JP7225014B2 - Maintenance management system and maintenance management method - Google Patents

Description

TECHNICAL FIELD Embodiments of the present invention relate to a maintenance management system and a maintenance management method.

Evaluation of equipment status such as aging deterioration tendency of control rod drive mechanism, presence or absence of abnormality, degree of abnormality in nuclear power plant equipped with boiling water reactor etc., selection of appropriate equipment to be inspected based on the evaluation result, and cause of abnormality There is known a system that supports inspection cycle optimization by identifying and predicting service life.

In a nuclear power plant, control rods are used for output control or emergency shutdown. The control rods are hydraulically inserted or withdrawn by a control rod drive mechanism connected to the lower portion thereof. Therefore, the control rod drive mechanism is required to have high reliability. In order to maintain this reliability, an overhaul inspection of the control rod drive mechanism is periodically carried out during regular inspections of nuclear power plants. This inspection is carried out on a timely basis. A typical 1,100,000 kW boiling water nuclear reactor has 185 control rod drive mechanisms installed, and a predetermined number of overhauls are carried out for each periodical inspection. The working time is a critical process of periodic inspection. Therefore, from the viewpoint of improving the reliability and economic efficiency of the control rod drive mechanism, in recent years, it has been considered to extend the inspection cycle of the control rod drive mechanism and reduce the number of inspections of the control rod drive mechanism per periodic inspection. ing.

Conventionally, there have been cases where the inspection period of the control rod drive mechanism was extended beyond the inspection period on a trial basis, and the condition was confirmed and the inspection period was extended. Furthermore, in order to improve the reliability and economic efficiency of the control rod drive mechanism, it is important to optimally select the equipment to be disassembled and inspected. The status is grasped by analyzing and evaluating the test results and inspection history. Also, the inspection period of each control rod drive mechanism is selected so as to be substantially constant. At this time, the condition of the facility is confirmed from the results of each function test of the control rod drive system, including the function of the hydraulic control unit that controls the drive of the control rod drive mechanism. Therefore, when an abnormality occurs in the control rod drive system, an expert judges the possible cause of the abnormality from the abnormality data and takes measures such as disassembly inspection.

JP-A-2-19790 JP-A-4-364499 JP-A-1-244395 JP-A-2-161364

In the inspection period of the control rod drive mechanism, the method of extending the inspection period based on the long-term operation results of the actual plant requires several cycles of operation, so it takes a considerable amount of time to put it into practical use. For example, if 27 units of 185 control rod drive mechanisms are inspected in one cycle, at least 7 cycles of operation are required to complete one cycle. Furthermore, it is necessary to accurately grasp the state of each control rod drive mechanism, including the behavior of the hydraulic control unit that controls the control rod drive mechanism, in order to select the object for overhaul inspection from among many control rod drive mechanisms. need to be evaluated. Therefore, a great deal of effort is required by experts. In addition, when an abnormality occurs, it is necessary to evaluate it at the control rod drive system level, and it is difficult to estimate the cause. In addition, as a countermeasure when an abnormality occurs, the event is resolved by repeating the drive several times, and as a precaution, it is often disassembled during the next periodic inspection. of process extension occurs. In addition, it is necessary to measure important physical quantities to grasp the state of the components of the control rod drive system.

As a solution to these problems, methods have been proposed, such as evaluation of aging deterioration tendency of the control rod drive mechanism using a database of test and inspection data, selection of targets for overhaul inspection, and identification of the cause of abnormality. data is required. However, the control rod drive mechanism is subject to preventive maintenance with a sufficient margin, so there is little data on aging deterioration or abnormalities. In addition, there is a problem that it is difficult to put the method to practical use only by using the database method, because the scale of the test facility for obtaining the data and the time limit are limited.

The embodiments of the present invention have been made in consideration of such circumstances, and it is an object of the present invention to provide a maintenance management technique that assists in deciding when to inspect a control rod drive system of a nuclear power plant.

A maintenance management system according to an embodiment of the present invention builds a physical model that can reproduce the state of a control rod drive system including a control rod drive mechanism of a nuclear power plant and equipment related to the operation of the control rod drive mechanism. A modeling processing unit, an analysis unit that performs calculations by reflecting parameters in equations formulated based on the physical model, and a measured data acquisition unit that acquires measured data obtained by actually measuring the state of the control rod drive system. a matching parameter specifying unit for specifying, as a matching parameter, the parameter whose calculation result of the physical model matches the measured data; and a recording unit for recording analysis data including the matching parameter and an analysis result of the matching parameter. an inspection timing determination unit that evaluates the progress of deterioration of the control rod drive mechanism based on the analysis data, obtains the timing and probability that an abnormality will occur in the control rod drive mechanism, and determines the inspection timing. .

An embodiment of the present invention provides a maintenance management technique that assists in deciding when to inspect the control rod drive system of a nuclear power plant.

1 is a block diagram showing a maintenance management system of this embodiment; FIG. Schematic diagram showing the configuration of a control rod drive system. Sectional drawing which shows the control-rod drive mechanism at the time of insertion. Sectional drawing which shows a control-rod drive mechanism at the time of extraction. Explanatory drawing which shows the physical model of the control rod drive system at the time of insertion. Explanatory drawing which shows the physical model of the control rod drive system at the time of withdrawal. Explanatory drawing for demonstrating the estimation method of an abnormality cause. A graph showing the response of analytical data to parameter changes. 4 is a graph showing test data for seal wear elements; Graph showing simulation results for seal wear factors. 4 is a flowchart showing maintenance management processing; 4 is a flowchart showing maintenance management processing;

Hereinafter, embodiments of a maintenance management system and a maintenance management method will be described in detail with reference to the drawings.

Reference numeral 1 in FIG. 1 denotes a maintenance management system of this embodiment. This maintenance management system 1 is a system that optimizes the inspection cycle of a control rod drive (CRD) in a nuclear power plant and supports maintenance work of the nuclear power plant.

When a large number of control rod drive mechanisms are provided, it is not possible to inspect all the control rod drive mechanisms in one periodic inspection, and only a predetermined number of control rod drive mechanisms are subject to inspection. Therefore, the control rod drive mechanism to be inspected is selected according to the progress of deterioration of the control rod drive mechanism. It is desirable that the control rod drive mechanism, which has deteriorated the most, should be subject to the next inspection, but it is difficult to grasp the actual progress of deterioration. Therefore, in this embodiment, a physical model of each control rod drive mechanism is constructed by a computer, these physical models are compared with actual measurement data, and the state of each control rod drive mechanism is grasped. Select the control rod drive mechanism that will be

As shown in FIG. 2, a nuclear power plant 2 is provided with a nuclear reactor 3 . A reactor 3 is housed in a pressure vessel 4 . A control rod drive mechanism 5 is provided below the pressure vessel 4 . The control rod drive mechanism 5 is a device for moving the control rods 6 into and out of the reactor 3 . In this embodiment, the hydraulic type used in the boiling water reactor 3 is exemplified as the driving method of the control rod drive mechanism 5 .

