Calibration method and device for nuclear reactor out-of-pile detector

Abstract

The embodiment of the invention provides a calibration method and device for an out-of-pile detector of a nuclear reactor, and belongs to the technical field of nuclear power. The method comprises the following steps: acquiring an upper current signal, a lower current signal and a first axial power offset detected by an out-of-pile detector of a nuclear reactor; determining an axial power offset calibration coefficient of the out-of-pile detector and a nuclear power calibration coefficient of the out-of-pile detector according to the upper current signal, the lower current signal and the first axial power offset; respectively correcting second axial power offset and nuclear power currently indicated by the out-of-pile detector through the axial power offset calibration coefficient and the nuclear power calibration coefficient to obtain target nuclear power; and obtaining the axial power deviation indicated by the out-of-pile detector through the target axial power deviation and the target nuclear power. According to the embodiment of the invention, the axial power deviation and the nuclear power are respectively corrected to obtain more accurate nuclear power and axial power deviation, so that the accuracy of the out-of-pile detector indication signal is improved.

Description

Technical Field

[0001] This application relates to the field of nuclear power technology, and in particular to a method and apparatus for calibrating an external detector of a nuclear reactor. Background Technology

[0002] External detectors in nuclear reactors play a crucial role in the safe operation of the reactor, as they are responsible for monitoring key parameters such as the power distribution of the reactor core and the position of control rods.

[0003] However, due to various factors such as detector probe drift, signal noise, detector sensitivity, and in-core control rod movement, there will be a certain deviation between the indicated values ​​of the external detectors and the actual values ​​in the reactor core. Excessive deviation can affect the safety of reactor core operation. Therefore, it is necessary to calibrate the external detectors to ensure that their indicated values ​​accurately reflect the reactor core operating parameters in real time. Summary of the Invention

[0004] The main objective of this application is to propose a calibration method and apparatus for an external detector of a nuclear reactor, which improves the accuracy of the external detector's indication value by correcting the core nuclear power and axial power deviations respectively.

[0005] To achieve the above objectives, a first aspect of this application proposes a calibration method for an external detector of a nuclear reactor, the method comprising:

[0006] The upper current signal, lower current signal, and first axial power offset detected by the external detector of the nuclear reactor are obtained. The upper current signal and the lower current signal are the current signals detected by the external detector during the simulated calibration experiment, and the first axial power offset is theoretically calculated during the simulated calibration experiment.

[0007] The axial power offset calibration coefficient of the external detector is determined based on the upper current signal, the lower current signal, and the first axial power offset.

[0008] Based on the upper current signal and the lower current signal, the nuclear power calibration coefficient of the external detector is determined;

[0009] The target axial power offset is obtained by correcting the second axial power offset currently indicated by the external detector using the axial power offset calibration coefficient.

[0010] The nuclear power currently indicated by the external detector is corrected using the nuclear power calibration coefficient to obtain the target nuclear power;

[0011] The axial power deviation indicated by the external detector is obtained by using the target axial power offset and the target nuclear power.

[0012] In some embodiments, the simulation of the xenon oscillation experiment comprises simulation of a xenon oscillation experiment;

[0013] The obtaining of the upper current signal, the lower current signal and the first axial power shift detected by the ex-core detector of the nuclear reactor comprises:

[0014] The control rod in the nuclear reactor is controlled to generate xenon oscillation, and a plurality of groups of the upper current signal, the lower current signal and the first axial power shift detected by the ex-core detector are obtained during the xenon oscillation.

[0015] In some embodiments, the determining of the axial power shift calibration coefficient of the ex-core detector according to the upper current signal, the lower current signal and the first axial power shift comprises:

[0016] The third axial power shift indicated by the ex-core detector is obtained through the upper current signal and the lower current signal, and the third axial shift is the axial power shift indicated by the ex-core detector under the calibration experiment;

[0017] The third axial power shift and the first axial power shift are functionally fitted to obtain the axial power shift calibration coefficient of the ex-core detector.

[0018] In some embodiments, the obtaining of the third axial power shift indicated by the ex-core detector through the upper current signal and the lower current signal comprises:

[0019] The upper current signal and the lower current signal are subtracted to obtain a first value;

[0020] The upper current signal and the lower current signal are added to obtain a second value;

[0021] The first value and the second value are divided to obtain the third axial power shift.

[0022] In some embodiments, the determining of the nuclear power calibration coefficient of the ex-core detector according to the upper current signal and the lower current signal comprises:

[0023] The function relationship between the upper current signal and the lower current signal is obtained by functionally fitting a plurality of groups of the upper current signal and the lower current signal detected by the ex-core detector obtained during the xenon oscillation;

[0024] The nuclear power calibration coefficient is determined based on the function relationship between the upper current signal and the lower current signal.

[0025] In some embodiments, the function fitting based on the multiple sets of the upper current signal and the lower current signal detected by the out-of-core detector during the xenon oscillation process obtains a functional relationship between the upper current signal and the lower current signal, including:

[0026] Mapping the multiple sets of current pairs on a two-dimensional coordinate axis to obtain multiple coordinate points, each of the current pairs including a set of the upper current signal and the lower current signal acquired during the xenon oscillation process;

[0027] Performing function fitting based on the multiple coordinate points to determine a target fitting straight line;

[0028] Taking a functional expression of the target fitting straight line as a functional relationship between the upper current signal and the lower current signal.

