Nuclear power plant safety injection system execution mechanism test period optimization method and device, storage medium and electronic equipment

Abstract

The invention relates to a nuclear power plant safety injection system execution mechanism test period optimization method and device, a storage medium and electronic equipment. The method comprises the steps of obtaining related information of equipment to be analyzed; carrying out historical performance analysis, determination theory analysis and probability theory analysis on the equipment based on the related information of the to-be-analyzed equipment to obtain a historical performance analysis result, a determination theory analysis result and a probability theory analysis result; judging whether the test period of the to-be-analyzed equipment can be prolonged or not according to the historical performance analysis result, the determination theory analysis result and the probability theory analysis result; if not, keeping the current test period; if yes, prolonging the test period of the to-be-analyzed equipment. The feasibility of prolonging the test period of the safety injection system executing mechanism can be effectively and comprehensively demonstrated and analyzed, and the economical efficiency of a nuclear power plant is improved on the premise that nuclear safety of the nuclear power plant is guaranteed by prolonging the test period.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plant safety injection systems, and more particularly to a method, device, storage medium and electronic equipment for optimizing the test cycle of an actuator of a nuclear power plant safety injection system. Background Art

[0002] The functions of the safety injection system (RIS) of a nuclear power plant are: in the event of a loss of coolant due to a small primary circuit rupture or a rupture of a secondary circuit steam pipe causing a drop in the average temperature of the primary circuit and resulting in coolant contraction, the RIS is used to replenish water into the primary circuit to re-establish the pressurizer water level; in the event of a loss of coolant due to a large primary circuit rupture, the RIS injects water into the core to re-flood and cool the core and limit the temperature rise of the fuel elements; in the event of a rupture of a secondary circuit steam pipe, a high-concentration boric acid solution is injected into the primary circuit to compensate for the positive reactivity caused by continuous supercooling of the primary circuit coolant and prevent the core from returning to criticality.

[0003] The injection system actuator test is designed to check valve operability (opening and closing). It also verifies the free movement of the check valve by opening the relevant valves and taking local flow readings. However, the current injection system actuator test is performed during the primary circuit water filling process, which prolongs the reactor pool filling time and impacts the overhaul critical path. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method, device, storage medium and electronic equipment for optimizing the test cycle of an actuator of a safety injection system of a nuclear power plant in response to the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a test cycle optimization method for the actuator of the safety injection system of a nuclear power plant, comprising the following steps:

[0006] Obtain relevant information about the device to be analyzed;

[0007] Performing equipment historical performance analysis based on the relevant information of the equipment to be analyzed to obtain historical performance analysis results;

[0008] Performing deterministic analysis based on the relevant information of the device to be analyzed to obtain a deterministic analysis result;

[0009] Performing a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result;

[0010] Determining whether the test period of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results;

[0011] If not, maintain the current test cycle;

[0012] If so, extend the test period of the device to be analyzed.

[0013] In the test cycle optimization method for the actuator of the safety injection system of a nuclear power plant according to the present invention, the relevant information of the equipment to be analyzed includes: historical periodic test results of the equipment to be analyzed, historical fault records of the equipment to be analyzed;

[0014] The performing of device historical performance analysis based on the relevant information of the device to be analyzed to obtain historical performance analysis results includes:

[0015] Determining whether the performance of the equipment to be analyzed is qualified based on the historical periodic test results;

[0016] If so, analyze the impact of the historical fault records on the extension of the test period of the equipment to be analyzed.

[0017] In the method for optimizing the test cycle of an actuator of a safety injection system of a nuclear power plant according to the present invention, analyzing the impact of the historical fault records on the extension of the test cycle of the equipment to be analyzed includes:

[0018] The following analysis is performed on each historical fault in the historical fault record:

[0019] Determine whether the current historical fault is subject to regular testing and inspection;

[0020] If it is not the content of the regular test and inspection, it is determined that it does not affect the extension of the test period of the equipment to be analyzed;

[0021] If it is the content of the periodic test and inspection, determine whether it can only be performed by means of the periodic test and inspection;

[0022] If other alternative inspection methods are available, it shall be determined that this does not affect the extension of the test period of the equipment to be analyzed;

[0023] If it can only be performed by means of the periodic test inspection, then determining whether the failure mode of the current historical failure is time-related;

[0024] If it is not related to time, it is determined that it does not affect the extension of the test period of the device to be analyzed, and the conditions for extending the test period of the device to be analyzed are met;

[0025] If it is related to time, it is determined that the test period of the device to be analyzed cannot be extended.

