Nuclear power plant maintenance configuration risk quantitative assessment system, method, equipment and medium

Abstract

The present application provides a quantitative risk assessment system, method, computer device and readable storage medium for nuclear power plant maintenance configuration. The user inputs the maintenance cycle of the nuclear power plant to be evaluated, retrieves the information related to this maintenance cycle, obtains the list of main isolation equipment in the major overhaul main isolation work order and the list of non-main isolation equipment in the major overhaul non-main isolation work order corresponding to any moment in the time node set, so as to obtain the nuclear power plant configuration combinations under different nuclear power plant operating states for quantitative calculation, accurately obtain the risk level of the nuclear power plant full-cycle maintenance configuration, and further realize the in-depth optimization of the maintenance plan for this maintenance cycle, improve the scientificity of nuclear power plant maintenance configuration risk management, shorten the major overhaul time while ensuring safety, and improve the economic benefits of the nuclear power plant.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear power plant safety management, and in particular to a system, method, computer equipment and readable storage medium for quantitatively assessing the maintenance configuration risk of a nuclear power plant. Background Art

[0002] Nuclear safety is a major issue concerning the overall national security, national economy and people's livelihood. During the maintenance process of nuclear power plants, the equipment will be isolated and decommissioned, which will affect the availability of the system in which it is located, making it impossible to perform its expected functions under possible accident conditions to achieve effective mitigation of accidents, bringing certain risks of core damage or radioactive release. It is particularly important to conduct risk assessment on nuclear power plant maintenance plans to avoid excessive or overly conservative maintenance risks and achieve a more reasonable balance between safety and economy.

[0003] In terms of risk assessment of nuclear power plant overhaul, although there have been relevant research works at home and abroad, they are mainly focused on qualitative analysis. Internationally, according to the research report of the Electric Power Research Institute (EPRI) on the nuclear power plants in service in the United States (CA:2011.1022999), the US nuclear power plants generally establish a defense in depth model to qualitatively analyze the availability of key safety functions of nuclear power plants during low power / shutdown to ensure the safety of overhaul.

[0004] In my country, most of the nuclear power plants in service also use qualitative analysis for overhaul risk analysis. In the prior art, the patent document "A method for evaluating the safety risk of shutdown during nuclear power plant overhaul" (application number: 202110726105.5) proposes a method for qualitatively analyzing overhaul risks by evaluating the availability level of each key safety function at any time of overhaul. The patent document "A method for developing a nuclear safety risk management tool for nuclear power plant overhaul" (application number: 202010489008.4) evaluates the redundancy and availability level of key safety functions of nuclear power plants by establishing a safety function analysis tree. This method belongs to the category of qualitative analysis. The patent document "A method and device for optimizing the maintenance strategy of a nuclear power plant" (application number: 201611123915.7) optimizes the maintenance strategy for specific aging failure modes and is not related to the overall risk level assessment of the power plant.

[0005] Qualitative analysis can obtain the availability of key safety functions of nuclear power plants, thereby ensuring safety to a certain extent, but it is difficult to accurately obtain the overall risk level of the power plant, and therefore it is difficult to achieve in-depth optimization of maintenance configuration. Summary of the invention

[0006] The present invention provides a nuclear power plant maintenance configuration risk quantitative assessment system, method, computer equipment and readable storage medium, which solves the problem of quantitative assessment of nuclear power plant full power cycle maintenance configuration risk. The nuclear power plant configuration combinations under different nuclear power plant operating states (POS) can be obtained and quantitatively calculated, and the full cycle maintenance configuration risk level of the power plant can be accurately obtained.

[0007] The first aspect of the present invention provides a nuclear power plant maintenance configuration risk quantitative assessment system, comprising: a user input unit, which is used to input the nuclear power plant maintenance round that needs to be assessed; an information retrieval unit, which is used to retrieve information, the information including the maintenance plan of the nuclear power plant maintenance round, a pre-established probabilistic safety assessment (PSA) real-time risk model and POS; a risk assessment unit, which performs risk assessment on the nuclear power plant maintenance round according to the information retrieved by the information retrieval unit; wherein the risk assessment unit includes: a node configuration module, which reads the maintenance time node set T from the maintenance plan cnf , the equipment extraction module, which is based on the maintenance time node set T cnf , screen out the equipment list that needs to be isolated, an equipment identification module, which determines whether the equipment list contains equipment in the PSA real-time risk model, and a risk calculation module, which determines the maintenance time node set T when the equipment list contains equipment in the PSA real-time risk model. cnf The corresponding POS is selected and the corresponding PSA real-time risk model is calculated according to the POS.

[0008] Preferably, the information retrieval unit is capable of retrieving information from the planning and scheduling system and the production management system, wherein the planning and scheduling system includes work orders for maintenance plans for all maintenance rounds of nuclear power plants; the production management system includes work orders for maintenance plans that are being executed and have been executed, and supervises the execution of the work orders for the maintenance plans, and manages the associated components of the isolation equipment in the work orders for the maintenance plans; wherein the work orders for the maintenance plans include overhaul plan work orders and routine maintenance plan work orders.

[0009] Preferably, the overhaul plan work order includes an overhaul main isolation work order and an overhaul non-main isolation work order, and the time node set T cnf Including the isolation start time and isolation release time of the overhaul main isolation work order, the planned start time and planned completion time of the overhaul non-main isolation work order, and the time of POS change; the equipment extraction module obtains the time node set T cnf At any time t i The corresponding main isolation equipment list in the overhaul main isolation work order and the non-main isolation equipment list in the overhaul non-main isolation work order; the equipment identification module determines whether the main isolation equipment list and the non-main isolation equipment list contain equipment in the PSA real-time risk model; the risk calculation module determines the time t when the main isolation equipment list and the non-main isolation equipment list contain equipment in the PSA real-time risk modeli The corresponding POS, and select the PSA real-time risk model corresponding to it for calculation according to the POS.

[0010] Preferably, the time node set T cnf includes the time range of the daily maintenance plan work orders that need risk assessment selected; the equipment extraction module filters the daily maintenance plan work orders containing isolated equipment within the time range, and obtains the isolated equipment of the unexecuted, in-execution, and executed daily maintenance plan work orders to form a total isolated equipment list; the equipment discrimination module determines whether the total isolated equipment list contains the equipment in the PSA real-time risk model; when the total isolated equipment list contains the equipment in the PSA real-time risk model, the risk calculation module selects the PSA real-time risk model corresponding to it for calculation according to the total isolated equipment list.

[0011] Preferably, the work order of the maintenance plan includes a work order number, a functional location, a planned start time, and a planned end time. The work order number is the identifier of the work order and remains consistent in the planned scheduling system and the production management system.

[0012] Preferably, at any moment t i the list of main isolation equipment in the corresponding major overhaul main isolation work order includes all the major overhaul main isolation equipment in the major overhaul main isolation work orders where the isolation start time is less than t i and the isolation release time is greater than t i of the major overhaul main isolation equipment.

[0013] Preferably, at any moment t i the list of non-main isolation equipment in the corresponding major overhaul non-main isolation work order includes all the isolated equipment in the major overhaul non-main isolation work orders where the planned start time is less than t i and the planned completion time is greater than t i of the isolated equipment.

