Nuclear power accident event tree model analysis method, electronic equipment and storage medium

Abstract

The invention provides a nuclear power accident event tree model analysis method, electronic equipment and a storage medium. The nuclear power accident event tree model analysis method comprises the following steps: taking one or more event trees corresponding to a target consequence in a nuclear power accident event tree model as a target event tree; determining an event tree chain corresponding to a first target event tree in response to determining that the input of an originating event head of the first target event tree in the target event trees includes consequences of other event trees, the event tree chain including a plurality of event trees connected in sequence in the nuclear power accident model, and the last event tree in the event tree chain being the first target event tree; the event tree chain is delinked to obtain a first delinking result of the first target event tree, and when each event tree in the event tree chain is analyzed, sequences with the same local boundary condition list are connected through an OR gate to form a sequence grouping top gate.

Description

Technical Field

[0001] The present application mainly relates to event tree analysis, and in particular to a nuclear power accident event tree model analysis method, electronic equipment and storage medium. Background Art

[0002] Probabilistic Safety Assessment (PSA) for nuclear power plants is a method for qualitatively and quantitatively evaluating the risks associated with nuclear power plant operations and maintenance activities. Based on a comprehensive, structured approach, it identifies plant failure scenarios and numerically estimates the risks to workers and the public. PSA analysis software provides PSA model development, quantitative calculations, and supporting analysis and management capabilities, serving as the professional foundation for conducting PSA work.

[0003] The commonly used logical model in PSA is the event tree / fault tree model. During the analysis of the event tree model, there are usually complex computational scenarios where several event trees are connected to form a cross-event tree sequence. For example, there are two levels of event trees connected in sequence, and each level of event tree contains 4 sequences. If each sequence at each level needs to be connected with each sequence at another level to form a sequence chain, then the total number of sequence chains that need to be connected and expanded into a fault tree model is 16; similarly, when the above event tree has three levels of event trees connected, the total number of sequence chains is as high as 64. Therefore, according to the logical structure of the event tree connection, the method of fully expanding each cross-event tree sequence will bring high computational overhead, making the computational analysis of complex event tree / fault tree structures difficult. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a nuclear power accident event tree model analysis method, electronic equipment and storage medium, so as to ensure the accuracy of event tree analysis while improving the analysis and calculation efficiency.

[0005] To solve the above technical problems, the present application provides a method for analyzing a nuclear power accident event tree model, wherein the nuclear power accident event tree model includes multiple event trees, each event tree includes an originating event header and at least one functional event header, each event tree includes one or more sequences, each sequence includes a branch result for at least one functional event header, wherein at least one branch result is associated with a local boundary condition list, and the final state of each sequence is the consequence of the corresponding event tree, and the final state of the sequence is the branch result of the last functional event header corresponding to the sequence. The method includes the following steps: taking one or more event trees corresponding to the target consequence in the nuclear power accident event tree model as the target event tree; in response to determining that the input of the originating event header of the first target event tree in the target event tree includes the consequences of other event trees, determining the event tree chain corresponding to the first target event tree, the event tree chain including multiple event trees connected in sequence in the nuclear power accident model, and the last event tree in the event tree chain is the first target event tree; decoupling the event tree chain to obtain a first decoupling result of the first target event tree, wherein when parsing each event tree in the event tree chain, sequences with the same local boundary condition list are connected through an OR gate to form a sequence grouping top gate.

[0006] Optionally, the step of decoupling the event tree chain to obtain the first decoupling result of the first target event tree further includes: determining each first target sequence of each event tree in the event tree chain, the final state of the first target sequence being the input of the originating event header of the next event tree sequentially connected to the event tree where the first target sequence is located; connecting the first target sequences with the same local boundary condition list in the first event tree of the event tree chain through an OR gate to form corresponding sequence grouping top gates, and taking each sequence grouping top gate of the first event tree as the decoupling result of the first event tree; sequentially combining each sequence grouping top gate of the current event tree with the decoupling result of the previous event tree for the second event tree to the last event tree of the event tree chain to obtain the decoupling result of the current event tree, wherein the decoupling result of the last event tree is the first decoupling result.