A control rod drive mechanism 5 is provided at the bottom of the pressure vessel 4 . The pressure vessel 4 and the control rod drive mechanism 5 are housed in the reactor containment vessel 7 . A hydraulic control unit 8 (HCU: Hydraulic Control Unit) composed of devices related to the operation of the control rod drive mechanism 5 is provided outside the reactor containment vessel 7 . One water pressure control unit 8 is provided for one control rod drive mechanism 5 . For example, when 185 control rod drive mechanisms 5 are provided, 185 hydraulic control units 8 are provided.

A pair of control rod drive mechanisms 5 and hydraulic control unit 8 constitute one control rod drive system 9 . The control rod drive mechanism 5 and the water pressure control unit 8 are connected to each other by an insertion pipe 10 and a withdrawal pipe 11 .

When the control rods 6 are to be inserted into the reactor 3, driving water is supplied from the water pressure control unit 8 to the control rod drive mechanism 5 through the insertion pipe 10, and from the control rod drive mechanism 5 through the withdrawal pipe 11. drive water is discharged toward the water pressure control unit 8. On the other hand, when the control rods 6 are withdrawn from the reactor 3, driving water is supplied from the water pressure control unit 8 to the control rod drive mechanism 5 through the withdrawal pipe 11, and the insertion pipe 10 is drawn from the control rod drive mechanism 5. The drive water is discharged toward the water pressure control unit 8 through.

The water pressure control unit 8 includes a directional control valve 12, a scram valve 13, a check valve 14, other valves 15, an accumulator 16, a filter 17, and various sensors 18. The various sensors 18 include flowmeters, pressure gauges, thermometers, and the like. These sensors 18 acquire measurement data such as the flow rate, water pressure, and water temperature that change according to the state of the control rod drive system 9 . Note that other equipment may be provided in the water pressure control unit 8 . In addition, it is preferable to install the various sensors 18 before or after the branching of each pipe. In this way, more information can be obtained than a small number of installed sensors.

Further, the water pressure control unit 8 is connected with a filling water pipe 19 , a driving water pipe 20 , a cooling water pipe 21 and a drain pipe 22 . These pipes 19 to 22 are branched on the way and connected to another control rod drive system 9 as well. Also, the water pressure control unit 8 is connected to a predetermined water system 23 through respective pipes 19-22.

A predetermined water system 23 is provided with equipment including a control rod driven water pump 24 , a filter 25 , a flow control valve 26 , a pressure control valve 27 , a flow stabilization valve 28 and various sensors 29 . Driving water is supplied to a predetermined water system 23 via a condensate system.

The control rod drive water pump 24 is provided separately from the control rod drive system 9, but the control rod drive system 9 operates based on the drive water supplied by the power of the control rod drive water pump 24. Therefore, the control rod drive water pump 24 may be regarded as part of the control rod drive system 9 .

As shown in FIGS. 3-4, the control rod drive mechanism 5 includes a housing 30 extending downward from the bottom of the pressure vessel 4 . This housing 30 is welded to the bottom of the pressure vessel 4 and integrated with the pressure vessel 4 .

A cylinder tube 31 is provided inside the housing 30 . A lower portion of the cylinder tube 31 is a rectangular base portion 31a. The base portion 31a is fixed to the lower flange portion 30a of the housing 30. As shown in FIG.

Although the cross section of the housing 30 is hatched in FIGS. 3 and 4, the hatching of the cross sections of the cylinder tube 31 and the base portion 31a is omitted for better understanding.

An index tube 32 is provided inside the cylinder tube 31 . A collet piston 33 is provided above the cylinder tube 31 . The index tube 32 is a tubular piston member. A piston tube 34 is provided inside the index tube 32 . The piston tube 34 has its lower end fixed to the base portion 31a, along which the index tube 32 can move in the vertical direction.

A coupling spud 35 to which the control rod 6 (see FIG. 2) is connected is provided at the upper end of the index tube 32 . The control rod 6 is inserted into the reactor 3 when the index tube 32 is raised. On the other hand, when the index tube 32 is lowered, the control rod 6 is withdrawn from the reactor 3 .

The outer peripheral surface of the index tube 32 is formed with a plurality of recesses 32a with which the engaging claws 33a of the collet piston 33 are engaged. These recesses 32a are arranged side by side in the vertical direction. When the index tube 32 rises, the engagement claw 33a of the collet piston 33 is engaged with the recess 32a at a predetermined position, thereby preventing the index tube 32 from falling.

The control rod drive mechanism 5 is provided with a first connection port 36 to which the insertion pipe 10 is connected and a second connection port 37 to which the withdrawal pipe 11 is connected. When the control rod 6 is inserted into the nuclear reactor 3, the drive water W is supplied from the first connection port 36 and the drive water W is discharged from the second connection port 37 (see FIG. 3). On the other hand, when the control rod 6 is withdrawn from the reactor 3, the drive water W is supplied from the second connection port 37 and the drive water W is discharged from the first connection port 36 (see FIG. 4).

A ball check valve 38 is provided near the first connection port 36 . The control rod drive mechanism 5 includes a channel 40 through which the drive water W flows in the chamber 39 below the index tube 32, a channel 41 through which the drive water W flows between the housing 30 and the cylinder tube 31, a collet piston 33 A channel 43 through which driving water W flows and a channel 44 in the center of the piston tube 34 are provided in a chamber 42 at the bottom of the piston tube 34 .

As shown in FIG. 3 , when the control rod 6 is inserted, the driving water W supplied from the first connection port 36 flows into the chamber 39 below the index tube 32 and pushes up the index tube 32 . Part of the drive water W supplied from the first connection port 36 passes through the orifice 45 and leaks into the furnace through between the housing 30 and the outer tube. Water passing through the orifice 45 is used as a medium for cooling the control rod drive mechanism 5 .

The driving water W that pushes up the index tube 32 rises through between the index tube 32 and the cylinder tube 31 and leaks into the furnace. Further, the driving water W that has pushed up the index tube 32 rises through the space between the index tube 32 and the piston tube 34 and flows from the gap 46 at the upper end of the piston tube 34 to the flow path 44 at the center of the piston tube 34. flow in. Then, it flows from this channel 44 toward the second connection port 37 .

As shown in FIG. 4 , when the control rod 6 is pulled out, the driving water W supplied from the second connection port 37 flows into the flow path 44 at the center of the piston tube 34 . Then, it descends from the gap 46 at the upper end of the piston tube 34 through the flow path 44 between the index tube 32 and the piston tube 34 to push the index tube 32 downward.