[0014] The second aspect of the present invention provides a method for quantitatively evaluating the risk of nuclear power plant maintenance configuration, including the following steps: Step S1, input the nuclear power plant maintenance cycle to be evaluated; Step S2, retrieve the maintenance plan, the pre-established PSA real-time risk model, and the POS of the nuclear power plant maintenance cycle; Step S3, read the maintenance time node set T cnf from the maintenance plan; Step S4, according to the maintenance time node set T cnf , screen out the list of equipment that needs to be isolated; Step S5, determine whether the equipment list contains the equipment included in the PSA real-time risk model. If it does not contain the equipment in the PSA real-time risk model, return to Step S3. If it contains the equipment in the PSA real-time risk model, then execute Step S6; Step S6, determine the POS corresponding to the maintenance time node set T cnf and select the PSA real-time risk model corresponding to it for calculation according to the POS.

[0015] Preferably, in step S2, the maintenance plan for the nuclear power plant maintenance round includes overhaul plan work orders, and the overhaul plan work orders include main isolation work orders for overhaul and non-main isolation work orders for overhaul; in step S3, the time node set T cnf includes the isolation start time and isolation release time of the main isolation work order for overhaul, the planned start time and planned completion time of the non-main isolation work order for overhaul, and the time of POS change; in step S4, the list of equipment that needs to be isolated is screened out by including obtaining the time node set T cnf at any moment t i in the corresponding main isolation equipment list in the main isolation work order for overhaul and the non-main isolation equipment list in the non-main isolation work order for overhaul;

[0016] Preferably, in step S2, the maintenance plan for the nuclear power plant maintenance round includes daily maintenance plan work orders; in step S3, the time node set T cnf includes the time range of the daily maintenance plan work orders that need to be risk-assessed; in step S4, the list of equipment that needs to be isolated is screened out by screening the daily maintenance plan work orders containing isolated equipment within the time range and obtaining the isolated equipment of the daily maintenance plan work orders that are being executed and have been executed to form a total isolated equipment list.

[0017] The third aspect of the present invention provides a computer device, including: one or more processors; a memory storing one or more programs thereon; when the one or more processors execute the one or more programs, the steps of the method described in the second aspect of the present invention are implemented.

[0018] The fourth aspect of the present invention provides a computer-readable storage medium, having a computer program stored thereon, and when the program is executed by a processor, the steps of the method described in the second aspect of the present invention are implemented.

[0019] For the nuclear power plant maintenance configuration risk quantitative assessment system, method, computer device and readable storage medium of the present invention, the user inputs the nuclear power plant maintenance round that needs to be evaluated, retrieves the information related to this maintenance round, obtains the time node set T cnf at any moment t i in the corresponding main isolation equipment list in the main isolation work order for overhaul and the non-main isolation equipment list in the non-main isolation work order for overhaul, so as to obtain the nuclear power plant configuration combinations under different POSs for quantitative calculation, accurately obtain the risk level of the nuclear power plant full-cycle maintenance configuration, and further realize the in-depth optimization of the maintenance plan for this maintenance round, improve the scientificity of the nuclear power plant maintenance configuration risk management, shorten the overhaul time while ensuring safety, and improve the economic benefits of the nuclear power plant. Description of the Drawings

[0020] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the attached drawings used in the embodiments of the present application. Obviously, the attached drawings described below are only specific embodiments of the present application, and those skilled in the art can obtain other embodiments based on the following attached drawings without creative efforts.

[0021] Figure 1 It is a functional block diagram of a quantitative risk assessment system for nuclear power plant maintenance configuration according to an embodiment of the present invention;

[0022] Figure 2 It is a data flow model of a quantitative risk assessment system for nuclear power plant maintenance configuration according to an embodiment of the present invention;

[0023] Figure 3 It is a flow chart of quantitative risk assessment according to an embodiment of the present invention;

[0024] Figure 4 It is a data flow model of a quantitative risk assessment system for nuclear power plant maintenance configuration according to another embodiment of the present invention;

[0025] Figure 5 It is a schematic diagram of the graphical user interface of a quantitative risk assessment system for nuclear power plant maintenance configuration according to a specific embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of the graphical user interface of POS time management according to a specific embodiment of the present invention;

[0027] Figure 7 It is a schematic diagram of the user interface for displaying the details of the overhaul plan according to a specific embodiment of the present invention;

[0028] Figure 8 It is an offline import template for the maintenance plan according to a specific embodiment of the present invention;

[0029] Figure 9 It is an instantaneous risk curve of quantitative analysis before optimizing the overhaul plan work order according to an embodiment of the present invention;

[0030] Figure 10 It is a risk magnification curve of quantitative analysis before optimizing the overhaul plan work order according to an embodiment of the present invention;

[0031] Figure 11 It is an accumulated risk curve of quantitative analysis before optimizing the overhaul plan work order according to an embodiment of the present invention;

[0032] Figure 12 It is an instantaneous risk curve of quantitative analysis after optimizing the overhaul plan work order according to an embodiment of the present invention;

[0033] Figure 13Cumulative risk curve after optimization of overhaul plan work order for an embodiment of the present invention;

[0034] Figure 14 Flow chart of quantitative risk assessment method for maintenance configuration of nuclear power plant for an embodiment of the present invention.

[0035] The accompanying drawings here are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Detailed implementation manners

[0036] To better understand the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0037] It should be clear that the following embodiments are only a part of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the following embodiments without creative efforts fall within the scope of protection of the present application.

[0038] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should be understood that the term " / and / " used herein is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0040] It should be noted that the orientation terms such as "upper", "lower", "left" and "right" described in the embodiments of the present application are described from the angles shown in the accompanying drawings and should not be construed as limitations on the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0041] During the maintenance process of a nuclear power plant, the isolation and withdrawal of equipment from operation will be involved, thus affecting the availability of the system in which it is located, making it difficult to perform its expected functions under possible accident conditions to effectively mitigate the accident, and bringing a certain risk of core damage or radioactive release. Conducting risk assessment on the maintenance plan of a nuclear power plant to avoid excessive or overly conservative maintenance risks and achieving a relatively reasonable balance between safety and economy is particularly important.

[0042] The maintenance plan of a nuclear power plant is divided into two parts: the overhaul plan and the daily plan.

[0043] The overhaul of a nuclear power plant is a process of isolating, testing, and maintaining multiple systems in the nuclear island and conventional island during the reactor shutdown and refueling period. This process is divided into three processes: the down phase, refueling, and the up phase. In the down phase, as the reactor power, temperature, and pressure gradually decrease to zero power, normal temperature, and atmospheric pressure, the main systems of the power plant are successively isolated and shut down for testing and maintenance. This process involves multiple buildings and systems, such as: the reactor emergency shutdown system, chemical and volume control system, normal residual heat removal system, automatic depressurization system, gravity injection and recirculation system, core makeup tank system, startup feedwater system, accumulator system, and various support systems, etc. During the reactor shutdown and refueling period, some important safety systems are tested and maintained. In the up phase, the reactor gradually heats up, pressurizes, and increases power to the full power level, during which the systems of the nuclear power plant are successively restored to operation.

[0044] During the entire overhaul period, according to different power, pressure, and temperature levels, as well as different system operation states, the nuclear power plant can be divided into multiple different POSs.

[0045] The daily plan of a nuclear power plant is a plan formulated under the full power operation condition to solve those defects that affect the normal function of the system and those defects that are relatively simple to repair and have little risk. It usually includes preventive maintenance and regular tests, and involves the withdrawal of local systems and equipment from operation. Compared with the daily plan, the overhaul plan involves more complex changes in the power, temperature, and pressure levels of the power plant, as well as configuration changes in the operation states of systems and equipment. The system operation process is more complex, with a greater risk change level, and it is one of the most important research contents in the risk assessment of the maintenance configuration of a nuclear power plant. The daily plan usually repairs the local equipment of a single system, involving fewer equipment, and the risk level change of the nuclear power plant is relatively small.