[0029] In some embodiments, the determination of the nuclear power calibration coefficient based on the functional relationship between the upper current signal and the lower current signal includes:

[0030] Multiplying the functional relationship between the upper current signal and the lower current signal by a nominal relative nuclear power of a reactor core on both sides of the equation to obtain a functional relationship between the nuclear power and the upper current and the lower current, the nominal relative nuclear power of the reactor core being a nuclear power in a flux map state;

[0031] Obtaining the nuclear power calibration coefficient based on the functional relationship between the nuclear power and the upper current signal and the lower current signal.

[0032] To achieve the above object, a second aspect of the embodiment of the present application proposes a calibration device for an out-of-core detector of a nuclear reactor, the device being applied to an electronic device, the electronic device including multiple computing threads, and the device including:

[0033] A data acquisition module, configured to acquire an upper current signal and a lower current signal detected by an out-of-core detector of a nuclear reactor and a first axial power offset, the upper current signal and the lower current signal being current signals detected by the out-of-core detector during a simulation calibration experiment, and the first axial power offset being theoretically calculated during the simulation calibration experiment;

[0034] A first determination module, configured to determine an axial power offset calibration coefficient of the out-of-core detector according to the upper current signal, the lower current signal, and the first axial power offset;

[0035] A first calculation module, configured to determine a nuclear power calibration coefficient of the out-of-core detector according to the upper current signal and the lower current signal;

[0036] a first correction module, configured to correct a second axial power offset indicated by the ex-core detector currently by the axial power offset correction coefficient, to obtain a target axial power offset;

[0037] a second correction module, configured to correct a nuclear power indicated by the ex-core detector currently by the nuclear power correction coefficient, to obtain a target nuclear power;

[0038] a second calculation module, configured to obtain an axial power deviation indicated by the ex-core detector by the target axial power offset and the target nuclear power.

[0039] In some embodiments, the simulation correction experiment includes a simulation xenon oscillation experiment.

[0040] The data acquisition module includes:

[0041] a simulation experiment submodule, configured to control a control rod in the nuclear reactor to cause the nuclear reactor to generate xenon oscillation, and acquire a plurality of groups of the upper current signal, the lower current signal and the first axial power offset detected by the ex-core detector during the xenon oscillation.

[0042] In some embodiments, the first determination module includes:

[0043] a first calculation submodule, configured to obtain a third axial power offset indicated by the ex-core detector by the upper current signal and the lower current signal, the third axial power offset being an axial power offset indicated by the ex-core detector in the correction experiment;

[0044] a second calculation submodule, configured to perform function fitting on the third axial power offset and the first axial power offset, to obtain the axial power offset correction coefficient of the ex-core detector.

[0045] To achieve the above object, a third aspect of embodiments of the present application provides an electronic device, which includes a memory and a processor, the memory stores a computer program, and the processor implements the correction method of the ex-core detector of the nuclear reactor when executing the computer program.

[0046] To achieve the above object, a fourth aspect of embodiments of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the correction method of the ex-core detector of the nuclear reactor.

[0047] The application provides a method and device for calibrating a nuclear reactor ex-core detector. The method comprises the following steps: obtaining an upper current signal, a lower current signal and a first axial power offset through a simulation calibration experiment; determining an axial power offset calibration coefficient according to the upper current signal, the lower current signal and the first axial power offset; and determining a nuclear power calibration coefficient according to the upper current signal and the lower current signal. The axial power offset and the nuclear power indicated by the ex-core detector are calibrated through the axial power offset calibration coefficient and the nuclear power calibration coefficient, so that the problem that the calibration accuracy is affected by the intercept in a linear relationship in the traditional method is avoided. The axial power offset and the nuclear power after calibration are calculated to obtain the axial power offset indicated by the ex-core detector with higher accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 FIG. 1 is a flowchart of a method for calibrating a nuclear reactor ex-core detector according to an embodiment of the application;

[0049] Figure 2 FIG. 2 is an implementation flowchart of the method for calibrating a nuclear reactor ex-core detector according to an embodiment of the application;

[0050] Figure 3 FIG. 3 is a schematic diagram of the relationship between the axial power offset measured in a nuclear reactor and the axial power offset indicated by an ex-core detector in a stable flux map and during xenon oscillation in an implementation manner according to an embodiment of the application;

[0051] Figure 4 FIG. 4 is a structural schematic diagram of a method and device for calibrating a nuclear reactor ex-core detector according to an embodiment of the application. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the application clearer, the application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and should not be used to limit the application.

[0053] It should be noted that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a manner different from the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification and claims and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application belongs. The terms used herein are only for the purpose of describing the embodiments of the application and are not intended to limit the application.

[0055] The out-of-core detector of the nuclear reactor plays a vital role in the safe operation of the reactor, which is responsible for monitoring the power distribution of the core, the position of the control rod and other key parameters.

[0056] However, due to the influence of factors such as probe drift, signal noise, detector sensitivity, and in-core control rod action, there will be a certain deviation between the indication value of the out-of-core detector and the actual value of the core. The deviation is too large to affect the safe operation of the core, so the out-of-core detector needs to be calibrated to ensure that its indication value can correctly reflect the core operating parameters in real time.

[0057] Based on this, the embodiment of the application provides a kind of nuclear reactor out-of-core detector's calibration method and device, by respectively to core nuclear power and axial power deviation is corrected, to improve the accuracy of the indication value of the out-of-core detector.

