Maintenance planning support method and maintenance planning support system

Abstract

To provide a maintenance plan support method capable of properly supporting maintenance activities for a nuclear power plant.SOLUTION: The present invention relates to a maintenance plan support method that supports a maintenance plan for a nuclear power plant by utilizing design and / or information from the field, and when a maintenance plan for preventing a facility management index is made based thereupon in maintenance activities and maintenance actions of facilities which are executed according to the maintenance plan, an update plan for a next maintenance plan which is determined from facility situations in the field and an update plan for a long-period maintenance plan after the next and subsequent maintenance plan are set for a long-period maintenance plan for a plurality of times of periodic inspections planned in advance.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a maintenance plan support method and a maintenance plan support system for supporting maintenance activities in a nuclear power plant. [Background technology]

[0002] Nuclear power plants are made up of hundreds of systems and numerous pieces of equipment, and in order to maintain safety and demonstrate the plant's performance, maintenance activities are carried out to maintain and improve reliability.

[0003] Since the beginning of construction, maintenance activities have been carried out under strict standards, but considering recent regulatory trends, operating records both domestically and overseas, and technological improvements since construction, there is a need to further optimize maintenance activities.

[0004] The maintenance support system of Patent Document 1 is disclosed to include a grouping unit that groups together multiple pieces of equipment installed in a plant that share common conditions related to equipment deterioration, and a display control unit that, for a designated representative piece of equipment set in each group, displays on a display device that no maintenance is required until the next inspection, even when deterioration of an equipment included in the group of the designated representative piece of equipment is detected, if the estimated time from when deterioration of the representative piece of equipment is detected until it fails is equal to or longer than a first predetermined value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-138712 Summary of the Invention [Problem to be solved by the invention]

[0006] Higher reliability is required in the operation of nuclear power plants in Japan after the earthquake disaster. Overseas examples include the proven regulations in the United States (ROP: Reactor Oversight Process) and industry best practices (for example, the Standard Nuclear Performance Model (SNPM)), both of which aim to optimize the maintenance of existing reactor plants from a comprehensive perspective. In Japan, too, there was a desire to build a maintenance process that promotes comprehensive optimization, taking inspiration from the United States, even though US regulations and operational experience differ.

[0007] The present invention is an invention for solving the above-mentioned problems, and an object of the present invention is to provide a maintenance plan support method and a maintenance plan support device that can appropriately support maintenance activities in a nuclear power plant. [Means for solving the problem]

[0008] In order to achieve the above object, the maintenance planning support method of the present invention is Control rod drive mechanism A maintenance plan support method for supporting a maintenance plan by utilizing information from design and / or a site, wherein maintenance activities and maintenance actions for equipment are carried out according to the maintenance plan, a step of monitoring signals related to the control of the control rod drive mechanism; a step of detecting a malfunction or a symptom of the malfunction of the control rod drive mechanism from the results of monitoring the signals; and a step of evaluating whether the malfunction or the symptom of the malfunction is progressing more rapidly than expected when it is determined in the evaluation step that the malfunction or the symptom of the malfunction is not progressing more rapidly than expected, and a step of evaluating a time-varying trend in the deterioration tendency of the control rod drive mechanism when it is determined that the malfunction or the symptom of the malfunction is not progressing more rapidly than expected when it is determined in the evaluation step that the malfunction or the symptom of the malfunction is not progressing more rapidly than expected; and a step of evaluating a relative change in the deterioration tendency of the control rod drive mechanism in comparison with similar equipment, The aforementioned Based on the determination result of the time change trend regarding the deterioration tendency and the determination result of the relative change regarding the deterioration tendency compared with similar devices, The present invention is characterized in that, for a long-term maintenance plan for a plurality of periodic inspections that have been prepared in advance, an update plan for the next maintenance plan determined based on the on-site equipment status and update plans for the next and subsequent long-term maintenance plans are set. Other aspects of the present invention will be described in the embodiments that will be described later. [Effects of the Invention]

