Efficient testing method for neutron pulse type detector and matched instrument device

Abstract

The invention discloses an efficient test method for a neutron pulse type detector and a matched instrument device, and relates to the field of reactor nuclear measurement. According to the technical scheme, the method is characterized in that through an unattended efficient test process, establishment of a multi-dimensional test model, design of an efficient detector matching interface, a remote diagnosis test method and a performance evaluation and report generation model, the transportation cost and the labor cost in the test process are reduced, and meanwhile the accuracy and objectivity of data obtained through test are improved; the timeliness of test report generation is greatly improved; according to the invention, the number of required channels can be flexibly configured according to actual demands, the whole test process is unattended, and high efficiency of data acquisition and retention, data analysis, report generation, instruction issuing, self-diagnosis, fault-tolerant processing and the like in the whole process is realized; the defects that an existing test method consumes manpower, is low in efficiency, low in operation standardization, low in high-efficiency degree and prone to interference of test results are overcome.

Description

Technical Field

[0001] The invention relates to the field of reactor nuclear measurement, and more specifically, to a high-efficiency testing method for a neutron pulse detector and a matching instrument device. Background Art

[0002] In the critical safety supervision services of reactor device filling with water, loading and replacing materials, physical startup, and zero-power physical test tasks, in order to ensure the safety of nuclear reactors during critical supervision or startup, it is necessary to regularly conduct on-pile or neutron source tests on the neutron detectors and instrument devices used in the reactor zero-power physical experiments, diagnose the health trend status of the instruments and equipment, and provide their performance evaluation analysis reports and metrological appraisal certificates.

[0003] At present, the test and calibration methods for the existing nuclear pulse neutron detector instruments and equipment involved in reactor core detection are relatively mature, but they are mainly aimed at the neutron detectors themselves, and the methods for the supporting secondary instruments and equipment are relatively lacking. At the same time, the current test and calibration of nuclear pulse neutron detectors are restricted by many factors. Many instruments and equipment have only undergone comprehensive nuclear test and calibration before leaving the factory or being put into use. In the later use process, there is a lack of regular and standardized test and calibration. Therefore, it is impossible to track the functional performance, technical status, and metrological status of the instruments and equipment in time, and it is impossible to follow up in time on the status of the nuclear measurement system and physical experiment supervision instruments and equipment involved in the reactor instrumentation and control, which affects the safety of nuclear facility operation and measurement accuracy.

[0004] Therefore, how to research and design an efficient testing method for neutron pulse detectors and supporting instruments and equipment that can overcome the above-mentioned defects is a problem that we urgently need to solve. Summary of the invention

[0005] In order to address the deficiencies in the prior art, the purpose of the present invention is to provide an efficient testing method for neutron pulse detectors and supporting instruments and devices, which can flexibly configure the required number of channels according to actual needs, and is unattended throughout the entire testing process, and the entire process of data collection and retention, data analysis, report generation, command issuance, self-diagnosis, fault-tolerant processing, etc. are all highly efficient.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: an efficient testing method for neutron pulse detectors and supporting instruments and devices, comprising the following steps:

[0007] S1: By constructing the test process model of the plateau curve, presetting the configuration parameters and judging the boundary values ​​of the conditions, the parameter setting and adjustment, process status tracking and abnormal data elimination, data collection and high-voltage plateau curve evaluation and analysis are completed during the high-voltage plateau curve test;

[0008] S2: By constructing a test process model of the discrimination threshold curve, and presetting configuration parameters and judgment condition boundary values, the parameter setting and adjustment, process status tracking and abnormal data elimination, data collection and discrimination threshold curve evaluation and analysis are completed during the discrimination threshold curve test process;

[0009] S3: By recording the current environmental parameters and setting the first two processes to obtain the working high pressure and identification threshold, the process status tracking and abnormal data identification, data collection and stability evaluation analysis are carried out for a long period of time to achieve the stability test of the complete set of instruments under stable neutron flux;

[0010] S4: By evaluating the linearity characteristics, neutron sensitivity measurement characteristics, and whether there are interval defects of the instrument, the complete set of instruments under the core based on dynamically changing neutron flux can be tested under the entire start-up source range;

[0011] S5: Map the test data and result conclusions in steps S1-S4 into the test report template model, and load the test process record data into the historical database of the corresponding equipment and instruments to realize the test of the equipment and instruments.

[0012] Furthermore, the implementation process of the test process model of the plateau curve is specifically as follows:

[0013] The instrument is turned on and operated, and after the heat engine is stable, the function self-check is performed, and the instrument background noise test is performed;

[0014] According to the factory reference parameters of the instrument to be tested and the neutron detector type or the parameters of the previous test conclusion, combined with the original nuclear pulse waveform capture function of the instrument, select and set the working threshold, and configure the detector working high-voltage range and high-voltage growth step of each test channel instrument, single neutron count acquisition time and sampling times, stable time after high-voltage change, and high-voltage loading termination conditions;

[0015] Select the corresponding plateau curve characteristic calculation formula model, and after the parameters are configured, enter the test and data entry process of this stage.

[0016] Furthermore, the method further comprises:

[0017] Dynamic tracking of nuclear pulse count growth rate N under unit growth high pressure Hv ;

[0018] When N A =0.8*N HvA When it is reached for the first time, N A The corresponding high pressure is the starting high pressure U of the plateau area. A , N HvA is the growth rate N of nuclear pulse counts collected in a steady state HvThe counting rate value at the first inflection point gradually decreases from large to small and approaches 0;

[0019] When N B =1.2*N HvB When it is reached for the first time, N B The endpoint discrimination threshold U corresponding to the high pressure plateau area B , N HvB is the growth rate N of nuclear pulse counts collected in a steady state Hv The high pressure value at the first inflection point gradually increases from small to large;

[0020] Based on the initial high pressure U A and endpoint discrimination threshold U B ,The recommended job screening threshold is determined through the job high voltage selection algorithm.

