A method and system for nuclear power plant maintenance risk analysis

Abstract

The present application belongs to the technical field of nuclear power plant maintenance management, and particularly relates to a nuclear power plant maintenance risk analysis method and system. The method comprises the following steps: step 1: combing basic information, control logic information and signal channel information of equipment; step 2: classifying maintenance risks of the equipment according to control logic results of the equipment and control logic results of adjacent equipment in the signal channel of the equipment; and step 3: analyzing the maintenance risks of the equipment. The present application can greatly reduce the manual analysis workload in the maintenance preparation process, improve the reliability of the maintenance risk analysis, reduce the unit shutdown or power transient caused by the incomplete risk analysis, and ensure the safe and stable operation of the unit.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power plant maintenance management technology, specifically relating to a method and system for nuclear power plant maintenance risk analysis. Background Technology

[0002] Nuclear power plant maintenance risk analysis is a highly specialized, challenging, and demanding preparatory task, especially for the maintenance of instrumentation, control, and electrical remote transmission equipment. This is because the equipment is highly interconnected, and a change in one part can have far-reaching consequences. It requires extensive review of drawings and rich maintenance experience, and typically includes: preparation of maintenance-related documents, including flowcharts, logic diagrams, simulation diagrams, termination diagrams, and other relevant drawings; assessment of the direct impact of equipment maintenance, i.e., analyzing the equipment's protection, control, alarm, and display functions through understanding the drawings; assessment of the work involved in equipment maintenance (including cable termination, work within termination boxes, and termination work within control cabinets), requiring identification of termination boxes and their locations; and assessment of potential risks during maintenance implementation, i.e., risk analysis related to the equipment being maintained, such as risk identification and assessment of other important equipment within the same termination box or control cabinet.

[0003] Currently, the risk analysis phase of maintenance work documentation packages mainly relies on manual analysis, which has the following drawbacks:

[0004] (1) Each analysis requires consulting a large number of drawings and reading them one by one, which is time-consuming and laborious;

[0005] (2) Since everyone’s business skills and sense of responsibility are different, the analysis results may not be the same or reliable.

[0006] (3) It is difficult to fully analyze the risks of maintenance paths and adjacent equipment, and the maximum maintenance risk is somewhat hidden.

[0007] (4) Unreachable (difficult) areas or key areas of concern are not intuitive enough and are difficult to describe in a timely manner before on-site implementation;

[0008] (5) The results of a single risk analysis are not retained. Each time a package is made, the analysis results are lost, resulting in a lack of maintenance accumulation.

[0009] There have been numerous incidents in operating power plants where inadequate risk assessments failed to identify risks in equipment maintenance access routes, and where accidental wiring during construction led to unit shutdowns and transients. Summary of the Invention

[0010] The purpose of this invention is to provide a method and system for risk analysis of nuclear power plant maintenance. It can automatically analyze the control logic of equipment and check the risks of adjacent equipment in the inspection channel, output the maximum risk that may occur when the equipment is working, and alert the person in charge and relevant personnel, thereby reducing the workload of manual analysis and the chance of errors, and improving the reliability of analysis results.

[0011] The technical solution of the present invention is as follows: A method for risk analysis of nuclear power plant maintenance, comprising the following steps:

[0012] Step 1: Organize the basic information, control logic information, and signal channel information of the equipment;

[0013] Step 2: Based on the control logic results of the equipment and the control logic results of adjacent equipment in its signal channel, classify the maintenance risks of the equipment;

[0014] Step 3: Analyze equipment maintenance risks.

[0015] The basic information includes equipment name, serial number, installation location, unit number, system number, etc.

[0016] The control logic information includes information on all end devices whose states will change accordingly after the device state changes, as indicated by the logic diagram.

[0017] The signal channel information includes information on all termination boxes, adapter boxes, cards, terminal blocks, cables, etc., that the device passes through from its actual installation location to the control system.

[0018] The maintenance risk levels of the aforementioned equipment, from highest to lowest, are as follows:

[0019] a. Direct shutdown: The equipment control logic is directly linked to the reactor shutdown signal;

[0020] b. Direct shutdown: The equipment control logic is directly linked to the turbine shutdown signal;

[0021] c. Accidental reactor shutdown: The equipment control logic does not have a associated reactor shutdown signal, but the adjacent equipment does have a associated reactor shutdown signal. There is a risk of accidentally triggering the shutdown signal during maintenance.

[0022] d. Accidental shutdown: The equipment control logic is not associated with the turbine shutdown signal, but the adjacent equipment is associated with the turbine shutdown signal. There is a risk of accidentally triggering the shutdown signal during the maintenance process.

[0023] e. Direct control interlocking: The equipment control logic is directly linked to the actions of other equipment;

[0024] f. Indirect control interlock: The equipment control logic is not directly related to the actions of other equipment, but its neighboring equipment is related to the actions of other equipment.

