System for deriving power plant severe accident mitigation strategy based on apparatus state information and method therefor

Abstract

The present invention relates to a system for deriving a power plant severe accident mitigation strategy based on apparatus state information, and the system comprises: an apparatus state diagnosis module that collects state data about apparatuses within a power plant in real time and diagnoses whether the apparatuses within the power plant may be driven; a strategy means evaluation module that configures apparatus combinations mitigating a severe accident at the power plant and evaluates the possibility of performing a function on each of the apparatus combinations; a strategy means determination module that recommends at least one optimal mitigation strategy means by comparing apparatus combinations capable of performing functions, which have been derived by the strategy means evaluation module, with each other; and an information provision interface that provides the derived at least one optimal mitigation strategy means to the outside.

Description

System and method for deriving severe accident mitigation strategies for power plants based on equipment status information

[0001] The present invention relates to a system for deriving a severe accident mitigation strategy for a power plant, and more specifically, to a system for deriving a severe accident mitigation strategy for a power plant based on equipment status information.

[0002] In nuclear power plants, a severe accident refers to an accident in which the nuclear fuel inside the reactor vessel is damaged to a large extent, exceeding design standards and causing significant damage to the core.

[0003] In the event of a severe accident, nuclear power plant operators respond using the Severe Accident Management Guidelines (SAMG) documented by the Technical Support Center (TSC); however, there is uncertainty regarding severe accident phenomena and environmental constraints in actual situations.

[0004] In particular, when a nuclear power plant enters a severe accident phase, available facilities are limited due to harsh environmental conditions, and technical decisions for accident recovery are difficult due to the uncertainty of human behavior; consequently, there are difficulties in establishing and implementing optimal severe accident mitigation strategies.

[0005] Currently, in the event of a major accident, equipment status information is recorded through operator diagnosis and manual notation on a checklist during the first stage of mitigation strategy execution; based on this checklist, the feasibility of executing the strategy is determined, and the method of execution is decided.

[0006] This approach is a factor that makes it difficult to take swift and effective measures, as the current operation of the Severe Accident Management Guidelines, which consists of eight mitigation strategies, takes a considerable amount of time and lacks flexibility when changing strategies.

[0007] The technical objective of the present invention to solve the aforementioned problems is to provide a means for storing status information of available equipment in a computerized database format in the event of a severe accident at a nuclear power plant, thereby enabling rapid identification of equipment status information and the derivation and implementation of an optimal severe accident mitigation strategy.

[0008] However, the problem to be solved by the present invention is not limited thereto and may be expanded in various ways without departing from the spirit and scope of the present invention.

[0009] To achieve the above objectives, a system for deriving a severe accident mitigation strategy based on equipment status information for a power plant according to one embodiment may include: an equipment status diagnosis module that collects status data of equipment within the power plant in real time and diagnoses whether the equipment within the power plant is operable; a strategic means evaluation module that configures equipment combinations to mitigate severe accidents in the power plant and evaluates the feasibility of performing functions for each of the equipment combinations; a strategic means determination module that compares the equipment combinations capable of performing functions derived from the strategic means evaluation module and recommends at least one optimal mitigation strategic means; and an information provision interface that provides the at least one derived optimal mitigation strategic means to the outside.

[0010] The above-mentioned equipment status diagnosis module can list the equipment necessary to mitigate the above-mentioned power plant major accident and transmit the operation status of the listed equipment to the above-mentioned strategic means evaluation module.

[0011] The above strategic means evaluation module can predict major accidents based on status data of equipment within the power plant stored in the database.

[0012] The status data of the equipment within the aforementioned power plant may be maintained at current values ​​in the database until the power plant can resume functioning after the recovery from the aforementioned major accident.

[0013] The plurality of means for mitigating the severe accident at the power plant are defined as combinations of severe accident mitigation devices, and the strategic means evaluation module can derive available means capable of performing functions among the plurality of means for mitigating the severe accident at the power plant by using a logic value indicating whether each of the severe accident mitigation devices is operating normally.

