time of start-up or operation of the reactor. . This calibration requires that the axial power distribution in the reactor be oscillated appropriately and that data on the power distribution in the reactor and the power values of nuclear instrumentation outside the reactor be obtained at several points.

  In order to measure such data, since disturbance is intentionally given to the axial power distribution of the reactor, it is preferable to avoid it as much as possible from the viewpoint of economics and safety of the operation of the reactor. In order to solve such a problem, Patent Document 1 obtains the product of the response matrix of the reactor core instrumentation calculated in advance by analysis and each of the plurality of axial power distributions of the target core obtained by analysis separately, From this result, there is disclosed a technique for obtaining predetermined calibration data by calculating the response of the upper and lower half detectors and obtaining the correlation between the response and each axial offset of the axial output distribution. .

Japanese Patent No. 1745150

  By the way, the technique disclosed in Patent Document 1 can evaluate the relationship between the inside and outside of the reactor and generate the AO value without causing a decrease in the output of the reactor or xenon oscillation. There is room to improve accuracy. Therefore, the present invention has been made in view of the above, and is a method for creating data for in-core / in-core nuclear instrumentation calibration that can improve the accuracy of the in-core / outside calibration formula, and for creating data for in-core / outside nuclear instrumentation calibration. It is an object of the present invention to provide a computer program, a method for determining in-core / internal nuclear instrumentation calibration time, a computer program for determining in-core / internal core instrumentation calibration time, and a system for creating data for in-core / outside nuclear instrumentation calibration.

  In order to achieve the above-described object, the method for creating data for calibration of the inner and outer cores of the reactor according to the present invention takes into account the temperature dependence and the procedure for obtaining the neutron flux distribution by analyzing the state of the reactor core. A procedure for determining an out-of-core detector response coefficient corresponding to the temperature distribution in the reactor determined based on an actual measurement value from a plurality of out-of-core detector response coefficients determined in advance, and the determined out-of-core detector response coefficient And the product of the neutron flux distribution of the core obtained by analysis, and calculating the response of the out-of-core detector based on the result, and the axial direction of the core corresponding to the response and the neutron flux distribution And a procedure for obtaining a correlation with the axial offset at.

  In this method of creating data for calibration of in-core and nuclear core, the response of the out-of-core detector is obtained for the core characteristics at the time of calibration, and the correlation between this response and the axial offset for the core characteristics at the time of calibration is obtained. . Thereby, the precision of the furnace internal / external calibration type can be greatly improved. Moreover, since the neutron flux distribution is used directly rather than indirect information such as the power distribution, the accuracy of the calibration equation inside and outside the reactor can be greatly improved. Furthermore, since the optimum out-of-core detector response coefficient is selected in consideration of temperature dependence, the accuracy of the in-furnace / outside calibration formula can be greatly improved. Here, “based on the actually measured value” includes not only directly measuring the temperature but also converting a parameter relating to the actually measured temperature distribution or converting the actually measured reactor power into the temperature distribution in the reactor ( The same applies below).

  The method for creating data for calibration of the inner and outer cores according to the present invention includes a procedure for analyzing the state of the core of the reactor to obtain a neutron flux distribution, and a plurality of radial directions obtained in advance in consideration of temperature dependence. Out-of-core detector response coefficient and axial out-of-core detector response coefficient The product of the procedure for determining the detector response coefficient, the out-of-core detector response coefficient in the radial direction, and the three-dimensional neutron flux distribution of the core obtained by analysis is obtained, and the three-dimensional neutron flux distribution is defined as 1 Conversion into a three-dimensional neutron flux distribution, a product of the axial out-of-core detector response coefficient and the one-dimensional neutron flux distribution is obtained, and a response of the out-of-core detector is calculated based on the result, The axial direction of the core corresponding to the three-dimensional neutron flux distribution Characterized in that it comprises a step of obtaining a correlation between the axial offset definitive, a.

  In this method of creating data for calibration of in-core and nuclear core, the response of the out-of-core detector is obtained for the core characteristics at the time of calibration, and the correlation between this response and the axial offset for the core characteristics at the time of calibration is obtained. . Thereby, the precision of the furnace internal / external calibration type can be greatly improved. Moreover, since the neutron flux distribution is used directly rather than indirect information such as the power distribution, the accuracy of the calibration equation inside and outside the reactor can be greatly improved. Furthermore, since the optimum out-of-core detector response coefficient is selected in consideration of temperature dependence, the accuracy of the in-furnace / outside calibration formula can be greatly improved. In addition, since the three-dimensional neutron flux distribution is used, the accuracy of the calibration equation inside and outside the furnace can be improved.

  The method for creating data for calibration of in-core / infrared core according to the present invention is the method for creating data for in-core / outside nuclear instrumentation calibration, wherein when calculating the response coefficient of the out-of-core detector, it is perpendicular to the axis of the core. In the cross section, the size of the unit section of the core is changed.

  This method for creating data for in-core / in-core nuclear instrumentation calibration has the same configuration as the method for creating data for in-core / outside nuclear instrumentation calibration, and therefore has the same operations and effects as the method for creating data for in-core / outside nuclear instrumentation calibration. Play. Furthermore, in this method for creating data for calibration of in-core / outside nuclear instrumentation, when obtaining the response coefficient of the out-of-core detector, the size of the unit section of the core is changed. Thereby, since the part with a large reactor outside detector response coefficient can be evaluated more finely, the accuracy of the in-furnace / outside calibration formula can be improved.

  The method for creating data for calibration of the inner and outer cores of the nuclear reactor according to the present invention is the method of creating data for calibration of the inner and outer cores of the reactor, wherein the unit classification is such that the outer periphery of the core is made finer than the interior of the core. Features.

  This method for creating data for in-core / in-core nuclear instrumentation calibration has the same configuration as the method for creating data for in-core / outside nuclear instrumentation calibration, and therefore has the same operations and effects as the method for creating data for in-core / outside nuclear instrumentation calibration. Play. Furthermore, in the method for creating the data for calibration of the inner and outer cores of the reactor, the unit division of the core makes the outer periphery of the core finer than the inside of the core. As a result, the outer peripheral portion of the core having a large reactor outside detector response coefficient can be evaluated in detail, so that the accuracy of the inside / outside calibration formula can be improved. In addition, since the response coefficient outside the reactor is small on the center side of the core, the calculation speed can be improved by making the unit division of the part larger than the outer peripheral part of the core.

  In the method for creating data for calibration of in-core / inner nuclear instrumentation according to the present invention, in the method for creating data for in-core / outer nuclear instrumentation calibration, in the procedure for obtaining the neutron flux distribution, measurement data of the reactor is used as an input condition. The core tracking analysis is performed, and the most accurate core state at present is analyzed.