[0021] Furthermore, the expression of the working high voltage selection algorithm is specifically:

[0022] N Hv =(N2-N1) / △H V21

[0023] U L =U B -U A

[0024] PS=10 4 *2(N B -N A ) / [(N B +N A )(N B -N A )]

[0025] U=U A +(U B -U A ) / 3

[0026] Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △H V21 is the difference between two threshold voltages, in V; U L is the slab length, unit V; N B is the plateau terminal voltage U B The counting rate under the condition, in cps; N A is the plateau terminal voltage U A The unit is cps; U is the recommended working high voltage, in V; PS is the plateau slope, in % / 100V.

[0027] Furthermore, the method further comprises:

[0028] Track nuclear pulse count acquisition and conduct statistical fluctuation analysis of data stream dynamic smoothing errors;

[0029] When the statistical error falls within the required range, the instrument system is considered to have entered a stable working state.

[0030] Furthermore, the method further comprises:

[0031] Through the instrument status parameter detection, the number of collected neutron pulses that are not within the statistical fluctuation error range is corrected;

[0032] In addition, abnormal data is eliminated through data flow analysis, and vacancies are filled through interpolation algorithms before data storage and analysis.

[0033] Furthermore, the implementation process of the test process model of the discrimination threshold curve is specifically as follows:

[0034] Set the instrument high voltage according to the recommended working high voltage, and configure the detector discrimination threshold range and threshold growth step, single neutron count acquisition time and sampling times, stabilization time after threshold change, and threshold loading termination conditions for each test channel instrument;

[0035] Select the corresponding threshold curve characteristic calculation formula model, and after the parameter configuration is completed, enter the test and data entry process of this stage.

[0036] Furthermore, the method further comprises:

[0037] Dynamically track the nuclear pulse count growth rate N under the unit growth threshold △v ;

[0038] When N △v ≤N △vA When , the turning point from the maximum to the minimum value is the starting discrimination threshold V of the threshold plateau area. A , N △vA The value of the nuclear pulse count growth rate in the steady state when it is at the starting point of the threshold plateau;

[0039] When N △v ≥N △vB When the value of the threshold plateau increases gradually from the minimum value, the threshold V is the end point of the threshold plateau. B , N △vB It is the value of the nuclear pulse count growth rate in the steady state when it is at the end of the threshold plateau;

[0040] The initial discrimination threshold V based on the threshold plateau A and endpoint discrimination threshold V B , the work identification threshold is determined through the threshold selection algorithm.

[0041] Furthermore, the expression of the threshold selection algorithm is specifically:

[0042] N △v =(N2-N1) / △V 21

[0043] V=V A +(V B -V A ) / 3

[0044] Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △V 21 is the difference between two threshold voltages, in mV; V is the working discrimination threshold, in mV.

[0045] Furthermore, the method further comprises:

[0046] By comparing the low-voltage power supply status value in the public data structure with the theoretical value, the working status of the power supply is analyzed and judged, and the statistical distribution of the output voltage value ripple and noise is calculated at the same time, and the dynamic changes of the power supply output performance indicators under the working status of the power supply are analyzed to diagnose and confirm the low-voltage power supply status of the device; the low-voltage power supply status is obtained through AD analog-to-digital conversion, and the data acquisition control status is obtained through the software operation error flag;

[0047] By analyzing and judging the data in the data structure of the actual loaded channel, the high voltage working state and the correlation analysis between the high voltage change and the instrument accuracy are obtained; the comprehensive analysis model of the high voltage setting value and the measured value in each channel gives the high voltage working state, and the high voltage output ripple noise distribution is obtained from the high voltage measured value to evaluate the high voltage real-time output quality;

[0048] And / or, perform functional inspections on all channels of the device through a preset self-test signal stream, and draw conclusions about the device status based on the device's low-voltage power supply working status and the channel's high-voltage working status, and quickly locate anomalies and perform adaptive recovery, or output alarms and provide reasonable solutions.

[0049] Furthermore, the neutron pulse detector adopts a fully digital neutron detector, specifically:

[0050] Construct a field bus that can flexibly cascade neutron counter tube detectors, and agree on a data interface for parameter download and data upload;

[0051] The structural design of the fully digital circuit of the neutron detector is realized through mechanical design, integrating the high-voltage and low-voltage supply of the neutron counting tube, the fully digital circuit design of the output signal and the integrated digital adapter of the interface circuit connected to the bus.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. The present invention provides an efficient testing method for neutron pulse detectors and supporting instruments and devices, which can flexibly configure the required number of channels according to actual needs, and is unattended during the entire testing process. The whole process of data collection and retention, data analysis, report generation, instruction issuance, self-diagnosis, fault-tolerant processing, etc. are all highly efficient, making up for the shortcomings of existing testing methods such as labor consumption, low efficiency, low operational standardization, low efficiency, and test results that are easily interfered with.

[0054] 2. The present invention, through the implementation of digital neutron detectors, first changes the traditional fully analog structure of the original neutron detector consisting of the neutron sensitive section, preamplifier, and signal high-voltage coaxial cable, removes two coaxial cables (high-voltage cable and nuclear pulse signal transmission cable) that affect the overall weight of the detector, reduces the existing weight of the detector by 2 / 3, and improves the mobility and flexibility of the detector test site, especially under the condition of simultaneous testing of multiple neutron detectors, which will greatly reduce the manpower and time consumed in the installation and layout process.