[0058] The calibration method and device of the nuclear reactor out-of-core detector provided by the embodiments of the present application are specifically described by the following embodiments. First, the calibration method of the nuclear reactor out-of-core detector in the embodiments of the present application is described.

[0059] Figure 1 The flowchart of the calibration method of the nuclear reactor out-of-core detector provided by the embodiments of the present application is shown in Figure 1 The calibration method of the nuclear reactor out-of-core detector proposed by the embodiments of the present application can include but is not limited to steps S101 to S106.

[0060] Step S101, obtain the upper current signal, the lower current signal and the first axial power offset detected by the out-of-core detector of the nuclear reactor, the upper current signal and the lower current signal are the current signals detected by the out-of-core detector during the simulation calibration experiment, and the first axial power offset is theoretically calculated during the simulation calibration experiment.

[0061] In this step, the out-of-core detector refers to a device for monitoring the neutron flux in the nuclear reactor, which is usually installed outside the reactor core and uniformly distributed along the core axis.

[0062] The upper current signal refers to the current signal of the out-of-core detector located in the top region of the core, wherein the top region of the core can be divided according to the actual situation, which is not specifically limited here.

[0063] The lower current signal refers to the current value of the out-of-core detector located in the bottom region of the core, wherein the bottom region of the core can be divided according to the actual situation, which is not specifically limited here.

[0064] The first axial power offset refers to the axial power offset theoretically calculated during the simulation calibration experiment.

[0065] Specifically, in the simulation calibration experiment, different operating states of the nuclear reactor are simulated, so that the upper current signal and the lower current signal corresponding to the different operating states are detected by the ex-core detector. Meanwhile, according to the physical model and operating parameters of the nuclear reactor, the first axial power shift in the simulation experiment state is theoretically calculated.

[0066] In step S102, an axial power shift calibration coefficient of the ex-core detector is determined according to the upper current signal, the lower current signal and the first axial power shift.

[0067] In this step, the axial power shift indicated by the ex-core detector can be obtained through the upper current signal and the lower current signal corresponding to the upper current signal.

[0068] Specifically, the axial power shift obtained through the upper current signal and the lower current signal can be used as an indicative predicted value, the first axial power shift obtained through theoretical calculation can be used as a true value, and the function relationship between the indicative predicted value and the true value can be obtained through function fitting on the indicative predicted value and the true value of the axial power shift, so as to obtain the axial power shift calibration coefficient of the ex-core detector.

[0069] In step S103, a nuclear power calibration coefficient of the ex-core detector is determined according to the upper current signal and the lower current signal.

[0070] In this step, the function relationship between the upper current signal and the lower current signal is obtained through function fitting on the upper current signal and the lower current signal, the relationship between the nuclear power and the upper current signal and the lower current signal is obtained through formula derivation on the function relationship between the upper current signal and the lower current signal by introducing the nuclear power variable, so as to obtain the nuclear power calibration coefficient of the ex-core detector.

[0071] In step S104, a target axial power shift is obtained by correcting a second axial power shift currently indicated by the ex-core detector through the axial power shift calibration coefficient.

[0072] In this step, in the actual operation process of the nuclear reactor, the ex-core detector can indicate the current second axial power shift in real time. Due to various factors, the indicated value may be deviated.

[0073] The axial power shift calibration coefficient obtained through step 102 is used to correct the second axial power shift, so as to obtain a more accurate target axial power shift, which provides a reliable basis for the operation adjustment of the nuclear reactor.

[0074] Step S105, correcting the nuclear power currently indicated by the ex-core detector by the nuclear power calibration coefficient to obtain a target nuclear power.

[0075] In this step, the nuclear power calibration coefficient determined in step 103 is used to correct the nuclear power indicated by the ex-core detector in real time to obtain a more accurate target nuclear power, so as to ensure that the operator can accurately grasp the power state of the nuclear reactor.

[0076] Step S106, obtaining an axial power deviation indicated by the ex-core detector by the target axial power deviation and the target nuclear power.

[0077] In this step, the axial power deviation refers to a parameter for characterizing the abnormality degree of the axial distribution of the reactor core power, which can be calculated by the axial deviation of the reactor core and the nuclear power of the reactor core.

[0078] Specifically, the product of the corrected target axial power deviation and the target nuclear power is taken as the axial power deviation indicated by the ex-core detector.

[0079] Through the above steps S101 to S106, the upper current signal, the lower current signal and the first axial power deviation are obtained by the simulation calibration experiment; and the axial power deviation calibration coefficient is determined according to the upper current signal, the lower current signal and the first axial power deviation, and the nuclear power calibration coefficient is determined according to the upper current signal and the lower current signal, so as to correct the axial power deviation and the nuclear power indicated by the ex-core detector by the axial power deviation calibration coefficient and the nuclear power calibration coefficient respectively, to avoid the problem that the calibration accuracy is affected by the intercept in the linear relationship in the traditional method, and then the corrected axial power deviation and the nuclear power are calculated to obtain the axial power deviation indicated by the ex-core detector with higher accuracy.

[0080] In some embodiments, the simulation calibration experiment includes a simulation xenon oscillation experiment, and the obtaining of the upper current signal, the lower current signal and the first axial power deviation detected by the ex-core detector of the nuclear reactor in step S101 can include but is not limited to step S201.