  This method for creating data for in-core / in-core nuclear instrumentation calibration has the same configuration as the method for creating data for in-core / outside nuclear instrumentation calibration, and therefore has the same operations and effects as the method for creating data for in-core / outside nuclear instrumentation calibration. Play. Furthermore, this method for creating data for calibration of the inner and outer cores of nuclear reactors targets the most probable core state at the present time including the past combustion history when performing core tracking analysis. Thereby, since the most accurate evaluation can be performed, the accuracy of the calibration equation inside and outside the furnace can be improved.

  A computer program for creating data for calibration of in-core / inner core instrumentation according to the present invention is characterized by causing a computer to execute the method for creating data for in-core / outer core instrumentation calibration. As a result, the above-described method for creating data for calibration of the in-core / outside nuclear instrument can be realized using a computer.

  The method for determining the in-core nuclear instrumentation calibration time according to the present invention includes a procedure for predicting the axial offset in the reactor after the present time by executing a future core combustion prediction analysis for the core at the present time, and after the present time. A procedure for predicting an out-of-furnace axial offset, and a step for obtaining a difference between the out-of-core axial offset and the in-furnace axial offset and determining a calibration time inside and outside the reactor based on the difference. .

  In this method of determining the calibration timing of the inner and outer cores, a core model having core characteristics predicted in the future is created, and the difference between the in-core axial offset and the out-of-core axial offset with respect to this core model is obtained. Determine the appropriate calibration time inside and outside the furnace. As a result, the calibration work inside and outside the furnace can be performed with the minimum number of times required, so that the amount of calibration work inside and outside the furnace can be greatly reduced.

  The in-core / outer nuclear instrumentation calibration time determination method according to the present invention is a method for determining the in-core / outer nuclear instrumentation calibration time in the procedure for predicting the in-core axial offset in accordance with the following: It is characterized by analyzing and analyzing the most accurate core state at the present time.

  Since the method for determining the calibration time for in-core and outer core instrumentation has the same configuration as the method for determining the calibration time for in-core and outer core instrumentation, the same operation and effect as the method for creating data for in-core and outer core instrumentation calibration are achieved. Furthermore, this core / inside nuclear instrumentation calibration time determination method targets the most probable core state at the present time including the past combustion history when performing core tracking analysis. Thereby, since the most accurate evaluation can be performed, the in-core / in-core nuclear instrument calibration time can be determined more accurately.

  A computer program for generating data for calibration of in-core / inner core instrumentation according to the present invention is characterized by causing a computer to execute the in-core / outer core instrumentation calibration time determination method. As a result, the above-described in-core / in-core nuclear instrument calibration time determination method can be realized using a computer.

  The system for creating data for calibration of inner and outer cores according to the present invention includes a core analysis unit that analyzes the state of the core of the reactor and obtains the neutron flux distribution of the reactor, and considers the temperature dependence of the neutrons And an out-of-core detector response coefficient storage unit for storing a plurality of out-of-core detector response coefficients determined in advance, and an out-of-core detector response coefficient corresponding to the temperature distribution in the reactor determined based on actual measurement A product of the response coefficient determination unit, the out-of-core detector response coefficient determined by the response coefficient determination unit, and the neutron flux distribution determined by the core analysis unit is obtained, and the out-of-core detection is performed based on the result An out-of-core detector response calculation unit that calculates a response of the reactor and calculates a correlation between the response and an axial offset in the core axis direction corresponding to the neutron flux distribution.

  This internal / external nuclear instrumentation calibration data creation system obtains the response of the out-of-core detector for the core characteristics at the time of calibration, and obtains the correlation between this response and the axial offset for the core characteristics at the time of calibration. . Thereby, the precision of the furnace internal / external calibration type can be greatly improved. Moreover, since the neutron flux distribution is used directly rather than indirect information such as the power distribution, the accuracy of the calibration equation inside and outside the reactor can be greatly improved. Furthermore, since the optimum out-of-core detector response coefficient is selected in consideration of temperature dependence, the accuracy of the in-furnace / outside calibration formula can be greatly improved.

  The following data generation system for in-core / in-core nuclear instrumentation calibration data according to the present invention is the above-mentioned in-core / outside core instrumentation data creation system, wherein the plurality of in-core detectors stored in the in-core detector response coefficient storage unit The response coefficient is obtained by making the size of the unit section in the outer periphery of the core smaller than the size of the unit section in the core in a cross section perpendicular to the axis of the core.

  Since the internal and external nuclear instrumentation calibration data creation system has the same configuration as the internal and external nuclear instrumentation calibration data creation system, the same operation and effect as the internal and external nuclear instrumentation calibration data creation method can be obtained. Play. Furthermore, in the data generation system for in-core / outside nuclear instrumentation calibration, the unit division of the core makes the outer periphery of the core finer than the inside of the core. As a result, the outer peripheral portion of the core having a large reactor outside detector response coefficient can be evaluated in detail, so that the accuracy of the inside / outside calibration formula can be improved. In addition, since the response coefficient outside the reactor is small on the center side of the core, the calculation speed can be improved by making the unit division of the part larger than the outer peripheral part of the core.

  The internal and external nuclear instrumentation calibration data creation system according to the present invention is the internal and external nuclear instrumentation calibration data creation system, in which the core analysis unit performs core tracking analysis using reactor measurement data as an input condition. The most accurate core state at the present time is analyzed.

  Since the internal and external nuclear instrumentation calibration data creation system has the same configuration as the internal and external nuclear instrumentation calibration data creation system, the same operation and effect as the internal and external nuclear instrumentation calibration data creation method can be obtained. Play. Furthermore, the data generation system for in-core / outside nuclear instrumentation calibration targets the most accurate core state at the present time including the combustion history so far when performing core tracking analysis. Thereby, since the most accurate evaluation can be performed, the accuracy of the calibration equation inside and outside the furnace can be improved.

  As described above, the method for creating in-core / internal nuclear instrumentation calibration data, the computer program for creating in-core / internal core instrumentation calibration data, the in-core / outside nuclear instrumentation calibration time determining method, and the in-core / internal core instrumentation calibration time determination according to the present invention The accuracy of the in-core / outside calibration formula can be improved in the computer program for generating data and the system for creating data for in-core / outside nuclear instrumentation calibration.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the best mode for carrying out the invention. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  The method for creating data for calibration of in-core and nuclear core instrumentation according to the first embodiment, the computer program for creating data for calibration of in-and-core nuclear instrumentation, and the data creation system for in-and-core nuclear instrumentation calibration are intended for core characteristics at the time of calibration. It is characterized in that the response of the out-of-core detector is obtained and the correlation between this response and the axial offset for the core characteristics at the time of calibration is obtained.