[0007] Optionally, for the first event tree and the second event tree connected sequentially in the event tree chain, the step of obtaining the top gates of each sequence group corresponding to the second event tree includes: passing each first local boundary condition list to the second event tree respectively, the first local boundary condition list is the local boundary condition list corresponding to each sequence group top gate corresponding to the first event tree, and the local boundary condition set of the originating event header of the second event tree contains the corresponding first local boundary condition list; for the second event tree corresponding to each first local boundary condition list, generating the second local boundary condition list corresponding to each first target sequence of the second event tree respectively, the second local boundary condition list sequentially contains the local boundary conditions in the local boundary condition set of the corresponding originating event header, and the local boundary conditions corresponding to each corresponding branch result; the first target sequence with the same second local boundary condition list in the second event tree is connected through an OR gate to form the sequence group top gate corresponding to the second event tree.

[0008] Optionally, the joint solution result includes joint solution sub-results of different local boundary condition lists corresponding to the event tree, wherein each sequence grouping top gate of the first event tree is a joint solution sub-result of the first event tree. For the first event tree and the second event tree connected sequentially in the event tree chain, according to the joint solution result of the first event tree and each sequence grouping top gate of the second event tree, the step of obtaining the joint solution result of the second event tree includes: for each sequence grouping top gate of the second event tree, determining the local boundary condition list in the first event tree contained in the sequence grouping top gate as the target local boundary condition list; for each sequence grouping top gate of the second event tree, connecting the joint solution sub-result corresponding to the target local boundary condition list in the first event tree with the sequence grouping top gate of the second event tree through an AND gate to obtain a joint solution sub-result of the second event tree.

[0009] Optionally, the method also includes: in response to determining that the input of the originating event header of the second target event tree in the target event tree does not contain the consequences of other event trees, parsing the second target event tree to obtain a second joint solution result of the second target event tree; connecting all the first joint solution results and the second joint solution results through an OR gate to obtain a total joint solution result corresponding to the target consequence.

[0010] Optionally, the step of parsing the second target event tree to obtain a second joint solution result of the second target event tree further includes: determining each second target sequence in the second target event tree, the final state of the second target sequence is the target consequence; connecting the second target sequences with the same local boundary condition list in the second target event tree through an OR gate to form a corresponding sequence grouping top gate; connecting each sequence grouping top gate of the second target event tree through an OR gate to obtain a second joint solution result.

[0011] Optionally, the method also includes: assigning values ​​to the joint solution total result according to the global boundary conditions of the nuclear power accident event tree model and the local boundary conditions in the list of local boundary conditions corresponding to the joint solution total result to obtain the model to be quantified; and performing quantitative analysis on the model to be quantified to obtain the accident frequency corresponding to the target consequence.

[0012] Optionally, the first joint solution result includes at least one first target sequence, and the second joint solution result includes at least one second target sequence. According to the global boundary conditions of the nuclear power accident event tree model and the local boundary conditions in the local boundary condition lists corresponding to the joint solution total results, the step of assigning the joint solution total results to obtain the model to be quantified further includes: for each first target sequence and second target sequence in each joint solution total result, copying the original model structure of each corresponding header, the header is the initiating event header or functional event header corresponding to the first target sequence or the second target sequence; for each copied original model structure, assigning the nodes in the copied original model structure according to the header boundary condition list corresponding to the header, to obtain the model to be quantified, wherein the header boundary condition list sequentially includes the local boundary conditions corresponding to each header from the initiating event header in the first target sequence or the second target sequence corresponding to the header in the local boundary condition list to the header, as well as the global boundary conditions.

[0013] Optionally, both the local boundary conditions and the global boundary conditions contain at least one event and a corresponding value, the event is a basic event or a room-shaped event, and the value is a logical value. The step of assigning values ​​to the nodes in the copied original model structure according to the header boundary condition list corresponding to the header further includes: when the event in the node is the same as the event in the header boundary condition list, replacing the event in the node with the value corresponding to the event in the header boundary condition list.