[0046] There are two methods for analyzing the risk of maintenance configuration: qualitative analysis and quantitative analysis. Qualitative analysis mainly analyzes the impact of equipment unavailability during maintenance on the availability of its series, system, and even the key safety functions of the nuclear power plant (including reactivity control, primary coolant inventory control, primary loop pressure control, core decay heat removal, and containment heat removal, etc.). For example, the normal residual heat removal system (RNS) consists of two identical first series (RNS-A) and second series (RNS-B). An important equipment in the RNS-A series is the residual heat removal pump. The unavailability of this pump may lead to the unavailability of the RNS-A series where it is located, and then reduce the redundancy of the RNS system, affecting the availability of containment heat removal. Qualitative analysis can obtain the availability of the key safety functions of the power plant, thus ensuring safety to a certain extent, but it is difficult to accurately obtain the overall risk level of the power plant, so it is difficult to achieve in-depth optimization of the maintenance configuration. Quantitative analysis is a process of obtaining the overall risk level of the power plant by establishing a real-time PSA risk model for the nuclear power plant under full power and low power / shutdown conditions, associating each system and equipment of the nuclear power plant under different operating conditions with the final safety analysis goal by combining event trees and fault trees, and analyzing in combination with the reliability and availability data of the power plant equipment. The overall level of the power plant is usually characterized by the core damage frequency (CDF) and the large early radioactive release frequency (LERF). For the risk assessment of maintenance configuration, the cumulative risk increment during maintenance, the incremental core damage probability (ICDP), and the incremental large early radioactive release probability (ILERP) also need to be considered. The quantitative assessment of the maintenance risk of the nuclear power plant can, on the one hand, obtain important parameters such as the instantaneous risk distribution and cumulative risk increment during the maintenance process, avoid excessive risk peaks and cumulative risk increments, and ensure the safety of maintenance. On the other hand, it can also avoid overly conservative maintenance plans, thus shortening the overhaul time while ensuring the safety of the nuclear power plant and improving economic efficiency.

[0047] Figure 1 The functional block diagram of the quantitative assessment system 100 for the maintenance configuration risk of a nuclear power plant according to an embodiment of the present invention.

[0048] As Figure 1 shown, the quantitative assessment system 100 for the maintenance configuration risk of a nuclear power plant according to an embodiment of the present invention includes a user input unit 1, an information retrieval unit 2, and a risk assessment unit 3.

[0049] The user input unit 1 is used to input the maintenance round 11 of the nuclear power plant to be evaluated (see Figure 2 ). The maintenance round 11 of the nuclear power plant is compiled according to the actual maintenance situation of the nuclear power plant and can be numbered according to the number of times of maintenance of each unit of the nuclear power plant. For example, for the second major overhaul of Unit 1, the overhaul round is 102, and this number can be compiled according to the actual situation, and no specific limitation is made here.

[0050] The information retrieval unit 2 is used to retrieve information, including the maintenance plan for the nuclear power plant maintenance round 11, the pre-established PSA real-time risk model, and POS, etc. After the user inputs the number of the nuclear power plant maintenance round 11 that needs to be evaluated through the user input unit 1, the information retrieval unit 2 retrieves the maintenance plan related to the maintenance round 11 according to the number of the maintenance round 11. The maintenance plans for each maintenance round 11 of the nuclear power plant are pre-customized by the nuclear power plant according to the actual situation, and they contain various maintenance-related information such as the unit numbers to be maintained, the planned start time and planned completion time of the maintenance.

[0051] During the operation of the nuclear power plant, the nuclear power plant will pre-establish a PSA real-time risk model, that is, a PSA risk model. The PSA risk model applies the probabilistic safety analysis method, considering changes in the design and operation of the nuclear power plant, new technical information, and information obtained from the operation of the nuclear power plant, etc., and can fully reflect the operation status of the nuclear power plant. PSA equipment is pre-specified in the PSA risk model, so that risk assessment can be carried out on the PSA equipment. For example, PSA equipment includes chemical and volume control system makeup pumps, start-up feed pumps, motor-operated valves, etc.

[0052] During the maintenance of the nuclear power plant, according to different power, pressure and temperature levels and different system operation states, the nuclear power plant can be divided into multiple POSs. Taking the AP1000 unit as an example, it can be divided into more than 10 different POSs, as shown in Table 1 for details. The POSs in Table 1 are only some exemplary descriptions. For different operation conditions of nuclear power plants, they can be divided into different POSs, which are not specifically limited here.

[0053] Table 1 Operating status table of AP1000 unit

[0054]

[0055]

[0056]

[0057] The risk assessment unit 3 conducts a risk assessment on the nuclear power plant maintenance round 11 according to the information retrieved by the information retrieval unit 2. After the user input unit 1 inputs the number of the nuclear power plant maintenance round 11 that needs to be evaluated, the information retrieval unit 2 retrieves the maintenance plan, PSA risk model related to the maintenance round 11, and the POS corresponding to the maintenance round 11 according to the number of the maintenance round 11. The risk assessment unit 3 calculates risk indicators for the maintenance round 11 according to the information retrieved by the information retrieval unit 2, so as to carry out the nuclear power plant risk assessment.

[0058] The risk assessment unit 3 includes a node configuration module 31, a device extraction module 32, a device discrimination module 33, and a risk calculation module 34.

[0059] The node configuration module 31 reads the maintenance time node set T from the maintenance plan related to the maintenance round 11 retrieved by the information retrieval unit 2. cnf , the maintenance time node set T cnf may include the key time points of each maintenance work order in the maintenance plan, such as the isolation start time and isolation release time when equipment isolation operations need to be performed, etc.

[0060] Based on the maintenance time node set T read by the node configuration module 31, cnf the device extraction module 32 filters out the list of devices that need to be isolated. The device extraction module 32 obtains the list of isolated devices corresponding to any moment t cnf in the maintenance time node set T. i

[0061] The device discrimination module 33 determines whether the list of devices that need to be isolated extracted by the device extraction module 32 contains the PSA devices predefined in the PSA risk model, that is, takes the intersection of the list of devices that need to be isolated and the PSA devices. If the intersection is empty, it directly skips. The device extraction module 32 obtains the list of isolated devices corresponding to any moment t cnf in the maintenance time node set T i+1 and performs configuration calculation at moment t. i+1 If the intersection is not empty, it enters the POS state recognition process, that is, enters the risk calculation module 34 for risk assessment calculation.

[0062] When the list of devices that need to be isolated contains the PSA devices in the PSA risk model, the risk calculation module 34 determines the POS corresponding to any moment t cnf in the maintenance time node set T i and selects the corresponding PSA risk model for calculation according to the POS. Before calculation, it is necessary to compare the POS at moment t i with the POS at moment t i-1 . If the POS states are the same, there is no need to calculate, and the risk result at moment t i-1 is directly adopted; if the POS states are different, risk calculation is performed at moment t i , and the calculation ends when i = N.

[0063] The nuclear power plant maintenance configuration risk quantitative assessment system 100 of the present invention solves the problem of quantitative assessment of the nuclear power plant full-power cycle maintenance configuration risk, can obtain the nuclear power plant configuration combinations under different POSs online and perform quantitative calculations, and accurately obtains the nuclear power plant full-cycle maintenance configuration risk level.