  FIG. 1-1 is an explanatory diagram of a configuration of a data creation system for in-core / outer nuclear instrumentation calibration according to the first embodiment. As shown in FIG. 1A, the data generation system for in-core / core nuclear instrumentation calibration according to the first embodiment is configured by connecting a calibration data creation unit 10 and a core monitoring unit 20 via a communication network 30. ing. The calibration data creation unit 10 includes a processing unit 10p and a storage unit 10m, and the processing unit 10p and the storage unit 10m are connected via an input / output port (I / O) 19. The input / output port (I / O) 19 is connected to the communication line network 30. The processing unit 10p includes a core monitoring unit 20, a data server 31 connected to the communication line network 30, and other processing. The unit 32 or the terminal 33 is configured to exchange data with each other.

  With this configuration, the calibration data creation unit 10 and the core monitoring unit 20 can be connected online. This eliminates the need for complicated data exchange between the two, so that the calibration work efficiency is greatly improved and the time required for the calibration work can be greatly shortened.

  The processing unit 10p includes a response coefficient determination unit 11, a neutron flux conversion unit 12, an out-of-core detector response calculation unit 13, and a calibration unit 14. These execute the method for creating the data for calibration of the inner and outer cores according to the first embodiment. The processing unit 10p may realize the functions of the response coefficient determination unit 11, the neutron flux conversion unit 12, and the like with dedicated hardware. Further, a computer program for realizing the functions of the response coefficient determination unit 11, the neutron flux conversion unit 12 and the like included in the processing unit 10p is configured by the processing unit 10p including a memory and a CPU (Central Processing Unit). These functions may be realized by loading them into a memory and executing them. The computer program is a method for creating in-core / internal nuclear instrumentation calibration data according to the first embodiment in combination with a computer program already recorded in the response coefficient determination unit 11, the neutron flux conversion unit 12 and the like included in the processing unit 10p. The processing procedure may be realized.

  The core monitoring unit 20 includes a core analysis unit 21, a monitoring unit 22, and a processing unit 23. These are connected to an input / output port (I / O) 29. The input / output port (I / O) 29 is connected to the communication line network 30, and the core analysis unit 21, the monitoring unit 22, and the like are connected to the communication line network 30, the calibration data creation unit 10, the data Data is exchanged with the server 31, another processing unit 32, or the terminal 33. A plant computer 34 that monitors and processes measurement data such as the output of the reactor 1, the coolant temperature, and the flow rate is connected to the input / output port (I / O) 29 of the core monitoring unit 20. Thereby, the core monitoring unit 20 can exchange data with the plant computer 34.

  The plant computer 34 takes in the measurement data of the reactor 1 measured by the in-core thermocouple / in-core nuclear instrumentation 41 of the reactor 1, various measurement systems 41, 42, and the like. Information measured by these measurement systems is converted into electrical signals by various signal processing devices 44 configured by combining a noise filter, an A / D converter, and the like, and then taken into the plant computer 34. Since the core monitoring unit 20 is connected to the plant computer 34 via the input / output port (I / O) 29, the measurement data of the nuclear reactor 1 acquired by the plant computer 34 is acquired and used for core analysis. Can do.

  The core analysis unit 21 sequentially captures various measurement data of the nuclear reactor 1, and performs core tracking analysis of the state of the core of the nuclear reactor that changes with time. Then, analyze the most accurate core state at present including the past combustion history, analyze the core behavior for the core state, or analyze the future core combustion prediction for the core state. Or do. The monitoring unit 22 monitors the operating state of the nuclear reactor 1 and monitors abnormalities of the nuclear reactor 1 and the like. The processing unit 23 complements the functions of the core analysis unit 21 and the monitoring unit 22 and controls data exchange with the calibration data creation unit 10 and the data server 31 connected to the communication network 30.

  Similarly to the processing unit 10p of the calibration data creation unit 10, the core analysis unit 21, the monitoring unit 22, and the processing unit 23 may realize these functions using dedicated hardware. Moreover, it comprises a memory and a CPU, and realizes these functions by loading a computer program for realizing the functions of the core analysis unit 21, the monitoring unit 22, and the processing unit 23 into the memory and executing it. It may be.

  FIG. 1-2 is an explanatory diagram of another configuration of the data generation system for in-core / outside nuclear instrumentation calibration according to the first embodiment. In this reactor internal / external nuclear instrumentation calibration data creation system, the calibration data creation unit 10 and the core monitoring unit 20 are configured by a single piece of hardware, thereby realizing the functions of both. This hardware is a plant monitoring / calibration unit 10a, and includes a processing unit 10p of the calibration data creation unit 10 and a core monitoring unit 20. The processing unit 10p of the calibration data creation unit 10 and the core monitoring unit 20 are connected by an input / output port (I / O) 29 and configured to exchange data with each other. In this way, if the processing unit 10p and the core monitoring unit 20 of the calibration data creation unit 10 are configured with a single piece of hardware, the processing speed can be further improved because there is no need to go through the communication network 30 or the like. . The processing unit 10p and the core monitoring unit 20 of the calibration data creation unit 10 are configured by a memory and a CPU, and a computer program for realizing the functions of the processing unit 10p and the core monitoring unit 20 is loaded into the memory. These functions may be realized by execution.

  Around the reactor 1, a lower outside detector 2 and an upper outside detector 3 are arranged to detect neutrons emitted from the reactor 1. A signal processing device 43 configured by combining a noise filter, an A / D converter, and the like is connected to the lower out-of-core detector 2 and the upper out-of-core detector 3, and is converted into an electric signal by this, It is taken into the plant computer 34.

During the operation of the nuclear reactor 1, the AO (Axial Offset) of the nuclear reactor is grasped based on the detection information of the neutrons obtained by the lower external detector 2 and the upper external detector 3. Here, AO is defined by (P _T −P _B ) / (P _T + P _B ). Here, P _T is the upper half power of the reactor, and P _B is the lower half power of the reactor. The axial power distribution deviation ΔI in the nuclear reactor is expressed by ΔI = AO × P using an axial offset AO (P is a relative power). Using this axial power distribution deviation ΔI, the axial neutron flux distribution in the reactor is monitored. The outputs of the lower outside detector 2 and the upper outside detector 3 taken into the plant computer 34 are used by the monitoring unit 22 of the core monitoring unit 20. In addition, the data is taken into the response coefficient determination unit 11 and the calibration unit 14 of the calibration data creation unit 10 through the communication line network 30 and is held during calibration inside and outside the furnace.

  The storage unit 10m includes a data server 31 and a core monitoring unit in addition to a computer program including a processing procedure of a method for creating data for calibration of in-core and nuclear cores according to the first embodiment, an out-of-core detector response coefficient database 18 described later. Various data acquired from 20 etc. is stored. Here, the storage unit 10m can be configured by a volatile memory such as a RAM (Random Access Memory), a nonvolatile memory such as a flash memory, or a combination thereof.