[0014] Optionally, it also includes that when multiple local boundary conditions in the header boundary condition list contain the same event, the value corresponding to the event in the last local boundary condition is used as the value corresponding to the event in the header boundary condition list; when at least one local boundary condition and the global boundary condition in the header boundary condition list contain the same event, the value corresponding to the event in the global boundary condition is used as the value corresponding to the event in the header boundary condition list; when the value corresponding to the event in the local boundary condition or the global boundary condition in the header boundary condition list has both logical true and logical false values, the logical true value is used as the value corresponding to the event in the local boundary condition or the global boundary condition.

[0015] Optionally, after assigning values ​​to the nodes in the copied original model structure according to the header boundary condition list corresponding to the header: the influence of each assigned node is sequentially transferred from bottom to top according to the Boolean logic relationship.

[0016] To solve the above technical problems, the present application provides an electronic device, comprising: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the above nuclear power accident event tree model analysis method.

[0017] To solve the above technical problems, the present application provides a computer-readable medium storing computer program code, which implements the above-mentioned nuclear power accident event tree model analysis method when executed by a processor.

[0018] Compared with the prior art, the present application has the following advantages: in the event tree chain corresponding to the dissociation target event tree, sequences with the same local boundary condition list are connected through an OR gate to form a sequence grouping top gate, which simplifies the dissociation result, thereby reducing the total number of expanded sequence chains, thereby improving the analysis and calculation efficiency and ensuring the accuracy of the analysis and calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0020] Figure 1 1 is a flow chart of a method for analyzing a nuclear power accident event tree model according to an embodiment of the present application;

[0021] Figure 2 yes Figure 1 Schematic diagram of the nuclear power accident event tree model;

[0022] Figure 3 yes Figure 1 Schematic diagram of the flow of sub-steps of step S13 shown;

[0023] Figure 4 yes Figure 2 Schematic diagram of decoupling event tree A1 and event tree A2 in the nuclear power accident event tree model shown;

[0024] Figure 5 yes Figure 3 The flowchart of obtaining the top gate of each sequence group corresponding to the second event tree in step S133 is shown;

[0025] Figure 6 yes Figure 3 The flowchart of obtaining the joint solution result of the second event tree in step S133 is shown;

[0026] Figure 7 yes Figure 1 The nuclear power accident event tree model analysis method shown further calculates the flow chart of accident frequency;

[0027] Figure 8 yes Figure 7 Schematic diagram of the flow of sub-steps of step S14 shown;

[0028] Figure 9 yes Figure 7 Schematic diagram of the flow of sub-steps of step S16 shown;

[0029] Figure 10 yes Figure 9 The schematic diagram of assigning a value to the function event header in step S16 is shown; and

[0030] Figure 11 is a block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0032] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0033] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The techniques, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0035] Flowcharts are used in this application to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0036] First, the relevant concepts of event trees and fault trees involved in this application are explained. An event tree is a tree structure consisting of a series of headers and branches, where the first header is the initiating event header and the remaining headers are functional event headers. For an event tree, deduction is used from left to right starting from the initiating event header, and different response scenarios are inferred to form different branches for each functional event header. The branch result of the last functional event header is a consequence of the event tree. Then, a path from the initiating event header to the consequence, including the branches corresponding to each header, is called a sequence. The sequence includes the branch results for each functional event header, and the consequence corresponding to the sequence is called the final state of the sequence. For example, if an event tree has 3 headers and each header has 4 branches, then the corresponding sequence of the event tree is 3*4=12. A fault tree is a tree structure consisting of various events and logic gates. According to the induction method, the top event (for example, the occurrence of an unexpected event) is decomposed into a combination of different causes from top to bottom. Fault tree events include basic events and room-shaped events. Basic events are events whose states are yet to be determined and whose probability is a certain probability or frequency value. Room-shaped events are events whose states are determined and whose probability can only be either true or false. Boundary conditions are sets of event-value pairs, for example, specifying that an event is true or false during analysis. Boundary conditions can be specified in the case settings or in the event tree header (for example, as boundary conditions in the initiating event header or the functional event header). True or false values ​​can be assigned to basic events, room-shaped events, and logic gates, and other boundary condition sets can be nested as entries. By using boundary condition sets, the static event tree or fault tree model structure can be dynamically modified along the sequence. Furthermore, by defining specific multidimensional boundary conditions, a large number of specific cases can be created from a small number of basic cases. Local boundary conditions are boundary conditions associated with functional event headers. It can be understood that for each sequence, each branch outcome corresponding to that sequence has a corresponding local boundary condition. In addition, the local boundary conditions corresponding to the sequence can form an associated local boundary condition list, which will be explained in detail later. It should be noted that the initiating event header also has associated boundary conditions, which have the same function as the local boundary conditions in this application, and are therefore also referred to as local boundary conditions. Global boundary conditions are boundary conditions associated with all headers. Both local boundary conditions and global boundary conditions contain at least one event and a corresponding value, where the event is a basic event or a room-shaped event, and the value is a logical value. The connection of event trees refers to a part of the input of the initiating event header of another event tree, where an event tree is connected to another event tree in sequence. In this case, the effectiveness of the consequence of the latter event tree depends on the effectiveness of the consequence of the previous event tree.For example, when the consequences of the previous event tree include consequence A and consequence B, and the input of the initiating event header of the subsequent event tree includes consequence B, the sequence in the subsequent event tree can only take effect when the sequence containing consequence B in the previous event tree takes effect. Conversely, when consequence A takes effect, the sequence in the subsequent event tree will not take effect.