Part of the driving water W supplied from the second connection port 37 is branched and flows toward the chamber 42 below the collet piston 33 . Then, the collet piston 33 is pushed up to open the engaging claw 33a and come off the concave portion 32a of the index tube 32. As shown in FIG. Further, the driving water W pushing up the collet piston 33 leaks into the furnace.

The drive water W that pushes down the index tube 32 passes between the index tube 32 and the piston tube 34 and leaks into the chamber 39 below the index tube 32 . Then, it is discharged from the first connection port 36 .

The control rod drive mechanism 5 is provided with various seal members 47 to 50 for operating the index tube 32 and the collet piston 33 while allowing the drive water W to leak.

For example, the top of the index tube 32 is provided with a stop piston seal 47 . Furthermore, in the lower portion of the index tube 32 , an inner seal 48 is provided on the inner peripheral surface that slides against the piston tube 34 , and an outer seal 49 is provided on the outer peripheral surface that slides against the cylinder tube 31 . Furthermore, the collet piston 33 is provided with a collet piston seal 50 .

These seal members 47 to 50 are parts that wear out due to aging or wear. For example, in the maintenance and inspection of the 185 control rod drive mechanisms 5, it is important to know which of the control rod drive mechanisms 5 the seal members 47 to 50 have worn out, and to perform the inspection at an appropriate time. At the time of inspection, the control rod drive mechanism 5 to be inspected is disassembled to check the state of consumption of the seal members 47-50.

The control rod drive system 9 of this embodiment inserts or withdraws the control rods 6 by adjusting the flow rate and pressure of the fluid flowing through the control rod drive system 9 using devices such as the pump 24 and various valves 12 to 15. is. That is, the control rod drive system 9 includes the control rod drive mechanism 5, the pump 24, various valves 12 to 15, the filter 17, the orifice 45, a sensor 18 such as a flow meter, a circuit for controlling the flow rate, and a circuit for driving the pump. Including electrical system.

Next, the system configuration of the maintenance management system 1 will be described with reference to the block diagram shown in FIG.

The maintenance management system 1 includes a modeling processing unit 51, an analysis unit 52, a difference determination unit 53, an initial parameter setting unit 54, a parameter update unit 55, a test and inspection database 56, a sensor group 57, and a measurement data reception unit 58. .

A physical model 59 and a group of equations 60 are constructed by the modeling processing unit 51 . Also, the difference determining section 53 , the initial parameter setting section 54 and the parameter updating section 55 constitute a matching parameter specifying section 61 . Furthermore, the test and inspection database 56 , the sensor group 57 and the measurement data receiving section 58 constitute the actual measurement data acquisition section 62 .

In addition, the maintenance management system 1 includes a recording unit 63, a data processing unit 64, an allowable range setting unit 65, a state determination unit 66, an inspection target selection unit 67, a measurement method selection unit 68, an abnormality cause identification unit 69, and an inspection timing determination unit. 70 , a result output section 71 , a main control section 72 , an information input section 73 and a communication section 74 .

Each part of the maintenance management system 1 is realized by executing a program stored in a memory or HDD by the CPU. The test and inspection database 56 is a collection of information stored in a memory or HDD and organized so that it can be searched or stored.

The maintenance management system 1 of this embodiment has hardware resources such as a CPU, a ROM, a RAM, and an HDD, and the CPU executes various programs to realize information processing by software using the hardware resources. It consists of computers. Furthermore, the maintenance management method of this embodiment is implemented by causing a computer to execute a program.

The modeling processing unit 51 constructs a physical model 59 that can reproduce the state of the control rod drive system 9 including the control rod drive mechanism 5 of the nuclear power plant 2 and devices related to its operation (FIGS. 5 to 6). reference). The control rod drive system 9 constructed as the physical model 59 includes a control rod drive water pump 24 that supplies drive water as a power source. In addition, valves or piping, control systems or associated electrical systems can all be modeled.

Furthermore, the modeling processing unit 51 formulates equations based on the physical model 59 to construct an equation group 60 . For example, a physical model 59 composed of a dynamic model representing the mechanical behavior of the equipment constituting the control rod drive system 9, a fluid model representing fluid behavior such as flow rate and pressure, etc. is constructed, and the corresponding formulation Construct a group of equations 60 that are represented by

The physical model 59 of this embodiment includes a dynamic model that represents the dynamic behavior of the control rod drive mechanism 5 and the pump 24 or valves 12-15 that are devices. It also includes a fluid model representing changes in the flow rate or pressure of fluid flowing through the control rod drive system 9 . It also includes a thermal model that expresses phenomena related to heat in the control rod drive system 9 . It also includes a control model for controlling the behavior of the equipment of the control rod drive system 9 . It also includes an electric circuit model representing the behavior of the electric system relating to the installation of the control rod drive system 9 . It also includes a physical property model that represents the characteristics of the material of the equipment of the control rod drive system 9 . Note that at least one of these models should be included.

Moreover, in this embodiment, the state of the control rod drive system 9 is reproduced by a combination of parameters defined by the physical model 59 . In this way, a physical model 59 reflecting the actual state of the control rod drive system 9 can be constructed. The equipment includes pumps or valves 12 - 15 of hydraulic control unit 8 corresponding to control rod drive mechanism 5 . Furthermore, the physical model 59 is constructed in association with identification information that allows the control rod drive system 9 to be individually identified. With these physical models 59, a simulation can be performed in which the situation of each control rod drive system 9 is reflected.

The analysis unit 52 performs calculations by reflecting parameters in a group of equations 60 formulated based on the physical model 59 . The analysis unit 52 outputs the calculation result obtained by substituting the initial parameters or updated parameters into the equation group 60 .

When the device to be reproduced is a valve, the parameters include the CV value of the valve. It also includes characteristics of the valve, such as the shape of the valve or the inner diameter of the valve. These parameters may be obtained based on valve specifications or by testing actual valves.

The difference determination unit 53 compares the calculation result of the physical model 59 by the analysis unit 52 and the measured data to determine whether there is a difference between them. The actual measurement data includes at least one of measurement data measured by the sensor group 57 installed in the control rod drive system 9 and test and inspection data when the equipment of the control rod drive system 9 was tested and inspected in the past. including The difference determination unit 53 determines, for example, whether or not the calculation result of the physical model 59 matches the measurement data or the drive water flow rate or drive water pressure data recorded in the test and inspection database 56 .

The initial parameter setting unit 54 sets initial values of parameters reflected in the equation group 60 of the physical model 59 . Parameters that match the measurement data of the control rod drive system 9 in normal operation are set as initial parameters. Alternatively, the initial parameters may be preset by the user.

The parameter updating unit 55 updates parameters to be reflected in the equation group 60 of the physical model 59 . For example, the parameters are updated so that the calculation result of the analysis unit 52 matches the measurement data or test and inspection data. Note that the parameters are updated repeatedly until they match.