[0014] The above strategic means evaluation module can simulate various severe accident scenarios, pre-evaluate combinations of severe accident mitigation devices corresponding to each scenario, and store them in a database.

[0015] The above strategic means determination module can verify the validity of each of the above available means by evaluating the necessity of execution using the power plant's safety variable data.

[0016] If there are at least two available means whose validity has been verified, at least one optimal mitigation strategy means can be derived using a predetermined evaluation indicator.

[0017] The above-mentioned predetermined evaluation indicators determine priority based on the sum of scores evaluated for each of the mitigation devices included in each of the above-mentioned available means according to predetermined items, wherein the items may include capacity, power class, safety / non-safety class, accessibility of operating measures, and strategic validity time.

[0018] The above-mentioned strategic means determination module assigns predetermined weights to each of the above-mentioned items, wherein the weights may be values ​​determined in advance through simulation, taking into account the reliability of the device, the validity of the strategy, and the probability of success.

[0019] The above strategic means determination module can derive at least one available means with high priority as the optimal mitigation strategic means and provide it externally through the information provision interface.

[0020] The above-mentioned strategic means determination module includes a feedback module, and the feedback module may include a function to evaluate the execution result of the optimal mitigation strategic means and adjust at least a portion of the weights used in the optimal mitigation strategic means.

[0021] The disclosed technology may have the following effects. However, this does not mean that a specific embodiment must include all of the following effects or only the following effects; therefore, the scope of the rights of the disclosed technology should not be understood as being limited by this.

[0022] According to the system for deriving a severe accident mitigation strategy based on equipment status information according to the embodiments of the present invention described above, when a severe accident occurs at a nuclear power plant, the status information of available equipment is digitized to mitigate the severe accident, and by presenting the optimal arrangement necessary for establishing and implementing a severe accident mitigation strategy, rapid and effective response to the severe accident is enabled.

[0023] In addition, in the event of a severe nuclear accident, it is possible to quickly derive the optimal operating strategy in situations where technical decisions for accident recovery are difficult.

[0024] FIG. 1 is an overall block diagram of a system for deriving a severe accident mitigation strategy for a power plant according to an embodiment of the present invention.

[0025] FIG. 2 is a figure showing the operation and diagnosis results of a device status diagnosis module according to an embodiment of the present invention.

[0026] FIG. 3 is a figure showing the operation of a strategic means evaluation module and the results of deriving a plurality of strategies according to an embodiment of the present invention.

[0027] Figure 4 is an overall flowchart of a method for deriving a major accident mitigation strategy according to an embodiment of the present invention.

[0028] FIG. 5 is a figure showing a method for deriving an optimal mitigation strategy in a critical accident determination module according to an embodiment of the present invention.

[0029] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail.

[0030] However, this is not intended to limit the invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0031] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0032] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0033] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0034] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0035] Hereinafter, preferred embodiments of the present invention will be described clearly and in detail with reference to the attached drawings so that a person skilled in the art can easily practice the present invention.

[0036] FIG. 1 is an overall block diagram of a system for deriving a severe accident mitigation strategy for a power plant according to an embodiment of the present invention.

[0037] The nuclear power plant severe accident mitigation strategy derivation system (100) illustrated in FIG. 1 may include an equipment condition diagnosis module (110), a strategic means evaluation module (120), a strategic means determination module (130), and an information provision interface (140).

[0038] The device signal (150) within the power plant is provided to the device status diagnosis module (110) and the information provision interface (140), and the nuclear power plant safety variable measurement signal (160) is provided to the strategic means determination module (130). Here, the device signal (150) may include a device measurement signal, a device control signal, and a device output signal.

[0039] The device status diagnosis module (110) develops a computer program that diagnoses and records the status of all devices necessary to mitigate major accidents. Here, the device status is entered as "0" [incapable] or "1" [normal] by diagnosing whether the device is operating normally, and the entered information can maintain the current value in the database state until the device can perform its function through subsequent recovery measures.