[0081] Step S201, controlling the control rods in the nuclear reactor to generate xenon oscillation, and obtaining a plurality of sets of the upper current signal, the lower current signal and the first axial power deviation detected by the ex-core detector during the xenon oscillation.

[0082] In this implementation, the xenon oscillation is a periodic fluctuation phenomenon of the axial power distribution caused by the accumulation and decay characteristics of the fission product xenon-135 (1 35 Xe) in the operation of the nuclear reactor, which has a significant impact on the core power distribution.

[0083] The xenon oscillation process can be simulated by changing the neutron flux distribution in the core through the lifting and inserting operation of the control rod. In the process, the upper current signal and the lower current signal of the ex-core detector will present periodic fluctuations with the change of the power distribution, and the first axial power offset at different times is derived based on the theoretical derivation of the nuclear reactor physics calculation program, forming a plurality of sets of dynamic correlation data.

[0084] Specifically, the plurality of upper current signals obtained in the xenon oscillation process can be represented by I U1 , I U1 ,..., I Un , where n is the total number of upper current signals obtained in the xenon oscillation process, and n is a positive integer greater than 1.

[0085] The plurality of lower current signals obtained in the xenon oscillation process can be represented by I L1 , I L1 ,..., I Ln , where n is the total number of lower currents obtained in the xenon oscillation process, and n is a positive integer greater than 1.

[0086] The plurality of first axial power offsets obtained in the xenon oscillation process can be represented by AO1, AO2,..., AO n , where n is the total number of axial power offsets obtained in the xenon oscillation process, and n is a positive integer greater than 1.

[0087] In the embodiment, by obtaining a plurality of sets of upper current signals, lower current signals and theoretically calculated first axial power offsets in the xenon oscillation process, more actual operation scene-based data is provided for subsequent accurate calculation of the calibration coefficient.

[0088] In other embodiments, the simulation of the calibration experiment also includes a core steady-state flux map experiment. A set of upper current signals, lower current signals and first axial power offsets can also be obtained through the core steady-state flux map experiment.

[0089] Specifically, the core steady-state flux map experiment refers to an experiment of obtaining the spatial distribution map of the neutron flux density (or power density) inside the core through measurement means during the constant power operation (steady state) of the nuclear reactor; wherein the core parameters under the core steady-state flux map can be obtained through theoretical simulation, or can be obtained through field measurement.

[0090] The upper current signal obtained through the core steady-state flux map experiment can be represented by I U0 .

[0091] The lower current signal obtained through the core steady-state flux map experiment can be represented by I L0 .

[0092] The first axial power shift obtained through the core steady-state flux map experiment can be denoted as AO0.

[0093] In addition, the nominal relative nuclear power of the core can also be obtained through theoretical calculation in the core steady-state flux map experiment, wherein the nominal relative nuclear power of the core can be denoted as W0.

[0094] It should be noted that a set of upper current, lower current, axial power shift and core nuclear power can be obtained in each core steady-state flux map experiment, and a set of upper current, lower current and axial power shift can be obtained in each xenon oscillation experiment, so the number of obtained upper current, lower current and first axial power shift is equal.

[0095] In some embodiments, the determining of the axial power shift calibration coefficient of the ex-core detector according to the upper current signal, the lower current signal and the first axial power shift in step S102 can include but is not limited to steps S301 to S302.

[0096] In step S301, a third axial power shift indicated by the ex-core detector is obtained through the upper current signal and the lower current signal, and the third axial shift is the axial power shift indicated by the ex-core detector in the calibration experiment.

[0097] In step S302, the third axial power shift and the first axial power shift are functionally fitted to obtain the axial power shift calibration coefficient of the ex-core detector.

[0098] In the present implementation, the third axial power shift can be calculated by the following formula 1:

[0099]

[0100] In the formula, AO ′ represents the third axial power shift, I U represents the upper current, I L represents the lower current.

[0101] Specifically, a plurality of first axial power shifts AO0, AO1, AO2...AO n indicated by the ex-core detector are obtained in the flux map state and the xenon oscillation process. ′ 0, AO ′ 1, AO ′ 2...AO ′ nThe function fitting is performed to obtain a fitting relationship AO=F(AO'), that is, a relationship between the in-pile AO (axial power offset) and the out-of-pile AO' (axial power offset indicated by the out-of-pile detector) is obtained, and F(AO') can be used as an axial power offset calibration coefficient.

[0102] It should be noted that the change range of AO and AO' is (-100%, 100%), and in general, the function relationship of the in-pile and out-of-pile axial power offset is a linear relationship, that is, AO=a*AO'+b.

[0103] The third axial power offset indicated by the out-of-pile detector is obtained through the upper current signal and the lower current signal, including the following contents:

[0104] The upper current signal and the lower current signal are subjected to difference calculation to obtain a first value;

[0105] The upper current signal and the lower current signal are subjected to addition calculation to obtain a second value;

[0106] The first value and the second value are subjected to ratio calculation to obtain the third axial power offset.

[0107] Specifically, "I U -I L " is used as the first value, and "I U +I L " is used as the second value.

[0108] In the actual operation condition, when the in-pile AO changes, it is considered that the linear relationship AO=F(AO') still exists, and the out-of-pile axial power offset can be calculated according to the above formula 1, that is, AO' is calculated through the upper and lower current signals of the out-of-pile detector in the current condition, and AO' obtained in the current condition is corrected through the relationship AO=F(AO') to obtain AO (i.e., the corrected axial power offset).