In this embodiment, the parameter updating unit 55 updates the parameters when the difference determining unit 53 determines that there is a difference. On the other hand, if the difference determination unit 53 determines that there is no difference, the parameters reflected in the physical model 59 are specified as matching parameters. In other words, the matching parameter specifying unit 61 composed of the difference determining unit 53, the initial parameter setting unit 54, and the parameter updating unit 55 specifies the parameter whose calculation result of the physical model 59 best matches the measured data as the matching parameter. do. In this way, matching parameters can be specified by updating various parameters and reflecting them in the physical model 59 .

The test and inspection database 56 stores test and inspection data obtained when equipment of the control rod drive system 9 was tested and inspected in the past. In addition, various information such as inspection history is stored. Furthermore, the test and inspection data are stored in association with identification information that allows each control rod drive system 9 to be individually identified.

A sensor group 57 is composed of a large number of various sensors 18 installed in the control rod drive system 9 . The various sensors 18 are not limited to being pre-installed in the control rod drive system 9, and may be added at each inspection. Also, the installation location of the sensor 18 that has already been installed may be changed.

The measurement data receiving section 58 receives measurement data from the sensor group 57 installed in the control rod drive system 9 . The actual measurement data is acquired by the actual measurement data acquiring section 62 composed of the test and inspection database 56 , the sensor group 57 and the measurement data receiving section 58 . In this way, it is possible to obtain actual measurement data that reflects the actual state of the control rod drive system 9 .

The recording unit 63 records analysis data including matching parameters and analysis results of the matching parameters. That is, when the calculation result of the analysis unit 52 matches the measured data, the calculation result and the matching parameter are recorded.

The data processing unit 64 processes the analysis data by data mining. In other words, data mining is performed on the analysis results and the data on the matching parameters recorded in the recording unit 63 . In this way, a large amount of data can be comprehensively processed. Data mining is a technique for extracting knowledge by comprehensively applying data analysis methods such as statistics, pattern recognition, and artificial intelligence to a large amount of data.

In addition, the data processing unit 64 may be provided with artificial intelligence (AI). An analysis technique based on artificial intelligence learning can be used for analysis using a computer in this embodiment. For example, a learning model generated by machine learning using a neural network, a learning model generated by other machine learning, a deep learning algorithm, a mathematical algorithm such as regression analysis can be used. Further, forms of machine learning include forms such as clustering and deep learning.

The maintenance management system 1 of this embodiment includes a computer with artificial intelligence that performs machine learning. For example, the maintenance management system 1 may be composed of one computer equipped with a neural network, or may be composed of a plurality of computers equipped with a neural network.

Here, a neural network is a mathematical model that expresses the characteristics of brain functions by computer simulation. For example, we present a model in which artificial neurons (nodes), which form a network through synaptic connections, change the strength of synaptic connections through learning and acquire problem-solving ability. Furthermore, the neural network acquires problem-solving ability through deep learning.

For example, a neural network is provided with an intermediate layer having 6 layers. Each layer of this intermediate layer consists of 300 units. In addition, by pre-learning a multi-layered neural network using learning data, it is possible to automatically extract feature amounts in patterns of changes in the state of a circuit or system. In addition, the multi-layered neural network can set arbitrary number of intermediate layers, number of units, learning rate, number of times of learning, and activation function on the user interface.

Note that deep reinforcement learning may be used in which a reward function is set for various types of information to be learned, and information with the highest value is extracted based on this reward function.

For example, CNN (Convolution Neural Network), which has a proven track record in image recognition, is used. In this CNN, the intermediate layer is composed of a convolutional layer and a pooling layer. The convolutional layer obtains the feature map by filtering nearby nodes in the previous layer. The pooling layer further reduces the feature map output from the convolution layer to obtain a new feature map. At this time, depending on which value of the region of interest is used, it is possible to absorb some deviation of the image.

A convolutional layer extracts local features of an image, and a pooling layer performs processing to combine the local features. These processes reduce the image while maintaining the features of the input image. In other words, CNN can significantly compress (abstract) the amount of information in an image. Then, using the abstracted image stored in the neural network, it is possible to recognize the input image and classify the image.

Deep learning includes various techniques such as autoencoder, RNN (Recurrent Neural Network), LSTM (Long Short-Term Memory), and GAN (Generative Adversarial Network). These methods may be applied to the deep learning of this embodiment.

The allowable range setting unit 65 presets a value of the allowable range used for determination by the state determination unit 66 or the inspection object selection unit 67 . This allowable range may be preset by the user. Also, the allowable range may be the same for all control rod drive systems 9 or may be different for each control rod drive system 9 .

The state determination section 66 determines the state of the control rod drive system 9 based on the processing result of the data processing section 64 . For example, the state determination unit 66 compares the analysis data with a predetermined allowable range, and determines whether or not the control rod drive system 9 is abnormal. In this way, it is possible to determine whether or not there is an abnormality based on a predetermined allowable range. Also, the degree of abnormality may be evaluated. Note that the analysis data may be compared with the upper threshold or the lower threshold of the allowable range (range of normal values). That is, the state of the control rod drive system 9 may be determined by comparing the value indicated by the processing result of the data processing unit 64 with a predetermined threshold value.

The indices for evaluating the state of the control rod drive system 9 used in the state determination unit 66 include the position and drive speed of the control rods 6, the amount of stall flow, and the drive water W flowing through the control rod drive system 9 ( fluid) flow rate, pressure, and temperature; leakage flow rate of driving water W generated in the control rod drive system 9; frictional force generated in the sliding portion of the control rod drive mechanism 5; , valve opening, and electrical system voltage and current. The stall flow amount is the amount of leakage when driving water is introduced while the control rod 6 is stopped at the lowest position.

When the state determination unit 66 determines that the system is normal, the inspection target selection unit 67 selects the control rod drive mechanism 5 to be inspected next time from among the plurality of control rod drive mechanisms 5 determined to be normal. Select.

Further, the inspection target selection unit 67 evaluates the progress of deterioration of the control rod drive mechanism 5 based on the analysis data, and selects the control rod drive mechanism 5 to be inspected next time. In this way, it is possible to determine whether or not the control rod drive mechanism 5 determined to be normal should be subjected to the next inspection in consideration of the progress of deterioration. Furthermore, the process of selecting the control rod drive mechanism 5 to be inspected next time can be automatically performed.

The measurement method selection unit 68 selects the type and installation position of the sensor 18 for monitoring the state of the control rod drive system 9 based on the analysis data. The measurement method selection unit 68 uses the data processing unit 64 to process the analysis data recorded in the recording unit 63, and uses these data to determine the optimum physical quantity and this The installation position of the sensor 18 for acquiring the physical quantity is selected. In this way, an appropriate type of sensor 18 can be provided at an appropriate position, and actual measurement data reflecting the actual state of the control rod drive system 9 can be acquired.