[0040] The equipment status diagnosis module (110) can collect status data of equipment within the power plant in real time and diagnose whether it is operating, list the equipment necessary to mitigate serious accidents in the power plant, and transmit the operating status of the listed equipment to the strategic means evaluation module (120).

[0041] The strategic means evaluation module (120) defines the means for each major accident mitigation strategy as a function and can configure a combination of equipment capable of performing the corresponding function. The most basic unit can be configured in the order of tank-valve-pump-valve. By substituting equipment status information (0 or 1) into the corresponding equipment combination and multiplying it, the possibility of the corresponding equipment combination performing the function can be indicated as "0" and "1". The strategic means evaluation module (120) lists and displays the equipment combinations capable of performing the function (combinations calculated as "1").

[0042] The strategic means evaluation module (120) can mutually evaluate at least two means of mitigating a severe accident in a power plant and can predict a severe accident based on status data of equipment within the power plant stored in a database. Here, the status data of equipment within the power plant can be maintained at current values ​​in the database until the power plant can perform its functions after recovery from the severe accident.

[0043] The strategic means evaluation module (120) can simulate various major accident scenarios and evaluate combinations of major accident mitigation devices corresponding to each scenario in advance and store them in a database.

[0044] The strategic means determination module (130) is a module that recommends the optimal mitigation strategic means by evaluating the severe accident mitigation effect for equipment combinations evaluated as feasible by the strategic means evaluation module (120). The strategic means determination module (130) can first receive power plant safety variable data and determine the necessity of executing the strategy through an evaluation of the strategy's effectiveness.

[0045] The strategic means determination module (130) executes the strategic means when there is one available strategic means based on the results of the strategic means evaluation module (120) and when there are two or more available strategic means. When there are two or more available strategic means, it determines the priority through a method of comparing evaluation indicators. Here, evaluation indicators can be pre-set to compare and evaluate strategic means, such as pump capacity, valve power grade, safety / non-safety grade of equipment, accessibility of operational measures (MCR / on-site measures), and strategic validity time (water source), and the score of the corresponding strategic means can be measured. At this time, a weight is multiplied by the score determined from each evaluation indicator, and the weight is a value determined in advance through simulation, taking into account the reliability of the equipment, the validity of the strategy, and the probability of success of the strategy. The priority can be determined in order of the highest score by comparing the sum of scores considering the weights for each strategic means. Finally, information is provided so that the optimal strategy based on the results derived by the strategic means determination module (130) can be verified by the TSC (Technical Support Office) or the power plant operator.

[0046] The strategic means determination module (130) can derive at least one optimal mitigation strategic means among at least two means for mitigating severe accidents in a power plant. Here, the at least two means for mitigating severe accidents in a power plant are defined as combinations of severe accident mitigation devices, and the strategic means evaluation module (120) can derive available means capable of performing functions among multiple means for mitigating severe accidents in a power plant by using a logical value indicating whether each of the severe accident mitigation devices is operating normally.

[0047] The strategic means determination module (130) evaluates the necessity of performing each of the available means using safety variable data of the power plant and verifies their validity, and if there are at least two available means whose validity has been verified, it can derive at least one optimal mitigation strategic means using a predetermined evaluation indicator. Here, the predetermined evaluation indicator determines priority based on the sum of scores evaluated for each mitigation device included in each of the available means according to predetermined items, wherein the items may include capacity, power class, safety / non-safety class, accessibility of operating measures, and strategic validity time.

[0048] The strategic means determination module (130) can assign predetermined weights to each item and sum them up.

[0049] The strategic means determination module (130) derives at least one available means with high priority as the optimal mitigation strategic means and provides it externally through the information provision interface (140).

[0050] The strategic means determination module (130) includes a feedback module (not shown), and the feedback module can evaluate the execution results of the derived optimal mitigation strategic means and adjust at least some of the weights used in the optimal mitigation strategic means.

[0051] The information provision interface (140) can provide at least one derived optimal mitigation strategy means to the outside.