[0037] The above descriptions of the relevant concepts of event trees and fault trees are provided. In the following embodiments, the event tree analysis method of the present application is described using a nuclear power accident model based on event trees and fault trees. In this embodiment, the nuclear power accident model includes multiple event trees, and the input of the initiating event header of at least one event tree includes the consequences in another event tree, i.e., there are interconnections between the event trees. Furthermore, the relevant headers in the event tree of this embodiment have the structure of a fault tree, i.e., the response conditions corresponding to some headers in the sequence of event trees are the top events of the fault tree. In the nuclear power accident model of this embodiment, the corresponding event tree is used to determine whether the nuclear power plant is ultimately in a safe state or a damaged state, and the causes in the corresponding fault tree include equipment failure, common cause failure, human error, etc. It should be noted that when the initiating event header of an event tree does not include the consequences of other event trees, the initiating event header only includes basic events and gates. Furthermore, in this embodiment, the input of each functional event header is any one or more of the basic events and gates.

[0038] Figure 1 FIG. 1 is a flow chart of a method for analyzing a nuclear power accident event tree model according to an embodiment of the present application. Figure 1 As shown, the nuclear power accident event tree model analysis method 100 includes the following steps. First, step S11 is to use one or more event trees corresponding to the target consequences in the nuclear power accident event tree model as target event trees. Specifically, in step S11, each event tree with the target consequence as the consequence in the nuclear power accident event tree model is respectively used as a target event tree. Step S12 is to determine the event tree chain corresponding to the first target event tree in response to determining that the input of the initiating event header of the first target event tree in the target event tree contains the consequences of other event trees, and the event tree chain includes multiple event trees connected in sequence in the nuclear power accident model, and the last event tree in the event tree chain is the first target event tree. Figure 2 This is a schematic diagram of the nuclear power accident event tree model, such as Figure 2As shown, the nuclear power accident event tree model A10 includes event trees A1, A2, A3, A4, A5 and A6, wherein the line between event tree A1 and event tree A2 indicates that the consequence CA1 in event tree A1 is the input of the initiating event header of event tree A2, the line between event tree A2 and event tree A3 indicates that the consequence CA2 in event tree A2 is the input of the initiating event header of event tree A3, the line between event tree A3 and event tree A4 indicates that the consequence CA3 in event tree A3 is the input of the initiating event header of event tree A4, and the line between event tree A2 and event tree A5 indicates that the consequence CA4 in event tree A2 is the input of the initiating event header of event tree A5. In addition, event tree A3 and event tree A6 respectively include target consequences, and the input of the initiating event header of event tree A1 does not include the consequences of other event trees. Then combined Figure 1 and Figure 2 , the specific processing process of step S2 is: determine that event tree A3 is the first target event tree, and determine the event tree connected to the first target event tree based on the consequences included in the input of the initiating event header of the first target event tree, that is, obtain event tree A2, and then determine the event tree A1 connected to it based on event tree A2. Therefore, when event tree A3 is the first target event tree, the corresponding event tree chain includes event tree A1, event tree A2 and event tree A3 connected in sequence. This shows that, in the present embodiment, for the event tree whose initiating event header includes the consequences of other event trees, the consequences of this event tree are affected by the other connected event trees. Therefore, for the first target event tree, it is necessary to continuously trace the source upwards with the first target event tree as the starting point until an event tree whose initiating event header does not include the consequences of other event trees is obtained, thereby obtaining the event tree chain corresponding to the first target event tree.