The abnormality cause identification unit 69 identifies the cause of the abnormality when the state determination unit 66 determines that the predetermined control rod drive mechanism 5 is abnormal. By doing so, it is possible to automatically perform the process of identifying the cause of the abnormality of the control rod drive mechanism to be inspected. In addition, the abnormality cause identification section 69 extracts possible causes in the control rod drive system 9 based on the analysis data, and performs processing for extracting portions (confirmation items) to be confirmed with priority. In this way, it is possible to grasp the portion to be confirmed with priority.

The inspection timing determining unit 70 evaluates the progress of deterioration of the control rod drive mechanism 5 based on the analysis data, obtains the timing and probability that an abnormality will occur in the control rod drive mechanism 5, and determines the next inspection timing (inspection cycle). judge. By doing so, it is possible to determine the inspection timing in consideration of the progress of deterioration of the control rod drive mechanism 5 .

The degree of progress of deterioration of the control rod drive mechanism 5 is determined by using, for example, a predicted value of deterioration predicted in advance, the degree of influence of deterioration on the control rod drive mechanism 5, and the probability of occurrence of a predetermined event based on deterioration as a threshold. , is obtained by comparing these threshold values with the values of the analysis data. In addition, the timing of the next inspection is the periodical inspection scheduled to be performed at the nearest time from the time when the evaluation was performed among the periodic inspections (inspection cycle) scheduled to be repeatedly performed.

The result output unit 71 outputs analysis and evaluation results. In other words, the results derived by the state determination unit 66, the inspection target selection unit 67, the measurement method selection unit 68, the abnormality cause identification unit 69, and the inspection time determination unit 70 are output. The evaluation result includes the selection result of the control rod drive mechanism 5 to be inspected next time. It also includes the inspection timing of the control rod drive mechanism 5 .

The maintenance management system 1 of this embodiment includes a display device such as a display for outputting analysis results. That is, the result output section 71 controls the image displayed on the display. The display may be separate from the computer main body, or may be integrated with the computer main body. Furthermore, the result output unit 71 may control the image displayed on the display of another computer connected via the network.

In addition, although a display is exemplified as a display device in the present embodiment, other modes may be used. For example, information may be displayed using a projector. Furthermore, a printer that prints information on a paper medium may be used as an alternative to the display. In other words, the target controlled by the result output unit 71 may include a projector or a printer.

The main control unit 72 comprehensively controls the maintenance management system 1 .

Predetermined information is input to the information input unit 73 according to the operation of the user who uses the maintenance management system 1 . The information input unit 73 includes an input device such as a mouse or keyboard. That is, predetermined information is input to the information input section 73 according to the operation of these input devices.

The communication unit 74 communicates with other computers. Through this communication, input/output of predetermined information is performed. Moreover, these communications may use a wired communication line or a wireless communication line. Note that the communication unit 74 may communicate with other computers via a WAN (Wide Area Network), an Internet line, or a mobile communication network.

Next, the physical model 59 will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 corresponds to FIG. 3 and is a physical model 59 of the control rod drive system 9 when the control rod 6 is inserted into the reactor 3 . FIG. 6 corresponds to FIG. 4 and is a physical model 59 of the control rod drive system 9 when the control rod 6 is withdrawn into the reactor 3 .

It is possible to quantitatively analyze the influence on the control rod drive mechanism 5 by replacing the behavior of each device that constitutes the control rod drive system 9 with a physical model 59 . For example, the flow rate from the seal members 47 to 50, the ball check valve 38, and the orifice 45 is calculated from the pressure loss as fluid resistance. Information included in the physical model 59 includes physical quantities such as the weight, elastic modulus, fluid density, and dimensions of the control rod 6 .

5 to 6, the physical model 59 includes a model 75 of the control rod 6, a model 76 of the index tube 32, a model 77 of the cylinder tube 31 and the piston tube 34, and a model 78 of the insertion pipe 10. , the model 79 of the withdrawal pipe 11, the flow of the drive water W, and the flow path through which the drive water W flows are reproduced. The control rod drive mechanism 5 has a piston structure so that the control rods 6 are driven by the fluid flowing through the system.

Furthermore, in the flow path through which the driving water W flows, a flow resistance model 80 including the stop piston seal 47 and the collet piston seal 50, a flow resistance model 81 including the inner seal 48, an outer seal 49, an orifice 45, and a ball reverse. A model 82 of flow resistance including stop valve 38 is reproduced.

Thus, based on the structure of the actual control rod drive system 9, the physical model 59 is substituted, and the equation group 60 based thereon is defined. It should be noted that the physical model 59 can also be used to evaluate the behavior in a state different from the normal state. In the control rod drive system 9, the control rods 6 may not be driven properly due to wear of the sliding parts or an increase in the leakage flow due to the inclusion of dust in the fluid in the equipment that constitutes the control rod drive system 9. In addition, leakage from valves or entrainment of air in the fluid may be cited as causes for the control rods 6 not being properly driven. Then, the behavior of the control rod drive system 9 such as flow rate or pressure changes for these causes. In this way, it becomes possible to evaluate a state different from normal.

Therefore, by constantly measuring the flow rate, pressure, temperature, etc. of the drive water W flowing through the control rod drive system 9 and tracking changes over time in these measured data, it is possible to detect an abnormality in the control rod drive system 9 or determine the cause of the abnormality. can be specified.

Next, a method of estimating the cause of abnormality (the cause of progress of deterioration) using actual measurement data and analysis data will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 shows a state in which the profile of the actual measurement data of the flow rate of the control rod drive system 9 and the profile of the analysis data are superimposed.

As shown in FIG. 7 , each graph such as Response A, Response B, etc., indicates the response of analytical data to changes in each parameter of the physical model 59 . These combinations determine the profile of the analysis data. In FIG. 7, the solid-line graph indicates before the parameter change, and the dotted-line graph indicates after the parameter change.

As shown in FIG. 8, when obtaining the actual measurement data, the actual measurement data are first obtained from the sensor group 57 installed in the control rod drive system 9 . Then, the profile of the analysis data that matches the profile of the performance data is specified.

As shown in FIG. 7, the response A reflects parameters indicating whether or not air is mixed in the drive water. For example, assume that there is a normal parameter profile (solid line) in which the driving water is not mixed with air. Here, if the drive water is mixed with air, it takes time to reach a predetermined flow rate, so the parameter profile (dotted line) changes to indicate an abnormality. Note that the parameter indicating abnormality changes according to the amount of mixed air.

Also, the response B reflects a parameter indicating the presence or absence of leakage of driving water. For example, suppose there is a normal parameter profile (solid line) with no leakage of drive water. Here, if there is a leak in the drive water, it will not reach a predetermined flow rate, so the parameter profile (dotted line) will change to indicate an abnormality. It should be noted that the parameter indicating abnormality changes according to the leak amount.

