Method and system for calibrating protection values ​​of intermediate range of off-core detectors

Abstract

This invention relates to a method and system for calibrating the protection settings of intermediate-range detectors in an off-core reactor, comprising the following steps: determining a flux level correction factor for neutrons in the reactor core; calculating a weighted power factor for the intermediate-range detector; determining a power distribution correction factor for the reactor core fuel assemblies based on the weighted power factor; and predicting the protection settings of the intermediate-range detector based on the flux level correction factor, the power distribution correction factor, and initial test data at the beginning of the intermediate-range detector's lifespan. This invention enables the prediction and calibration of the protection settings of intermediate-range detectors in a nuclear power unit's instrumentation system without requiring load shedding or power reduction. It solves the problem of expected transient protection settings changing with the power level corresponding to cyclic operation in cases where emergency shutdown fails, thus ensuring the safe operation of the unit.

Description

Technical Field

[0001] This invention relates to the technical field of nuclear reactors, and more specifically, to a method and system for calibrating protection settings for the intermediate range of an external detector. Background Technology

[0002] Currently, the intermediate range protection settings of the instrumentation system are calibrated at 30% FP power during the initial physical testing phase at the beginning of each life cycle. When the instrumentation system reaches its upper limit at high power levels, deep load shedding and power reduction are required for intermediate range data acquisition. Therefore, there is no suitable window for recalibration during normal unit operation. As burnup increases, core power distribution and flux levels change, rendering the protection settings obtained at the beginning of the life cycle inapplicable. This may cause changes in the power level corresponding to the instrumentation system protection settings, impacting the safe operation of the unit. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for calibrating the protection setting value of the intermediate range of an external detector, in order to address the deficiencies of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: to construct a method for calibrating the protection setting value of the intermediate range of an off-chip detector, comprising the following steps:

[0005] Determine the core neutron flux level correction factor;

[0006] Calculate the weighted power factor of the intermediate range detector;

[0007] Based on the weighted power factor, determine the power distribution correction factor for the core fuel assembly;

[0008] Based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, the protection setting value of the intermediate range detector is predicted.

[0009] In the protection setting calibration method for the intermediate range of the off-core detector described in this invention, the step of determining the core neutron flux level correction factor includes:

[0010] Acquire power distribution data and corresponding cycle burnup data for the core peripheral components;

[0011] Obtain core neutron flux level data and corresponding cycle burnup data;

[0012] Based on the power distribution data of the core peripheral components and the corresponding cycle burnup data, the trend of the power distribution of the core peripheral components with cycle burnup is obtained.

[0013] Based on the core neutron flux level data and the corresponding cycle burnup data, the trend of the overall core flux level changing with cycle burnup is obtained.

[0014] The flux level correction factor is determined based on the trends of the power distribution of the core peripheral components with cycle burnup and the trends of the overall core flux level with cycle burnup.

[0015] In the protection setting calibration method for the intermediate range of the off-site detector described in this invention, the calculation of the weighted power factor of the intermediate range detector includes:

[0016] Obtain the intermediate range response factor;

[0017] The weighted power factor is calculated by combining the power distribution data of the reactor core fuel assemblies and the intermediate range response factor.

[0018] In the protection setting calibration method for the intermediate range of the external detector described in this invention, determining the power distribution correction factor of the core fuel assembly based on the weighted power factor includes:

[0019] Obtain the intermediate range detector weighted power factor corresponding to different fuel consumption states;

[0020] The power distribution correction factor is calculated based on the weighted power factor of the intermediate range detector corresponding to the different fuel consumption states.

[0021] In the protection setting calibration method for the intermediate range of the off-site detector described in this invention, the step of predicting the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan includes:

[0022] Obtain test data at the beginning of the lifespan of the intermediate range detector;

[0023] Based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula, the protection setting value of the intermediate range detector is calculated.

[0024] In the protection setting calibration method for the intermediate range of the off-pile detector described in this invention, the test data is: the measured current value at the beginning of the lifespan of the intermediate range detector.

[0025] The step of calculating the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the initial test data of the intermediate range detector at the beginning of its lifespan, combined with the protection setting calculation formula, includes:

[0026] Based on the flux level correction factor, the power distribution correction factor, and the measured current value at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula, the protection setting value of the intermediate range detector is calculated.