[0055] 3. The present invention reduces the transportation cost and labor cost in the test process through an unattended and efficient test process, the establishment of a multi-dimensional test model, the design of an efficient detector matching interface, a remote diagnosis test method, and a performance evaluation and report generation model, while improving the accuracy and objectivity of test data obtained and greatly improving the timeliness of test report generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0057] Figure 1 is a schematic diagram of the arrangement of neutron detectors in an embodiment of the present invention;

[0058] Figure 2 is a structural schematic diagram of a neutron detector structure in an embodiment of the present invention;

[0059] Figure 3 It is a logic block diagram of multi-dimensional automatic test in an embodiment of the present invention;

[0060] Figure 4 It is a test data acquisition flow chart in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0062] The test and calibration methods for traditional nuclear pulse neutron detector instruments and equipment involved in reactor core detection are relatively mature, but they are mainly aimed at the neutron detectors themselves, and the methods for supporting secondary instruments and equipment are relatively lacking. At the same time, the current test and calibration of nuclear pulse neutron detectors are restricted by many factors. Many instruments and equipment have only undergone comprehensive nuclear test and calibration before leaving the factory or being put into use. In the later use process, there is a lack of regular and standardized test and calibration. Therefore, it is impossible to track the functional performance, technical status, and metrological status of the instruments and equipment in time, and it is impossible to follow up on the status of the nuclear measurement system and physical experiment supervision instruments and equipment involved in the reactor instrumentation and control in time, affecting the safe operation of nuclear facilities and measurement accuracy.

[0063] The reason for the above situation is that the existing nuclear pulse neutron detector instrument and equipment testing method for reactor core detection has the following deficiencies:

[0064] a. During the test, existing neutron detectors are equipped with coaxial cables of varying lengths from 30m to 80m, which consumes a lot of manpower and material resources in the process of disassembly, assembly, layout, and scene switching. When testing multiple devices simultaneously, due to the differences in device architecture, interface definition, and control method, each device needs to be operated, recorded, supervised, and adjusted separately, which requires additional manpower to track the test. The entire process lacks efficient methods and flexibility.

[0065] b. The instrument and equipment status monitoring and judgment, process parameter setting and timing selection, data recording and entry, data calculation and analysis, and result reporting during the test are all performed by the test personnel and implemented step by step. The entire test process lasts a long time, is inefficient, wastes manpower, and is prone to human intervention in the test results, introducing human bias, making the test process lack standardization and objectivity.

[0066] c. Existing test equipment is unable to store test data in real time due to backward design or low system integration, the amount of manually recorded data is small and single, there is a lack of related auxiliary correction data, and it is impossible to retain records of test data throughout the entire test process. As a result, subsequent data entry processing is cumbersome and time-consuming, there is a lack of real-time correction capabilities for test data, and the output of conclusion reports is inefficient. It is impossible to meet the refined analysis requirements of instrument and equipment testing, and the ability to iteratively analyze the test process and mine data gaps.

[0067] Embodiment: An efficient testing method for a neutron pulse detector and its supporting instrumentation

[0068] Step 1

[0069] In order to facilitate the modular design and easy expansion and customization of neutron pulse detectors and their instrument devices, the instrument hardware and software design adopts the reconfigurable design concept of "tight internalization and loose coupling" for development and design. In the present invention, it is first necessary to realize automatic state monitoring and control of pulsed neutron counter tubes. The hardware adopts bus cascade to increase or decrease the actual number of neutron counter tubes required, and at the same time, it is equipped with hardware channel identification technology to configure and load the required channels, so as to realize high-voltage control, threshold setting, pulse width setting, baseline setting, neutron pulse full digital acquisition parameters and state parameter monitoring of each neutron counter detector channel.

[0070] like Figure 1 As shown, the technical steps to realize a fully digital neutron detector are as follows:

[0071] 1) Build a field bus that can flexibly cascade neutron counting tube detectors, agree on the data interface for parameter download and data upload, and ensure that detector parameter changes, status data and measurement data can be stably and reliably transmitted during normal instrument operation.

[0072] 2) Mechanical design is required to realize the structural design of the fully digital circuit of the neutron detector, the integrated design of the digital probe, the integrated digital adapter to realize the high and low voltage supply of the neutron counting tube, the fully digital circuit design of the output signal, and the interface circuit for accessing the bus.

[0073] like Figure 2 As shown in the figure, through the implementation of digital neutron detectors, the traditional fully analog structure of the original neutron detector consisting of the neutron sensitive section, preamplifier, and signal high-voltage coaxial cable is changed first, and the two coaxial cables (high-voltage cable and nuclear pulse signal transmission cable) that affect the overall weight of the detector are removed, reducing the existing weight of the detector by 2 / 3, and improving the mobility and flexibility of the detector at the test site, especially under the condition of simultaneous testing of multiple neutron detectors, which will greatly reduce the manpower and time consumed in the installation and layout process.

[0074] In addition, without the high-voltage power supply and signal transmission of long cables, the cable layout path is free from interference from harsh environments, such as vibration or trampling, electromagnetic radiation, electrostatic induction, contact reliability, etc., which will be coupled to the transmitted nuclear pulse signal through the cable, reducing the signal-to-noise ratio of the signal transmission and even causing the instrument to be unusable. In addition, the high-voltage fluctuations caused by interference will also cause the neutron detector to operate in an unstable state.

[0075] In the present invention, the main amplifier function and pulse discrimination and display function analog instrument architecture originally located in the secondary instrument in the main control room are replaced by full digital nuclear pulse technology, and integrated into the neutron detector to realize digital nuclear pulse discrimination and technology, forming a new full digital neutron detector; at the same time, data bus communication is added, and networking can be carried out based on the designed bus protocol, and the number of neutron detector channels to be tested can be flexibly configured. It can interact and communicate with the host computer of the test system to complete data status transmission and control configuration distribution, thereby changing the shortcomings of existing neutron detectors that cannot adapt to networking, rough data records, and poor contrast of synchronous operations. On this hardware basis, the efficiency and refinement of various test requirements can be greatly improved.