[0009] According to the present invention, maintenance activities for nuclear power plants can be appropriately supported. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a configuration of a maintenance plan support system according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram illustrating an example of configuration data of a device management DB. [Figure 3] FIG. 10 is a diagram showing an example of data configuration of an FMEA DB. [Figure 4] FIG. 10 is a diagram illustrating an example of configuration data of a maintenance activity / monitoring item DB. [Figure 5] FIG. 10 is a diagram showing an example of data constituting a field maintenance and monitoring data DB. [Figure 6] FIG. 10 is a diagram illustrating an example of configuration data of a work plan management DB. [Figure 7] FIG. 10 is a diagram illustrating an example of data (long-term maintenance plan) in a maintenance plan management DB. [Figure 8] FIG. 10 is a diagram illustrating an example of data (next maintenance plan) in a maintenance plan management DB. [Figure 9] 10 is a flowchart showing details of a maintenance plan support process during plant operation. [Figure 10] 10 is a flowchart showing details of a maintenance plan support process during a regular inspection period. [Figure 11] 10 is a flowchart showing a process (part 1) of reflecting data in a maintenance plan. [Figure 12] 10 is a flowchart showing a second reflection process in a maintenance plan. [Figure 13A] FIG. 10 is a diagram showing a method (time change) for selecting candidates for inspection at the next regular inspection. [Figure 13B] This figure shows the method for selecting candidates for inspection at the next regular inspection (changes in similar individuals). [Figure 14A] FIG. 10 is a diagram showing an example of a recommended device to be maintained next based on a long-term plan. [Figure 14B] This figure shows an example of a recommended equipment to be maintained next (the number of years of use of similar equipment) based on a long-term plan. [Figure 15A] FIG. 10 is a diagram showing an example of a recommended plan for future regular inspections (a plan that standardizes the number of units). [Figure 15B] This figure shows an example of a recommended plan for future regular inspections (a plan to maintain a large number of units during a certain regular inspection). [Figure 16A]FIG. 10 is a diagram showing a base example (Nth operation cycle and Nth periodic inspection) for reviewing maintenance tasks and cycles. [Figure 16B] FIG. 10 is a diagram showing a base example for reviewing maintenance tasks and cycles (time change in the case where only the tasks performed while the plant is down are plotted). [Figure 17] FIG. 10 is a diagram illustrating an example of visualization of constraints for a long-term maintenance plan. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment for carrying out the present invention will be described in detail with reference to the accompanying drawings. <Maintenance planning support system> FIG. 1 is a diagram showing the configuration of a maintenance plan support system 300 according to this embodiment. The maintenance plan support system 300 includes a maintenance plan support device 100 and a database device 200, which is an external storage device. The maintenance plan support device 100 includes a processing unit 10, a memory unit 20, an input unit 30, an output unit 40, and a communication unit 50. The processing unit 10 includes an equipment status management unit 11 that manages the performance, deterioration, failure, and other conditions of the nuclear power plant through inspection, testing, monitoring, and patrol; a maintenance plan update unit 12 that updates the maintenance plan for the next operation cycle based on the status of the nuclear power plant and updates the long-term maintenance plan for the next and subsequent operation cycles; a maintenance execution management unit 13 that manages maintenance management indicators, maintenance tasks and cycles that are required by laws, regulations, standards, and criteria, as well as the resources required for maintenance and the number of units to be maintained; and a maintenance plan drafting unit 14 that drafts maintenance plans.

[0012] The memory unit 20 stores configuration management extraction information 21, FMEA extraction information 22, maintenance activity and monitoring item extraction information 23, field maintenance and monitoring extraction information 24, work plan management extraction information 25, maintenance plan management extraction information 26, etc.

[0013] In FIG. 1, the processing unit 10 is a central processing unit (CPU) that executes various programs stored in RAM, a HDD, etc. The memory unit 20 is a HDD that stores various data required for the maintenance plan support device 100 to execute processing. The input unit 30 is a device for inputting instructions to a computer, such as a keyboard or a mouse, and inputs instructions such as program startup. The output unit 40 is a display or the like that displays the execution status and execution results of processing by the maintenance plan support device 100. The communication unit 50 exchanges various data and commands with other devices via the network NW.

[0014] The database device 200 has a configuration management DB 210, an FMEA DB 220, a maintenance activity and monitoring item DB 230, a field maintenance and monitoring data DB 240, a work plan management DB 250, and a maintenance plan management DB 260. Note that "DB" means database. FMEA is an abbreviation for Failure Mode and Effect Analysis, and is a systematic analysis method of potential failures with the aim of preventing failures and malfunctions.