[0025] g. Impact on alarm display: The control logic of the equipment and its adjacent equipment has no functions for stopping the stack, shutting down, or control interlocking, which only affects the alarm display.

[0026] Step 3 includes the following steps:

[0027] S0: Enter the device number to be analyzed;

[0028] S1: Based on the basic equipment information and control logic information, determine its direct maintenance risks, such as one or more of the following: direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g.

[0029] S2: Based on the signal channel of the device, find the "adjacent devices" of the current device, that is, devices that share the same junction box, the same transfer box terminal block, the same cabinet terminal block, and the same card;

[0030] S3: Traverse the above adjacent equipment and, according to the method in step S1, find its direct maintenance risks, such as one or more of the following: direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g. The direct maintenance risks of adjacent equipment are the "accidental contact risks" of the current equipment. The corresponding relationship is that direct shutdown a is converted to accidental contact shutdown c, direct shutdown b is converted to accidental contact shutdown d, and direct control interlock e is converted to indirect control interlock f.

[0031] S4: Sort all the maintenance risks of the current equipment according to the risk level, and take the highest risk as the highest maintenance risk of the current equipment;

[0032] S5: Summarize and output the risk analysis results to form a "Risk Assessment Form".

[0033] A nuclear power plant maintenance risk analysis system includes an information input module, an equipment storage module, a comprehensive risk analysis module, and a risk analysis single output module.

[0034] The information entry module includes basic equipment information, equipment control logic information, equipment signal channel information, on-site photos of the equipment, and experience feedback information.

[0035] The device storage module includes: basic device information, device control logic information, device signal channel information, on-site photos of the device, experience feedback information, modification records of device information, information of responsible persons, and other log information.

[0036] The comprehensive risk analysis module includes: retrieving device information from the device storage section of the second part of the system based on the device number input by the user, and obtaining risk analysis data;

[0037] The risk analysis form output module includes: outputting the obtained data in a visual form to the screen or printer, adding necessary watermarks, timestamps, visual labels to prevent human error, etc., to form a risk analysis form.

[0038] The beneficial effects of this invention are as follows: This invention can greatly reduce the amount of manual analysis work in the maintenance preparation process, improve the reliability of maintenance risk analysis, reduce unit shutdowns or power transients caused by incomplete or inadequate risk analysis, and ensure the safe and stable operation of the unit. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the equipment maintenance risk analysis process in a nuclear power plant maintenance risk analysis method provided by the present invention.

[0040] Figure 2 This is a schematic diagram of a nuclear power plant maintenance risk analysis system provided by the present invention. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] A method for risk analysis in nuclear power plant maintenance includes the following steps:

[0043] Step 1: Organize the basic information, control logic information, and signal channel information of the equipment.

[0044] The basic information includes equipment name, serial number, installation location, unit number, system number, etc.

[0045] The control logic information includes information on all end devices whose states will change accordingly after the device state changes, as indicated by the logic diagram.

[0046] The signal channel information includes information on all termination boxes, adapter boxes, cards, terminal blocks, cables, etc., along the route from the actual installation location of the equipment to the control system (such as relay racks, PLC cards, DCS cards, etc.).

[0047] Step 2: Based on the control logic results of the equipment and the control logic results of adjacent equipment in its signal channel, the maintenance risks of the equipment are divided into seven types:

[0048] The seven maintenance risk levels, from highest to lowest, are as follows:

[0049] a. Direct shutdown: The equipment control logic is directly linked to the reactor shutdown signal.

[0050] b. Direct shutdown: The equipment control logic is directly linked to the turbine shutdown signal.

[0051] c. Accidental reactor shutdown: The equipment control logic does not have a associated reactor shutdown signal, but its neighboring equipment does. There is a risk of accidentally triggering the shutdown signal during maintenance.

[0052] d. Accidental shutdown: The equipment control logic is not associated with the turbine shutdown signal, but the adjacent equipment is associated with the turbine shutdown signal. There is a risk of accidentally triggering the shutdown signal during the maintenance process.

[0053] e. Direct control interlock: The equipment control logic is directly linked to the actions of other equipment (such as valve opening and closing or pump start and stop).

[0054] f. Indirect control interlock: The equipment control logic is not directly related to the actions of other equipment, but its neighboring equipment is related to the actions of other equipment.

[0055] g. Impact on alarm display: The control logic of the equipment and its adjacent equipment has no functions for stopping the stack, shutting down, or control interlocking, which only affects the alarm display.

[0056] Step 3: Analyze equipment maintenance risks

[0057] like Figure 1 As shown, the specific steps are as follows:

[0058] S0: Enter the device number to be analyzed

[0059] S1: Based on the basic equipment information and control logic information, the direct maintenance risks can be directly determined, such as one or more of the following: direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g.