[0076] Step 2

[0077] like Figure 3 As shown, the automatic test content includes four aspects: high-voltage plateau curve test and evaluation, discrimination threshold curve test and evaluation, stability test and evaluation, and actual pile test evaluation. It is carried out in a serial and progressive sequential logic, in which the evaluation order of the high-voltage plateau curve and the discrimination threshold curve can be interchanged. On this basis, the high-voltage plateau area range (initial high voltage and cut-off high voltage), plateau width, plateau slope, recommended working high voltage, discrimination threshold range, and recommended discrimination threshold are obtained as neutron detector configuration parameters for the subsequent test process.

[0078] The whole test process in the present invention is as follows: first, by constructing a test process model of a plateau curve, presetting configuration parameters, judgment condition boundary values, etc., parameter setting and adjustment, process state tracking and abnormal data elimination, data collection and high-voltage plateau curve evaluation and analysis are completed during the high-voltage plateau curve test; then, by using a test process model of a discrimination threshold curve, presetting configuration parameters, judgment condition boundary values, etc., parameter setting and adjustment, process state tracking and abnormal data elimination, data collection and discrimination threshold curve evaluation and analysis are completed during the discrimination threshold curve test; the stability test is a stability test process of a complete set of instruments under a specific neutron source (stable neutron flux), recording the current environmental parameters, setting the first two processes to obtain the working high voltage and discrimination threshold, and tracking the process state and identifying abnormal data, data collection and stability evaluation and analysis for a long period of time; the on-pile test is a test of a complete set of instruments under the core based on a dynamically changing neutron flux (from the natural background to the neutron flux that makes the neutron detector reach the saturation zone) under the entire start-up source range, evaluating the linear characteristics of the instrument, the neutron sensitivity measurement characteristics, and whether there are interval defects.

[0079] Automatic switching analysis and judgment, self-diagnosis throughout the test, and identification and elimination of abnormal data run through the four links of the above test process. Automatic switching analysis and judgment refers to the functions of when to read data, when to adjust high voltage or threshold in steps, when to stop the increase of high voltage and end the current process during the test; self-diagnosis throughout the test, real-time monitoring of low-voltage and high-voltage output status during the test (fluctuations in load current and output voltage, deviations from set values, etc.) to evaluate the health status of analytical instruments and equipment, and assist in evaluating the interference of current data. In addition, the reliability and correctness of instrument connection are checked through the high-voltage fluctuation method.

[0080] (1) Constructing the test process model of the plateau curve and analyzing and judging it

[0081] The plateau curve characteristic test of the present invention focuses on realizing online identification, judgment, collection and storage of required test data without human intervention, and automatically inputting a preset calculation and analysis model to quickly obtain the required plateau curve characteristic results.

[0082] The steps for implementing the test process model of the plateau curve are as follows: start the instrument and run it, perform a self-check on the functions after the heat engine stabilizes, and perform a background noise test on the instrument. Based on the factory reference parameters of the instrument to be tested and the neutron detector type or the parameters of the previous test conclusion, combined with the original nuclear pulse waveform capture function of the instrument, select and set the working threshold, clarify and configure the detector working high-voltage range and high-voltage growth step of each test channel instrument, the single neutron count acquisition time and number of samplings, the stabilization time after the high-voltage change, the high-voltage loading termination conditions and other parameters, select a suitable plateau curve characteristic calculation formula model, and after the parameter configuration is completed, enter the test and data entry process of this stage.

[0083] Taking the BF3 neutron proportional counter tube as an example, the threshold is selected as 250mV, the high voltage loading range is 0-2500V, the high voltage growth step is set to 50V, and it can be selected as an integer multiple of 25V. The smaller the step, the finer the plateau curve is obtained. Combined with the test time and progress requirements, result accuracy and other factors, the operation process is as follows: ① Set the neutron source, detector, and physical experiment special instruments according to Figure 1 ② Set the instrument parameters, set the discrimination threshold to 250mV, sampling time to 100s (10 samplings, 10s counting each time, the length of each sampling is selected according to the neutron source strength, when the neutron source strength is low, extend the sampling time, otherwise shorten the sampling time, ensure that the cumulative neutron count rate in each sampling time period should be guaranteed within 10 3order of magnitude (during normal operation to reduce the impact of statistical fluctuations in radioactive measurements on the results), stabilization time 180s, high voltage increase step 50V, high voltage setting range 0~2500V, stable reading model (in the same group of data, the abnormal data with a deviation of more than 20% will be identified, associated and confirmed and eliminated, and the data will be corrected and replaced), plateau boundary value judgment model (the smaller the high voltage step, the more accurate the boundary value), high voltage increase termination judgment condition (when the counting rate increases to 120% of the counting rate at the plateau high voltage, stop further increasing the high voltage); ③ Enter the unmanned test mode, the first step is to set the high voltage to 0V, stabilize for 180s, start to eliminate abnormal data and record and store 10 groups of neutron counting rates under 100s, calculate 10 count average values ​​are imported into the analysis model input interface; the second step is to increase the high voltage to 50V, stabilize for 180s, start to remove abnormal data and record and store 10 groups of neutron count rates under 100s, calculate the 10 count average values ​​and import them into the analysis model input interface; the subsequent third step to the 50th step (n = | 2500 / 50 | = 50, or replace the denominator 2500V with the high voltage increase termination value), all perform the previous operations (stabilize for 180s, start to remove abnormal data and record and store 10 groups of neutron count rates under 100s, calculate the 10 count average values ​​and import them into the analysis model input interface), so far the data entry of this link has been completed, the input data of the characteristic calculation model of the plateau curve is ready, and the test data flow is as follows Figure 4 As shown; ④ The required high-voltage plateau curve of the neutron detector will be drawn in real time through the preset plateau curve characteristic calculation model, and the high-voltage working plateau area and its boundary value of the BF3 neutron counter tube will be determined simultaneously, the plateau length and plateau slope performance indicators will be calculated, and the recommended working discrimination threshold will be given.