[0027] In the protection setting calibration method for the intermediate range of the off-pile detector described in this invention, the protection setting calculation formula satisfies:

[0028] I2 = α * β * I1;

[0029] Where I2 is the protection setting of the intermediate range detector; α is the flux level correction factor; β is the power distribution correction factor; and I1 is the measured current value at the beginning of the intermediate range detector's lifespan.

[0030] The present invention also provides a protection setting calibration system for the intermediate range of an external detector, comprising:

[0031] The first determining unit is used to determine the core neutron flux level correction factor.

[0032] The calculation unit is used to calculate the weighted power factor of the intermediate range detector;

[0033] The second determining unit is used to determine the power distribution correction factor of the core fuel assembly based on the weighted power factor.

[0034] The prediction unit is used to predict the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan.

[0035] The present invention also provides an electronic device, comprising: a memory and a processor; the memory is used to store program instructions, and the processor is used to execute the steps of the method described above according to the program instructions stored in the memory.

[0036] The present invention also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0037] The method and system for calibrating the protection settings of the intermediate range detectors of the external reactor, as described in this invention, have the following beneficial effects: The method includes the following steps: determining the flux level correction factor for neutrons in the reactor core; calculating the weighted power factor of the intermediate range detector; determining the power distribution correction factor for the reactor core fuel assemblies based on the weighted power factor; and predicting the protection settings of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the initial test data of the intermediate range detector at the beginning of its lifespan. This invention enables the prediction and calibration of the protection settings of the intermediate range detectors in the instrumentation system of a nuclear power unit without requiring load shedding or power reduction. It solves the problem that the expected transient protection settings change with the power level corresponding to the cyclic operation when an emergency shutdown fails, thus ensuring the safe operation of the unit. Attached Figure Description

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0039] Figure 1 This is a flowchart illustrating the protection setting calibration method for the intermediate range of an external detector provided in an embodiment of the present invention.

[0040] Figure 2 This is a graph showing the trend of power distribution of the reactor core peripheral components as a function of cycle burnup, provided in an embodiment of the present invention.

[0041] Figure 3 This is a graph showing the trend of overall core flux level as a function of cycle burnup, provided in an embodiment of the present invention.

[0042] Figure 4 This is a theoretical power distribution diagram of 30% FP at the beginning and end of the service life provided in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the intermediate range response factor provided in an embodiment of the present invention;

[0044] Figure 6 This is a deviation statistics chart of the theoretical calibration method provided in the embodiments of the present invention;

[0045] Figure 7 This is a schematic diagram of the protection setting calibration system for the intermediate range of an external detector provided in an embodiment of the present invention. Detailed Implementation

[0046] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0047] refer to Figure 1 This is a flowchart illustrating an optional embodiment of the protection setting calibration method for the intermediate range of an external detector provided by the present invention.

[0048] like Figure 1 As shown, the method for calibrating the protection setting value of the intermediate range of the external detector includes the following steps:

[0049] Step S101: Determine the core neutron flux level correction factor.

[0050] Optionally, in some embodiments, determining the core neutron flux level correction factor includes: acquiring core peripheral component power distribution data and corresponding cycle burnup data; acquiring core neutron flux level data and corresponding cycle burnup data; obtaining the core peripheral component power distribution trend with cycle burnup based on the core peripheral component power distribution data and corresponding cycle burnup data; obtaining the core overall flux level trend with cycle burnup based on the core neutron flux level data and corresponding cycle burnup data; and determining the flux level correction factor based on the core peripheral component power distribution trend with cycle burnup and the core overall flux level trend with cycle burnup.

[0051] Specifically, the power distribution data of the core peripheral components and the corresponding cycle burnup data can be obtained through detection methods or directly extracted from historical data stored in a database. This invention does not impose any specific limitations.

[0052] Similarly, the flux level data of neutrons in the reactor core and the corresponding cycle burnup data can also be obtained by detection methods, or directly extracted from historical data stored in a database. This invention does not impose any specific limitations.

[0053] In some embodiments, the trends of power distribution of peripheral core components with cycle burnup and the trends of overall core flux level with cycle burnup can be obtained by software analysis and calculation.