[0026] In the test cycle optimization method for the actuator of the safety injection system of a nuclear power plant according to the present invention, the relevant information of the equipment to be analyzed includes: defense-in-depth evaluation factors, safety margins and related regulations;

[0027] The performing of deterministic analysis based on the relevant information of the device to be analyzed to obtain the deterministic analysis result includes:

[0028] Determining whether the extended test period of the equipment to be analyzed is consistent with the defense in depth principle based on the defense in depth evaluation requirements;

[0029] If it is consistent with the defense in depth principle, then judging whether the extended test period of the equipment to be analyzed satisfies the safety margin based on the impact result of the extended test period; if it is inconsistent with the defense in depth principle, then judging that the test period cannot be extended;

[0030] If the safety margin is met, then judging whether the relevant regulations are met based on the impact of the test period extension; if the safety margin is not met, then judging that the test period of the device to be analyzed cannot be extended;

[0031] If the relevant regulations are met, it is determined that the conditions for extending the test period of the equipment to be analyzed are met; if the relevant regulations are not met, it is determined that the test period of the equipment to be analyzed cannot be extended.

[0032] In the test cycle optimization method for the actuator of the safety injection system of a nuclear power plant according to the present invention, judging whether the extended test cycle of the equipment to be analyzed meets the safety margin based on the impact result of the extended test cycle includes:

[0033] Based on the impact of the extended test period, determine whether the acceptance criteria for the safety analysis in the final safety analysis report are met; or based on the impact of the extended test period, determine whether the revised content accommodates the uncertainties of the analysis and data.

[0034] In the test cycle optimization method for the actuator of the safety injection system of a nuclear power plant according to the present invention, the relevant information of the equipment to be analyzed includes: the test cycle and the failure probability of the equipment to be analyzed;

[0035] The performing a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result includes:

[0036] Performing risk assessment based on the relationship between the test cycle of the equipment to be analyzed and the failure probability of the equipment to obtain a risk increment;

[0037] Determine whether the risk increment is within the acceptable risk criteria;

[0038] If so, it is determined that the conditions for extending the test period of the equipment to be analyzed are met;

[0039] If not, it is determined that the test period of the device to be analyzed cannot be extended.

[0040] In the test cycle optimization method for the actuator of the safety injection system of a nuclear power plant according to the present invention, the historical performance analysis result, the deterministic analysis result and the probabilistic analysis result all include: whether the test cycle can be extended or not;

[0041] The determining whether the test period of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results includes:

[0042] If the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results all indicate that the test period can be extended, then it is determined that the test period of the device to be analyzed can be extended;

[0043] If any one or more of the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results indicate that the test period cannot be extended, it is determined that the test period of the device to be analyzed cannot be extended.

[0044] The present invention also provides a test cycle optimization device for an actuator of a safety injection system of a nuclear power plant, comprising:

[0045] An information acquisition unit, used to acquire relevant information of the device to be analyzed;

[0046] A historical performance analysis unit, configured to perform a historical performance analysis of the device based on the relevant information of the device to be analyzed, and obtain a historical performance analysis result;

[0047] A deterministic analysis unit, configured to perform a deterministic analysis based on the relevant information of the device to be analyzed to obtain a deterministic analysis result;

[0048] A probability analysis unit, configured to perform a probability analysis based on the relevant information of the device to be analyzed to obtain a probability analysis result;

[0049] a cycle extension judgment unit, configured to judge whether the test cycle of the equipment to be analyzed can be extended based on the historical performance analysis result, the deterministic analysis result, and the probabilistic analysis result;

[0050] The test cycle extension unit is used to maintain the current test cycle when the cycle cannot be extended, and to extend the test cycle of the device to be analyzed when the cycle can be extended.

[0051] The present invention also provides a storage medium storing a computer program, wherein the computer program is suitable for being loaded by a processor to execute the steps of the above-mentioned method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant.

[0052] The present invention also provides an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the above-mentioned method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant by calling the computer program stored in the memory.