[0064] Figure 2 The data flow model of the risk quantitative assessment system 100 for nuclear power plant maintenance configuration according to an embodiment of the present invention.

[0065] As Figure 2 shown, the information retrieval unit 2 can retrieve the information of the planned scheduling system 4 and the production management system 5. The planned scheduling system 4 includes work orders for the maintenance plans of all nuclear power plant maintenance rounds 11. The production management system 5 includes work orders for the maintenance plans that are being executed and have been executed, supervises the execution of the work orders for the maintenance plans, and manages the associated components of the isolated equipment in the work orders for the maintenance plans. Among them, the work orders for the maintenance plans include overhaul plan work orders 41 and daily maintenance plan work orders 42 (see Figure 4 ).

[0066] In the planned maintenance of nuclear power plants, multiple nuclear power plant maintenance rounds 11 are usually set, and a detailed maintenance plan is configured for each maintenance round 11. Each maintenance plan in each maintenance round 11 can include multiple work orders. These work orders are created in the planned scheduling system 4, and all work order information can be read in the planned scheduling system 4. The work orders are divided into two categories. One category is work orders for on-line tests or maintenance that do not require isolation operations. The other category is work orders that require isolation and shutdown for tests or maintenance operations. These work orders affect the normal operation of the system and are the work orders that need to be quantitatively evaluated for risks. After the work orders are created in the planned scheduling system 4, they need to be synchronized to the production management system 5 for supervised execution.

[0067] Please continue to refer to Figure 2 , the overhaul plan work order 41 includes an overhaul main isolation work order 411 and an overhaul non-main isolation work order 412. The time node set T cnf includes the isolation start time t 1sk and the isolation release time t 1ek of the overhaul main isolation work order 411, the planned start time t 2sj and the planned completion time t 2ej of the overhaul non-main isolation work order 412, and the time of POS change. The equipment extraction module 32 obtains the list of main isolation equipment in the overhaul main isolation work order 411 and the list of non-main isolation equipment in the overhaul non-main isolation work order 412 corresponding to any moment t cnf in the time node set T i . The equipment discrimination module 33 determines whether the list of main isolation equipment and the list of non-main isolation equipment contain the equipment in the PSA risk model. When the list of main isolation equipment and the list of non-main isolation equipment contain the equipment in the PSA risk model, the risk calculation module 34 determines the POS corresponding to the moment t i , and selects the corresponding PSA risk model for calculation according to the POS.

[0068] During the major overhaul of a nuclear power plant, each system or train is isolated and taken out of service in a planned manner according to the operating requirements of the plant under different POSs. This system / train-level withdrawal and isolation plan is called the major overhaul master isolation plan. The major overhaul master isolation plan can be displayed in the planning and scheduling system 4 through the major overhaul master isolation work order 411 with a coded representation following certain rules. For example, the code TC-SGS-01 represents the master isolation plan (or main line plan) for series 01 of the steam generator system (SGS) of unit 1. These codes are called the master isolation codes C (or main line plan codes). The isolation code is the number assigned by the nuclear power plant to each set of equipment to be isolated, which is used to associate the isolated equipment with the work order in the production management system 5. The isolation codes are compiled as needed and there is no fixed limit on the quantity.

[0069] The major overhaul master isolation information M can be obtained through the major overhaul master isolation work order 411. The user inputs the maintenance round 11 in the user input unit 1, and the information retrieval unit 2 reads the major overhaul master isolation work order 411 of the major overhaul master isolation plan from the planning and scheduling system 4, so as to obtain the master isolation information M of this major overhaul master isolation work order 411, including the master isolation code C, the isolation start time t 1sk and the isolation release time t 1ek and other information.

[0070] The information retrieval unit 2 can read all the major overhaul plan work orders 41 through the planning and scheduling system 4 and obtain the work order information of all the major overhaul plan work orders 41. The work orders of each maintenance plan include the work order number B, the functional location P, the planned start time t 2sj and the planned completion time t 2ej and other information. Among them, the work order number B is the unique identifier of the work order and remains consistent in the planning and scheduling system 4 and the production management system 5. After reading all the major overhaul plan work orders 41, screen the major overhaul plan work orders 41 that require equipment isolation according to certain isolation rules. Here, the isolation rules are specifically formulated according to the actual situation of different nuclear power plants and can be directly identified according to the isolation number. That is, when compiling the work order number B, assign an isolation number to the work order that needs to be isolated. Then, when reading the work order number B, the work order with the isolation number needs to be isolated; it can also be judged according to the type of work order. When formulating the maintenance work order, a work order permit type can be assigned to each work order. For example, the work order permit type "PW" represents "maintenance", "PT" represents "test", or "PW-PT" represents "maintenance to test". These work orders with permit types are the work orders that require equipment isolation. The above isolation rules are only for illustrative purposes, and different nuclear power plants can select appropriate isolation rules according to the actual situation.

[0071] Please continue to refer to Figure 2, in the production management system 5, the equipment object that needs to be isolated is called "Functional Location P". During the implementation of the work order, for the isolation operation of Functional Location P, it is necessary to close the associated components (such as valves, switches, etc.) upstream and downstream of Functional Location P, so as to achieve the isolation operation of Functional Location P. The equipment that needs to be isolated related to the isolated equipment object is called "Hanging Tag Location G". For example, when isolating a certain pump, it is usually necessary to close and isolate the valves upstream and downstream of the pump. At this time, the pump is Functional Location P and the valve is Hanging Tag Location G. These associated components are stored in the production management system 5 for unified management. The isolation of these associated components related to the major overhaul main isolation can be called sub-isolation. Assigning an isolation number (such as CL22529) to these associated components is called sub-isolation code C z , sub-isolation code C z is associated with the major overhaul main isolation. Therefore, in the production management system 5, the relevant Functional Location P and associated components can be queried through the major overhaul main isolation work order 411, that is, the relevant sub-isolation information can be queried in the production management system 5 through the main isolation code C. These sub-isolation information includes sub-isolation code C z , Functional Location P, Hanging Tag Location G, and information such as the sub-isolation work order 4111 (the work order associated with the sub-isolation). The isolation equipment information of the major overhaul main isolation work order 411 includes the Functional Location P and Hanging Tag Location G of all sub-isolations associated with the main isolation. The isolation start time of the isolation equipment of the major overhaul main isolation work order 411 is the same as the isolation start time t of the major overhaul main isolation work order 411 1sk The isolation release time of the isolation equipment of the major overhaul main isolation work order 411 is the same as the isolation release time t of the major overhaul main isolation work order 411 1ek is the same.

[0072] According to the actual operation situation of the nuclear power plant, about 40% of the major overhaul plan work orders 41 during the major overhaul of the nuclear power plant are associated with the major overhaul main isolation work order 411, and about 60% of the major overhaul plan work orders 41 are not associated with the major overhaul main isolation work order 411. Integrating all the sub-isolation work orders 4111 included in the main isolation, the major overhaul main isolation work order 411 is obtained. Subtracting the total major overhaul plan work order 41 from the set of the major overhaul main isolation work order 411, the major overhaul non-main isolation work order 412 is obtained. The isolation equipment of the major overhaul non-main isolation work order 412 is the Functional Location P of the work order. The isolation start time of the isolation equipment of the major overhaul non-main isolation work order 412 is the planned start time t of the major overhaul non-main isolation work order 412 2sj , and the isolation release time of the isolation equipment of the major overhaul non-main isolation work order 412 is the planned completion time t of the major overhaul non-main isolation work order 412 2ej .