[0052] FIG. 2 is a figure showing the operation and diagnosis results of a device status diagnosis module according to an embodiment of the present invention.

[0053] The device condition diagnosis module (110) illustrated in FIG. 2 receives the water level of the tank (201, 202), data of the valve (203, 204, 205, 208, 209), data of the pump (206, 207), and the pressure value of the RCS (Reactor Coolant System) (210), diagnoses the availability of the tank (201, 202), valve (203, 204, 205, 208, 209), pump (206, 207), and RCS (Reactor Coolant System) (210) as a logical value "1" if available and a logical value "0" if unavailable, and can create a device availability table (220) indicating the availability status for each device list.

[0054] FIG. 3 is a figure showing the operation of a strategic means evaluation module and the results of deriving a plurality of strategies according to an embodiment of the present invention.

[0055] The strategic means evaluation module (120) derives availability evaluation results (310, 320, 330, 340) for multiple strategies including combinations of devices that mitigate major accidents, and the diagnosis of the device combinations (311, 321, 331, 341) included in each of the availability evaluation results (310, 320, 330, 340) for multiple strategies can be performed using an AND logic with a device availability table (220) that lists the availability of devices. For example, among the availability evaluation results (310) for strategy "A", the diagnosis result "0" (314) of combination "A1" (312) means that there is a device that is unavailable among the devices included in combination "A1" (312). On the other hand, the diagnosis result "1" (315) of combination #A2 (312) shows that all devices included in combination #A2 (312) are available.

[0056] Figure 4 is an overall flowchart of a method for deriving a major accident mitigation strategy according to an embodiment of the present invention.

[0057] First, the effectiveness of the strategy is evaluated (420) using the power plant safety variable (450) for the "A" strategy (410) derived from the strategy means evaluation module (120), and if there is a need to execute the strategy (421), available means (i.e., equipment combinations) are derived using the available evaluation results for the equipment combinations executed in the strategy means evaluation module (120), and if there are at least two derived available means (431), the priority of the strategy means is determined using the information from the equipment measurement and equipment control signals (470) and the equipment database (480) to derive at least one optimal major accident mitigation strategy.

[0058] For "A" strategy (410), the effectiveness of the strategy is evaluated using power plant safety variables (450) (420), and if there is no need to execute the strategy, at least one optimal major accident mitigation strategy can be determined for "B" strategy (49) through the same process.

[0059] FIG. 5 is a figure showing a method for deriving an optimal mitigation strategy in a critical accident determination module according to an embodiment of the present invention.

[0060] FIG. 5 shows a strategic means evaluation graph (500) showing evaluation indicators used to derive the optimal mitigation strategy in the critical accident decision module, and a specific strategic means evaluation method (510).

[0061] The strategic means evaluation graph (500) shows evaluation items and weights (501, 502, 503, 504) for each vertex, 501 is a pump flow rate with weight A, 502 is a pump safety / unsafe rating with weight B, 503 is a valve power rating with weight C, 504 is an operational measure accessibility including weight D, and 505 is a power effective time with weight E.

[0062] The device combination 1 (511) presented in the strategic means evaluation method (510) shows an evaluation value (XX) (570) evaluated as the sum of (weight A × 10 (pump flow rate)) (520), (weight B × 10 (pump safety / unsafety rating)) (530), (weight C × 10 (valve power rating)) (540), (weight D × 8 (accessibility to operation measures)) (550), and (weight E × 6 (power effective time)) (560).

[0063] Device combination 2 (512) shows the evaluation value (YY) as an evaluation result of the same method used in device combination 1 (511).

[0064] Device combination 3 (513) also shows the evaluation value (ZZ) as an evaluation result using the same method used in device combination 1 (511).

[0065] In the final result (514), it is shown that the device combination 1 (511), which has a higher evaluation value, is ranked first, and then device combination 2 (512) is ranked next.