[0084] High-voltage termination addition algorithm: Dynamically track the nuclear pulse count growth rate N under unit-increasing high voltage Hv ; When N A =0.8*N HvA When it is reached for the first time, N A The corresponding high pressure is the starting high pressure U of the plateau area. A , N HvA is the growth rate N of nuclear pulse counts collected in a steady state Hv The counting rate value at the first inflection point gradually decreases from large to small and approaches 0; when N B =1.2*N HvB When it is reached for the first time, N B The endpoint discrimination threshold U corresponding to the high pressure plateau area B , N HvB is the growth rate N of nuclear pulse counts collected in a steady state Hv The high pressure value at the first inflection point that gradually increases from small to large; based on the initial high pressure U of the plateau area A and endpoint discrimination threshold U B,The recommended job screening threshold is determined through the job high voltage selection algorithm.

[0085] The specific expression of the working high voltage selection algorithm is:

[0086] N Hv =(N2-N1) / △H V21

[0087] U L =U B -U A

[0088] PS=10 4 *2(N B -N A ) / [(N B +N A )(N B -N A )]

[0089] U=U A +(U B -U A ) / 3

[0090] Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △H V21 is the difference between two threshold voltages, in V; U L is the slab length, unit V; N B is the plateau terminal voltage U B The counting rate under the condition, in cps; N A is the plateau terminal voltage U A The unit is cps; U is the recommended working high voltage, in V; PS is the plateau slope, in % / 100V.

[0091] Counting stability algorithm: Track nuclear pulse counting acquisition and perform statistical fluctuation analysis of data stream dynamic smoothing errors. When the statistical error falls within the required range, it is considered that the instrument system has entered a stable working state.

[0092] Neutron counting preprocessing model: During the stability observation process, the neutron source is stable, the instrument parameters are fixed, and the number of collected neutron pulses should also be within the statistical fluctuation error range. If it exceeds the range, it is caused by external interference or the stability of the instrument itself. Therefore, auxiliary corrections can be made through instrument status parameter detection. At the same time, abnormal data can be eliminated through data flow analysis, and vacancies are filled through interpolation algorithms before data storage and analysis.

[0093] (2) Constructing the test process model and analysis and judgment of the threshold curve

[0094] In order to obtain the threshold characteristics of the neutron pulse counting tube and supporting instruments, it is necessary to match the threshold range and interval threshold step of the loaded detector under a specific working high voltage, and the single neutron counting acquisition time. All channels in use will be connected and configured according to actual needs, and data collection will be carried out during the test. The threshold plateau, plateau width, and automatic termination threshold curve test of the neutron counting tube will be determined through data collection and analysis and judgment models.

[0095] After completing the first part of the test, enter the second part of the threshold test process. The test process model implementation steps of the threshold curve are: set the instrument high voltage according to the recommended working high voltage in the first step, clarify and configure the detector identification threshold range and threshold growth step of each test channel instrument, single neutron count acquisition time and sampling times, stabilization time after threshold change, threshold loading termination conditions and other parameters, select the appropriate threshold curve characteristic calculation formula model, and enter the test and data entry process of this stage after the parameter configuration is completed.

[0096] Taking the BF3 neutron proportional counter tube as an example, the high voltage is selected as the recommended working high voltage, the threshold loading range is 0-1000mV, the threshold growth step is set to 50mV, and it can be selected as an integer multiple of 25mV. The smaller the step, the finer the threshold curve is. Combined with the test duration, progress requirements, result accuracy and other factors, the operation process is as follows: ① After the first part is completed, there is no need to shut down and restart to continue the test, set the relevant parameters of the instrument, set the working high voltage to the recommended working high voltage, sampling time 100s (sample 10 times, count 10s each time, the selection of each sampling time is based on the neutron source intensity. When the neutron source intensity is low, the sampling time is extended, otherwise the sampling time is shortened to ensure that the cumulative neutron count rate in each sampling time period should be guaranteed within 10 3order of magnitude (during normal operation, to reduce the impact of statistical fluctuations in radioactive measurements on the results), stabilization time 180s, threshold increase step 50mV, threshold setting range 0~1000mV, stable reading model (in the same group of data, abnormal data with a deviation of more than 20% will be identified, associated and confirmed and eliminated, and data correction and replacement), plateau boundary value judgment model (the smaller the threshold step, the more accurate the boundary value), threshold increase termination judgment condition (when the counting rate increases to 150% of the counting rate in the threshold plateau, stop continuing to increase the high voltage); ③ Enter the unmanned test mode, the first step is to set the threshold to 0mV, stabilize for 180s, start to eliminate abnormal data and record and store 10 groups of neutron counting rates under 100s, calculate the 10 count averages and import them into the analysis model input interface; the second step is to set the threshold Increase to 50mV, stabilize for 180s, start to remove abnormal data and record and store 10 groups of neutron count rates under 100s, calculate the 10 count average values ​​and import them into the analysis model input interface; the subsequent third step to the 20th step (n=|1000 / 50|=20) all execute the previous operations (stabilize for 180s, start to remove abnormal data and record and store 10 groups of neutron count rates under 100s, calculate the 10 count average values ​​and import them into the analysis model input interface), so far the data entry of this link has been completed, and the input data of the threshold curve characteristic calculation model is ready; ④ The required neutron detector discrimination threshold plateau curve will be drawn in real time through the preset threshold curve characteristic calculation model, and the discrimination threshold plateau area and its boundary value of the BF3 neutron counting tube and supporting instruments will be determined simultaneously, and the recommended discrimination threshold setting value will be given.