Further, parameters of various kinds of responses such as response C, response D, . . . are set. These responses may include, in addition to the amount of air mixed in and the amount of drive water leaked, factors such as dust entrapment, wear of members, and sliding resistance.

Then, the profile of these response parameters is compared with the profile of the measured data. By adjusting each parameter, it is possible to obtain analysis data that matches the actual measurement data. For example, when the profile of the parameter indicating the abnormality of response A matches the profile of the measured data, it is found that the drive water is mixed with air. Furthermore, when the profile of parameters indicating abnormality in response B matches the profile of the measured data, it is found that there is a leak in the drive water. That is, when the analysis data is fitted to the measured data as shown in FIG. 8, it can be seen how many components of each response A, B, C, D, . . .

It should be noted that there are cases where the profile of the parameter indicating an abnormality in both response A and response B matches the profile of the measured data. may be used for evaluation. Furthermore, by using a large number of response parameters for comparison, the situation of the control rod drive system 9 can be grasped.

In addition, in this embodiment, the parameters related to the driving water W are exemplified, but other aspects may be used. For example, it may be a parameter of the current value flowing through the electric circuit, or a parameter of the temperature of each part of the control rod drive mechanism 5 .

As shown in FIG. 1, the difference determination unit 53 has a function of comparing the profile of the measured data from the start of operation to the stop of the operation of the control rod drive mechanism 5 with the profile of the analysis data, and determining whether there is a difference between the two. Prepare. When it is determined that there is this difference, the parameter update unit 55 updates the initial parameters and further updates the updated parameters, and the analysis unit 52 updates the analysis data.

Then, when it is determined that there is no difference between the measured data and the analysis data, the analysis data and the updated parameters are stored in the recording unit 63 . In this recording unit 63, every time the control rod drive mechanism 5 is driven, it is stored with time information regardless of whether the parameters have been updated. In the recording unit 63, analysis data is stored in association with identification information that allows each control rod drive mechanism 5 to be individually identified.

It should be noted that the magnitude of the difference from the initial parameters (including normal parameters) may be compared for each parameter. Then, when the state determination unit 66 determines that there is an abnormality, a parameter with a large deviation can be identified as the main cause of the abnormality (the cause of progress of deterioration).

Further, when the state determination unit 66 determines that the control rod drive mechanism 5 is normal, the inspection target selection unit 67 extracts the control rod drive mechanism 5 corresponding to the parameters greatly deviating from the initial parameters. Then, the predicted value calculated by the data processing unit 64 and the event occurrence probability are evaluated together, and the control rod drive mechanism 5 to be subjected to the next overhaul is selected.

The result of identifying the cause or the result of selecting the control rod drive mechanism 5 to be inspected next time is output from the result output unit 71 . This makes it possible to quantitatively determine the main cause of an abnormality or select the control rod drive mechanism 5 to be inspected next time, without depending on the skill level of the person making the decision.

The measurement method selection unit 68 selects the optimum type of sensor 18 or the installation location of the sensor 18 for identifying the cause of abnormality or selecting the control rod drive mechanism 5 to be overhauled next time. For example, the physical model 59 is used to evaluate the behavior of the control rod drive system 9 in response to an abnormality in advance. Based on the degree of influence or probability of occurrence calculated by the analysis unit 52, the physical quantity to be measured, the sensor 18 for the measurement, and the installation position thereof are selected. The type and installation location of the selected sensor 18 are output by the result output unit 71 .

Most aging deterioration events of the control rod drive system 9 are wear of the seal members 47 to 50 of the control rod drive mechanism 5 due to insertion or withdrawal of the control rod 6 . Therefore, it is possible to predict the life of the control rod drive mechanism 5 by evaluating the time change of the wear amount. The temporal change in the amount of wear of these seal members 47-50 can be obtained in advance by theoretical formulas or tests. Also, the change over time of the leakage flow due to wear of the seal members 47-50 may be obtained by a test.

Next, a method for predicting the life of the control rod drive mechanism 5 will be described with reference to FIGS. 9 to 10. FIG. FIG. 9 shows seal wear test data. For example, the results obtained by testing the relationship between the change in wear of the inner seal 48 or the outer seal 49 and the sliding distance and the variation thereof are shown.

FIG. 10 shows a graph obtained by calculating the time change of the drive speed of the control rod 6 by reflecting the test result of measuring the time change of the wear amount of the seal members 47 to 50 in the physical model 59 . This analysis result shows the relationship between the driving speed of the control rod 6 and the sliding time by performing analysis and data processing reflecting the test result.

For example, the data-processed driving speed of the control rods 6 has variations in the seal wear test data Q, so statistical processing in the data processing unit 64 outputs a probability distribution P of the driving speed at a certain time. From this result and the allowable range R for the driving speed, it becomes possible to predict the life of the control rod 6 probabilistically. Note that the allowable range R is preset in the allowable range setting unit 65 . For example, the time when the lower limit of the probability distribution P falls below the lower limit of the allowable range R is defined as the life T. Then, the predicted life T or the probability of reaching the life T is output by the result output unit 71 .

Next, maintenance management processing executed by the maintenance management system 1 will be described with reference to flowcharts of FIGS. 11 and 12. FIG. Note that the block diagram shown in FIG. 1 will be referred to as appropriate.

As shown in FIG. 11 , first, in step S11, the modeling processing unit 51 constructs a physical model 59 and a group of equations 60 of the control rod drive system 9 .

In the next step S<b>12 , the initial parameter setting unit 54 sets initial values of parameters reflected in the equation group 60 of the physical model 59 .

In the next step S<b>13 , the analysis unit 52 reflects parameters in the equation group 60 formulated based on the physical model 59 and executes calculation. Then, the calculation result obtained by substituting the parameters into the equation group 60 is output.

In the next step S<b>14 , the difference determination unit 53 acquires test and inspection data as actual measurement data from the test and inspection database 56 .

In the next step S<b>15 , the measurement data receiving section 58 receives measurement data from the sensor group 57 . Then, the difference determination section 53 acquires measurement data as actual measurement data from the measurement data reception section 58 .

In the next step S16, the difference determination unit 53 compares the calculation result of the physical model 59 by the analysis unit 52 and the measured data to determine whether there is a difference between them.

In the next step S17, if the result of determination by the difference determination unit 53 is that there is no difference between the calculation result of the physical model 59 and the measured data (NO in step S17), the process proceeds to step S19, which will be described later. On the other hand, if there is a difference between the calculation result of the physical model 59 and the measured data (YES in step S17), the process proceeds to step S18.

When it is assumed that there is no difference between the calculation result of the physical model 59 and the measured data, not only the calculation result of the physical model 59 and the measured data are the same, but also the difference between them falls within a predetermined range. Including cases. In other words, a permissible difference range may be set in advance, and it may be determined whether the difference is equal to or less than the upper limit value of the range or equal to or greater than the lower limit value.