[0073] Determine the POS status based on the information obtained from the above major overhaul main isolation work order 411 and major overhaul non-main isolation work order 412, so as to match the corresponding PSA risk model and perform risk assessment calculations.

[0074] Figure 3 It is a flowchart for quantitatively assessing risks of the risk assessment unit 3 according to an embodiment of the present invention.

[0075] As Figure 3 shown, the steps for the risk assessment unit 3 to calculate the risk index for a certain maintenance round 11 based on the information retrieved by the information retrieval unit 2 are as follows:

[0076] Step Sa, the node configuration module 31 retrieves the maintenance time node set T from the maintenance plan related to the maintenance round 11 retrieved by the information retrieval unit 2 cnf =[t 0 , t 1 , t 2 …t i …t N , where t 0 , t 1 , t 2 …t i …t N represents the maintenance time in the maintenance plan, corresponding to N possible POS status change time points.

[0077] Step Sb, screen out the main isolation time set T of the major overhaul main isolation work order 411 from the maintenance time node set T cnf configured in step Sa 1 ={[t 1s0 , t 1e0 [t 1s1 , t 1e1 …[t 1sk , t 1ek …[t 1sN1 , t 1eN1}, t 1sk represents the isolation start time including the t i moment, and t 1ek represents the isolation release time including the t i moment.

[0078] Step Sc, the equipment extraction module 32 extracts from the main isolation time set T 1 ={[t 1s0 , t 1e0 [t 1s1 , t 1e1 …[t 1sk , t 1ek …[t 1sN1 , t 1eN1} Screen the main isolation information. Traverse all major overhaul main isolation work orders 411 and judge whether t i satisfies t 1sk ≤t i ≤t 1ek .

[0079] Step Sd, merge the main isolation equipment of the major overhaul main isolation work order 411 with the isolation start time t 1sk less than t i , and the isolation release time t 1ek greater than t i into the main isolation equipment list corresponding to the moment t i .

[0080] At any moment t i , the main isolation equipment list in the major overhaul main isolation work order 411 corresponding to it includes all the main isolation equipment in all major overhaul main isolation work orders 411 with the isolation start time less than t i and the isolation release time greater than t i .

[0081] Meanwhile, delete the major overhaul main isolation work order 411 with the isolation release time t 1ek less than t i from the major overhaul main isolation work order 411 to improve the search speed of the main isolation equipment at the moment t i+1 .

[0082] Step Se, when t i does not satisfy t 1sk ≤t i ≤t 1ek , judge whether k is less than N1, where k represents the kth main isolation equipment list and N1 is the number of all main isolation equipment lists. When k < N1, enter the screening of the main isolation information in the (k + 1)th isolation period. When k = N1, that is, after traversing all major overhaul main isolation work orders 411, screen out all the main isolation equipment to form the main isolation equipment list.

[0083] Step Sf, screen out the non-main isolation work order time set T cnf of the major overhaul non-main isolation work order 412 from the maintenance time node set T 2 configured in step Sa, T 2s0 ={[t 2e0 [t 2s1 [t 2e1 …[t 2sj [t 2ej …[t 2sN2 [t 2eN2}, t 2sj represents the planned start time including the t i th moment, t 2ejIndicates the planned completion time at the t-th i moment.

[0084] Step Sg, the device extraction module 32 filters non-primary isolation information from the non-primary isolation work order time set T 2 ={[t 2s0 , t 2e0 [t 2s1 , t 2e1 …[t 2sj , t 2ej …[t 2sN2 , t 2eN2}. Traverse all major overhaul primary isolation work orders 411 and judge whether t i satisfies t 2sj ≤t i ≤t 2ej .

[0085] Step Sh, merge the non-primary isolation equipment in the major overhaul non-primary isolation work order 412 whose planned start time t 2sj is less than t i and whose planned completion time t 2ej is greater than t i into the non-primary isolation equipment list corresponding to the t i moment.

[0086] The non-primary isolation equipment list in the major overhaul non-primary isolation work order 412 corresponding to any moment t i includes all the non-primary isolation equipment in the major overhaul non-primary isolation work order 412 whose planned start time t 2sj is less than t i and whose planned completion time t 2ej is greater than t i .

[0087] At the same time, delete the major overhaul non-primary isolation work order 412 whose planned completion time t 2ej is less than t i from the major overhaul non-primary isolation work order 412 to improve the search speed of non-primary isolation equipment at the t i+1 moment.

[0088] Step Si, when t i does not satisfy t 2sj ≤t i ≤t 2ej , judge whether j is less than N2, where j represents the j-th non-primary isolation equipment list and N2 is the number of all non-primary isolation equipment lists. When j < N2, enter the screening of primary isolation information in the (j + 1)-th isolation period. When j = N2, that is, finish traversing all major overhaul non-primary isolation work orders 412, screen out all non-primary isolation equipment, and form a non-primary isolation equipment list.

[0089] Step Sj, merge the master isolation equipment list and the non-master isolation equipment list obtained in Step Se and Step Si into the total equipment list that needs to be isolated.

[0090] Step Sk, the equipment discrimination module 33 determines whether the equipment list that needs to be isolated contains the PSA equipment specified in the PSA risk model in advance, that is, take the intersection of the equipment list that needs to be isolated and the PSA equipment. If the intersection is empty, directly skip to Step Sm to judge the moment t i whether i satisfies i < N; if the intersection is not empty, it means that the equipment list that needs to be isolated contains PSA equipment, then enter Step Sn to enter the POS state recognition to judge the current moment t i of the POS.

[0091] Step Sp, after determining the POS, judge the current moment t i whether the total equipment list that needs to be isolated and the POS at the current moment t i-1 are the same as the total equipment list that needs to be isolated and the POS at the previous moment t i-1 If the total equipment list that needs to be isolated and the POS are both the same, there is no need to calculate, and directly adopt the risk result at the moment t i Then enter Step Sm to judge whether the moment t

[0092] satisfies i < N; if the total equipment list that needs to be isolated and the POS are different in one or both, then enter Step Sq. i Step Sq, the risk calculation module 34 selects the corresponding PSA real-time risk model according to the POS for risk quantitative assessment calculation. After the calculation is completed, enter Step Sm to judge whether the moment t i+1 whether i satisfies i < N. When i < N, return to Step Sa to perform the risk quantitative assessment calculation at the moment t

[0093] For the nuclear power plant maintenance configuration risk quantitative assessment system 100 of the present invention, the user inputs the nuclear power plant maintenance cycle 11 that needs to be evaluated, retrieves the information related to the maintenance cycle 11, and obtains the time node set T cnf for any moment t i in the corresponding master isolation work order and the non-master isolation work order of the overhaul in the overhaul master isolation work order, so as to obtain the nuclear power plant configuration combinations under different POSs for quantitative calculation, and can accurately obtain the risk level of the nuclear power plant full-cycle maintenance configuration, and then realize the in-depth optimization of the maintenance plan for the maintenance cycle 11, improve the scientificity of the nuclear power plant maintenance configuration risk management, shorten the overhaul time while ensuring safety, and improve the economic benefits of the nuclear power plant.

[0094] The evaluation processes of the daily maintenance plan work order 42 and the major overhaul plan work order 41 are mainly the same. The differences are as follows: First, the daily plan is usually carried out during the power operation of the nuclear power plant and does not involve multiple POS state switches; Second, the risk assessment of the daily maintenance plan work order 42 needs to consider the impact of the work orders being executed currently; Third, the daily maintenance plan work order 42 does not involve the main isolation plan and is usually operated on a work order basis.