[0053] The method, device, storage medium and electronic device for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to the present invention have the following beneficial effects: including: obtaining relevant information of the equipment to be analyzed; performing historical performance analysis, deterministic analysis and probabilistic analysis of the equipment based on the relevant information of the equipment to be analyzed, and obtaining historical performance analysis results, deterministic analysis results and probabilistic analysis results; judging whether the test cycle of the equipment to be analyzed can be extended based on the historical performance analysis results, deterministic analysis results and probabilistic analysis results; if not, maintaining the current test cycle; if so, extending the test cycle of the equipment to be analyzed. The present invention can effectively and comprehensively demonstrate the feasibility of extending the test cycle of the actuator of the safety injection system, and by extending the test cycle, the economic efficiency of the nuclear power plant can be improved while ensuring that nuclear safety is met. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0055] Figure 1 This is a flow chart of a test cycle optimization method for an actuator of a safety injection system in a nuclear power plant provided by the present invention;

[0056] Figure 2 It is a schematic diagram of the process of equipment failure analysis provided by the present invention;

[0057] Figure 3 This is a schematic diagram of an event tree provided by the present invention;

[0058] Figure 4 This is a fault tree diagram provided by the present invention;

[0059] Figure 5 This is a schematic diagram of the inherent relationship between the equipment failure probability and the test cycle provided by the present invention;

[0060] Figure 6 This is a relationship diagram between the equipment failure probability and the test cycle provided by the present invention;

[0061] Figure 7 The present invention provides a logic block diagram of a test cycle optimization system for an actuator of a safety injection system in a nuclear power plant. DETAILED DESCRIPTION

[0062] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0063] In order to solve the problem that the existing injection system actuator test will prolong the time of reactor pool water filling and affect the overhaul critical path, the present invention analyzes the test cycle of the injection system actuator test to verify the feasibility of extending the test cycle. When it is determined that the test cycle can be extended, the actuator test cycle is extended, thereby improving the flexibility of work arrangements during the overhaul and meeting the construction period requirements of a short overhaul.

[0064] refer to Figure 1 In a preferred embodiment, the method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant includes the following steps:

[0065] Step S101: Obtain relevant information of the device to be analyzed.

[0066] Optionally, in an embodiment of the present invention, the equipment to be analyzed is an actuator of a nuclear plant's injection system, which includes but is not limited to related valves of the injection system (such as RIS020 / 021 / 023 / 029 / 030 / 031 / 061 / 062 / 063 / 064VP, etc.) and related check valves of the reactor coolant system (such as RCP122 / 222 / 322VP and RCP120 / 220 / 320VP, etc.).

[0067] Optionally, in some embodiments, the relevant information of the equipment to be analyzed may include but is not limited to: historical periodic test results of the equipment to be analyzed, historical failure records of the equipment to be analyzed; defense-in-depth evaluation factors, safety margins and related regulations; test cycles of the equipment to be analyzed and equipment failure probabilities, etc.

[0068] Step S102: performing a historical performance analysis of the device based on the relevant information of the device to be analyzed to obtain a historical performance analysis result.

[0069] The historical performance of the device to be analyzed is analyzed to determine whether the device performance is good and whether the conditions for extending the test cycle are met. Optionally, in some embodiments, performing a historical performance analysis of the device based on relevant information of the device to be analyzed and obtaining the historical performance analysis results include: determining whether the performance of the device to be analyzed is qualified based on historical periodic test results; and if so, analyzing the impact of historical fault records on extending the test cycle of the device to be analyzed. If it is determined that the device performance is good and historical faults have no impact on extending the test cycle of the device, the historical performance analysis result indicates that the test cycle can be extended; otherwise, the test cycle cannot be extended.

[0070] In some embodiments, the historical periodic test result may be the test pass rate of the current periodic test. Specifically, the test pass rate of the current periodic test is required to be greater than 95%. The test pass rate can be obtained by dividing the number of test failures by the total number of tests.

[0071] In some embodiments, analyzing the impact of historical fault records on the extension of the test cycle of the device to be analyzed includes performing the following analysis on each historical fault in the historical fault records:

[0072] S01: Determine whether the current historical fault is the content of regular test and inspection.

[0073] S02: If it is not part of the regular test and inspection, it is determined that it does not affect the extension of the test period of the equipment to be analyzed.

[0074] S03: If it is the content of regular test and inspection, determine whether it can only be executed by means of regular test and inspection.

[0075] S04: If there are other alternative inspection methods, it is determined that it does not affect the extension of the test period of the equipment to be analyzed.

[0076] S05: If the fault can only be performed by means of periodic testing and inspection, determine whether the failure mode of the current historical fault is time-related.

[0077] S06: If it is not related to time, it is determined that it does not affect the extension of the test period of the device to be analyzed, and the conditions for extending the test period of the device to be analyzed are met. At this time, the historical performance analysis result shows that the test period can be extended.