[0015] The data stored in each DB is explained below. The configuration management DB 210 is a database composed of design requirements, design documents, and actual data for the power plant. Regarding systems and equipment (collectively referred to as "facilities") that are the subject of maintenance, the target equipment for maintenance activities such as inspection, testing, monitoring, and repair, and the timing (cycle) of such activities are specified for equipment that is more important from the perspective of maintaining and improving safety, in order to maintain the required specifications and functions. When changing the inspection cycle for a certain piece of equipment, as in this embodiment, the change must, in principle, be made within the scope that complies with laws and regulations. For example, a rule may require non-destructive testing of a certain percentage of the total within a specified number of years, such as every 10 years.

[0016] FMEA DB220 is a database that contains information on the deterioration modes of equipment that make up a power plant, i.e., failure locations, deterioration mechanisms, effects of deterioration, severity of deterioration, frequency of deterioration, and effective maintenance activities and monitoring items.

[0017] The maintenance activity and monitoring item DB230 is a database containing information on the maintenance activities and monitoring items of the power plant, i.e., their content, frequency, and the deterioration phenomena that are the target. Here, the maintenance activities and monitoring items for the equipment that are the target of maintenance include those specified by laws and regulations in the "Configuration Management DB210." From the perspective of maintaining safety, if the target equipment and implementation timing (cycle) of maintenance and monitoring to maintain the functionality of more important equipment (facilities, systems) are specified, it is necessary to comply with them.

[0018] The field maintenance and monitoring data DB 240 is a database that stores the actual on-site status of the maintenance activities and monitoring items specified in the maintenance activity and monitoring item DB 230. In other words, it is information on the deterioration state of the equipment (or information required to determine the deterioration state). If the results of maintenance activities or trends in monitoring parameters may indicate a malfunction or deterioration, a request for corrective activities such as function recovery will be generated.

[0019] The work plan management DB 250 is a database that stores standard information that serves as the basis for creating on-site work plans. Specifically, it is a single package of information (see Figure 6) related to the maintenance of a certain piece of equipment, and is a collection of multiple individual maintenance activities (= work orders) that make up the maintenance of that equipment. In order to create a work plan with a certain amount of time, number of people, and parts, this database contains information that organizes the standard time, work personnel, and parts and equipment required for that work for each work order.

[0020] The maintenance plan management DB 260 stores and manages information about the next operation cycle, i.e., the maintenance plan related to operation and subsequent periodic inspection, for the equipment to be maintained, and information about the long-term maintenance plan including operation and subsequent periodic inspection for the next and subsequent operation cycles, for example, for about 5 to 10 operation cycles in the future. Therefore, information about each equipment to be maintained is stored.

[0021] <Examples of data configuration for each DB> Figure 2 shows an example of configuration data in the configuration management DB 210. The configuration management DB 210 is composed of categories and their configuration data. Categories include design requirements, facility configuration information, and physical configuration. For example, design requirements include legal regulations, design criteria documents, and calculation and analysis results.

[0022] Figure 3 shows an example of the data configuration of the FMEA DB 220. The FMEA DB 220 contains data such as equipment name, deterioration mode, effective maintenance activities and monitoring items. The deterioration mode includes the failure location, deterioration mechanism, deterioration impact, deterioration severity, and deterioration frequency. In Figure 3, for example, the equipment includes a control drive mechanism, ◇◇ pump, XX valve, △△ valve, etc.

[0023] The control rod drive (CRD) consists of the CRD body, a spool piece, and a motor unit. The control rod drive includes a part housed in the control rod drive mechanism housing installed at the bottom of the reactor pressure vessel and a shaft seal for the drive shaft housed in the spool piece attached to the bottom. Figure 3 shows that in the case of the spool piece of the control rod drive mechanism, deterioration of the resin in the seal may cause leakage.

[0024] Further details of the control rod drive mechanism will be explained. The improved control rod drive mechanism (hereafter referred to as FMCRD, an abbreviation for Fine Motion Control Rod Drive) is a device for driving the control rods, and is hydraulically driven during scram and electrically driven during normal control rod operation. In scram operation, the control rods are inserted using high-pressure water from the hydraulic control unit. In normal operation, the motor drives the step insertion and withdrawal, and the motor drives the continuous insertion and withdrawal. Of these, in normal operation, the rotation of the motor is converted into linear motion using a ball screw mechanism to insert and withdraw the control rods.

[0025] The structure of the FMCRD consists of a part housed inside the control rod drive mechanism housing (CRD housing) installed at the bottom of the reactor pressure vessel, a spool piece attached to the bottom that houses wear parts such as the drive shaft seal, and an electric motor.The part housed inside the CRD housing is called the CRD main body, and includes the hollow piston that transmits movement to the control rod, the ball screw mechanism, etc.