[0097] Threshold-based termination addition algorithm: Dynamically track the nuclear pulse count growth rate N under the unit growth threshold △v ; When N △v ≤N △vA When , the turning point from the maximum to the minimum value is the starting discrimination threshold V of the threshold plateau area. A , N △vA is the value of the nuclear pulse count growth rate in the steady state when it is at the starting point of the threshold plateau; when N △v ≥N △vB When the value of the threshold plateau increases gradually from the minimum value, the threshold V is the end point of the threshold plateau. B , N △vB is the value of the nuclear pulse count growth rate in the stable state at the end of the threshold plateau; based on the starting discrimination threshold V A and endpoint discrimination threshold V B , the work identification threshold is determined through the threshold selection algorithm.

[0098] By tracking and searching the count rate change value under the unit threshold section by section, the refined high-voltage interval can more accurately find the starting point and end point of the plateau area of ​​the plateau curve, and the interval and boundary value can be determined according to different selection modes.

[0099] The expression of the threshold selection algorithm is as follows:

[0100] N △v =(N2-N1) / △V 21

[0101] V=V A +(V B -V A ) / 3

[0102] Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △V 21 is the difference between two threshold voltages, in mV; V is the working discrimination threshold, in mV.

[0103] (3) The present invention also analyzes and determines the working state of the power supply by comparing the low-voltage power supply state value in the public data structure with the theoretical value, and simultaneously calculates the statistical distribution of the output voltage value ripple and noise, and analyzes the dynamic changes of the power supply output performance indicators under the power supply working state, so as to diagnose and confirm the low-voltage power supply state of the device, and facilitate the correlation analysis of subsequent incidental events; the low-voltage power supply state is obtained through AD analog-to-digital conversion, and the data acquisition control state is obtained through the software operation error flag.

[0104] Secondly, the high-voltage working state and the correlation analysis between high-voltage changes and instrument accuracy are obtained by analyzing and judging the data in the data structure actually loaded into the channel. The comprehensive analysis model of the high-voltage setting value and the measured value in each channel gives the high-voltage working state, and the high-voltage output ripple noise distribution is obtained from the high-voltage measured value to evaluate the real-time output quality of the high-voltage, which is also convenient for correlation analysis of occasional events; the working state of the channel is confirmed by the single-channel analysis results, and the abnormal points (individual or common) are located by analyzing the working state results of all channels online, which is convenient for quickly providing decision-making basis for the diagnosis model.

[0105] Finally, the preset self-test signal flow is used to perform functional inspections on all channels of the device. Combined with the working status of the device's low-voltage power supply and the high-voltage working status of the channels, a conclusion on the device status is quickly drawn. It also has the ability to quickly locate anomalies and perform adaptive recovery, or output alarms and provide reasonable solutions.

[0106] It is necessary to conduct historical tracking for all tested detectors, conduct comparative analysis on detector performance at the same time point, and also conduct statistical analysis on the test data of all previous detectors to derive trend analysis on detector performance changes and predict detector lifespan.

[0107] Step 2

[0108] The stability test targets the equipment to be tested under a long period of operation. For the unchanged measurement target, the instrument's measurement accuracy, instrument health stability, failure rate, environmental adaptability, etc. are obtained during the entire test process. In addition, the test can be compared with the parameter indicators of the previous test cycle to obtain the attenuation trend and attenuation amount of the relevant performance indicators.

[0109] After completing the above tests, set the instrument high voltage according to the recommended working high voltage determined above, set the discrimination threshold according to the recommended threshold, clarify and configure the test time and sampling interval of the detector of each test channel instrument, the single neutron count acquisition time and sampling times, the abnormal data elimination judgment threshold, and the stability curve characteristic calculation formula model. After the parameters are configured, enter the test and data entry process of this stage.

[0110] Taking the BF3 neutron proportional counter tube as an example, the high voltage is selected as the recommended working high voltage, and the threshold is the recommended identification threshold. The operation process is as follows: ① After the second part is completed, there is no need to shut down and restart to continue the test. Set the relevant parameters of the instrument, the test time is set to 48h, the sampling time interval is 0.5h (select according to actual needs), and the sampling time is 100s each time (sample 10 times, each time for 10s of counting, and the selection of each sampling time is based on the neutron source intensity. When the neutron source intensity is low, the sampling time is extended, otherwise the sampling time is shortened to ensure that the cumulative neutron counting rate of each sampling time period should be guaranteed within 10 3 The data is pre-processed to obtain readings using a stable reading model (in the same group of data, abnormal data with a deviation of more than 20% is identified, associated, confirmed, and removed, and the data is corrected and replaced); ③ Enter the unmanned test mode. The first step is to remove abnormal data at the beginning of the test at time 0, record and store 10 groups of neutron count rates under 100s, calculate the average value of 10 counts and import them into the analysis model input interface; the second step is to remove abnormal data 0.5h after the test, record and store 10 groups of neutron count rates under 100s, calculate 10 count average values ​​are imported into the analysis model input interface; the subsequent third step to step 96 (n = |48 / 0.5| = 96) all perform the previous operations (start to remove abnormal data and record and store 10 groups of neutron count rates under 100s, calculate 10 count average values ​​and import them into the analysis model input interface), so far the data entry of this link has been completed, and the input data of the stable characteristic calculation model of the steady-state neutron count rate curve is ready; ④ The required neutron detection neutron count rate stability curve will be drawn in real time through the preset stable characteristic calculation model, and the discreteness of the neutron count rate in this process will be determined to evaluate the stability. The relevant test performance indicators of the previous test cycle are obtained by calling the database, and the corresponding indicators obtained this time are compared, and the change rate of different indicators is calculated to obtain the comprehensive stability of the instrument system in the previous test cycle.