[0054] Alternatively, in some other embodiments, the overall core flux level can be obtained as a function of cycle burnup by simulating the core power operation burnup history using software.

[0055] in, Figure 2 This is a graph showing the trend of power distribution of peripheral components of a nuclear power plant unit during historical cycles as a function of burnup. Figure 3 This is a graph showing the trend of the overall core flux level of a nuclear power plant in a historical cycle as a function of cycle burnup.

[0056] Depend on Figure 2 It can be seen that as core burnup deepens and combustible poisons within the reactor are consumed, the power weight at the periphery of the core continuously changes. From Figure 3 It can be seen that as the core burnup deepens and fissile nuclides are consumed, the overall neutron flux level of the core continues to rise.

[0057] Therefore, based on the trends of power distribution of core peripheral components with cycle burnup and the trends of overall core flux level with cycle burnup, flux level correction factors can be determined.

[0058] Specifically, the core neutron flux level correction factor can be expressed by the following formula:

[0059] α=φ2 / φ1 (1).

[0060] Wherein, φ1: the core flux level corresponding to burn-out state 1; φ2: the core flux level corresponding to burn-out state 2.

[0061] Step S102: Calculate the weighted power factor of the intermediate range detector.

[0062] In some embodiments, calculating the weighted power factor of the intermediate range detector includes: obtaining the intermediate range response factor; and combining the power distribution data of the core fuel assembly with the intermediate range response factor to calculate the weighted power factor.

[0063] Specifically, as burnup in the reactor core increases, the core power distribution also changes. In this embodiment of the invention, by analyzing the core power operation burnup data, the change in the core fuel assembly power distribution with burnup can be obtained, specifically as follows: Figure 4 shown.

[0064] Depend on Figure 4 It can be seen that the power of each core fuel assembly has a different impact on the measurement current of the intermediate range detector (where the contribution of the power of each core fuel assembly to the measurement current of the intermediate range detector (i.e., the intermediate range response factor) is as follows: Figure 5 As shown. Therefore, the weighted power factor of the intermediate range detector can be calculated by obtaining the intermediate range response factor and combining it with the power distribution of the core fuel assembly.

[0065] Specifically, the weighted power factor of the intermediate range detector satisfies the following condition:

[0066] σ=ΣXi×Pi (2).

[0067] Where Xi: the intermediate range response factor corresponding to position i; Pi: the core fuel assembly power corresponding to position i.

[0068] Step S103: Determine the power distribution correction factor for the reactor core fuel assembly based on the weighted power factor.

[0069] In some embodiments, determining the power distribution correction factor of the reactor core fuel assembly based on the weighted power factor includes: obtaining the intermediate range detector weighted power factor corresponding to different burnup states; and calculating the power distribution correction factor based on the intermediate range detector weighted power factor corresponding to different burnup states.

[0070] Specifically, the power distribution correction factor of the reactor core fuel assembly satisfies the following conditions:

[0071] β=σ2 / σ1 (3).

[0072] Where σ1: weighted power factor of the intermediate range detector corresponding to fuel consumption state 1; σ2: weighted power factor of the intermediate range detector corresponding to fuel consumption state 2.

[0073] Therefore, by calculating the weighted power factor of the intermediate range detector under different burnup conditions, and then combining it with equation (3), the power distribution correction factor of the reactor core fuel assembly can be calculated.

[0074] Step S104: Based on the flux level correction factor, power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, predict the protection setting value of the intermediate range detector.

[0075] In some embodiments, predicting the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan includes: obtaining the test data at the beginning of the intermediate range detector's lifespan; and calculating the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula.

[0076] Optionally, in this embodiment of the invention, the test data is the measured current value at the beginning of the lifespan of the intermediate range detector.

[0077] In some embodiments, the protection setting of the intermediate range detector is calculated based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula. This includes: calculating the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the measured current value at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula.

[0078] In this embodiment of the invention, the constant value calculation formula is expressed as follows:

[0079] I2=α*β*I1 (4).

[0080] Where I2 is the protection setting of the intermediate range detector; α is the flux level correction factor; β is the power distribution correction factor; and I1 is the measured current value at the beginning of the intermediate range detector's lifespan.