[0026] Figure 4 is a diagram showing an example of data configuration of the maintenance activity / monitoring item DB 230. The maintenance activity / monitoring item DB 230 includes inspection items, monitoring items, and test items for the target equipment. The inspection items include the frequency of maintenance and the target deterioration events. The monitoring items include the frequency of monitoring and the target deterioration events. Similarly, the test items include the frequency of testing and the target deterioration events. Specifically, in the case of the control rod drive mechanism, it can be seen that the inspection item of disassembling and inspecting the main body is carried out every x years.

[0027] Figure 5 is a diagram showing an example of data configuration of the field maintenance and monitoring data DB 240. The field maintenance and monitoring data DB 240 in Figure 5 is data corresponding to the maintenance activity and monitoring item DB 230 in Figure 4. Specifically, in the case of the control rod drive mechanism, an inspection item is an overhaul inspection of the main body, which is carried out every x years to confirm its integrity.

[0028] 6 is a diagram showing an example of data configuration of the work plan management DB 250. The work plan management DB 250 has work packages, standard plan values, and related documents. Specifically, it can be seen that the target device is CRD-M001, the work order ID number is A01, the work time is x days, the number of workers is x, and the upper part is to be disassembled and inspected.

[0029] FIG. 7 is a diagram showing an example of data (long-term maintenance plan) in the maintenance plan management DB 260A. The maintenance plan management DB 260A includes information such as equipment name, maintenance activity, number of target equipment units in operation, number of target equipment units in the Nth regular inspection, number of target equipment units in the N+1th regular inspection, ..., and number of target equipment units in the N+10th regular inspection. Specifically, in the case of the control rod drive mechanism, in the Nth regular inspection, three CRD bodies will be disassembled and inspected, and all of them will be subject to current monitoring. It can also be seen that 10 spool pieces will be disassembled and inspected.

[0030] Figure 8 is a diagram showing an example of data (next maintenance plan) in the maintenance plan management DB 260B. Figure 8 is an example of detailed data for the next maintenance plan in Figure 7. The maintenance plan management DB 260B includes information on equipment name, maintenance activity, and target equipment for maintenance during the Nth periodic inspection (target equipment is marked with a circle). Specifically, in the case of the control rod drive mechanism, three CRD bodies will be overhauled during the Nth periodic inspection, and the target rods are #51, #52, and #53. Since all CRD bodies are subject to current monitoring, all rods are subject to overhaul. Furthermore, ten spool pieces will be overhauled, and the target rods are #51, #52, #53, #54, . . ., #58, #59, and #60.

[0031] <Maintenance planning support processing> 9 is a flowchart showing details of the maintenance plan support process S100 during plant operation. When the equipment status management unit 11 detects a malfunction or a symptom thereof in a system or equipment to be maintained (YES in step S102) by carrying out maintenance activities (such as monitoring and testing during operation) during operation of the nuclear power plant (step S101), the unit proceeds to step S103, and when it does not detect a malfunction or a symptom thereof in the system or equipment to be maintained (NO in step S102), the unit returns to step S101.

[0032] The equipment status management unit 11 evaluates whether corrective action is required for the malfunction (step S103), and if corrective action is not required (step S103, not required), proceeds to step S106, and if it determines that corrective action is required for the malfunction (step S106, required), proceeds to step S104.

[0033] In step S106, the equipment status management unit 11 continues operation of the plant, returns to step S101, acquires monitoring and test data during operation (step S107), calculates and records maintenance management indexes (step S108), and proceeds to reflecting the maintenance plan (step S110, see Figure 11).

[0034] In step S104, the equipment status management unit 11 formulates a plan for corrective action and executes it, acquires measurement data before the maintenance (step S105), and then proceeds to step S108.

[0035] 10 is a flowchart showing details of the maintenance plan support process S200 for a periodic inspection period. When the facility status management unit 11 detects a malfunction or a symptom thereof in a system or equipment to be maintained (YES in step S202) through the implementation of maintenance activities (such as monitoring and testing during operation) while the nuclear power plant is out of operation (step S201), the facility status management unit 11 proceeds to step S203, and when it does not detect a malfunction or a symptom thereof in a system or equipment to be maintained (NO in step S202), the facility status management unit 11 returns to step S201.