In step S<b>18 , the parameter updating unit 55 updates parameters to be reflected in the equation group 60 of the physical model 59 . Then, the process returns to step S13 described above.

In step S19, the difference determining unit 53 (matching parameter specifying unit 61) specifies the parameters reflected in the physical model 59 as matching parameters when it is determined that there is no difference.

In the next step S20, the recording unit 63 records the analysis data including the matching parameters and the analysis results of the matching parameters.

In the next step S21, the main control unit 72 determines whether or not there is an unanalyzed control rod drive system 9 or not. Here, if there is an unanalyzed control rod drive system 9 (YES in step S21), the process returns to step S11, and the physical model 59 of the remaining control rod drive system 9 is constructed and analyzed. On the other hand, if there is no unanalyzed control rod drive system 9 (NO in step S21), the process proceeds to step S22.

As shown in FIG. 12, in the next step S22, the data processing unit 64 performs data mining processing. In this data mining process, the analysis results recorded in the recording unit 63 and the data relating to the matching parameters are processed to acquire information relating to the state of the control rod drive system 9 .

In the next step S23, the state determination section 66 determines the state of the control rod drive system 9 to be evaluated based on the processing result of the data processing section 64. FIG.

In the next step S24, if the result of determination by the state determination unit 66 is that there is no abnormality in the control rod drive system 9 to be evaluated (NO in step S24), the process proceeds to step S28, which will be described later. On the other hand, if there is an abnormality in the control rod drive system 9 to be evaluated (YES in step S24), the process proceeds to step S25.

In step S25, the abnormality cause identification unit 69 extracts possible causes in the control rod drive system 9 based on the analysis data, and extracts parts (confirmation items) that should be confirmed with priority.

In the next step S26, the abnormality cause identification unit 69 identifies the cause of the abnormality when the state determination unit 66 determines that the control rod drive mechanism 5 to be evaluated is abnormal.

In the next step S27, the result output unit 71 designates the control rod drive mechanism 5 determined to be abnormal by the state determination unit 66, and outputs a notification to that effect. Then, the process ends. If the nuclear power plant 2 is in operation when this notification is given, the operation of the nuclear power plant 2 may be stopped.

In step S28, the main control unit 72 determines whether or not there is an unevaluated control rod drive system 9. Here, if there is an un-evaluated control rod drive system 9 (YES in step S28), the process returns to step S29 and the remaining control rod drive system 9 is evaluated. On the other hand, if there is no unevaluated control rod drive system 9 (NO in step S28), the process proceeds to step S31.

In the next step S29, the measurement method selection unit 68 selects the type and installation position of the sensor 18 for monitoring the state of the control rod drive system 9 based on the analysis data.

In the next step S30, the inspection target selection unit 67 selects the control rod drive mechanism 5 to be inspected next time from among the plurality of control rod drive mechanisms 5 determined to be normal by the state determination unit 66. That is, the inspection timing of each control rod drive mechanism 5 is determined.

In the next step S31, the inspection target selection unit 67 evaluates the progress of deterioration of the control rod drive mechanism 5 based on the analysis data.

In the next step S32, the inspection target selection unit 67 selects the control rod drive mechanism 5 to be inspected next time from among the plurality of control rod drive mechanisms 5 determined to be normal by the state determination unit 66.

In the next step S<b>33 , the result output section 71 outputs the result derived by the state determination section 66 , inspection target selection section 67 , measurement method selection section 68 , abnormality cause identification section 69 and inspection timing determination section 70 . Then, the process ends.

In the present embodiment, determination of an arbitrary value (a value such as a difference) using a reference value (threshold value, upper limit value or lower limit value of an allowable range) is based on whether or not an arbitrary value is equal to or greater than the reference value. It may be a judgment, or a judgment of "whether or not an arbitrary value exceeds a reference value". Alternatively, it may be determined whether "an arbitrary value is equal to or less than a reference value" or "whether an arbitrary value is less than a reference value". Moreover, the reference value may not be fixed, but may be variable. Therefore, a value within a predetermined range may be used instead of the reference value to determine whether an arbitrary value falls within the predetermined range. Alternatively, the error generated in the apparatus may be analyzed in advance, and a predetermined range including the error range around the reference value may be used for determination.

In addition, in the flowchart of the present embodiment, each step is exemplified in a form in which each step is executed in series. good. Also, some steps may be executed in parallel with other steps.

The system of this embodiment includes a dedicated chip, an FPGA (Field Programmable Gate Array), a GPU (Graphics Processing Unit), or a CPU (Central Processing Unit) processor such as a control device highly integrated, ROM (Read Only Memory) or RAM (Random Access Memory), external storage devices such as HDD (Hard Disk Drive) or SSD (Solid State Drive), display devices such as displays, and input devices such as mice or keyboards , and a communication interface. This system can be realized with a hardware configuration using a normal computer.

It should be noted that the program executed by the system of the present embodiment is pre-installed in a ROM or the like and provided. Alternatively, this program can be stored as an installable or executable file on a non-transitory computer-readable storage medium such as CD-ROM, CD-R, memory card, DVD, flexible disk (FD), etc. may be stored and provided.

Also, the program executed by this system may be stored on a computer connected to a network such as the Internet, downloaded via the network, and provided. In addition, this system can also be configured by combining separate modules that independently perform each function of the constituent elements and are interconnected by a network or a dedicated line.

In addition, although the system applied to a boiling water reactor (BWR: Boiling Water Reactor) is illustrated in this embodiment, another aspect may be sufficient. For example, the system of this embodiment may be applied to an advanced boiling water reactor (ABWR) or a pressurized water reactor (PWR).

In this embodiment, a hydraulic control rod drive mechanism is exemplified, but other modes may be used. For example, the present embodiment may be applied to a magnetic jack type, roller nut type, or rack and pinion type control rod drive mechanism.

In this embodiment, a system for assisting maintenance work of the control rod drive system 9 is exemplified, but other aspects may be adopted. For example, the present embodiment may be applied to a system that supports maintenance work of a scram system for emergency shutdown of the nuclear reactor 3 .

In this embodiment, the data processing unit 64 processes the analysis data by data mining, but other modes may be used. For example, analysis data may be processed manually. Also, the analysis data may be processed by a conventional computer that does not have AI,

In this embodiment, since the behavior of the devices of the control rod drive system 9 is obtained by calculation using the physical model 59, the state of all the control rod drive systems 9 can be reproduced regardless of the presence or absence of actual measurement data. By analyzing the response to parameter changes related to equipment failure using this, the degree of influence of the control rod drive system 9 can be obtained. , identification of the cause of an abnormality, and selection of the control rod drive mechanism 5 to be overhauled next time.