[0081] Therefore, after determining the flux level correction factor, power distribution correction factor, and the measured current value at the beginning of the intermediate range detector's lifespan, the protection setting value of the intermediate range detector can be quickly calculated using equation (4).

[0082] This invention calculates the core power distribution and flux level changes with burnup, and combines this with the IRC (Intermediate Range Detector) probe response factor to calculate the core periphery power weight, thereby calculating the power level change with burnup corresponding to the ATWT (Anticipated Transient of Failure to Shutdown) setting. By incorporating field measurement data (i.e., measured current values) from the initial cycle, it achieves the function of theoretically calibrating the IRC protection setting, solving the problem of the ATWT setting changing with the power level corresponding to the cycle operation.

[0083] To verify the reliability of this invention, in one specific embodiment, data from the beginning and end of a certain cycle's lifespan are selected, and correction factors are calculated based on power distribution and flux levels. This achieves two calculations: 1. For the same current value, the power level corresponding to the ATWT protection setting is calculated. 2. For 30% FP, the theoretical ATWT calibration result at the end of the lifespan is calculated.

[0084] The theoretical calculation values ​​(i.e., the predicted values ​​in Table 1) for each cycle of each unit in a power plant were collected and compared with the actual values ​​collected during on-site overhaul shutdown current tracking. The data is shown in Table 1. Statistical analysis of data deviations was performed, and the results are shown below. Figure 6 .

[0085] Table 1. Statistics on the Deviation between Theoretical Calculations and Measured Data

[0086]

[0087] In Table 1, RT represents high-flux emergency shutdown (corresponding to 25% power), ATWT represents the expected transient of failure to shut down the reactor (corresponding to 30% FP power), and C1 corresponds to 20% FP power.

[0088] As can be seen from Table 1, the calibration method of the present invention has a high degree of consistency with the actual field data.

[0089] refer to Figure 7 This is a schematic diagram of an optional embodiment of the protection setting calibration system for the intermediate range of an external detector provided by the present invention.

[0090] The protection setting calibration system for the intermediate range of the external detector can be used to implement the protection setting calibration method for the intermediate range of the external detector disclosed in the embodiments of the present invention.

[0091] like Figure 7 As shown, the protection setting calibration system for the intermediate range of the external detector includes:

[0092] The first determining unit 701 is used to determine the core neutron flux level correction factor.

[0093] The calculation unit 702 is used to calculate the weighted power factor of the intermediate range detector.

[0094] The second determining unit 703 is used to determine the power distribution correction factor of the core fuel assembly based on the weighted power factor.

[0095] The prediction unit 703 is used to predict the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan.

[0096] The present invention also provides an electronic device, comprising: a memory and a processor; the memory is used to store program instructions, and the processor is used to execute the steps of the protection setting calibration method for the intermediate range of an off-site detector disclosed in the embodiments of the present invention according to the program instructions stored in the memory.

[0097] The present invention also provides a storage medium storing a computer program thereon, wherein when the computer program is executed by a processor, it implements the steps of the protection setting calibration method for the intermediate range of an off-site detector disclosed in the embodiments of the present invention.

[0098] This invention is based on modeling and calculating the trend of changes in the core neutron flux level and distribution as burnup increases, thereby obtaining the change in the power weight of the core periphery, and thus realizing the trend of power level change corresponding to the IRC protection setting flip. On this basis, the theoretical calibration of the IRC protection setting is realized.

[0099] Compared to traditional on-site calibration schemes that can only be performed during the late stages of the cycle when the unit is deeply deloaded and running for a long time, which involves complex unit power increase and decrease operations, this invention can avoid introducing additional risks to core reactivity control and power generation loss, while also taking into account the safety and economic benefits of the unit.

[0100] Furthermore, this invention can theoretically calibrate the intermediate range IRC protection setting value in the later stages of the cycle, reducing the risk of human intervention in the IRC protection function during unit shutdown and power reduction.