[0036] The equipment status management unit 11 evaluates whether corrective action is required for the malfunction (step S203), and if corrective action is not required (step S203, not required), proceeds to step S206, and if it determines that corrective action is required for the malfunction (step S206, required), proceeds to step S204.

[0037] In step S206, the equipment status management unit 11 continues the periodic inspection, returns to step S201, and evaluates whether additional measurement is necessary (step S207). If additional measurement is necessary (step S207, necessary), additional measurement data is acquired (step S208), and the maintenance management index is calculated and recorded (step S2 09). On the other hand, if additional measurement is not required (step S207, not required), the equipment status management unit 11 proceeds to step S110.

[0038] In step S204, the equipment status management unit 11 formulates a plan for corrective action, carries it out, acquires measurement data before the maintenance (step S205), and then proceeds to step S209.

[0039] Fig. 11 is a flowchart showing the process of reflecting in a maintenance plan (part 1). Fig. 12 is a flowchart showing the process of reflecting in a maintenance plan (part 2). In the process of reflecting in a maintenance plan (step S110), the equipment status management unit 11 determines whether the discovered malfunction is estimated to be an expected deterioration mode (step S301), and if it is estimated to be an expected deterioration mode (step S301, YES), the process proceeds to step S302, and if it is not estimated to be an expected deterioration mode (step S301, NO), the process proceeds to step S306.

[0040] In step S302, the equipment status management unit 11 evaluates the current progress of the deterioration mode and evaluates whether the deterioration has progressed more than expected (step S303). If the deterioration has progressed more than expected (step S303, YES), the equipment status management unit 11 adds the deterioration mode to candidates for maintenance during plant operation and the next regular inspection (step S304), adds the deterioration mode to related DBs (e.g., FMEA DB 220, maintenance activity / monitoring item DB 230) (step S305), and terminates the process. On the other hand, if the deterioration has not progressed more than expected (step S303, NO), the process proceeds to step S309 (see FIG. 12).

[0041] In step S306, the equipment status management unit 11 identifies the range of the affected systems and equipment, adds the affected systems and equipment to candidates for maintenance during plant operation and the next regular inspection (step S307), adds them to related DBs (e.g., FMEA DB 220, maintenance activity and monitoring item DB 230) (step S308), and terminates the process.

[0042] In step S309 of FIG. 12, the equipment status management unit 11 determines whether there is a relative change in the deterioration trend over time, and if there is a relative change in the deterioration trend over time (step S309, YES), proceeds to step S317, and if there is no relative change in the deterioration trend over time (step S309, NO), proceeds to step S310.

[0043] In step S310, the equipment status management unit 11 determines whether there is a relative change in the deterioration trend compared to similar equipment, and if there is a relative change in the deterioration trend compared to similar equipment (step S310, YES), proceeds to step S317, and if there is no relative change in the deterioration trend compared to similar equipment (step S310, NO), proceeds to step S311.

[0044] In step S317, the maintenance plan update unit 12 adds the plant to candidates for maintenance during plant operation and the next periodic inspection.

[0045] In step S311, the equipment status management unit 11 evaluates the future progress of the deterioration mode, and then the process proceeds to step S312.

[0046] In step S312 (see Figures 16A and 16B), the equipment status management unit 11 checks the trend of maintenance management indicators (e.g., KPI; Key Performance Indicator), checks the maintenance tasks and number of units to be maintained for the equipment or similar equipment, and the expected operating period of the equipment (step S313, see Figures 15A and 15B), and checks the laws, regulations, standards, and constraints on the long-term maintenance plan (step S314, see Figure 17).

[0047] Figure 15A is a diagram showing an example of a recommended plan for future regular inspections (Case A: a plan that standardizes the number of units). Figure 15B is a diagram showing an example of a recommended plan for future regular inspections (Case B: a plan to maintain a large number of units at a certain regular inspection). The number of years that each piece of equipment will be used in future long-term plans is shown in a table or other format, and the recommended plan is presented as a case study of candidates for future regular inspection plans. In Figure 15A, the number of units inspected for maintenance activities has been standardized to three or four units. On the other hand, Figure 15B shows that the number of units inspected at the N+1 regular inspection is 30 units, and at the Nth regular inspection it is 1 unit.

[0048] Fig. 16A is a diagram showing an example of a base for reviewing maintenance tasks and cycles (the Nth operation cycle and the Nth periodic inspection). Fig. 16B is a diagram showing an example of a base for reviewing maintenance tasks and cycles (time change in the case where only the tasks performed while the plant was shut down are plotted). Figs. 16A and 16B are the bases for reviewing maintenance tasks and cycles.