  Next, a method for creating the data for calibration of the inner and outer reactor cores according to the first embodiment will be described. FIG. 2 is a flowchart illustrating a processing procedure of a method for creating data for calibration of in-core / outside nuclear instrumentation according to the first embodiment. First, the core analysis unit 21 performs core tracking analysis using measurement data related to the operation of the reactor 1 as an input condition, thereby analyzing the core behavior of the most accurate core state including the combustion history so far. (Step S101). This core behavior analysis may be configured so that the core analysis unit 21 automatically executes periodically. Thus, by using the most probable core state as the target of core behavior analysis, the accuracy of the calibration equation inside and outside the reactor can be greatly improved. When creating data for calibration inside and outside the core, first, the monitoring unit 22 included in the core monitoring unit 20 determines the reactor power, the core inlet temperature, and the core outlet temperature distribution at the time of creating the data for calibration inside and outside the core. Ask. And the bypass water flow temperature T1 of the bypass water flow part 102 and the cooling water flow temperature T2 of the cooling water flow part 104 are evaluated from the information regarding this temperature (step S102). Here, the reactor power, the reactor core inlet temperature, and the reactor core outlet temperature distribution are based on the measured reactor output, reactor core inlet temperature, reactor core outlet temperature held in the monitoring unit 22, or neutrons from the reactor output and the reactor core. Distribution etc. may be measured and the core analysis part 21 may obtain | require by analysis based on this.

  At the same time, the core analysis unit 21 of the core monitoring unit 20 performs a simulated core analysis that gives a disturbance to the core, changes the core power distribution, and obtains multiple points (N points) of data regarding the three-dimensional neutron flux distribution and the AO in the reactor. obtain. Here, the three-dimensional neutron flux distribution is represented by φj (x, y, z) [j = 1, 2,... N], and the in-core AO is AOj [j = 1, 2,. N]. Here, the accuracy of the reactor internal / external calibration formula can be greatly improved by directly using the three-dimensional neutron flux distribution instead of the indirect information of the power distribution of the reactor.

  The out-of-core detector response coefficient in the radial direction and the out-of-core detector response coefficient in the axial direction are obtained in advance by analyzing the multi-group neutron transport calculation, and are stored in the storage unit 10m as the out-of-core detector response coefficient database 18. ing. Thus, the storage unit 10m functions as an out-of-core detector response coefficient storage unit. Here, the radial direction is the diameter (axis x or y) direction of the nuclear reactor 1, and the axial direction is the axial (z) direction of the nuclear reactor 1. Next, a procedure for obtaining the out-of-core detector response coefficient will be described. FIG. 3 is a cross-sectional view showing a cross section perpendicular to the axis of the nuclear reactor. FIG. 4 is a cross-sectional view showing the relationship between the nuclear reactor and the detector. FIG. 5 is a side view showing the relationship between the nuclear reactor and the detector. In the method for creating data for calibration of in-core / in-core nuclear instrumentation according to the first embodiment, an out-of-core detector response coefficient used for determining the relationship between the neutron flux and the detector current is obtained.

  Here, the out-of-core detector current at the z-axis position Z of the nuclear reactor 1 is I (z), and the detector region is from 1 (lower end) to Z (upper end). The z axis of the nuclear reactor 1 is an axis parallel to the longitudinal direction of the hollow pressure vessel, and is an axis parallel to the fuel assembly inserted into the nuclear reactor. The three-dimensional neutron flux distribution is φ (x, y, z), and the core region is from 1 to X, Y, Z. The current value of the lower lower outside detector 2 is Ibot = ΣI (i) (i = Zb1 to Zb2), and the current value of the upper outside detector 3 is Itop = ΣI (i) (i = Zt1 to Zt2). And Here, Zb1 is the lower end of the lower outside detector 2, Zb2 is the upper end of the lower outside detector 2, Zt1 is the lower end of the upper outside detector 3, and Zt2 is the upper end of the upper outside detector 3. . As shown in FIG. 3, the neutron flux emitted from the core 100 is detected by the lower or upper reactor detectors 2 and 3 provided outside the pressure vessel 105 of the reactor 1 and measured as a current value. .

  A procedure for obtaining the out-of-core detector response coefficient in the cross section perpendicular to the z-axis, that is, the radial out-of-core detector response coefficient RadR (x, y, T) will be described. When obtaining the radial out-of-core detector response coefficient RadR (x, y, T), it is two-dimensional, the temperature dependence on the radial direction of the neutron flux, and the unit of the fuel assembly in the nuclear reactor Consider classification. The radial out-of-core detector response coefficient RadR (x, y, T) in the radial cross section shown in FIG. 4 is the area of the lower or upper out-of-core detector 2, 3 from the area of the core 100 in the radial cross section. Is the ratio of the relative neutron flux to reach The radial out-of-core detector response coefficient RadR (x, y, T) can be obtained by analyzing the neutron multigroup transport calculation in the radial cross section shown in FIG.

  As a result of diligent research, the present inventors have determined that the bypass water flow of the bypass water flow portion 102 and the cooling water flow of the cooling water flow portion 104 are outside the furnace, as a result of intensive studies in determining the radial out-of-core detector response coefficient RadR (x, y, T). It was found that the influence on the detector response coefficient is large. Accordingly, in determining the radial out-of-core detector response coefficient RadR (x, y, T), the bypass water flow in the bypass water flow section 102 and the cooling water flow in the cooling water flow section 104 that have a great influence on the out-of-core detector response coefficient. Analyzes the temperature of the part parametrically. Then, a multidimensional radial out-of-core detector response coefficient RadR (x, y, T) is obtained in consideration of the temperature dependence of the neutron flux. Here, the temperature dependency is represented by T = {T1, T2} and is given as the temperature T. That is, it is represented by a matrix of the bypass portion water flow temperature T1 and the cooling water flow temperature T2.

  The unit section of the core region is preferably handled as follows. In other words, the out-of-core detector response coefficient is large at the outer periphery of the core 100 where the distance to the lower or upper in-core detectors 2 and 3 is small. The present inventors found this as a result of earnest research. From this knowledge, as shown in FIGS. 3 and 4, the unit section is made smaller in the outer peripheral portion of the core 100. Thereby, the accuracy of the furnace internal / external calibration formula can be improved. Moreover, since the response coefficient outside the reactor is small on the center side of the core 100, the calculation speed can be improved by making the unit section of the part larger than the outer peripheral part of the core 100.