[0109] In some embodiments, the determination of the nuclear power calibration coefficient of the out-of-pile detector according to the upper current signal and the lower current signal in step S103 can include but is not limited to steps S401 to S402.

[0110] Step S401: performing function fitting based on the plurality of groups of the upper current signal and the lower current signal detected by the out-of-pile detector obtained in the xenon oscillation process to obtain a function relationship of the upper current signal and the lower current signal.

[0111] Step S402: determining the nuclear power calibration coefficient based on the function relationship of the upper current signal and the lower current signal.

[0112] In this implementation, the upper and lower current signals detected by multiple sets of off-chip detectors during the xenon oscillation process are fitted using a function. Generally, there is a linear relationship between the upper and lower currents. The functional relationship between the upper and lower currents can be expressed by the following formula 2:

[0113] I U =H(I L )+M (2);

[0114] In the formula, I U Indicates the upper current, I L H represents the lower current, M represents the constant term after function fitting, and H(I) represents the lower current. L ) represents a function of the lower current, determined based on the function fitting results.

[0115] Furthermore, considering the core power, the core power can be substituted into Formula 2 above to obtain the relationship between the core power and the upper and lower currents, thereby obtaining the core power calibration coefficient.

[0116] Specifically, step S401, which involves performing function fitting on the upper and lower current signals detected by multiple sets of external detectors during the xenon oscillation process to obtain the functional relationship between the upper and lower current signals, may include, but is not limited to, steps S501 to S503.

[0117] Step S501: Map multiple sets of current pairs onto a two-dimensional coordinate axis to obtain multiple coordinate points. Each current pair includes an upper current signal and a lower current signal obtained during the xenon oscillation process.

[0118] Step S502: Perform function fitting based on the multiple coordinate points to determine the target fitted line;

[0119] Step S503: Use the functional expression of the target fitted straight line as the functional relationship between the upper current signal and the lower current signal.

[0120] In this implementation, each upper current and its corresponding lower current form a current pair. Multiple current pairs are mapped onto a two-dimensional coordinate axis to obtain multiple coordinate points. Linear regression analysis is performed based on multiple coordinate points, such as using the least squares method, to determine the optimal target fitting line. The functional expression of the target fitting line is used as the functional relationship between the upper current signal and the lower current signal.

[0121] The functional expression of the target fitted line can be represented by the following formula 3:

[0122] I U =c*IL + d (3) ;

[0123] wherein I U represents the upper current, I L represents the lower current, c represents the slope of the target fitting straight line, and d represents the intercept of the target fitting straight line.

[0124] The function expression of the target fitting straight line is taken as the functional relationship of the upper current signal and the lower current signal, and according to the formula 2 and the formula 3, H(I L ) = c * I L , and M = d.

[0125] Therefore, the functional relationship of the upper current signal and the lower current signal can also be written as the formula 3.

[0126] In some embodiments, the determining the nuclear power calibration coefficient based on the functional relationship of the upper current signal and the lower current signal in the step S402 can further include but is not limited to including the steps S601 to S602.

[0127] The step S601, multiplying the nominal relative nuclear power of the core on both sides of the equation of the functional relationship of the upper current signal and the lower current signal to obtain the functional relationship of the nuclear power and the upper current and the lower current, the nominal relative nuclear power of the core being the nuclear power in the flux map state;

[0128] The step S602, obtaining the nuclear power calibration coefficient based on the functional relationship of the nuclear power and the upper current signal and the lower current signal.

[0129] In the present implementation, the nominal relative nuclear power of the core can be substituted into the first expression to transform the first expression to determine the nuclear power calibration coefficient in consideration of the core nuclear power.

[0130] Specifically, W0 can be multiplied on both sides of the formula 2, and then the equation is transformed to obtain the following formula 4:

[0131] Formula 4:

[0132]

[0133] wherein W0 represents the nuclear power in the steady-state flux map of the core, M represents a constant term, I U represents the upper current, H(I L ) represents the function about the lower current.

[0134] According to the formula 4, the following formula 5 can be obtained:

[0135]

[0136] P represents the core nuclear power indicated by the ex-core detector in any state.

[0137] According to formula 5, the nuclear power calibration coefficient is

[0138] In other embodiments, the core axial power deviation indicated by the ex-core detector can be calculated by formula 6 as follows:

[0139] ΔI=P*AO (6);

[0140] In formula 6, ΔI represents the core axial power deviation indicated by the ex-core detector, P represents the corrected core nuclear power indicated by the ex-core detector (i.e., the target nuclear power), and AO represents the corrected axial power deviation indicated by the ex-core detector (i.e., the target axial power deviation).

[0141] In the present embodiment, for the calculation of the core axial power deviation indicated by the ex-core detector, the axial power deviation and the core nuclear power are calculated respectively, which avoids the problem that the existing calibration method is affected by the intercept in the linear relationship, so that a more accurate core axial power deviation is obtained.

[0142] The implementation process of the calibration method of the ex-core detector of the nuclear reactor provided in the present embodiment is described as follows, as shown in Figure 2 FIG. 1 is a flowchart of the calibration method of the ex-core detector of the nuclear reactor provided in the present embodiment. Figure 2 FIG. 1 is a flowchart of the calibration method of the ex-core detector of the nuclear reactor provided in the present embodiment.