[0049] Figure 17 is a diagram showing an example of visualization of constraints on a long-term maintenance plan. The horizontal axis shows the expected number of days for regular inspections, and the vertical axis shows the number of units that can be maintained. Regarding how many units a work team can maintain, the maximum and minimum numbers of units that can be maintained are calculated as a case study. Note that data from the work plan management DB 250 (see Figure 6) is used for the calculation.

[0050] Then, returning to Figure 12, the maintenance plan update unit 12 adds the candidate to be subject to maintenance during plant operation, reflects this in the next and subsequent long-term maintenance plans (step S315), and updates the next maintenance plan from the above long-term maintenance plan (step S316, see Figures 14A and 14B).

[0051] FIG. 14A is a diagram showing an example of equipment recommended for the next maintenance based on a long-term plan. FIG. 14B is a diagram showing an example of equipment recommended for the next maintenance based on a long-term plan (the number of years of use of similar solids). The number of years each piece of equipment has been in use is shown in a table or the like in the long-term plan. If there is an abnormality during operation, that is given priority, and if there is no abnormality, the equipment is recommended for the next maintenance based on the number of years of use. For example, referring to FIG. 14B, it can be seen that lot numbers #203, #204, and #205 are the solids recommended for the next maintenance.

[0052] (Example of monitoring the control rod drive mechanism) The main structure of the FMCRD consists of 205 control rods, the same number as the control rods, installed below the reactor pressure vessel (inside the reactor containment vessel). The electric motors used to drive the FMCRD continuously are controlled from a control panel installed outside the reactor containment vessel.

[0053] Tests of the control rod drive mechanism are conducted during operation and periodic inspections. Tests during operation are conducted over a set period of time, such as one month, to cycle through all 205 rods, and only within a limited range of vertical positions (such as one notch) that each control rod can be driven (hereinafter referred to as "in-operation tests").

[0054] Furthermore, during the periodic inspections carried out while the plant is shut down, maintenance activities such as disassembly and inspections and part replacements are carried out on the FMCRD main body, spool pieces, motors, etc. After that, before restarting the plant, a test is carried out on all 205 units to operate the control rods over the entire range of their driving range (up and down positions, hereafter referred to as a normal driving test).

[0055] Since the control rod drive mechanism is composed of mechanical mechanisms such as ball screws and electrical components such as electric motors, it is desirable to ensure reliability through appropriate maintenance activities against mechanical and electrical deterioration.

[0056] Therefore, one example of FMCRD maintenance activities would be to monitor control signals.For comparison, if vibrations, sounds, etc. of the FMCRDs were to be measured, it would be necessary to install vibration and sound sensors on each of the 205 units installed inside the reactor containment vessel, lay cables for transmitting signals, and enable measurements to be taken outside the containment vessel.

[0057] On the other hand, when monitoring control signals, it is possible to more easily monitor all FMCRDs by measuring the control signals directly or indirectly from a control panel originally installed outside the reactor containment vessel.

[0058] Direct measurements include waveforms such as the operating time required to move within a specified vertical range and drive voltage. Indirect measurements include current waveforms obtained by installing a current transformer or other circuit in a control panel. Regarding waveforms such as voltage and current, feature quantities such as signal magnitude (peak value) and frequency spectrum components may be extracted.

[0059] In this way, the control signals of the motor can be monitored during an in-service test as an in-service monitoring of the FMCRD, and the control signals of the motor can be monitored during a regular inspection as an in-service test.

[0060] Fig. 13A is a diagram showing a method for selecting an inspection candidate for the next regular inspection (changes over time), and Fig. 13B is a diagram showing a method for selecting an inspection candidate for the next regular inspection (changes in similar individuals). As shown in steps S309 and S310 of the flowchart in Figure 12, the monitored signals can be used to draft an update plan for the maintenance plan based on the overall change in the deterioration trend over time of the control signals of each FMCRD or the feature values ​​extracted therefrom (step S309, see Figure 13A), or the relative change through mutual comparison of the control signals of the FMCRD in question and the other FMCRDs or the feature values ​​extracted therefrom (step S310, see Figure 13B). In other words, if there is a change over time or a change through mutual comparison, it can be used to add the device to the list of candidates for the next maintenance target. For example, referring to Figure 13B, it can be seen that rod #203 is the recommended device for the next maintenance.