[0078] S07: If it is related to time, it is determined that the test period of the device to be analyzed cannot be extended. In this case, the historical performance analysis result shows that the test period cannot be extended.

[0079] Specifically, such as Figure 2As shown, first determine whether the current historical fault is the content of this periodic test and inspection. If the current historical fault is not related to the content of the periodic test and inspection, then the fault will not affect the extension of the periodic test cycle. If the current historical fault is the content of the periodic test and inspection, then further determine whether there is an inspection method with a shorter cycle that can also detect the current historical fault. If there is an alternative inspection method with a shorter cycle, then determine that the current historical fault does not affect the extension of the periodic test cycle. Specifically, if there is no alternative inspection method, then analyze whether the failure mode of the current historical fault is time-related. As the equipment operating time increases, the probability of equipment failure will increase. If the test cycle is extended, this type of fault cannot be discovered and eliminated in time when it occurs, affecting the availability of the equipment.

[0080] Step S103: performing deterministic analysis on the relevant information of the device to be analyzed to obtain a deterministic analysis result.

[0081] By conducting deterministic analysis on the equipment to be analyzed, the compliance of the equipment to be analyzed with defense in depth, safety margin, regulations, guidelines, specifications and standards can be determined.

[0082] Optionally, in some embodiments, a deterministic analysis is performed based on relevant information of the device to be analyzed, and obtaining the deterministic analysis results includes: determining whether extending the test period of the device to be analyzed is consistent with the defense-in-depth principle based on the defense-in-depth evaluation requirements; if it is consistent with the defense-in-depth principle, determining whether the extended test period of the device to be analyzed meets the safety margin based on the impact results of the extended test period; if it is inconsistent with the defense-in-depth principle, determining that the test period cannot be extended; if the safety margin is met, determining whether relevant regulations are met based on the impact results of the extended period; if the safety margin is not met, determining that the test period of the device to be analyzed cannot be extended; if relevant regulations are met, determining that conditions for extending the test period of the device to be analyzed are met; if relevant regulations are not met, determining that the test period of the device to be analyzed cannot be extended. Determining whether extending the test period of the device to be analyzed meets the safety margin based on the impact results of the extended test period includes: determining whether the acceptance criteria of the safety analysis in the final safety analysis report are met based on the impact results of the extended test period; or determining whether the revised content accommodates the uncertainty of the analysis and data based on the impact results of the extended test period.

[0083] Specifically, for deterministic analysis of the equipment to be analyzed, first confirm whether the extended test period of the equipment to be analyzed satisfies the principle of defense in depth, that is, whether it is consistent with the principle of defense in depth. Then, safety margin analysis is performed.

[0084] Defense in depth consists of many requirements, which are summarized below. These factors can be used as criteria for evaluating defense in depth. If all of the following conditions are met, it is considered consistent with the defense in depth principle:

[0085] (1) A reasonable balance between prevention of core damage, prevention of containment failure and consequence mitigation is maintained (i.e., the extension of the test period does not change the balance between these prevention and mitigation principles). This balance needs to meet the acceptance criteria for specific design basis accidents and transients.

[0086] (2) Avoid reliance on procedural activities as compensating measures associated with license baseline changes (e.g., changes that are primarily based on high-reliability estimates of procedural assumptions).

[0087] (3) The redundancy, independence and diversity of the system are maintained.

[0088] (4) Prevention of potential common cause failures is maintained, and the possibility of introducing new common cause failure mechanisms is evaluated (for example, it should be considered whether the expected operational changes caused by the extension of the test cycle will introduce any new common cause failure modes that have not been considered before).

[0089] (5) The independence of the physical barrier will not be weakened.

[0090] (6) Measures to prevent human errors are maintained (for example, consideration should be given to whether the expected operational changes due to the extension of the test period will change the expected operator response or introduce any new human errors that have not been considered previously, such as modifying maintenance performed during an outage to be performed during power operation, which may involve different personnel and different activities).

[0091] (7) Comply with general design principles.

[0092] Safety margin analysis:

[0093] When the consistency with the principle of defense in depth is met, it is necessary to further evaluate whether the impact of the extended test period is consistent with the principle of maintaining an adequate safety margin. Among them, the acceptance criteria for evaluation are as follows: Adequate safety margin is maintained when the following conditions are met:

[0094] The acceptance criteria for the safety analysis in the Final Safety Analysis Report (FSAR) must be met; or the proposed revisions must have sufficient margins to accommodate the uncertainties in the analysis and data. For example, an extension of the test period will not adversely affect any assumptions or inputs to the safety analysis, or, if such inputs are affected, verification should be performed to ensure that adequate safety margins still exist.