FIG. 6A is a cross-sectional view of the fuel assembly. FIGS. 6-2 and 6-3 are explanatory views showing unit sections of the fuel assembly. As shown in FIG. 6A, the fuel assembly 5 is configured by inserting a plurality of fuel rods 6 and thimbles 7 without the fuel rods 6 into a lattice-like cell. In this example, 25 thimbles are inserted into a 17 × 17 cell. A plurality of fuel assemblies 5 are collected to constitute the core 100. The unit division of the fuel assembly 5a arranged on the outer peripheral portion of the core 100 is divided by the unit of the fuel rod 6, for example, as shown in FIG. In this case, the coordinates of each section are (x _i , y _i ) to (x _{i + 17} , y _{i + 17} ). On the other hand, the unit division of the fuel assembly 5b arranged inside the core 100 is, for example, as shown in FIG. In this case, the coordinates of each section are (x _i , y _i ) to (x _{i + 1} , y _{i + 1} ). Thus, the unit division of the outer peripheral part of the core 100 is made smaller than the inside.

  The radial out-of-core detector response coefficient RadR (x, y, T) is obtained under the conditions of all (x, y) coordinates and a plurality of temperatures T. A plurality of different out-of-core detector response coefficients RadR (x, y, T) in different radial directions constitute the out-of-core detector response coefficient database 18 and are stored in the storage unit 10m of the calibration data creation unit 10. The The out-of-core detector response coefficient RadR (x, y, T) in the radial direction may be obtained by, for example, the response coefficient determination unit 11 included in the calibration data creation unit 10 or connected to the communication network 30. The other processing unit 32 may obtain and store it in the storage unit 10m of the calibration data creation unit 10.

  Next, an out-of-core detector response coefficient in a cross section parallel to the z-axis, that is, an out-of-core detector response coefficient | AxR (T) | In this case, temperature dependence is taken into consideration. The axial out-of-core detector response coefficient | AxR (T) | is a relative value that reaches from the core 100 region to the lower or upper out-of-core detectors 2 and 3 in a cross section parallel to the axial z direction. It is the ratio of neutron flux. The axial out-of-core detector response coefficient | AxR (T) | can be obtained by analyzing the neutron multigroup transport calculation in a cross section parallel to the axis z direction shown in FIG.

  At this time, for the water flow in the bypass water flow portion 102 and the cooling water flow in the cooling water flow portion 104 that have a great influence on the response coefficient of the out-of-core detector, the temperature of the portion is analyzed parametrically, and a multidimensional axis having temperature dependence is analyzed. The out-of-core detector response coefficient | AxR (T) | The temperature dependency is represented by T = {T1, T2}. That is, it is represented by a matrix of the bypass water flow temperature T1 in the bypass water flow portion 102 and the cooling water flow temperature T2.

  The axial out-of-core detector response coefficient | AxR (T) | is obtained under a plurality of conditions of temperature T, and the plurality of out-of-core detector response coefficients | AxR (T) | The coefficient database 18 is configured. Here, the out-of-core detector response coefficient | AxR (T) {Z, Z} | is represented by the lower or upper portion of the axial region of the core 100 from 1 (lower end) to Z as shown in the equation (1). If the axial region of the out-of-furnace detectors 2 and 3 is from 1 (lower end) to Z (upper end), a Z × Z matrix is obtained.

  The response coefficient determination unit 11 of the calibration data creation unit 10 acquires the bypass water flow temperature T1 and the cooling water flow temperature T2 obtained by the monitoring unit 22 via the communication line network 30. Then, the response coefficient determination unit 11 calculates the bypass water flow temperature and the cooling water flow from the temperature T obtained from the out-of-core detector response coefficient stored in the storage unit 10m and the acquired bypass water flow temperature T1 and the cooling water flow temperature T2. A radial out-of-core detector response coefficient and an axial out-of-core detector response coefficient in consideration of the temperature are determined (step S103). This method will be described.

FIG. 7 is an explanatory diagram showing a method for determining the out-of-core detector response coefficient. The out-of-core detector response coefficient database 18 stores tables 17 _k , 17 _{k + 1,} etc., each of which combines a plurality of radial and axial out-of-core detector response coefficients obtained under a plurality of temperature conditions T _k. ing. The radial and axial out-of-core detector response coefficients stored in one table 17 _k are obtained under the same temperature condition T _k . Temperature dependence is evaluated by the bypass water flow temperature Tm1 and the cooling water flow temperature Tm2. The temperature dependency is obtained from a matrix of the bypass water flow temperature Tm1 and the cooling water flow temperature Tm2, and is given as temperature information Tm. The response coefficient determination unit 11 selects a combination of the radial out-of-core detector response coefficient and the axial out-of-core detector response coefficient having the temperature dependency information (Tm).

At this time, if there is no match with the temperature dependency information (Tm), to select the table 17 _k, 17 _{k + 1} satisfies the relationship _{T k <Tm <T k +} 1. Then, according to the ratio of the magnitudes of T _k , T _{k + 1,} and Tm, interpolation is performed between the radial and axial out-of-core detector response coefficients described in the tables 17 _k and 17 _{k + 1.} Ask. By such a method, the out-of-core detector response coefficient RadR (x, y, Tm) and the out-of-core detector response coefficient | AxR (Tm) {Z, Z} | are determined.

  When the radial out-of-core detector response coefficient and the axial out-of-core detector response coefficient are determined (step S103), the neutron flux conversion unit 12 of the calibration data creation unit 10 determines the diameter determined by the response coefficient determination unit 11. The out-of-core detector response coefficient RadR (x, y, Tm) is obtained, and the three-dimensional neutron flux distribution φ obtained by the core analysis unit 21 using this is weighted in consideration of the out-of-core detector response. Conversion into a dimensional neutron flux distribution (step S104). This is according to the following procedure.

  The three-dimensional neutron flux distribution is converted into a weighted one-dimensional neutron flux distribution φw (z) in consideration of the out-of-core detector response, using the radial out-of-core detector response coefficient RadR (x, y, Tm). (See equation (2)). At this time, since the out-of-core detector response coefficient RadR (x, y, Tm) in the radial direction is determined by the response coefficient determination unit 11 with reference to the temperature information Tm evaluated by the core analysis unit 21, Temperature dependence is taken into account.

  Next, the out-of-core detector response calculation unit 13 determines the one-dimensional neutron flux distribution φw (z) and the out-of-core detector response coefficient | AxR (Tm) {Z , Z} | is used to obtain the out-of-core detector response R (zz) (step S105).

  The core analysis unit 21 obtains neutron flux distributions in various z-axis directions, and an axial reactor response matrix is applied to the z-axis neutron flux distributions. As a result, the out-of-core detector response R (zz) of the detector region Det (zz) at the z-axis direction position zz can be expressed by Expression (3). The out-of-core detector response R (zz) is a relative value.