[0061] The maintenance plan support method and maintenance plan support device 100 of the present embodiment described above have the following features. (1) A maintenance plan support method for a nuclear power plant that supports maintenance plans by utilizing information from design and / or the field, wherein in equipment maintenance activities and actions (e.g., equipment inspection, testing, monitoring, patrol) carried out in accordance with a maintenance plan, a maintenance plan to prevent such activities is formulated based on equipment management indicators (e.g., the status of performance, deterioration, and malfunctions), and an update plan for the next maintenance plan and update plans for the next and subsequent long-term maintenance plans are set for a long-term maintenance plan for multiple periodic inspections formulated in advance, the update plan being determined from the equipment status on-site. This makes it possible to appropriately support maintenance activities in the nuclear power plant.

[0062] (2) In (1) above, when setting an update plan for the next maintenance plan, the update plan is created using both information on the time-varying trends of the performance, deterioration, and malfunction status of the equipment in question, and information on mutual comparison of the deterioration and malfunction status of similar equipment (steps S309, S310, see Figures 13A and 13B).

[0063] (3) In (1) above, when setting an update plan for the next maintenance plan, the operation period of the equipment or similar equipment to be maintained is calculated from the long-term maintenance plan, and an update plan is created using the operation period (see Figures 14A and 14B).

[0064] (4) In (1) above, when setting the next and subsequent update proposals for the long-term maintenance plan, calculate the future maintenance tasks and number of units to be maintained for the equipment or similar equipment to be maintained, as well as the expected operating period of the equipment (see Figures 15A and 15B).

[0065] (5) In (2) above, when setting an update plan for the next maintenance plan, the monitoring task for understanding the performance, deterioration, and malfunction status of the equipment is classified into whether it is performed while the power plant is operating or while the plant is stopped, and whether the monitoring task requires disassembly of the equipment, and the results of performing the monitoring task and the degree of the performance, deterioration, and malfunction status of the equipment are recorded as maintenance management indicators (see Figures 16A and 16B).

[0066] (6) In (4) above, when setting the proposal for updating the long-term maintenance plan for the next and subsequent years, at least information on the resources such as the standard number of days and number of personnel required for the maintenance tasks of the equipment and information on the estimated number of days for the periodic inspections scheduled to be carried out in the future is used to calculate the maximum number of units for which maintenance tasks will be carried out on the equipment and the minimum number of units for which maintenance tasks will be carried out on the equipment, which is required under the constraint that it does not exceed the cycle of the maintenance tasks imposed on the equipment (see Figure 17).

[0067] (7) A maintenance plan support device 100 for a nuclear power plant that supports maintenance plans by utilizing information from design and / or the field, includes an equipment status management unit 11 that manages equipment management indicators of the nuclear power plant (e.g., the status of performance, deterioration, and malfunctions) through equipment maintenance activities and maintenance actions (e.g., inspection, testing, monitoring, and patrol), a maintenance plan update unit 12 that updates the maintenance plan for the next operating cycle based on the status of the nuclear power plant and updates the long-term maintenance plan for the next and subsequent operating cycles, and a maintenance execution management unit 13 that manages maintenance management indicators, maintenance tasks and cycles that are required by laws, regulations, standards, and criteria, the resources required for maintenance, and the number of units to be maintained. This makes it possible to appropriately support maintenance activities for the nuclear power plant.

[0068] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, or the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, part of the configuration of each embodiment can be added, deleted, or replaced with other configurations. Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be implemented in hardware, in part or in whole, by designing, for example, an integrated circuit. Furthermore, the above-described configurations, functions, etc. may be implemented in software, by a processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD. [Explanation of symbols]

[0069] 10 Processing section 11 Equipment Status Management Department 12 Maintenance Plan Update Division 13 Maintenance Execution Management Department 14. Conservation Planning Department 20 Memory section 21 Configuration management extraction information 22 FMEA Extraction Information 23 Maintenance activities / monitoring item extraction information 24 Field Maintenance and Monitoring Extraction Information 25 Work plan management extraction information 26 Maintenance Plan Management Extraction Information 30 Input section 40 Output section 50 Communications Department 100 Maintenance planning support device 200 Database Device 210 Configuration management DB 220 FMEA DB 230 Maintenance activities / monitoring item DB 240 Field Maintenance and Monitoring Data DB 250 Work plan management database 260 Maintenance Plan Management DB 300 Maintenance Planning Support System S100, S200 Maintenance planning support processing