[0143] Step 1: Obtain the core steady flux map and the parameters in the xenon oscillation process, including the core nuclear power W, the core axial power deviation AO, the upper current signal I U of the ex-core detector, and the lower current signal I L of the ex-core detector.

[0144] Step 2: Obtain the core axial deviation calibration coefficient according to the relationship between the core axial power deviation AO in the xenon oscillation process and the core axial power deviation AO' indicated by the detector, and obtain the nuclear power calibration coefficient according to the relationship between the upper current signal I U and the lower current signal I L of the ex-core detector in the xenon oscillation process.

[0145] Step 3: Based on the core axial deviation calibration coefficient and the nuclear power calibration coefficient, correct the core axial power deviation and the core nuclear power indicated by the ex-core detector at the current moment to obtain the corrected core axial power deviation indicated by the ex-core detector and the corrected core nuclear power.

[0146] Specifically, this application proposes a method for separately calibrating the external detector indicator (AO) and the indicator nuclear power. For the calibration method of the external detector indicator (AO), multiple core states (AO0, AO1, AO2...AO) are obtained by simulating flux map states and theoretical xenon oscillation experiments. n and external detector indication AO ′ 0, AO ′ 1. AO ′ 2...AO ′ n The linear relationship AO' = a*AO + b is determined by function fitting of multiple sets of core AO and external detector indication AO', and the fitting linear coefficients a and b are obtained. In actual operation, when the in-core AO changes, it is assumed that the linear relationship AO = F(AO') still exists. The axial power offset outside the core can be calculated according to the above formula 1, that is, AO' is calculated from the current signals of the upper and lower parts of the external detector under the current operating condition, and then the AO' obtained under the current operating condition is corrected by the relationship AO = F(AO') to obtain AO (i.e., the corrected axial power offset).

[0147] The correction of the axial power offset (ΔI) indicator signal is determined by the nominal relative power W0 under the current operating condition and the calibrated external AO (i.e., calculated using Equation 6 above). The calibration of the external detector's indicated nuclear power is obtained by simulating the theoretical flux diagram and the xenon oscillation test process, yielding the upper current I of the external detector under multiple core conditions. U0 I U1 I U1 ....I Un With the lower current I L0 I L1 I L1 ....I Ln For the upper current I of multiple sets of external detectors U and lower current I L Perform function fitting to obtain I. U and I L A linear relationship exists as shown in Formula 3 above. Considering the current nominal relative power W0 of the reactor core, multiplying both sides of this relationship (Formula 3) by W0 transforms it into Formula 4 above. Then, the indicated nuclear power P of the external detector can be calculated using Formula 5 above. In actual operating conditions, once the current fitting coefficients c and d of the upper and lower parts of the external detector are determined, the calibrated indicated nuclear power can be calculated using Formula 5 above.

[0148] The above embodiments are illustrated below through experimental verification:

[0149] For a certain pressurized water reactor, the relationship between the core AO and the external AO' during the steady-state flux diagram and xenon oscillation is as follows:Figure 3 As shown, after function fitting, the slope a of the fitting straight line is 0.8763, and the intercept b is 20.205, which is far from 0.

[0150] The results of the core nuclear power indicated by the ex-core detector and the ΔI verification after the ex-core detector is calibrated using the existing calibration method (for example, the xenon oscillation method or the one-point method) under the full power working condition (the nominal core nuclear power is 100% FP, and the in-core AO is 64.18%) are shown in Table 1, and the results show that there is a significant deviation in the indicated power after calibration, indicating that the calibration method is no longer applicable.

[0151] Table 1

[0152] Parameter Value Indicated power (%FP) 111.8648 Power deviation -11.8648 Indicated ΔI -64.18 ΔI deviation 0

[0153] The results of the core nuclear power indicated by the ex-core detector and the ΔI verification after the ex-core detector is calibrated using the calibration method of the ex-core detector of the nuclear reactor provided in the embodiments of the present application are shown in Table 2.

[0154] Table 2

[0155] Parameter Value Indicated power (%FP) 99.9949 Power deviation 0.0051 Indicated ΔI -64.15 ΔI deviation -0.03

[0156] Therefore, using the calibration method of the ex-core detector of the nuclear reactor provided in the embodiments of the present application can effectively solve the problem that the existing calibration method is not applicable, and greatly improves the accuracy of the indicated signal of the ex-core detector.

[0157] Please refer to Figure 4 is a structural schematic diagram of a calibration device for an ex-core detector of a nuclear reactor provided in the embodiments of the present application, and the second aspect of the embodiments of the present application provides a calibration device 800 for an ex-core detector of a nuclear reactor. The device 800 is applied to an electronic device, the electronic device includes a plurality of computing threads, and the calibration device 800 for the ex-core detector of the nuclear reactor includes:

[0158] A data acquisition module 801 is configured to acquire an upper current signal, a lower current signal, and a first axial power offset detected by an ex-core detector of a nuclear reactor. The upper current signal and the lower current signal are current signals detected by the ex-core detector during a simulation calibration experiment, and the first axial power offset is theoretically calculated during the simulation calibration experiment.

[0159] A first determination module 802 is configured to determine an axial power offset calibration coefficient of the ex-core detector according to the upper current signal, the lower current signal, and the first axial power offset.

[0160] A first calculation module 803 is configured to determine a nuclear power calibration coefficient of the ex-core detector according to the upper current signal and the lower current signal.