  By the above procedure, the out-of-core detector response R (zz) in a certain core power distribution is obtained. Since the internal / external calibration equation cannot be obtained with only one point, all the data relating to the three-dimensional neutron flux distribution and AO in the reactor core power distribution obtained by the core analysis unit 21 of the core monitoring unit 20, or all of them. The out-of-core detector response R (zz) is obtained for a plurality of points. Thereafter, the calibration unit 14 obtains a normalization constant C using the out-of-core detector response and the out-of-core detector measurement current value, and multiplies the relative response equation by the normalization constant to obtain the measurement current value and the in-core AO. Is obtained, that is, a calibration equation inside and outside the furnace is obtained (step S106). This procedure will be described.

  From the equation (3), the detector response of the upper or lower in-core detectors 2 and 3, that is, the relative detector response value Rc is Rcbot = ΣR (i) [i = Zb1 to Zb2], Rctop = ΣR (i) [I = Zt1 to Zt2]. FIG. 8 is an explanatory diagram showing the relationship between the relative detector response and the in-furnace AO. Here, the in-core AO on the horizontal axis in FIG. 8 is the in-core AO obtained by the core analysis unit 21 of the core monitoring unit 20 performing a simulated core analysis that gives disturbance to the core. The relative detector response value Rc is a value obtained based on the three-dimensional neutron flux distribution obtained by the core analysis unit 21 corresponding to the in-core AO.

  FIG. 9A is an explanatory diagram illustrating the principle relationship between the number of incident neutrons, the detector response, and the detector current value. FIG. 9-2 is an explanatory diagram illustrating a relationship between a detector response and a detector current value. As shown in FIG. 9A, the relative detector response value Rc of the lower or upper reactor detectors 2 and 3 and the measured current value Im of the lower or upper reactor detectors 2 and 3 It is proportional to the number of neutrons incident on the outer detectors 2 and 3. Therefore, as shown in FIG. 9B, the relative detector response value Rc of the lower or upper reactor detectors 2 and 3 is proportional to the measured current value Im of the lower or upper reactor detectors 2 and 3. However, the intercept of the current value may not become zero due to an effect other than the incident neutron.

  If the proportional constant (hereinafter referred to as a normalization constant) C = Im / Rc between the relative detector response value Rc of the lower or upper reactor detectors 2 and 3 and the measured current value Im is obtained, The relative detector response value Rc of the out-of-core detectors 2 and 3 can be converted into the detector current value I. FIG. 10 is an explanatory diagram showing the relationship between the detector current value and the in-furnace AO. The normalization constant C is obtained from the measurement result at one point. For example, as shown in FIG. 10, the measured current value Im of the lower or upper in-core detectors 2 and 3 is obtained at a certain point, and the in-furnace AOm corresponding to the measured current value Im is measured. In an actual reactor, the relationship between the inside of the reactor and the outside of the reactor is actually measured at the first start after the fuel change or during operation. From this actual measurement result, a measured current value Im and a corresponding measurement furnace AOm are obtained. Then, a relative detector response value Rc corresponding to the measurement furnace AOm is obtained, and a normalization constant C = Im / Rc is determined. Thereby, it can obtain | require by detector electric current value I = CxRc. However, if there is an effect other than incident neutrons, the normalization constant is determined in consideration of the influence.

  By the above procedure, the furnace internal / external calibration formulas Itop = a × AO + b and Ibot = c × AO + d can be obtained (a to d are constants, and I is a detector current value). By the way, as the nuclear reactor is activated and the operation proceeds, the relationship between the inside and outside of the reactor when the reactor is activated for the first time gradually shifts. In order to readjust this, it is necessary to periodically evaluate and adjust the relationship between the inside and outside of the reactor. In the first embodiment, the core analysis unit 21 calculates the three-dimensional neutron flux w (x, y, z) based on the most accurate core model currently created by the core analysis unit 21 by periodic core tracking calculation. Ask. Further, the bypass water flow temperature T1 and the cooling water flow temperature T2 are obtained based on the actually measured data. When evaluating and adjusting the relationship between the inside of the reactor and the outside of the reactor, the calibration data creation unit 10 obtains the information at that time and obtains the inside / outside calibration equation, thereby detecting the outside of the lower or upper reactor. Calibrate the AO of vessels 2 and 3. In this way, it is possible to trace and analyze the core that changes from time to time, and to obtain the calibration formula inside and outside the reactor based on the core information at the time of calibration. Can be made.

  As described above, in the first embodiment, the neutron flux distribution is calculated from the core state at the most accurate calibration time including the past combustion history by periodic core tracking analysis based on the measurement data of the reactor that changes from time to time. In addition to obtaining, an out-of-core detector response coefficient corresponding to the temperature distribution in the reactor obtained based on the actual measurement value is selected. Then, the product of the selected out-of-core detector response coefficient and the neutron flux distribution obtained by the analysis is obtained, and the response of the out-of-core detector is calculated based on this result, and the correlation between this response and the axial offset is calculated. Obtain the internal and external calibration formula. As described above, the temperature information in the reactor is actually measured and the optimum response coefficient outside the reactor is applied based on this information, so that the accuracy of the in-core / outside calibration equation can be greatly improved. Moreover, in Example 1, when calculating | requiring an external detector response coefficient, the magnitude | size of the unit division in a core outer peripheral part is made finer than the inside of a core. As a result, the outer peripheral portion of the core having a large reactor outside detector response coefficient can be evaluated in detail, so that the accuracy of the inside / outside calibration formula can be improved. In addition, since the response coefficient outside the reactor is small on the center side of the core, the calculation speed can be improved by making the unit division of the part larger than the outer peripheral part of the core.

  In addition, the core characteristics of the reactor that change from time to time are tracked and analyzed, and the neutron flux distribution is calculated based on this, and the response of the out-of-core detector is used to greatly improve the accuracy of the calibration data. be able to. Furthermore, in Example 1, since the three-dimensional out-of-core detector response coefficient is used, the accuracy of the calibration data can be greatly improved. In addition, since the three-dimensional neutron flux distribution is used instead of indirect information such as the power distribution in the reactor, the accuracy of the calibration data can be greatly improved. Further, in the first embodiment, the core analysis unit 21 included in the core monitoring unit 20 acquires and analyzes information on the core of the nuclear reactor that changes from moment to moment, so that it is based on the most accurate core information at the time of calibration. A neutron flux distribution and an out-of-core detector response coefficient can be obtained to obtain an in-and-out calibration formula. Thereby, the precision of the furnace internal / external calibration type can be greatly improved. The configuration of the first embodiment can be appropriately applied to the following embodiments. Moreover, if it has the structure similar to Example 1, there exists an effect | action similar to Example 1, and an effect.