[0095] For the daily maintenance plan work order 42, the time node set T cnf includes the time range of the selected daily maintenance plan work orders that need risk assessment; the equipment extraction module 32 screens the daily maintenance plan work orders 42 containing isolation equipment within the time range and obtains the isolation equipment of the unexecuted, executing, and executed daily maintenance plan work orders 42 to form a total isolation equipment list; the equipment discrimination module 33 determines whether the total isolation equipment list contains the equipment in the PSA real-time risk model; when the total isolation equipment list contains the equipment in the PSA real-time risk model, the risk calculation module 34 selects the corresponding PSA real-time risk model according to the total isolation equipment list for calculation.

[0096] Figure 4 This is the data flow model of the nuclear power plant maintenance configuration risk quantitative assessment system 100 according to another embodiment of the present invention.

[0097] As Figure 4 shown, the process of the risk assessment data flow model of the daily maintenance plan work order 42 is divided into two parallel processes: the planning and scheduling system 4 and the production management system 5. The planning and scheduling system 5 contains the work order information of the planned execution. The production management system 5 contains the information of the executing and executed work orders.

[0098] Judge whether the evaluation time node t satisfies t > t now , t now is the current time. When t > t now , it means that the daily maintenance plan work order 42 including the t moment has not been executed and belongs to the work order of the planned execution. Query the information of the daily maintenance plan work order 42 in the planning and scheduling system 4. The planning and scheduling system 4 stores the work breakdown structure list 421 (Work Breakdown Structures, abbreviated as WBS list) of the daily maintenance plan work order 42. The WBS list 421 contains the information of the daily maintenance plan work order 42 within a certain time interval. Read the WBS list 421 corresponding to the daily maintenance plan work order 42 at the t moment to provide the user with the option to select the time range of the daily maintenance plan work order 42 to be evaluated, and use this time range as the time node set T of the daily maintenance plan work order 42 cnfThen, filter the daily maintenance plan work orders 42 within the selected time range according to the isolation rules, and filter out the daily maintenance plan work orders 42 that contain isolated equipment. The isolation rules can be filtered according to the work order number B and the work order permit types "PW", "PT", or "PW-PT". Finally, obtain the isolation information of the daily maintenance plan work order 42. The functional location P of the daily maintenance plan work order 42 is used as the isolated equipment, and the isolation start time of the isolated equipment of the daily maintenance plan work order 42 is the planned start time t of the daily maintenance plan work order 42 2sj The isolation release time of the isolated equipment of the daily maintenance plan work order 42 is the planned completion time t of the daily maintenance plan work order 42 2ej .

[0099] When t ≤ t now , it means that the daily maintenance plan work order 42 containing the moment t is being executed or has been executed, and query the information of this daily maintenance plan work order 42 in the production management system 5

[0100] The daily maintenance plan work order 42 being executed refers to the one whose actual start time is less than the current moment t now and the planned completion time t 2ej is greater than the current moment t now For the daily maintenance plan work order 42, its status is generally indicated as "In Progress (INPRG)". The isolated equipment includes the functional location P of the daily maintenance plan work order 42 and the work order isolation instruction D. The work order isolation instruction D is the isolated equipment group corresponding to the isolation code of the work order in the production management system 5. The isolation start time of the isolated equipment of the daily maintenance plan work order 42 is the actual start time of the daily maintenance plan work order 42, and the isolation release time is the planned completion time t 2ej .

[0101] The daily maintenance plan work order 42 that has been executed refers to the one whose actual completion time is less than the current moment t now For the daily maintenance plan work order 42, its isolated equipment includes the functional location P of the daily maintenance plan work order 42 and the equipment code corresponding to the work order isolation instruction. Its status is generally indicated as "Completed (COMP)". The isolation start time of the isolated equipment of the daily maintenance plan work order 42 is the actual start time t of the daily maintenance plan work order 42 k , and the isolation release time is the actual completion time t c .

[0102] Combine the isolated equipment obtained from the planning and scheduling system 4 with the isolated equipment obtained from the production management system 5 to obtain the total isolated equipment list, which is used as the input of the risk calculation module 34 to perform the risk quantitative assessment calculation of the daily maintenance plan work order 42

[0103] The risk assessment of the daily maintenance plan work order 42 provided by the present invention can also be used for the quantitative assessment of the maintenance history risk of a nuclear power plant to perform configuration risk management threshold setting analysis.

[0104] Figure 5 It is a schematic diagram of the graphical user interface of the nuclear power plant maintenance configuration risk quantitative assessment system 100 according to a specific embodiment of the present invention. Figure 6 It is a schematic diagram of the graphical user interface of the POS time management according to a specific embodiment of the present invention. Figure 7 It is a schematic diagram of the user interface for displaying the details of the overhaul plan according to a specific embodiment of the present invention. Figures 5 - 7 The graphical user interface (GUI) in [reference] is only an example, and the nuclear power plant maintenance configuration risk quantitative assessment system 100 of the present invention is not limited to Figures 5 - 7 the GUI layout of [reference].

[0105] As Figure 5 shown, in the GUI, there is an input window 1001 of the user input unit 1. Through the input window 1001, the maintenance round 11 of the nuclear power plant to be evaluated can be input. After the input is completed, click the "Import Overhaul Plan" button 1002, and the information retrieval unit 2 can import the information of the overhaul plan work order 42 from the plan scheduling system 4. After the import, the risk assessment unit 3 of the nuclear power plant maintenance configuration risk quantitative assessment system 100 automatically processes the information of the imported overhaul plan work order 42 and displays it in the form of a Gantt chart. The main isolation code C of the overhaul main isolation work order 411 is displayed in the first area 1005 of the GUI, and the planned start time t 2sj and the planned completion time t 2ej of each main isolation are displayed in the Gantt chart. The specific time of the planned start time t 2sj and the planned completion time t 2ej can be displayed in the first floating box 1008 on the Gantt chart. Similarly, the information of the overhaul non-main isolation work order 412 can be displayed.

[0106] As Figure 6 shown, after the maintenance round 11 is input, click the "POS Management" button 1003 to enter the GUI for POS time setting, and the start and end times of each POS can be set. After the setting is completed, close this page to return to Figure 5 the page of [reference].

[0107] Please continue to refer to Figure 5 , and then click the "Display Overhaul Plan" button 1004 to select and query the detailed information of each overhaul main isolation work order 411 or overhaul non-main isolation work order 412, as Figure 7 shown. Figure 7The example in [ID] shows the details of the main isolation code C as OTC-RCS-01 (isolation in the first phase of RCS), including the system name, isolation code, start time, end time, and the corresponding device list information. Information can be edited, added, and deleted. After querying and setting are completed, close this page to return to Figure 5 the page.

[0108] Please continue to refer to Figure 5 , when it is not convenient to obtain data from the planning and scheduling system 4 and the production management system 5, or when the user needs to evaluate offline data according to specific circumstances, the user can also import the offline data into the nuclear power plant maintenance configuration risk quantitative assessment system 100 through the user input unit 1. In Figure 5 , click the "Select File" button 1018 to select the maintenance plan data file to be quantitatively evaluated for risk, and then click the "Import Maintenance Plan" button 1019 to achieve the offline import of the maintenance plan data.

[0109] Figure 8 This is the offline import template for the maintenance plan of a specific embodiment of the present invention.