[0095] Finally, it is necessary to determine whether relevant regulations are met, that is, to evaluate whether the extension of the test cycle meets the relevant provisions of laws, guidelines, specifications, and standards. Among them, the common laws, guidelines, specifications, and standards related to periodic testing are as follows:

[0096] HAF102 (the "Regulations on the Design Safety of Nuclear Power Plants") states: To maintain the functional capabilities of structures, systems, and components important to safety, their design must be capable of calibration, testing, maintenance, repair and replacement, inspection, and monitoring throughout the life of the nuclear power plant, and must meet requirements to demonstrate that reliability objectives are met. Extending the test cycle only changes the test execution period, while still meeting the requirements of this regulation.

[0097] HAF103 (i.e., "Safety Regulations for Commissioning and Operation of Nuclear Power Plants"): Section 6.1 of this regulation states that the maintenance, testing, supervision, and inspection programs shall take into account operating limits and conditions and other applicable nuclear safety management requirements, and shall be regularly evaluated based on operating experience. The operating organization shall evaluate the impact of new maintenance, testing, supervision, and inspection strategies on safety; Section 6.4 states that the operating organization shall determine the frequency of preventive and predictive maintenance, testing, supervision, and inspection of individual structures, systems, and components based on the following factors:

[0098] 1) The importance of structures, systems and components to safety;

[0099] 2) its inherent reliability;

[0100] 3) the possibility of performance degradation during operation and aging characteristics;

[0101] 4) Operational experience.

[0102] HAD103 / 01 (Operational Limits and Conditions and Operating Procedures for Nuclear Power Plants): Section 6.2 states that the monitoring frequency should be determined based on reliability analysis, including probabilistic safety assessment (when available), and empirical research based on existing monitoring results; or, in the absence of these two results, based on supplier recommendations. The justification for extending the test cycle should consider insights from the probabilistic safety assessment and historical feedback from test execution to determine the optimal test cycle.

[0103] HAD103 / 09 (i.e., "Supervision of Items Important to Safety in Nuclear Power Plants"): Section 4.1.3 states: When determining the frequency of supervision, the following items shall be considered: (1) the safety importance of the item and the need to meet reliability objectives; (2) the manufacturer's recommendations and information such as type test results, durability test results, and phantom load test results; (3) expected failure mechanisms, results of reliability analysis, service life of items and systems, component types, and operating conditions; (4) failure experience gained from maintenance and feedback from experience of this nuclear power plant and other similar nuclear power plants; (5) the degree of automation of supervision. Section 4.3 states: The determined frequency of supervision shall be re-evaluated periodically, and the following items shall be considered for this purpose: (1) the performance of the system or component, especially its failure rate; (2) the corrective actions taken after a failure occurs; (3) the performance of similar systems and components in similar nuclear power plants and under similar environmental conditions; (4) design changes related to the system or component; (5) information on failure modes that cause abnormal events or accidents; and (6) the aging effects of components.

[0104] A query of its historical test and operation records shows that the equipment has good reliability. Based on operational experience feedback and risk analysis, the test cycle is extended to meet the requirements of HAF103 and HAD103 / 09.

[0105] GB / T 5204 (i.e. "Periodic Testing and Monitoring of Nuclear Power Plants and Safety Systems"): Section 6.5.1 stipulates that the initial test interval or subsequent changes in test intervals should be determined using a deterministic or risk-based approach (or a combination of the two); Section 6.5.6 stipulates that the test interval may be changed to adapt to the plant's operating mode, but it must be demonstrated that such changes have no adverse effects on the expected performance of the equipment being tested, and that such changes will not cause adverse effects on public health and safety or core damage.

[0106] It should be noted that the above are only relevant and general regulations / guidelines / specifications / standards. In actual applications, other specific regulations / guidelines / specifications / standards may also need to be met based on actual conditions. The specific requirements will be determined by regular testing and verification of relevant equipment.

[0107] Among them, when it is determined that the principle of defense in depth is met, and the safety margin and relevant regulations are met, the deterministic analysis result is that the test period can be extended, otherwise the test period cannot be extended.

[0108] Step S104: performing a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result.

[0109] By performing a probabilistic analysis on the equipment to be analyzed, it can be confirmed whether the risk introduced by the test cycle change meets the requirements of the risk acceptance criteria.