  In the second embodiment, a core model having a core characteristic predicted at a future time point is created, and a difference between the in-core AO and the out-of-core AO with respect to the core model is obtained to determine an appropriate in-core / outside calibration time. There are features. The in-core AO is obtained by core analysis. The out-of-core AO is calculated from the in-core neutron flux distribution using the out-of-core detector response coefficient in the reactor radial direction and the out-of-core detector response coefficient in the reactor axial direction. Here, the in-furnace AO is an axial offset (AO) determined on the basis of the in-furnace output distribution, and the out-of-furnace AO is an axial offset (AO) obtained by an out-of-furnace detector.

In obtaining the in-core AO and the out-of-core AO, first, the core combustion prediction analysis is executed on the most probable core model at the present time. At a certain time t ₁ , the in-core power distribution is P1 (x, y, z) and the in-core neutron flux distribution is φ1 (x, y, z). The in-furnace AO is obtained using the in-furnace power distribution P1. At this time, in-furnace AO = (Pta−Pba) / (Pta + Pba). The in-furnace AO is calculated from the in-furnace power distribution P1. Here, Pta is the reactor upper half output, and Pba is the reactor lower half output. Pta is calculated by Pta = ΣΣΣP1 (x, y, z) {x: 1 to X; y: 1 to Y; z: Z / 2 to Z}, and Pba is calculated as Pba = ΣΣΣP1 (x, y, z) {x: 1 to X; y: 1 to Y; z: 1 to Z / 2}.

  The out-of-core AO is obtained from the in-core neutron flux distribution using the radial out-of-core detector response coefficient RadR (x, y, T) and the axial out-of-core detector response coefficient AxR (T). Can do. Out-of-furnace AO = (Ptb−Pbb) / (Ptb + Pbb). Here, Ptb is the reactor upper half output, and Pbb is the reactor lower half output. Ptb = ΣR (z) {z: Z / 2 to Z}, and Pbb = ΣR (z) {z: 1 to Z / 2}. The out-of-core detector response ΣR (z) is obtained by ΣR (z) = ΣAxR (T) × φw (i) {i: 1 to Z}. Then, φw (i) = ΣΣφ1 (x, y, z) × RadR (x, y, T) {x: 1 to X; y: 1 to Y}. In addition, for the calculation of the out-of-core detector response ΣR (z), the calculation procedure of the out-of-core detector response in the method for creating the in-core / outside nuclear instrumentation calibration data described in the first embodiment can be used.

By the above procedure, the in-furnace AO and the out-of-furnace AO at time t ₁ can be obtained, and ΔAO which is the difference between the two can be obtained. Then, by sequentially executing the above procedure at time t _{2 and} time t ₃ , the in-core AO, the out-of-core AO, and ΔAO that is the difference between them can be obtained at each time point. Next, the procedure of the method for creating the data for calibration of the inner and outer cores according to the second embodiment will be described. In addition, Example 2 is realizable with the preparation system (refer FIG. 1) of the data for a nuclear instrumentation calibration concerning Example 1 (refer FIG. 1). In the following description, please refer to FIG.

  FIG. 11 is a flowchart illustrating a processing procedure of a method for generating data for calibration of in-core / outside nuclear instrumentation according to the second embodiment. FIG. 12 is a flowchart illustrating a method for creating data for in-core / outside nuclear instrument calibration according to the second embodiment. First, the core analysis unit 21 of the core monitoring unit 20 uses a periodic core tracking calculation to target the most probable core model including the combustion history so far, based on the operation plan of the reactor after the current time, etc. Combustion analysis is executed (step S201). Based on this core model, the in-core AO after the present time is predicted (step S202).

  Next, the core analysis unit 21 predicts the out-of-core AO from the present time onward based on the reactor operation plan and the like from the present time based on the core model of the core combustion analysis (step S203). The out-of-furnace AO can be obtained by the method for creating data for calibration inside and outside the core according to the first embodiment.

Next, the core analysis unit 21 obtains a difference ΔAO between the predicted value of the in-core AO predicted based on the current core model and the predicted value of the out-of-core AO (step S204). Then, the core analysis unit 21 determines an optimum in-core / outside calibration time based on the ΔAO so as to minimize the number of inside / outside calibration operations (step S205). Dotted lines shown in FIG. 12, in the case where the furnace inner and outer calibration time point t _1, shows the difference between the predicted furnace AO and outside the furnace AO after the furnace and out calibration (ΔAO), the solid line the furnace and out calibration t ₁ The difference (ΔAO) between the in-furnace AO and the out-of-furnace AO estimated after the in-furnace / outside calibration in the case where the above is not performed is shown.

Explaining with the example shown in FIG. 12, by the time point t ₁ , there is a tendency for the out-of-furnace AO to expand relative to the in-furnace AO. Conventionally, fearing this expansion trend, it was necessary to calibrate the inside and outside of the furnace at time t ₁ , and then perform calibration inside and outside the furnace twice or three times (for example, at time t ₂ or t ₃ ). . However, if ΔAO can be predicted, it is possible to obtain a prediction that continues to be within the allowable range of ΔAO. If ΔAO shifts within the allowable range, the calibration inside and outside the furnace does not need to be performed at the time t1, and therefore zero calibration inside and outside the furnace is sufficient.

  As described above, in the second embodiment, a core model having a core characteristic predicted at a future time point is created, and a difference between the in-core AO and the out-of-core AO with respect to the core model is obtained, and an appropriate in-core / outside calibration time is determined. . As a result, the calibration work inside and outside the furnace can be performed with the minimum number of times required, so that the amount of calibration work inside and outside the furnace can be greatly reduced. As a result, the efficiency of the configuration work can be improved.

  The method for creating data for in-core / in-core nuclear instrument calibration according to the first and second embodiments can be realized by executing a program prepared in advance on a computer system such as a personal computer or a workstation. This program can be distributed via a network such as the Internet. The program can also be executed by being recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, and a DVD and being read from the recording medium by the computer. The “computer system” here includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a recording medium such as a floppy (registered trademark) disk, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a hard disk built in a computer system. Say. Furthermore, the “computer-readable recording medium” is a program that is dynamically programmed for a short time, such as a communication line when a program is transmitted through a network such as the Internet or a communication line network such as a telephone line. Such as a volatile memory inside a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time. Further, the program may be for realizing a part of the functions described above, and may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

  As described above, the method for creating in-core / internal nuclear instrumentation calibration data according to the present invention, the computer program for creating in-core / outside nuclear instrumentation calibration data, the in-core / outside nuclear instrumentation calibration time determining method, and the in-core / internal nuclear instrumentation calibration time determining A computer program and a data generation system for in-core / in-core nuclear instrumentation calibration are useful for calibrating an in-core detector of a nuclear reactor, and are particularly suitable for improving the accuracy of an in-core / outside calibration formula.