[0111] The data in this process are fully retained and analyzed, the number of abnormalities in the nuclear pulse count growth rate is counted, and tracking and positioning analysis are performed to determine whether the cause is the instrument's own health status, external inspection interference factors, or changes in environmental factors, so as to evaluate the overall status of the instrument.

[0112] Step 3

[0113] The target test of the reactor is to test the equipment under the actual application conditions. The neutron flux of the reactor core start-up source area can cover the measurement range of the equipment (0~10 6 cps), and this process has no blind spot test in the continuous change range. At the same time, the calibrated neutron detector of the same model can be used for relative comparison calibration, and the standard neutron counting tube can be used to calibrate the equipment to be tested to obtain the real quantitative performance indicators.

[0114] After completing the above tests, the detector must first be installed in the reactor core to be tested, and the test conditions must be prepared. The instrument high pressure and discrimination threshold must be determined as mentioned above. The single neutron count acquisition time and sampling times of the detector of each test channel instrument, the abnormal data elimination judgment threshold, etc. must be clearly defined and configured. Once the parameters are configured, the test and data entry process of this stage will begin.

[0115] Taking the BF3 neutron proportional counter tube as an example, the operation process is as follows: ① Start the instrument, set the parameters, preheat for 20 minutes after the instrument works normally, track the reactor core startup process, track and obtain the neutron count rate in real time and save it, stabilize the reading model (the abnormal data with a sudden deviation of the neutron count rate exceeding 50% under a specific control rod position is identified, associated and confirmed, and eliminated, and the data is corrected and replaced, except for short periods); ③ Enter the unmanned test mode. The first step is to eliminate abnormal data and record and store 10 groups of neutron count rates under 100s after the first rod position is raised and stabilized, and calculate the 10 count averages and import them into the analysis model input interface; the second step is to eliminate abnormal data and record and store 100s after the second rod position is raised and stabilized. s, calculate the 10-count average value and import it into the analysis model input interface; in the subsequent third step to the nth step (the number of times after the reactor subcriticality is greater than 0.996), perform the previous operations (start to eliminate abnormal data and record and store the 10 groups of neutron count rates under 100s, calculate the 10-count average value and import it into the critical extrapolation model input interface); ④ Continue to track the neutron count rate during the process of lifting the rod and starting the pile, record and store it, and guide the reactor power level to enter the intermediate measurement area. At this time, the detector is close to the saturation area and is about to exceed the effective measurement interval. Draw the neutron count rate distribution curve during the whole process, and compare the trend consistency of the neutron tube count rate curve, whether there is a power outage in the middle, and whether there is a fault abnormality in the process.

[0116] Utilize the test data and result conclusions from the previous parts to map and fill in the test report template model. At the same time, load the data recorded during the entire test process into the historical database of the equipment and instruments to ensure that the information is accurate, comprehensive, and traceable, such as the test environment status, condition preparation status, test equipment number and identification, test time, participants, test content, vertical and horizontal comparison analysis reference, conclusion and other modules.

[0117] Under the refined test model with high requirements and high precision, the original method is even more impossible to complete. It can only be completed under the content of the present invention through the instrument device under the preset process model under unattended operation. At the same time, when the adaptive strategy cannot switch to solve the emergency, the device will send an alarm message to the communication terminal of the on-duty personnel via Ethernet, reminding the staff to carry out emergency processing and return to the scene in time to deal with the abnormality, so as to ensure the progress of the test.

[0118] Working principle: The present invention can flexibly configure the required number of channels according to actual needs, and is unattended during the entire test process. The data collection and retention, data analysis, report generation, instruction issuance, self-diagnosis, fault-tolerant processing, etc. throughout the process are all highly efficient, making up for the shortcomings of existing test methods such as labor consumption, low efficiency, low operational standardization, low efficiency, and test results that are easily disturbed.

[0119] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0120] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0121] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0123] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An efficient testing method for a neutron pulse detector and its supporting instruments and devices, characterized in that: The following steps are involved: S1: By constructing the test process model of the plateau curve, presetting the configuration parameters and judging the boundary values ​​of the conditions, the parameter setting and adjustment, process status tracking and abnormal data elimination, data collection and high-voltage plateau curve evaluation and analysis are completed during the high-voltage plateau curve test; S2: By constructing a test process model of the discrimination threshold curve, and presetting configuration parameters and judgment condition boundary values, the parameter setting and adjustment, process status tracking and abnormal data elimination, data collection and discrimination threshold curve evaluation and analysis are completed during the discrimination threshold curve test process; S3: By recording the current environmental parameters and setting the first two processes to obtain the working high pressure and identification threshold, the process status tracking and abnormal data identification, data collection and stability evaluation analysis are carried out for a long period of time to achieve the stability test of the complete set of instruments under stable neutron flux; S4: By evaluating the linearity characteristics, neutron sensitivity measurement characteristics, and whether there are interval defects of the instrument, the complete set of instruments under the core based on dynamically changing neutron flux can be tested under the entire start-up source range; S5: Map the test data and result conclusions in steps S1-S4 into the test report template model, and load the test process record data into the historical database of the corresponding equipment and instruments to realize the test of the equipment and instruments.