[0060] S2: Based on the signal channel of the device, find the "adjacent devices" of the current device, that is, devices that share the same junction box, the same transfer box terminal block, the same cabinet terminal block, and the same card;

[0061] S3: Traverse the above adjacent equipment and, according to the method in step S1, find one or more of its direct maintenance risks (direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g). The direct maintenance risks of adjacent equipment are the "accidental contact risks" of the current equipment. The corresponding relationship is that direct shutdown a is converted to accidental contact shutdown c, direct shutdown b is converted to accidental contact shutdown d, and direct control interlock e is converted to indirect control interlock f.

[0062] S4: Sort all maintenance risks currently existing in the equipment according to risk level, and take the highest risk as the highest maintenance risk for the current equipment.

[0063] S5: Summarize and output the risk analysis results to form a "Risk Assessment Form".

[0064] like Figure 2 As shown, a nuclear power plant maintenance risk analysis system includes...

[0065] The information entry module includes: basic equipment information, equipment control logic information, equipment signal channel information, on-site photos of the equipment, and experience feedback information.

[0066] The device storage module includes: basic device information, device control logic information, device signal channel information, on-site photos of the device, experience feedback information, modification records of device information, information of responsible persons, and other log information.

[0067] The comprehensive risk analysis module includes the core part of this system, which retrieves device information from the device storage part of the second part of the system based on the device number input by the user, runs the risk analysis method described in this invention, and obtains risk analysis data.

[0068] The risk analysis sheet output module includes: outputting the data obtained from Part 3 above in a visual form to the screen or printer, adding necessary watermarks, timestamps, visual markings to prevent human error, etc., to form a risk analysis sheet as a reference document for nuclear power plant maintenance work.

Claims

1. A method for risk analysis in nuclear power plant maintenance, characterized in that, Includes the following steps: Step 1: Organize the basic information, control logic information, and signal channel information of the equipment; Step 2: Based on the control logic results of the equipment and the control logic results of adjacent equipment in its signal channel, classify the maintenance risks of the equipment; Step 3: Analyze equipment maintenance risks; Step 3 includes the following steps. S0: Enter the device number to be analyzed; S1: Based on the basic equipment information and control logic information, determine its direct maintenance risks, including one or more of the following: direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g. S2: Based on the signal channel of the device, find the adjacent devices of the current device, that is, devices that share the same junction box, the same adapter box terminal block, the same cabinet terminal block, or the same card; S3: Traverse the above adjacent equipment and, according to the method in step S1, find its direct maintenance risks, including one or more of the following: direct shutdown a, direct shutdown b, direct control interlock e, and impact on alarm display g. The direct maintenance risks of adjacent equipment are the accidental contact risks of the current equipment. The corresponding relationship is that direct shutdown a is converted to accidental shutdown c, direct shutdown b is converted to accidental shutdown d, and direct control interlock e is converted to indirect control interlock f. S4: Sort all the maintenance risks of the current equipment according to the risk level, and take the highest risk as the highest maintenance risk of the current equipment; S5: Summarize and output the risk analysis results to form a risk assessment form.

2. The nuclear power plant maintenance risk analysis method as described in claim 1, characterized in that: The basic information includes equipment name, serial number, installation location, unit number, and system number.

3. The nuclear power plant maintenance risk analysis method as described in claim 1, characterized in that: The control logic information includes information on all end devices whose states will change accordingly after the device state changes, as indicated by the logic diagram.

4. The nuclear power plant maintenance risk analysis method as described in claim 1, characterized in that: The signal channel information includes information on all termination boxes, adapter boxes, cards, terminal blocks, and cables that the device passes through along its route from its actual installation location to the control system.

5. The nuclear power plant maintenance risk analysis method as described in claim 1, characterized in that: The maintenance risk levels of the aforementioned equipment, from highest to lowest, are as follows: a. Direct shutdown: The equipment control logic is directly linked to the reactor shutdown signal; b. Direct shutdown: The equipment control logic is directly linked to the turbine shutdown signal; c. Accidental reactor shutdown: The equipment control logic does not have a associated reactor shutdown signal, but the adjacent equipment does have a associated reactor shutdown signal. There is a risk of accidentally triggering the shutdown signal during maintenance. d. Accidental shutdown: The equipment control logic is not associated with the turbine shutdown signal, but the adjacent equipment is associated with the turbine shutdown signal. There is a risk of accidentally triggering the shutdown signal during the maintenance process. e. Direct control interlocking: The equipment control logic is directly linked to the actions of other equipment; f Indirect control interlock: The equipment control logic is not directly related to the actions of other equipment, but its neighboring equipment is related to the actions of other equipment; g. Impact on alarm display: The control logic of the equipment and its adjacent equipment does not have the functions of stopping the stack, shutting down, or control interlocking, which only affects the alarm display.

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