It is explanatory drawing which shows the structure of the preparation system of the data for a nuclear instrumentation calibration according to Example 1. FIG. It is explanatory drawing which shows the other structure of the preparation system of the data for a nuclear instrumentation calibration according to Example 1. FIG. 3 is a flowchart illustrating a processing procedure of a method for creating data for calibration of in-core / outside nuclear instrumentation according to the first embodiment. It is sectional drawing which shows the inside of a cross section perpendicular | vertical to the axis | shaft of a nuclear reactor. It is sectional drawing which shows the relationship between a nuclear reactor and a detector. It is a side view which shows the relationship between a nuclear reactor and a detector. It is sectional drawing of a fuel assembly. It is explanatory drawing which shows the unit division of a fuel assembly. It is explanatory drawing which shows the unit division of a fuel assembly. It is explanatory drawing which shows the method of determining an out-of-core detector response coefficient. It is explanatory drawing which shows the relationship between a relative detector response and in-furnace AO. It is explanatory drawing which shows the fundamental relationship between the number of incident neutrons, a detector response, and a detector electric current value. It is explanatory drawing which shows the relationship between a detector response and a detector electric current value. It is explanatory drawing which shows the relationship between a detector electric current value and in-furnace AO. 6 is a flowchart illustrating a processing procedure of a method for creating data for calibration of in-core and outer core instrumentation according to a second embodiment. 6 is a flowchart showing a method for creating data for calibration of in-core / outside nuclear instrumentation according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor 2 Lower outside detector 3 Upper outside detector 5, 5a, 5b Fuel assembly 6 Fuel rod 10 Calibration data preparation part 10m Storage part 10p Processing part 10a Plant monitoring / calibration part 11 Response coefficient determination part 12 Neutron flux converter 13 Out-of-core detector response calculation unit 14 Calibration unit 20 Core monitoring unit 21 Core analysis unit 22 Monitoring unit 23 Processing unit 30 Communication line network 100 Core 102 Bypass water flow unit 104 Cooling water flow unit 105 Pressure vessel

Claims (12)

Analyzing the state of the reactor core and obtaining the neutron flux distribution;
The outside of the reactor corresponding to the temperature distribution in the reactor determined based on the actual measurement values from the response coefficients obtained in advance by taking into account the temperature dependence evaluated by the bypass water flow temperature and the cooling water flow temperature. A procedure for determining the detector response coefficient;
The product of the determined out-of-core detector response coefficient and the neutron flux distribution of the core obtained by analysis is obtained, and the response of the out-of-core detector is calculated based on the result, and the response and the neutron flux A procedure for obtaining a correlation with an axial offset in the axial direction of the core corresponding to the distribution;
A method for creating data for calibration of in-core / outside nuclear instrumentation. Analyzing the state of the reactor core and obtaining the neutron flux distribution;
Based on measured values from multiple radial out-of-core detector response coefficients and axial out-of-core detector response coefficients determined in consideration of the temperature dependence evaluated by the bypass water flow temperature and the cooling water flow temperature. A procedure for determining a radial out-of-core detector response coefficient and an axial out-of-core detector response coefficient corresponding to the required temperature distribution in the reactor;
Obtaining the product of the radial out-of-core detector response coefficient and the three-dimensional neutron flux distribution of the core obtained by analysis, converting the three-dimensional neutron flux distribution into a one-dimensional neutron flux distribution, The product of the axial out-of-core detector response coefficient and the one-dimensional neutron flux distribution is obtained, and the response of the out-of-core detector is calculated based on the result, and the response and the three-dimensional neutron flux distribution A procedure for obtaining a correlation with an axial offset in the axial direction of the core;
A method for creating data for calibration of nuclear instrumentation inside and outside the reactor, comprising:   3. The in-core / outer nuclear instrumentation according to claim 1, wherein when the response coefficient of the out-of-core detector is obtained, the size of a unit section of the core is changed in a cross section perpendicular to the axis of the core. How to create calibration data.   The method for creating data for calibration of core / external core instrumentation according to claim 3, wherein the unit section is such that the outer periphery of the core is made finer than the inside of the core.   5. The method according to claim 1, wherein in the procedure for obtaining the neutron flux distribution, core tracking analysis is performed using reactor measurement data as an input condition, and the most accurate core state at the present time is analyzed. The method for creating the data for calibration of in-core and outer core instrumentation as described.   A computer program for creating data for calibration inside and outside the nuclear reactor, which causes a computer to execute the method for creating data for calibration inside and outside the nuclear reactor according to any one of claims 1 to 5. By performing future core combustion prediction analysis for the core at the present time, a procedure to predict the axial offset in the reactor after the current time,
A procedure for predicting the axial offset outside the reactor after the present time;
Obtaining a difference between the outside axial offset and the inside axial offset, and determining the inside / outside calibration timing based on the difference;
A method for determining the calibration timing of the inner and outer cores of the nuclear reactor.   The in-core / outer nuclear meter according to claim 7, wherein in the step of predicting the in-core axial offset, the core tracking analysis is performed using the measurement data of the reactor as an input condition, and the most accurate core state at the present time is analyzed. How to determine the calibration time.   A computer program for determining the in-core / in-core nuclear instrumentation calibration time for in-core / in-core nuclear instrument calibration, which causes a computer to execute the method for creating the in-core / outside nuclear instrumentation calibration data described in claim 7 or 8. Analyzing the state of the core of the reactor, and obtaining a neutron flux distribution of the reactor;
An out-of-core detector response coefficient storage unit for storing a plurality of out-of-core detector response coefficients determined in advance in consideration of the temperature dependence of neutrons evaluated by the bypass water flow temperature and the cooling water flow temperature ;
A response coefficient determination unit for determining an out-of-core detector response coefficient corresponding to the temperature distribution in the reactor determined based on the actual measurement;
Obtain the product of the out-of-core detector response coefficient determined by the response coefficient determination unit and the neutron flux distribution determined by the core analysis unit, and calculate the response of the out-of-core detector based on this result And an out-of-core detector response calculation unit for obtaining a correlation between the response and the axial offset in the core axis direction corresponding to the neutron flux distribution,
A system for creating data for calibration of nuclear instrumentation inside and outside the reactor.   The plurality of out-of-core detector response coefficients stored in the out-of-core detector response coefficient storage unit is the cross section perpendicular to the axis of the core, and the size of the unit section in the outer periphery of the core is determined inside the core. 11. The system for creating data for calibration of in-core / outside nuclear instrumentation according to claim 10, wherein the system is determined more finely than the size of the unit section.   The in-core nuclear instrumentation calibration data according to claim 10 or 11, wherein the core analysis unit performs core tracking analysis using measurement data of the reactor as an input condition, and analyzes the most accurate core state at the present time. Creation system.

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