[0110] Optionally, in some embodiments, a probability analysis is performed based on the relevant information of the device to be analyzed, and the probability analysis results are obtained, including: performing a risk assessment based on the relationship between the test cycle of the device to be analyzed and the failure probability of the device to be analyzed to obtain a risk increment; judging whether the risk increment is within the acceptable risk criteria; if so, determining that the conditions for extending the test cycle of the device to be analyzed are met; if not, determining that the test cycle of the device to be analyzed cannot be extended. The relationship between the test cycle of the device to be analyzed and the failure probability of the device is as follows: Figure 5 shown.

[0111] Specifically, the risks of nuclear power plants can be reflected by the core damage frequency (CDF) and the early large release frequency (LERF). The risks caused by the extension of the test cycle are mainly reflected in the changes in the CDF and LERF values before and after the test cycle is changed.

[0112] The impact of the extension of the periodic test cycle on the unit risk is mainly characterized by △CDF and △LERF, see formula (1) and formula (2).

[0113] △CDF=CDF1-CDF0 (1);

[0114] △LERF=LERF1-LERF0 (2).

[0115] In equations (1) and (2), △CDF represents the core damage frequency increment after the test period is extended; △LERF represents the early large release frequency increment after the test period is extended; CDF1 and LERF1 represent the risk values after the test period is extended; CDF0 and LERF0 represent the risk values before the test period is extended. The risk increment is △CDF and △LERF.

[0116] After the test period is extended, the total risk change of all events (internal events, external events and shutdown events) must meet the risk criteria, among which the risk acceptability criteria are:

[0117] △CDF<1.0E-06 / reactor-year and △LERF<1.0E-07 / reactor-year.

[0118] Risk Assessment:

[0119] The PSA model (i.e., risk calculation software) is a logical model that combines event trees and fault trees, in which the event tree is triggered by a possible initiating event (an initiating event refers to an event that causes disturbances to the nuclear power plant and may cause core damage. Whether the event will cause core damage depends on whether the mitigation system operates successfully), confirms the safety functions required to mitigate the initiating event, analyzes the subsequent processes of success or failure of each safety function, confirms whether it will cause core damage or early large-scale release, and then combines data analysis to calculate the frequency of occurrence of core damage or early large-scale release. The fault tree is used to analyze the failure probability of the mitigation system. It is a deductive analysis method from top to bottom (from system to component) and from system failure to failure cause. By assigning values to each cause, the failure probability of the mitigation system can be obtained. The structure of the event tree and fault tree is as follows. Figure 3 and Figure 4 shown.

[0120] In the analysis of periodic test cycle changes, it is usually considered that the periodic test cycle has an intrinsic relationship with equipment reliability. Figure 5 The failure probability of the equipment or component being tested is proportional to the test period. Therefore, the longer the test period, the greater the failure probability of the system or equipment, and vice versa.

[0121] Based on the relationship between the test cycle and equipment reliability, the changes in the failure parameters of the relevant equipment are reflected in the risk calculation software (PSA model) by extending the test cycle, and the changes in CDF and LERF can be obtained.

[0122] The aforementioned actuators include RIS020 / 021 / 023 / 029 / 030 / 031 / 061 / 062 / 063 / 064VP, RCP122 / 222 / 322VP RCP120 / 220 / 320VP and other valves, such as Figure 6 As shown in the figure, taking the modification of the RIS020VP rejection as an example, the probability of RIS023VP rejection in the fault tree changes from "2.57E-04" before the cycle extension to "5.14E-04" after the cycle extension. Because the cycle is doubled, the corresponding failure probability is also doubled. After the modification is completed, the CDF and LERF after the cycle extension can be calculated using the PSA model. Subtracting these from the CDF and LERF calculated before the cycle extension can determine the risk increase ΔCDF and ΔLERF caused by the cycle extension. The calculation results are shown in Table 1.

[0123] Table 1: Risk increase due to extended test period ( / combustion*year)

[0124]

[0125] It can be seen from Table 1 that after the test period is extended, the risk acceptability criteria are met.

[0126] When the risk acceptability criteria are met, it can be determined that the conditions for extending the test period of the equipment to be analyzed are met. At this time, the probability analysis result is that the test period can be extended, otherwise the test period cannot be extended.

[0127] Step S105: judging whether the test cycle of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results and the probabilistic analysis results; if not, maintaining the current test cycle.

[0128] In the embodiment of the present invention, the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results all include: whether the test period can be extended or whether the test period cannot be extended.