[0161] The first correction module 804 is configured to correct the second axial power offset indicated by the ex-core detector by using the axial power offset correction coefficient, to obtain a target axial power offset.

[0162] The second correction module 805 is configured to correct the nuclear power indicated by the ex-core detector by using the nuclear power correction coefficient, to obtain a target nuclear power.

[0163] The second calculation module 806 is configured to obtain an axial power deviation indicated by the ex-core detector by using the target axial power offset and the target nuclear power.

[0164] In some embodiments, the simulation correction experiment includes a simulation xenon oscillation experiment.

[0165] The data acquisition module 801 includes:

[0166] The simulation experiment submodule is configured to control the control rods in the nuclear reactor to generate xenon oscillation, and to acquire a plurality of groups of the upper current signal, the lower current signal, and the first axial power offset detected by the ex-core detector during the xenon oscillation.

[0167] In some embodiments, the first determination module 802 includes:

[0168] The first calculation submodule is configured to obtain a third axial power offset indicated by the ex-core detector by using the upper current signal and the lower current signal, the third axial power offset being an axial power offset indicated by the ex-core detector during the correction experiment.

[0169] The second calculation submodule is configured to perform function fitting on the third axial power offset and the first axial power offset, to obtain the axial power offset correction coefficient of the ex-core detector.

[0170] In some embodiments, the first calculation submodule includes:

[0171] The first calculation unit is configured to perform difference calculation on the upper current signal and the lower current signal, to obtain a first value.

[0172] The second calculation unit is configured to perform addition calculation on the upper current signal and the lower current signal, to obtain a second value.

[0173] The third calculation unit is configured to perform ratio calculation on the first value and the second value, to obtain the third axial power offset.

[0174] In some embodiments, the first determination module 802 includes:

[0175] The first fitting sub-module is configured to perform function fitting based on the groups of the upper current signal and the lower current signal detected by the out-of-core detector during the xenon oscillation to obtain a function relationship between the upper current signal and the lower current signal.

[0176] The first determining sub-module is configured to determine the nuclear power calibration coefficient based on the function relationship between the upper current signal and the lower current signal.

[0177] In some embodiments, the first fitting sub-module comprises:

[0178] The coordinate mapping unit is configured to map the groups of current pairs on a two-dimensional coordinate axis to obtain a plurality of coordinate points, each of the current pairs comprising a group of the upper current signal and the lower current signal acquired during the xenon oscillation.

[0179] The first fitting unit is configured to perform function fitting based on the plurality of coordinate points to determine a target fitting straight line.

[0180] The first determining unit is configured to take a function expression of the target fitting straight line as a function relationship between the upper current signal and the lower current signal.

[0181] In some embodiments, the first determining sub-module comprises:

[0182] The formula derivation unit is configured to multiply the function relationship between the upper current signal and the lower current signal by a nominal relative nuclear power of a reactor core on both sides of an equation to obtain a function relationship between the nuclear power and the upper current and the lower current, the nominal relative nuclear power of the reactor core being a nuclear power in a flux map state.

[0183] The second determining unit is configured to obtain the nuclear power calibration coefficient based on the function relationship between the nuclear power and the upper current signal and the lower current signal.

[0184] The specific embodiments of the calibration method and device 800 of the out-of-core detector of the nuclear reactor are basically the same as the specific embodiments of the calibration method of the out-of-core detector of the nuclear reactor, and thus will not be described herein again.

[0185] The method and device for calibrating a nuclear reactor ex-core probe provided by the embodiments of the present application obtain an upper current signal, a lower current signal and a first axial power offset through a simulation calibration experiment; determine an axial power offset calibration coefficient according to the upper current signal, the lower current signal and the first axial power offset, and determine a nuclear power calibration coefficient according to the upper current signal and the lower current signal, so as to correct the axial power offset and the nuclear power indicated by the ex-core probe through the axial power offset calibration coefficient and the nuclear power calibration coefficient, to avoid the problem that the calibration accuracy is affected by the intercept in the linear relationship in the traditional method, and then calculate through the corrected axial power offset and the nuclear power, to obtain the axial power offset indicated by the ex-core probe with higher accuracy.

[0186] The embodiments described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that, with the evolution of technology and the appearance of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0187] Those skilled in the art can understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and can include more or fewer steps than shown in the figures, or combine certain steps or different steps.

[0188] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, that is, can be located in one place or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0189] Those skilled in the art can understand that all or some of the steps in the above disclosed method, the function modules / units in the system and the device can be implemented as software, firmware, hardware and their appropriate combinations.

[0190] The terms "first", "second", "third", "fourth" and the like (if any) in the specification of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0191] It should be understood that, in the application, "at least one" means one or more, "multiple" means two or more. "And / or" is used to describe the relationship between the associated objects, which means that there can be three relationships, for example, "A and / or B" can represent three cases: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0192] In several embodiments provided in the application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the above units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0193] The units described above as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0194] In addition, the functional units in each embodiment of the application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0195] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes multiple instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program storage media.

[0196] The preferred embodiments of the embodiments of the present application are described above with reference to the accompanying drawings, and are not limited to the scope of the embodiments of the present application. Any modifications, equivalent replacements and improvements made by those skilled in the art without departing from the scope and essence of the embodiments of the present application shall be within the scope of the embodiments of the present application.