[0101] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0102] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0103] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0104] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for calibrating the protection setting value of an external detector in the intermediate range, characterized in that, Includes the following steps: Determine the core neutron flux level correction factor; The determination of the core neutron flux level correction factor includes: acquiring core peripheral component power distribution data and corresponding cycle burnup data; acquiring core neutron flux level data and corresponding cycle burnup data; obtaining the core peripheral component power distribution trend with cycle burnup based on the core peripheral component power distribution data and corresponding cycle burnup data; obtaining the core overall flux level trend with cycle burnup based on the core neutron flux level data and corresponding cycle burnup data; and determining the flux level correction factor based on the core peripheral component power distribution trend with cycle burnup and the core overall flux level trend with cycle burnup. Calculate the weighted power factor of the intermediate range detector; the calculation of the weighted power factor of the intermediate range detector includes: obtaining the intermediate range response factor; and calculating the weighted power factor by combining the power distribution data of the core fuel assembly and the intermediate range response factor. Based on the weighted power factor, a power distribution correction factor for the core fuel assembly is determined; the determination of the power distribution correction factor for the core fuel assembly based on the weighted power factor includes: obtaining the weighted power factor of the intermediate range detector corresponding to different burnup states; and calculating the power distribution correction factor based on the weighted power factor of the intermediate range detector corresponding to different burnup states. Based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, the protection setting value of the intermediate range detector is predicted. The protection setting calculation formula satisfies: I2 = α*β*I1; Where I2 is the protection setting of the intermediate range detector; α is the flux level correction factor; β is the power distribution correction factor; and I1 is the measured current value at the beginning of the intermediate range detector's lifespan.

2. The method for calibrating the protection setting value of the intermediate range of the external detector according to claim 1, characterized in that, The step of predicting the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan includes: Obtain test data at the beginning of the lifespan of the intermediate range detector; Based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula, the protection setting value of the intermediate range detector is calculated.

3. The method for calibrating the protection setting value of the intermediate range of the external detector according to claim 2, characterized in that, The test data is: the measured current value at the beginning of the lifespan of the intermediate range detector; The step of calculating the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the initial test data of the intermediate range detector at the beginning of its lifespan, combined with the protection setting calculation formula, includes: Based on the flux level correction factor, the power distribution correction factor, and the measured current value at the beginning of the intermediate range detector's lifespan, combined with the protection setting calculation formula, the protection setting value of the intermediate range detector is calculated.

4. A protection setting calibration system for the intermediate range of an external detector, characterized in that, include: The first determining unit is used to determine the core neutron flux level correction factor. The determination of the core neutron flux level correction factor includes: acquiring core peripheral component power distribution data and corresponding cycle burnup data; acquiring core neutron flux level data and corresponding cycle burnup data; obtaining the core peripheral component power distribution trend with cycle burnup based on the core peripheral component power distribution data and corresponding cycle burnup data; obtaining the core overall flux level trend with cycle burnup based on the core neutron flux level data and corresponding cycle burnup data; and determining the flux level correction factor based on the core peripheral component power distribution trend with cycle burnup and the core overall flux level trend with cycle burnup. A calculation unit is used to calculate the weighted power factor of the intermediate range detector; the calculation of the weighted power factor of the intermediate range detector includes: obtaining the intermediate range response factor; and combining the power distribution data of the core fuel assembly with the intermediate range response factor to calculate the weighted power factor. The second determining unit is used to determine the power distribution correction factor of the core fuel assembly based on the weighted power factor; the determination of the power distribution correction factor of the core fuel assembly based on the weighted power factor includes: obtaining the intermediate range detector weighted power factor corresponding to different burnup states; and calculating the power distribution correction factor based on the intermediate range detector weighted power factor corresponding to different burnup states. The prediction unit is used to predict the protection setting of the intermediate range detector based on the flux level correction factor, the power distribution correction factor, and the test data at the beginning of the intermediate range detector's lifespan. The protection setting calculation formula satisfies: I2 = α*β*I1; Where I2 is the protection setting of the intermediate range detector; α is the flux level correction factor; β is the power distribution correction factor; and I1 is the measured current value at the beginning of the intermediate range detector's lifespan.

5. An electronic device, characterized in that, include: Memory and processor; The memory is used to store program instructions, and the processor is used to execute the steps of the method according to any one of claims 1-3 according to the program instructions stored in the memory.

6. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1-3.

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