Claims

1. A maintenance planning support method for a control rod drive mechanism of a nuclear power plant, which supports a maintenance plan by utilizing information from design and / or a site, monitoring signals related to control of the control rod drive mechanism during facility maintenance activities and maintenance actions carried out in accordance with the maintenance plan; detecting a malfunction or a symptom of the malfunction in the control rod drive mechanism from the result of monitoring the signal; and if it is determined that the malfunction or the symptom of the malfunction is an expected deterioration, evaluating whether the malfunction or the symptom of the malfunction is progressing more than expected; a step of determining a time-varying trend of deterioration of the control rod drive mechanism when it is determined in the evaluating step that the malfunction or a symptom of the malfunction has progressed less than expected; and a step of determining a relative change in the deterioration trend of the control rod drive mechanism in comparison with similar equipment, Based on the determination result of the time-varying trend regarding the deterioration tendency and the determination result of the relative change regarding the deterioration tendency in comparison with similar equipment, an update plan for the next maintenance plan determined from the on-site equipment status and update plans for the next and subsequent long-term maintenance plans are set for the long-term maintenance plan for multiple periodic inspections that were planned in advance. A maintenance planning support method comprising:

2. The step of detecting a malfunction or a symptom of the malfunction of the control rod drive mechanism from the signal monitoring results includes a step of calculating a maintenance management index from the signal monitoring results and information on the malfunction or the symptom of the malfunction of the control rod drive mechanism.

2. The maintenance planning support method according to claim 1.

3. When setting up an update plan for the next conservation plan, From the long-term maintenance plan, calculate the operation period of the equipment or similar equipment to be maintained, and use the operation period to create a renewal plan.

2. The maintenance planning support method according to claim 1.

4. When setting the next and subsequent updates to the long-term conservation plan, Calculate future maintenance tasks and the number of units to be maintained for the equipment or similar equipment to be maintained, as well as the expected operation period of the equipment.

2. The maintenance planning support method according to claim 1.

5. When setting up an update plan for the next conservation plan, Regarding the monitoring tasks for grasping the status of malfunctions such as performance, deterioration, and breakdowns of the equipment, the monitoring tasks are classified according to whether they are performed while the power plant is in operation or while the plant is stopped, and whether the monitoring tasks require disassembly of the equipment, and the results of the implementation of the monitoring tasks and the degree of malfunctions such as performance, deterioration, and breakdowns of the equipment are recorded as maintenance management indicators.

2. The maintenance planning support method according to claim 1.

6. When setting the next and subsequent updates to the long-term conservation plan, By using at least information on the standard number of days and number of personnel required for maintenance tasks on the equipment, and information on the estimated number of days for periodic inspections scheduled to be carried out in the future, the maximum number of units on which maintenance tasks will be carried out on the equipment and the minimum number of units on which maintenance tasks will be carried out on the equipment, which is required under the constraint that the number does not exceed the cycle of the maintenance tasks imposed on the equipment, are calculated.

5. The maintenance planning support method according to claim 4.

7. A maintenance planning support device for a control rod drive mechanism of a nuclear power plant, which supports a maintenance plan by utilizing information from design and / or a site, an equipment status management unit that manages the control rod drive mechanism of the nuclear power plant through maintenance activities and maintenance actions; a maintenance plan update unit that updates a maintenance plan for a next operation cycle based on the status of the control rod drive mechanism and updates a long-term maintenance plan for the next and subsequent operation cycles, The equipment status management unit monitoring a signal related to the control of the control rod drive mechanism, and detecting a malfunction or a symptom of the malfunction of the control rod drive mechanism from the monitoring result of the signal; If the malfunction or symptom of the malfunction of the control rod drive mechanism is an assumed deterioration, assessing whether the deterioration is progressing more than expected; When it is evaluated that the malfunction or the symptom of the malfunction of the control rod drive mechanism is not progressing as expected, determining a time-varying trend regarding the deterioration tendency of the control rod drive mechanism, and determining a relative change regarding the deterioration tendency of the control rod drive mechanism in comparison with similar equipment; The maintenance plan update unit updates the maintenance plan for the next operation cycle based on the determination result of the time-varying trend regarding the deterioration tendency and the determination result of the relative change regarding the deterioration tendency compared with similar equipment, and updates the long-term maintenance plan for the next and subsequent operation cycles. A maintenance planning support device characterized by:

Images