[0129] Optionally, in some embodiments, judging whether the test cycle of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results includes: if the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results are all test cycles that can be extended, then judging that the test cycle of the equipment to be analyzed can be extended; if any one or more of the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results are test cycles that cannot be extended, then judging that the test cycle of the equipment to be analyzed cannot be extended.

[0130] Step S106: If yes, extend the test period of the device to be analyzed.

[0131] It should be noted that there is no strict order requirement for the above steps S101 to S106, that is, steps S101 to S106 are not required to be performed in sequence, for example, step S102, step S103 and step S104 can be performed simultaneously.

[0132] refer to Figure 7 The present invention also provides a test cycle optimization device for an actuator of a safety injection system of a nuclear power plant.

[0133] like Figure 7 As shown in the figure, the test cycle optimization device for the actuator of the safety injection system of the nuclear power plant includes:

[0134] The information acquisition unit 701 is used to acquire relevant information of the device to be analyzed.

[0135] The historical performance analysis unit 702 is configured to perform a historical performance analysis of the device based on the relevant information of the device to be analyzed, and obtain a historical performance analysis result.

[0136] The deterministic analysis unit 703 is configured to perform a deterministic analysis based on the relevant information of the device to be analyzed to obtain a deterministic analysis result.

[0137] The probabilistic analysis unit 704 is configured to perform a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result.

[0138] The cycle extension judgment unit 705 is used to judge whether the test cycle of the device to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results and the probabilistic analysis results.

[0139] The test cycle extension unit 706 is configured to maintain the current test cycle when the cycle cannot be extended, and to extend the test cycle of the device to be analyzed when the cycle can be extended.

[0140] Specifically, the specific coordination operation process between the various units in the nuclear power plant safety injection system actuator test cycle optimization device can refer to the above-mentioned nuclear power plant safety injection system actuator test cycle optimization method, which will not be repeated here.

[0141] This invention can effectively and comprehensively demonstrate the feasibility of extending the test cycle for injection system actuators. Extending the test cycle can improve the economic efficiency of nuclear power plants while ensuring nuclear safety. For example, if the regular test cycle for a valve is 18 months and, after feasibility analysis, it can be extended to 36 months, the extended test cycle can reduce the test frequency. Since this test is on the overhaul critical path, the extended test cycle can avoid affecting this critical path and increase the flexibility of work arrangements during the overhaul.

[0142] In addition, an electronic device of the present invention includes a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program to implement a test cycle optimization method for an actuator of a safety injection system of a nuclear power plant as described in any one of the above. Specifically, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed by an electronic device and, when executed, performs the above functions defined in the method of the embodiment of the present invention. The electronic device in the present invention can be a terminal such as a notebook, a desktop, a tablet computer, a smart phone, or a server.

[0143] In addition, the present invention provides a storage medium having a computer program stored thereon. When executed by a processor, the computer program implements any of the above-mentioned methods for optimizing the test cycle of an actuator of a safety injection system of a nuclear power plant. Specifically, it should be noted that the storage medium of the present invention may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. Computer-readable storage media may be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or component. In the present invention, a computer-readable signal medium may include a data signal transmitted in baseband or as part of a carrier wave, which carries computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wires, optical cables, RF (radio frequency), or any suitable combination thereof.

[0144] The computer-readable medium may be included in the electronic device, or may exist independently without being incorporated into the electronic device.

[0145] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0146] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0147] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0148] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. All equivalent variations and modifications within the scope of the claims of the present invention are intended to be covered by the claims of the present invention.

Claims

1. A method for optimizing the test cycle of an actuator of a safety injection system of a nuclear power plant, characterized in that: The following steps are involved: Obtain relevant information about the device to be analyzed; Performing equipment historical performance analysis based on the relevant information of the equipment to be analyzed to obtain historical performance analysis results; Performing deterministic analysis based on the relevant information of the device to be analyzed to obtain a deterministic analysis result; Performing a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result; Determining whether the test period of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results; If not, maintain the current test cycle; If so, extend the test period of the device to be analyzed.

2. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 1, characterized in that: The relevant information of the equipment to be analyzed includes: historical periodic test results of the equipment to be analyzed, and historical fault records of the equipment to be analyzed; The performing of device historical performance analysis based on the relevant information of the device to be analyzed to obtain historical performance analysis results includes: Determining whether the performance of the equipment to be analyzed is qualified based on the historical periodic test results; If so, analyze the impact of the historical fault records on the extension of the test period of the equipment to be analyzed.

3. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 2, characterized in that: The analysis of the impact of the historical fault records on the extension of the test period of the equipment to be analyzed includes: The following analysis is performed on each historical fault in the historical fault record: Determine whether the current historical fault is subject to regular testing and inspection; If it is not the content of the regular test and inspection, it is determined that it does not affect the extension of the test period of the equipment to be analyzed; If it is the content of the periodic test and inspection, determine whether it can only be performed by means of the periodic test and inspection; If other alternative inspection methods are available, it shall be determined that this does not affect the extension of the test period of the equipment to be analyzed; If it can only be performed by means of the periodic test inspection, then determining whether the failure mode of the current historical failure is time-related; If it is not related to time, it is determined that it does not affect the extension of the test period of the device to be analyzed, and the conditions for extending the test period of the device to be analyzed are met; If it is related to time, it is determined that the test period of the device to be analyzed cannot be extended.

4. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 1, characterized in that: The relevant information of the equipment to be analyzed includes: defense-in-depth evaluation factors, safety margins and related regulations; The performing of deterministic analysis based on the relevant information of the device to be analyzed to obtain the deterministic analysis result includes: Determining whether the extended test period of the equipment to be analyzed is consistent with the defense in depth principle based on the defense in depth evaluation requirements; If it is consistent with the defense in depth principle, then judging whether the extended test period of the equipment to be analyzed satisfies the safety margin based on the impact result of the extended test period; if it is inconsistent with the defense in depth principle, then judging that the test period cannot be extended; If the safety margin is met, then judging whether the relevant regulations are met based on the impact of the test period extension; if the safety margin is not met, then judging that the test period of the device to be analyzed cannot be extended; If the relevant regulations are met, it is determined that the conditions for extending the test period of the equipment to be analyzed are met; if the relevant regulations are not met, it is determined that the test period of the equipment to be analyzed cannot be extended.

5. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 4, characterized in that: The determining, based on the impact result of the extended test period, whether the extended test period of the equipment to be analyzed satisfies the safety margin includes: Based on the impact of the extended test period, determine whether the acceptance criteria for the safety analysis in the final safety analysis report are met; or based on the impact of the extended test period, determine whether the revised content accommodates the uncertainties of the analysis and data.

6. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 1, characterized in that: The relevant information of the equipment to be analyzed includes: the test cycle of the equipment to be analyzed and the probability of equipment failure; The performing a probabilistic analysis based on the relevant information of the device to be analyzed to obtain a probabilistic analysis result includes: Performing risk assessment based on the relationship between the test cycle of the equipment to be analyzed and the failure probability of the equipment to obtain a risk increment; Determine whether the risk increment is within the acceptable risk criteria; If so, it is determined that the conditions for extending the test period of the equipment to be analyzed are met; If not, it is determined that the test period of the device to be analyzed cannot be extended.

7. The method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to claim 1, characterized in that: The historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results all include: whether the test period can be extended or not; The determining whether the test period of the equipment to be analyzed can be extended based on the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results includes: If the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results all indicate that the test period can be extended, then it is determined that the test period of the device to be analyzed can be extended; If any one or more of the historical performance analysis results, the deterministic analysis results, and the probabilistic analysis results indicate that the test period cannot be extended, it is determined that the test period of the device to be analyzed cannot be extended.

8. A test cycle optimization device for an actuator of a safety injection system of a nuclear power plant, characterized in that: include: An information acquisition unit, used to acquire relevant information of the device to be analyzed; A historical performance analysis unit, configured to perform a historical performance analysis of the device based on the relevant information of the device to be analyzed, and obtain a historical performance analysis result; A deterministic analysis unit, configured to perform a deterministic analysis based on the relevant information of the device to be analyzed to obtain a deterministic analysis result; A probability analysis unit, configured to perform a probability analysis based on the relevant information of the device to be analyzed to obtain a probability analysis result; a cycle extension judgment unit, configured to judge whether the test cycle of the equipment to be analyzed can be extended based on the historical performance analysis result, the deterministic analysis result, and the probabilistic analysis result; The test cycle extension unit is used to maintain the current test cycle when the cycle cannot be extended, and to extend the test cycle of the device to be analyzed when the cycle can be extended.

9. A storage medium, characterized in that: The storage medium stores a computer program, which is suitable for being loaded by a processor to execute the steps of the method for optimizing the test cycle of the actuator of the safety injection system of a nuclear power plant according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the test cycle optimization method of the actuator of the safety injection system of a nuclear power plant as claimed in any one of claims 1 to 7 by calling the computer program stored in the memory.

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