[0110] As Figure 8 shown, the offline import template for the maintenance plan includes information such as isolation code, planned start time t 2sj and planned completion time t 2ej and so on.

[0111] Please continue to refer to Figure 5 , after importing the work order of the maintenance plan for the maintenance round 11, click the "Calculate" button 1007 to calculate the overhaul risk curve for this maintenance round 11.

[0112] Figure 9 This is the quantitative analysis instantaneous risk curve of the overhaul plan work order before optimization of an embodiment of the present invention. Figure 10 This is the quantitative analysis risk magnification curve of the overhaul plan work order before optimization of an embodiment of the present invention. Figure 10 Compared with Figure 9 , the risks under each POS are normalized. For nuclear power plants using the benchmark risk multiple as the risk threshold, it can more clearly show the relative change level of the risk throughout the maintenance cycle.

[0113] As Figure 9As shown, after entering the maintenance round 11 on the GUI page, the instantaneous risk curve before optimization of an example overhaul plan work order 41 is calculated through the nuclear power plant maintenance configuration risk quantitative assessment system 100, which represents the change of the absolute risk of the overhaul plan work order 41 of the nuclear power plant unit over time. The first curve 1011 represented by a solid line represents the overhaul absolute risk value under each POS, and the second curve 1012 of the first risk area represented by a dashed line represents the benchmark risk under each POS (i.e., the risk when no equipment in the nuclear power plant is withdrawn). The dots on the first curve 1011 represent different nuclear power plant configuration states, which are the nuclear power plant states after isolation of certain isolation equipment / functional positions P. A second floating box 1009 can be floatingly displayed on each nuclear power plant configuration state to view important risk information such as the instantaneous risk CDF, POS state, and time of each power plant configuration state.

[0114] As Figure 10 shown, a third floating box 1020 can be displayed in the risk magnification curve to display the instantaneous risk CDF magnification, POS state, and time information of each nuclear power plant configuration state.

[0115] In Figure 9 and Figure 10 the abscissa of the curve represents the overhaul time, and the vertical dashed line represents the demarcation line of each POS; the ordinate represents the risk value. The blank part 1017 without a curve in the middle represents that the nuclear power plant is in the refueling period. At this time, the nuclear power plant has completely stopped operating, there is no risk, and no analysis is required. According to the nuclear power plant risk threshold management regulations, the risks of each POS are divided into the first risk area 1013, the second risk area 1014, the third risk area 1015, and the fourth risk area 1016 from low to high. The nuclear power plant risk threshold is the threshold given according to the nuclear power plant operation data and risk management regulations. See Table 2 for details.

[0116] Table 2 Nuclear Power Plant Quantitative Analysis Risk Threshold

[0117]

[0118] Among them, the fourth risk area 1016 represents an unacceptable risk level and is not allowed to enter actively. In Figure 9 and Figure 10In the example shown, in each POS state in Table 1, a part of the risks of POS11, POS12, and POS13 enter the fourth risk area 1016. Through the calculation and analysis of the nuclear power plant risk after the restoration of the equipment in each nuclear power plant configuration state in the fourth risk area 1016, it can be known that the reason for the relatively high risks of POS11-13 is that the test time arrangements of the two devices, the pneumatic valves PXS-PL-108A and PXS-PL-108B at the outlet of the passive residual heat removal system heat exchanger in the main isolation code C, are unreasonable, and the tests need to be completed and PXS-PL-108A and PXS-PL-108B restored to be available before entering POS11.

[0119] Figure 11 This is the quantitative analysis cumulative risk curve before the optimization of the overhaul plan work order for an embodiment of the present invention. Hovering the mouse can display the fourth floating box 1010, and important risk information such as the allowed configuration time ACT and the cumulative risk increment ICDP of each nuclear power plant configuration state can be seen. The cumulative risk also gradually increases from POS11 to POS13 and enters the fourth risk area 1016.

[0120] Figure 12 This is the quantitative analysis instantaneous risk curve after the optimization of the overhaul plan work order for an embodiment of the present invention; Figure 13 This is the quantitative analysis cumulative risk curve after the optimization of the overhaul plan work order for an embodiment of the present invention.

[0121] According to Figure 7 the quantitative analysis instantaneous risk curve calculated in, adjust POS11-POS13 in the unacceptable fourth risk area 1016, and adjust the test / maintenance time of the pneumatic valves PXS-PL-108A and PXS-PL-108B at the outlet of the passive residual heat removal system heat exchanger, and the optimized instantaneous risk curve is as shown in Figure 12 shown, and the cumulative risk curve is as shown in Figure 13 shown.

[0122] From Figure 12 and Figure 13 it can be seen that both the instantaneous risk and the cumulative risk of the optimized overhaul plan work order 41 of the nuclear power plant are small, and each POS does not enter the fourth risk area 1016, belonging to an acceptable risk level. The overall risk distribution is relatively balanced and is in a reasonable range of risk conservatism, and there is a possibility of adjusting and merging the overhaul time window and shortening the overhaul time.

[0123] Figure 14 This is the flow chart of the quantitative assessment method for the risk of nuclear power plant maintenance configuration for an embodiment of the present invention.

[0124] As shown in Figure 14As shown, the method for quantitatively evaluating the risk of nuclear power plant maintenance configuration according to the present invention includes the following steps: Step S1, input the maintenance round 11 of the nuclear power plant to be evaluated; Step S2, retrieve the maintenance plan, the pre-established PSA real-time risk model, and the POS of the nuclear power plant maintenance round 11; Step S3, read the set of maintenance time nodes T from the maintenance plan cnf ; Step S4, according to the set of maintenance time nodes T cnf , screen out the list of equipment that needs to be isolated; Step S5, determine whether the equipment list contains the equipment included in the PSA real-time risk model. If it does not contain the equipment in the PSA real-time risk model, return to Step S3. If it contains the equipment in the PSA real-time risk model, then execute Step S6; Step S6, determine the POS corresponding to the set of maintenance time nodes T cnf , and select the corresponding PSA real-time risk model according to the POS for calculation.

[0125] In Step S2, the maintenance plan of the nuclear power plant maintenance round 11 includes overhaul plan work orders, and the overhaul plan work orders include overhaul main isolation work orders and overhaul non-main isolation work orders; In Step S3, the set of time nodes T cnf includes the isolation start time and isolation release time of the overhaul main isolation work order, the planned start time and planned completion time of the overhaul non-main isolation work order, and the time of POS change; In Step S4, the list of equipment that needs to be isolated screened out includes obtaining the list of main isolation equipment in the overhaul main isolation work order and the list of non-main isolation equipment in the overhaul non-main isolation work order corresponding to any moment t cnf in the set of time nodes T i .

[0126] In Step S2, the maintenance plan of the nuclear power plant maintenance round 11 includes daily maintenance plan work orders; In Step S3, the set of time nodes T cnf includes the time range of the selected daily maintenance plan work orders that need risk assessment; In Step S4, the list of equipment that needs to be isolated screened out includes screening out the daily maintenance plan work orders containing isolated equipment within the time range, and obtaining the isolated equipment of the daily maintenance plan work orders that are being executed and have been executed to form a total isolated equipment list.

[0127] The present invention also provides a computer device, including: one or more processors; a memory, on which one or more programs are stored; when the one or more processors execute the one or more programs, the steps of the method for quantitatively evaluating the risk of nuclear power plant maintenance configuration according to the present invention are implemented.