Since it is possible to systematically and quantitatively identify the cause of the abnormality and select the control rod drive mechanism to be overhauled next time, the judgment can be made with high reliability regardless of the judge. In addition, regarding equipment life prediction, it is possible to calculate the time until failure without conducting large-scale tests by grasping temporal changes in parameters in advance using theoretical formulas or element tests. In addition, data analysis including variations in actual equipment data enables probabilistic life prediction, so it is possible to formulate an appropriate inspection plan.

According to the above-described embodiments, by providing a matching parameter identification unit that identifies a parameter whose calculation result of the physical model matches the measured data as a matching parameter, it is possible to determine the inspection timing of the control rod drive system of the nuclear power plant. can support.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Maintenance management system, 2... Nuclear power plant, 3... Nuclear reactor, 4... Pressure vessel, 5... Control rod drive mechanism, 6... Control rod, 7... Reactor containment vessel, 8... Water pressure control unit, 9... Control Rod drive system 10 Insertion pipe 11 Withdrawal pipe 12 Directional control valve 13 Scram valve 14 Check valve 15 Other valves 16 Accumulator 17 Filter 18 Sensor 19 ... Filling water pipe 20 ... Driving water piping 21 ... Cooling water piping 22 ... Drainage piping 23 ... Water system 24 ... Control rod driving water pump 25 ... Filter 26 ... Flow control valve 27 ... Pressure control valve 28 ... Flow stabilizing valve 29 ... Sensor 30 ... Housing 30a ... Flange part 31 ... Cylinder tube 31a ... Base part 32 ... Index tube 32a ... Concave part 33 ... Collet piston 33a Engagement claw 34 Piston tube 35 Coupling spud 36 First connection port 37 Second connection port 38 Ball check valve 39 Chamber 40, 41 Flow path 42 Chamber 43, 44 Flow path 45 Orifice 46 Gap 47 Stop piston seal 48 Inner seal 49 Outer seal 50 Collet piston seal 51 Modeling section 52 Analysis section , 53... difference determination unit, 54... initial parameter setting unit, 55... parameter update unit, 56... test and inspection database, 57... sensor group, 58... measurement data reception unit, 59... physical model, 60... equation group, 61 Matching parameter identification unit 62 Measured data acquisition unit 63 Recording unit 64 Data processing unit 65 Allowable range setting unit 66 State determination unit 67 Inspection object selection unit 68 Measurement method selection unit , 69... Abnormality cause identification unit, 70... Inspection timing determination unit, 71... Result output unit, 72... Main control unit, 73... Information input unit, 74... Communication unit, 75... Control rod model, 76... Stop piston model, 77... model of cylinder tube and piston tube, 78... model of insertion pipe, 79... model of withdrawal pipe, 80... model of flow resistance including stop piston seal and collet piston seal, 81... flow resistance including inner seal model, 82... flow resistance model including outer seal, orifice and ball check valve, P... probability distribution, Q... seal wear test data, R... tolerance, W... drive water.

Claims (11)

a modeling processing unit that constructs a physical model capable of reproducing the state of a control rod drive system including a control rod drive mechanism of a nuclear power plant and equipment related to the operation of the control rod drive mechanism;
an analysis unit that performs calculations by reflecting parameters in equations formulated based on the physical model;
a measured data acquisition unit that acquires measured data obtained by actually measuring the state of the control rod drive system;
a matching parameter identifying unit that identifies, as a matching parameter, the parameter whose calculation result of the physical model matches the measured data;
a recording unit for recording analysis data including the matching parameters and analysis results of the matching parameters;
an inspection timing determination unit that evaluates progress of deterioration of the control rod drive mechanism based on the analysis data, obtains the timing and probability of occurrence of an abnormality in the control rod drive mechanism, and determines inspection timing;
comprising
Maintenance management system. The match parameter identification unit
a parameter updating unit that updates the parameters to be reflected in the physical model;
a difference determination unit that compares the calculation result of the physical model and the measured data and determines whether there is a difference between them;
with
updating the parameter by the parameter update unit when the difference determination unit determines that there is a difference;
If the difference determination unit determines that there is no difference, the parameter reflected in the physical model is set as the matching parameter;
The maintenance management system according to claim 1. The actual measurement data acquisition unit acquires at least one of measurement data measured by a sensor installed in the control rod drive system and test and inspection data obtained when equipment of the control rod drive system was tested and inspected in the past. Acquired as the measured data,
The maintenance management system according to claim 1 or 2. The physical model is
a mechanical model that represents the mechanical behavior of the control rod drive mechanism and the pump or valve that is the equipment;
a fluid model representing changes in flow rate or pressure of fluid flowing through the control rod drive system;
a thermal model that expresses a phenomenon related to heat in the control rod drive system;
a control model for controlling the behavior of equipment of the control rod drive system;
an electric circuit model representing the behavior of an electric system related to the equipment of the control rod drive system;
a physical property model representing the characteristics of the material of the equipment of the control rod drive system;
including at least one of
reproduce the state of the control rod drive system by the combination of the parameters defined in the physical model;
The maintenance management system according to any one of claims 1 to 3. A data processing unit that processes the analysis data by data mining,
The maintenance management system according to any one of claims 1 to 4. a state determination unit that determines the state of the control rod drive system based on the processing result of the data processing unit;
an inspection target selection unit that selects the control rod drive mechanism to be inspected when the state determination unit determines that the control rod drive mechanism is normal;
an abnormality cause identification unit that identifies the cause of an abnormality when the state determination unit determines that there is an abnormality;
comprising
The maintenance management system according to claim 5. The state determination unit compares the analysis data with a predetermined allowable range, and determines whether or not there is an abnormality in the control rod drive system.
The maintenance management system according to claim 6. The inspection target selection unit evaluates the progress of deterioration of the control rod drive mechanism based on the analysis data, and selects the control rod drive mechanism to be inspected.
The maintenance management system according to claim 6 or 7. The cause-of-abnormality identification unit extracts possible causes of the control rod drive system based on the analysis data, and extracts parts to be confirmed with priority.
The maintenance management system according to any one of claims 6 to 8. A measurement method selection unit that selects the type and installation position of a sensor that monitors the state of the control rod drive system based on the analysis data,
The maintenance management system according to any one of claims 1 to 9. constructing a physical model capable of reproducing the state of a control rod drive system including a control rod drive mechanism of a nuclear power plant and equipment related to the operation of the control rod drive mechanism;
a step of performing an operation by reflecting parameters in an equation formulated based on the physical model;
a step of acquiring measured data obtained by actually measuring the state of the control rod drive system;
a step of identifying the parameter whose calculation result of the physical model matches the measured data as a matching parameter;
recording analysis data including the matching parameters and analysis results of the matching parameters;
a step of evaluating progress of deterioration of the control rod drive mechanism based on the analysis data, determining the timing and probability of occurrence of an abnormality in the control rod drive mechanism, and determining inspection timing;
including,
Maintenance management method.

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