[0066] [Explanation of the symbol]

[0067] 100: Nuclear Severe Accident Mitigation Strategy Derivation System

[0068] 110: Device Status Diagnosis Module

[0069] 120: Strategic Means Evaluation Module

[0070] 220: Availability Table by Device

[0071] 500: Strategic Instruments Evaluation Graph

[0072] 510: Method of evaluating total means

[0073] 201, 202: Tank

[0074] 203, 204, 205, 208, 209: Valve

[0075] 206, 207: Pump

[0076] 210: RCS(Reactor Coolant System)

Claims

1. As a system for deriving severe accident mitigation strategies for power plants based on equipment status information, A device status diagnosis module that collects status data of devices within a power plant in real time and diagnoses whether the devices within the power plant are operational; A strategic means evaluation module that configures combinations of equipment to mitigate major accidents at the above-mentioned power plant and evaluates the feasibility of functioning for each of the said combinations of equipment; A strategic means determination module that recommends at least one optimal mitigation strategic means by comparing combinations of devices capable of performing functions derived from the above strategic means evaluation module; and A system for deriving a severe accident mitigation strategy for a power plant, comprising an information provision interface that provides at least one optimal mitigation strategy means derived above to the outside.

2. In Paragraph 1, A system for deriving a strategy to mitigate a severe accident at a power plant, wherein the above-mentioned equipment status diagnosis module lists the equipment necessary to mitigate the severe accident at the power plant and transmits the operation status of the listed equipment to the above-mentioned strategic means evaluation module.

3. In Paragraph 1, The above strategic means evaluation module is a system for deriving severe accident mitigation strategies for power plants, which predicts severe accidents based on status data of equipment within the power plant stored in a database.

4. In Paragraph 1, A system for deriving a severe accident mitigation strategy for a power plant, wherein the status data of the equipment within the power plant is maintained at current values ​​in the database until the power plant can perform its functions after recovery from the severe accident.

5. In Paragraph 1, A system for deriving a strategy to mitigate severe accidents in a power plant, wherein multiple means for mitigating severe accidents in the power plant are defined as combinations of severe accident mitigation devices, and the strategic means evaluation module derives available means capable of performing functions among the multiple means for mitigating severe accidents in the power plant by using a logic value indicating whether each of the severe accident mitigation devices is operating normally.

6. In Paragraph 5, The above-mentioned strategic means evaluation module is a power plant severe accident mitigation strategy derivation system that simulates various severe accident scenarios, pre-evaluates combinations of severe accident mitigation devices corresponding to each scenario, and stores them in a database.

7. In Paragraph 6, The above strategic means determination module is a system for deriving a severe accident mitigation strategy for a power plant, which evaluates the necessity of executing each of the above available means using safety variable data of the power plant and verifies their validity.

8. In Paragraph 7, A system for deriving a severe accident mitigation strategy for a power plant, wherein if there are at least two available means with verified validity, the system derives at least one optimal mitigation strategy means using a predetermined evaluation indicator.

9. In Paragraph 8, A system for deriving a severe accident mitigation strategy for a power plant, wherein the above-mentioned predetermined evaluation indicators determine priority based on the sum of scores evaluated for each of the mitigation devices included in each of the above-mentioned available means according to predetermined items, and the items include capacity, power class, safety / non-safety class, accessibility of operating measures, and strategy validity time.

10. In Paragraph 9, A system for deriving a severe accident mitigation strategy for a power plant, wherein the above-mentioned strategic means determination module assigns predetermined weights to each of the above-mentioned items, wherein the weights are values ​​determined in advance through simulation considering the reliability of the device, the validity of the strategy, and the probability of success.

11. In Paragraph 10, A system for deriving a severe accident mitigation strategy for a power plant, wherein the above-mentioned strategic means determination module derives at least one available means with high priority as an optimal mitigation strategy means and provides it externally through the above-mentioned information provision interface.

12. In Paragraph 11, A system for deriving a severe accident mitigation strategy for a power plant, wherein the above-mentioned strategic means determination module includes a feedback module, and the feedback module includes a function to evaluate the execution results of the optimal mitigation strategy means and adjust at least a portion of the weights used in the optimal mitigation strategy means.

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