Claims

1. A calibration method for an external detector of a nuclear reactor, characterized in that, The method includes: The upper current signal, lower current signal, and first axial power offset detected by the external detector of the nuclear reactor are obtained. The upper current signal and the lower current signal are the current signals detected by the external detector during the simulated calibration experiment, and the first axial power offset is theoretically calculated during the simulated calibration experiment. The axial power offset calibration coefficient of the external detector is determined based on the upper current signal, the lower current signal, and the first axial power offset. Based on the upper current signal and the lower current signal, the nuclear power calibration coefficient of the external detector is determined; The target axial power offset is obtained by correcting the second axial power offset currently indicated by the external detector using the axial power offset calibration coefficient. The nuclear power currently indicated by the external detector is corrected using the nuclear power calibration coefficient to obtain the target nuclear power; The axial power deviation indicated by the external detector is obtained by using the target axial power offset and the target nuclear power.

2. The method according to claim 1, characterized in that, The simulated calibration experiment includes a simulated xenon oscillation experiment; The acquisition of the upper current signal, lower current signal, and first axial power offset detected by the external detectors of the nuclear reactor includes: The control rods inside the nuclear reactor are controlled to generate xenon oscillations in the nuclear reactor, and during the xenon oscillation process, the upper current signal, the lower current signal, and the first axial power offset detected by multiple sets of external detectors are acquired.

3. The method according to claim 1, characterized in that, The step of determining the axial power offset calibration coefficient of the external detector based on the upper current signal, the lower current signal, and the first axial power offset includes: The third axial power offset indicated by the external detector is obtained through the upper current signal and the lower current signal. The third axial offset is the axial power offset indicated by the external detector under the calibration experiment. The axial power offset calibration coefficient of the external detector is obtained by fitting the third axial power offset and the first axial power offset to a function.

4. The method according to claim 3, characterized in that, The process of obtaining the third axial power offset indicated by the external detector through the upper current signal and the lower current signal includes: The difference between the upper current signal and the lower current signal is calculated to obtain a first value; The upper current signal and the lower current signal are added together to obtain the second value; The third axial power offset is obtained by calculating the ratio of the first value and the second value.

5. The method according to claim 2, characterized in that, The step of determining the nuclear power calibration coefficient of the external detector based on the upper current signal and the lower current signal includes: Based on the upper current signal and the lower current signal detected by the multiple sets of the external detectors obtained during the xenon oscillation process, a function fitting is performed to obtain the functional relationship between the upper current signal and the lower current signal; Based on the functional relationship between the upper current signal and the lower current signal, the nuclear power calibration coefficient is determined.

6. The method according to claim 5, characterized in that, The step of performing function fitting on the upper and lower current signals detected by multiple sets of external detectors during the xenon oscillation process to obtain the functional relationship between the upper and lower current signals includes: Multiple sets of current pairs are mapped onto a two-dimensional coordinate axis to obtain multiple coordinate points. Each current pair includes an upper current signal and a lower current signal obtained during the xenon oscillation process. Based on the multiple coordinate points, a function is fitted to determine the target fitted line; The functional expression of the target fitted straight line is used as the functional relationship between the upper current signal and the lower current signal.

7. The method according to claim 5, characterized in that, The determination of the nuclear power calibration coefficient based on the functional relationship between the upper current signal and the lower current signal includes: Multiply both sides of the equation relating the upper current signal and the lower current signal by the nominal relative nuclear power of the reactor core to obtain the functional relationship between the nuclear power and the upper and lower currents. The nominal relative nuclear power of the reactor core is the nuclear power under the flux diagram state. Based on the functional relationship between the nuclear power and the upper and lower current signals, the nuclear power calibration coefficient is obtained.

8. A calibration device for an external detector of a nuclear reactor, characterized in that, The device is applied to an electronic device, the electronic device including multiple computing threads, and the device includes: The data acquisition module is used to acquire the upper current signal, lower current signal, and first axial power offset detected by the external detector of the nuclear reactor. The upper current signal and the lower current signal are the current signals detected by the external detector during the simulated calibration experiment, and the first axial power offset is theoretically calculated during the simulated calibration experiment. The first determining module is used to determine the axial power offset calibration coefficient of the external detector based on the upper current signal, the lower current signal and the first axial power offset. The first calculation module is used to determine the nuclear power calibration coefficient of the external detector based on the upper current signal and the lower current signal. The first correction module is used to correct the second axial power offset currently indicated by the off-pile detector using the axial power offset calibration coefficient, so as to obtain the target axial power offset; The second correction module is used to correct the nuclear power currently indicated by the external detector using the nuclear power calibration coefficient to obtain the target nuclear power; The second calculation module is used to obtain the axial power deviation indicated by the external detector through the target axial power offset and the target nuclear power.

9. The apparatus according to claim 8, characterized in that, The simulated calibration experiment includes a simulated xenon oscillation experiment; The data acquisition module includes: The simulation experiment submodule is used to control the control rods inside the nuclear reactor to make the nuclear reactor generate xenon oscillations, and to acquire the upper current signal, the lower current signal, and the first axial power offset detected by multiple sets of external detectors during the xenon oscillation process.

10. The apparatus according to claim 8, characterized in that, The first determining module includes: The first calculation submodule is used to obtain the third axial power offset indicated by the external detector through the upper current signal and the lower current signal. The third axial offset is the axial power offset indicated by the external detector under the calibration experiment. The second calculation submodule is used to perform function fitting on the third axial power offset and the first axial power offset to obtain the axial power offset calibration coefficient of the off-pile detector.

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