[0128] The present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method for quantitatively evaluating the risk of nuclear power plant maintenance configuration according to the present invention are implemented.

[0129] The nuclear power plant maintenance configuration risk quantitative assessment system 100, method, computer device and readable storage medium of the present invention solve the problem of quantitative assessment of the maintenance configuration risk during the full power cycle of a nuclear power plant. It can obtain the configuration combinations of the nuclear power plant under different POS states and perform quantitative calculations to accurately obtain the risk level of the full-cycle maintenance configuration of the nuclear power plant, including information such as instantaneous risk distribution, cumulative risk increment, and allowable configuration time. Furthermore, it can realize the in-depth optimization of the maintenance plan, improve the scientificity of the nuclear power plant maintenance configuration risk management, shorten the overhaul time while ensuring safety, and improve the economic benefits of the power plant.

[0130] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A quantitative risk assessment system for nuclear power plant maintenance configuration, characterized in that, it includes a user input unit for inputting the nuclear power plant maintenance rounds to be evaluated; an information retrieval unit for retrieving information, where the information includes the maintenance plan of the nuclear power plant maintenance rounds, a pre-established probabilistic safety assessment real-time risk model, and the operating status of the nuclear power plant; a risk assessment unit for performing risk assessment on the nuclear power plant maintenance rounds according to the information retrieved by the information retrieval unit; wherein, the risk assessment unit includes: A node configuration module that reads a set of maintenance time nodes T from the maintenance plan cnf , Device extraction module, which filters out the list of devices that need to be isolated according to the set of maintenance time nodes T cnf , and filters out the list of devices that need to be isolated an equipment discrimination module for judging whether the equipment list contains the equipment in the probabilistic safety assessment real-time risk model, A risk calculation module, which determines the set of maintenance time nodes T when the equipment list includes the equipment in the probabilistic safety assessment real-time risk model cnf for the corresponding operating state of the nuclear power plant, and selects the corresponding probabilistic safety assessment real-time risk model for calculation according to the operating state of the nuclear power plant.

2. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 1, characterized in that, the information retrieval unit can retrieve information from the planned scheduling system and the production management system, the planned scheduling system includes work orders for the maintenance plans of all the nuclear power plant maintenance rounds; the production management system includes work orders for the maintenance plans that are being executed and have been executed, supervises the execution of the work orders for the maintenance plans, and manages the associated components of the isolated equipment in the work orders for the maintenance plans; wherein, the work orders for the maintenance plans include overhaul plan work orders and daily maintenance plan work orders.

3. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 2, characterized in that, the overhaul plan work orders include main isolation work orders and non-main isolation work orders for overhauls, The set of time nodes T cnf includes the isolation start time and isolation release time of the major overhaul main isolation work order, the planned start time and planned completion time of the major overhaul non-main isolation work order, and the time of change in the operating state of the nuclear power plant; The device extraction module obtains the time node set T cnf any moment t i corresponding main isolation device list in the major overhaul main isolation work order and non-main isolation device list in the major overhaul non-main isolation work order; the equipment discrimination module judges whether the main isolation equipment list and the non-main isolation equipment list contain the equipment in the probabilistic safety assessment real-time risk model; When the risk calculation module determines that the main isolation equipment list and the non-main isolation equipment list contain the equipment in the probabilistic safety assessment real-time risk model, it judges the operating state of the nuclear power plant at the moment t i and selects the corresponding probabilistic safety assessment real-time risk model for calculation according to the operating state of the nuclear power plant 4. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 2, characterized in that, The time node set T cnf includes the time range of the selected daily maintenance plan work orders that require risk assessment; the equipment extraction module screens the daily maintenance plan work orders containing isolated equipment within the time range and obtains the isolated equipment of the unexecuted, being-executed, and executed daily maintenance plan work orders to form a total isolated equipment list; the equipment discrimination module judges whether the total isolated equipment list contains the equipment in the probabilistic safety assessment real-time risk model; when the total isolated equipment list contains the equipment in the probabilistic safety assessment real-time risk model, the risk calculation module selects the corresponding probabilistic safety assessment real-time risk model according to the total isolated equipment list for calculation.

5. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 2, characterized in that, the work orders for the maintenance plans include work order numbers, functional locations, planned start times, and planned end times, and the work order numbers are identifiers of the work orders and are consistent in the planned scheduling system and the production management system.

6. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 3, characterized in that, At any given moment t i The list of main isolation equipment in the corresponding major overhaul main isolation work order includes all major overhaul main isolation equipment in which the isolation start time is less than t i and the isolation release time is greater than t i in the major overhaul main isolation work order.

7. The quantitative risk assessment system for nuclear power plant maintenance configuration according to claim 3, characterized in that, At any given moment t i The list of non-primary isolation equipment in the corresponding major overhaul non-primary isolation work order includes all isolation equipment in major overhaul non-primary isolation work orders where the planned start time is less than t i and the planned completion time is greater than t i of the isolation equipment.

8. A method for quantitatively assessing the risk of nuclear power plant maintenance configuration, characterized in that, it includes the following steps: Step S1, input the nuclear power plant maintenance rounds to be evaluated; Step S2, retrieve the maintenance plan for the maintenance round of the nuclear power plant, the pre-established probabilistic safety assessment real-time risk model, and the operating status of the nuclear power plant; Step S3, read the maintenance time node set T from the maintenance plan cnf ; Step S4, according to the set of maintenance time nodes T cnf , filter out the list of devices that need to be isolated; Step S5, determine whether the equipment list contains the equipment included in the probabilistic safety assessment real-time risk model. If it does not contain the equipment in the probabilistic safety assessment real-time risk model, return to Step S3. If it contains the equipment in the probabilistic safety assessment real-time risk model, then execute Step S6; Step S6, determine the operating state of the nuclear power plant corresponding to the set T of maintenance time nodes cnf and select the corresponding probabilistic safety assessment real-time risk model for calculation according to the operating state of the nuclear power plant.

9. The method for quantitatively assessing the risk of nuclear power plant maintenance configuration according to claim 8, characterized in that, in Step S2, the maintenance plan for the maintenance round of the nuclear power plant includes a major overhaul plan work order, and the major overhaul plan work order includes a major overhaul main isolation work order and a major overhaul non-main isolation work order; In step S3, the time node set T cnf includes the isolation start time and isolation release time of the major overhaul main isolation work order, the planned start time and planned completion time of the major overhaul non-main isolation work order, and the time of the change in the operating state of the nuclear power plant; In step S4, the list of devices that need to be isolated includes obtaining the set of time nodes T cnf any moment t i corresponding master isolation device list in the master overhaul isolation work order and non-master isolation device list in the non-master overhaul isolation work order.

10. The method for quantitatively assessing the risk of nuclear power plant maintenance configuration according to claim 8, characterized in that, in Step S2, the maintenance plan for the maintenance round of the nuclear power plant includes a daily maintenance plan work order; In step S3, the time node set T cnf includes the time range of the daily maintenance plan work orders selected for risk assessment; in Step S4, the equipment list screened out that needs to be isolated includes screening the daily maintenance plan work orders containing isolated equipment within the time range, and obtaining the isolated equipment of the daily maintenance plan work orders being executed and already executed to form a total isolated equipment list.

11. A computer device, characterized in that, the device includes: one or more processors; a memory having one or more programs stored thereon; when the one or more processors execute the one or more programs, the steps of the method according to any one of claims 8 to 10 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, when the program is executed by a processor, the steps of the method according to any one of claims 8 to 10 are implemented.

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