2. The efficient testing method for a neutron pulse detector and its supporting instrument according to claim 1, characterized in that: The implementation process of the test process model of the plateau curve is specifically as follows: The instrument is turned on and operated, and after the heat engine is stable, the function self-check is performed, and the instrument background noise test is performed; According to the factory reference parameters of the instrument to be tested and the neutron detector type or the parameters of the previous test conclusion, combined with the original nuclear pulse waveform capture function of the instrument, select and set the working threshold, and configure the detector working high-voltage range and high-voltage growth step of each test channel instrument, single neutron count acquisition time and sampling times, stable time after high-voltage change, and high-voltage loading termination conditions; Select the corresponding plateau curve characteristic calculation formula model, and after the parameters are configured, enter the test and data entry process of this stage.

3. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 2 is characterized in that: The method further includes: Dynamic tracking of nuclear pulse count growth rate N under unit growth high pressure Hv ; When N A =0.8*N HvA When it is reached for the first time, N A The corresponding high pressure is the starting high pressure U of the plateau area. A , N HvA is the growth rate N of nuclear pulse counts collected in a steady state Hv The counting rate value at the first inflection point gradually decreases from large to small and approaches 0; When N B =1.2*N HvB When it is reached for the first time, N B The endpoint discrimination threshold U corresponding to the high pressure plateau area B , N HvB is the growth rate N of nuclear pulse counts collected in a steady state Hv The high pressure value at the first inflection point gradually increases from small to large; Based on the initial high pressure U A and endpoint discrimination threshold U B ,The recommended job screening threshold is determined through the job high voltage selection algorithm.

4. The efficient testing method for a neutron pulse detector and its supporting instrument according to claim 3 is characterized in that: The expression of the working high voltage selection algorithm is specifically: N Hv =(N2-N1) / △H V21 IN L =U B -IN A PS=10 4 *2(N B -N A ) / [(N B +N A )(N B -N A )] U=U A +(In B -IN A ) / 3 Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △H V21 is the difference between two threshold voltages, in V; U L is the slab length, unit V; N B is the plateau terminal voltage U B The counting rate under the condition, in cps; N A is the plateau terminal voltage U A The unit is cps; U is the recommended working high voltage, in V; PS is the plateau slope, in % / 100V.

5. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 2, characterized in that: The method further includes: Track nuclear pulse count acquisition and conduct statistical fluctuation analysis of data stream dynamic smoothing errors; When the statistical error falls within the required range, the instrument system is considered to have entered a stable working state.

6. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 2, characterized in that: The method further includes: Through the instrument status parameter detection, the number of collected neutron pulses that are not within the statistical fluctuation error range is corrected; In addition, abnormal data is eliminated through data flow analysis, and vacancies are filled through interpolation algorithms before data storage and analysis.

7. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 1, characterized in that: The implementation process of the test process model of the discrimination threshold curve is specifically as follows: Set the instrument high voltage according to the recommended working high voltage, and configure the detector discrimination threshold range and threshold growth step, single neutron count acquisition time and sampling times, stabilization time after threshold change, and threshold loading termination conditions for each test channel instrument; Select the corresponding threshold curve characteristic calculation formula model, and after the parameter configuration is completed, enter the test and data entry process of this stage.

8. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 7, characterized in that: The method further includes: Dynamically track the nuclear pulse count growth rate N under the unit growth threshold △v ; When N △v ≤N △vA When , the turning point from the maximum to the minimum value is the starting discrimination threshold V of the threshold plateau area. A , N △vA The value of the nuclear pulse count growth rate in the steady state when it is at the starting point of the threshold plateau; When N △v ≥N △vB When the value of the threshold plateau increases gradually from the minimum value, the threshold V is the end point of the threshold plateau. B , N △vB It is the value of the nuclear pulse count growth rate in the steady state when it is at the end of the threshold plateau; The initial discrimination threshold V based on the threshold plateau A and endpoint discrimination threshold V B , the work identification threshold is determined through the threshold selection algorithm.

9. The efficient testing method for a neutron pulse detector and its supporting instrument according to claim 8, characterized in that: The expression of the threshold selection algorithm is specifically: N △v =(N2-N1) / △V 21 V=V A +(V B -V A ) / 3 Where N2 is the count rate at the current threshold voltage, in cps; N1 is the count rate at the previous threshold setting voltage, in cps; △V 21 is the difference between two threshold voltages, in mV; V is the working discrimination threshold, in mV.

10. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 1, characterized in that: The method further includes: By comparing the low-voltage power supply status value in the public data structure with the theoretical value, the working status of the power supply is analyzed and judged, and the statistical distribution of the output voltage value ripple and noise is calculated at the same time, and the dynamic changes of the power supply output performance indicators under the working status of the power supply are analyzed to diagnose and confirm the low-voltage power supply status of the device; the low-voltage power supply status is obtained through AD analog-to-digital conversion, and the data acquisition control status is obtained through the software operation error flag; By analyzing and judging the data in the data structure of the actual loaded channel, the high voltage working state and the correlation analysis between the high voltage change and the instrument accuracy are obtained; the comprehensive analysis model of the high voltage setting value and the measured value in each channel gives the high voltage working state, and the high voltage output ripple noise distribution is obtained from the high voltage measured value to evaluate the high voltage real-time output quality; And / or, perform functional inspections on all channels of the device through a preset self-test signal stream, and draw conclusions about the device status based on the device's low-voltage power supply working status and the channel's high-voltage working status, and quickly locate anomalies and perform adaptive recovery, or output alarms and provide reasonable solutions.

11. The efficient testing method for a neutron pulse detector and its supporting instruments and devices according to claim 1, characterized in that: The neutron pulse detector adopts a fully digital neutron detector, specifically: Construct a field bus that can flexibly cascade neutron counter tube detectors, and agree on a data interface for parameter download and data upload; The structural design of the fully digital circuit of the neutron detector is realized through mechanical design, integrating the high-voltage and low-voltage supply of the neutron counting tube, the fully digital circuit design of the output signal and the integrated digital adapter of the interface circuit connected to the bus.

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