[0039] Continue to refer to Figure 1 Step S13 is to disassociate the event tree chain to obtain a first joint solution result of the first target event tree, wherein when parsing each event tree in the event tree chain, the sequences with the same local boundary condition list are connected through an OR gate to form a sequence grouping top gate. Figure 3 , step S13 includes the following sub-steps. Step S131 is to determine each first target sequence of each event tree in the event tree chain, and the final state of the first target sequence is the input of the originating event header of the next event tree sequentially connected to the event tree where the first target sequence is located. Figure 2 If event tree A3 includes sequence A31 and sequence A32, and the final state of sequence A21 is the input of the originating event header of event tree A3, while the final state of sequence A21 is not the input of the originating event header of event tree A3, then sequence A21 is the first target sequence, while sequence A22 is not. In other words, in this embodiment, only the sequences related to the first target event tree are subsequently processed.

[0040] Continue to refer to Figure 3 Step S132 connects the first target sequences in the first event tree of the event tree chain with the same local boundary condition list through an OR gate to form corresponding sequence grouping top gates, and uses the sequence grouping top gates of the first event tree as the joint solution result of the first event tree. In this embodiment, the local boundary condition list of each sequence sequentially includes the local boundary conditions corresponding to the branch results from the originating event header to the last functional event header of the event tree in which the sequence is located. Figure 4 yes Figure 2 The sequence diagram of event tree A1 and event tree A2 in nuclear power accident event tree model A10. Figure 4 As shown, event tree A1 has an originating event header IE1, a functional event header FE1, and a functional event header FE2. The originating event header IE1 has a local boundary condition BC1. The functional event header FE1 has two response conditions, namely response condition FE1 and response condition -FE1, and response condition FE1 has a local boundary condition BC3, while response condition -FE1 has a local boundary condition BC2. The functional event header FE2 also has two response conditions, namely response condition FE2 and response condition -FE2, but the local boundary conditions corresponding to response condition FE2 and response condition -FE2 are both empty, that is, they do not have corresponding local boundary conditions. Therefore, the sequences from top to bottom in event tree A1 are sequence OA11 corresponding to branches IE1&-FE1&-FE2, sequence OA12 corresponding to branches IE1&-FE1&FE2, sequence OA13 corresponding to branches IE1&FE1&-FE2, and sequence OA14 corresponding to branches IE1&FE1&FE2. It should be noted that the final states of the four sequences of event tree A1, namely consequence 1, are all inputs of the initiating event header of event tree A2, that is, the above four sequences are all first target sequences. Figure 4 The local boundary condition lists corresponding to the first target sequence OA11 are BC1&BC2, the local boundary condition lists corresponding to the first target sequence OA12 are BC1&BC2, the local boundary condition lists corresponding to the first target sequence OA13 are BC1&BC3, and the local boundary condition lists corresponding to the first target sequence OA14 are BC1&BC3. The joint solution RA1 of event tree A1 then includes two sequence grouping top gates DA1. One of these top gates, DA11, includes the first target sequence OA11 and the first target sequence OA12, both of which have local boundary condition lists BC1&BC2. The other top gate, DA12, includes the first target sequence OA13 and the first target sequence OA14, both of which have local boundary condition lists BC1&BC3.

[0041] Continue to refer to Figure 3Step S133 is to sequentially combine the top gates of each sequence group of the current event tree with the joint solution results of the previous event tree for the second event tree to the last event tree in the event tree chain, and obtain the joint solution results of the current event tree, wherein the joint solution result of the last event tree is the first joint solution result. Figure 5 In step S133, for the first event tree and the second event tree connected in sequence in the event tree chain, the process 200 of obtaining the top gates of each sequence group corresponding to the second event tree includes the following steps. Step S21 is to pass each first local boundary condition list to the second event tree respectively. The first local boundary condition list is the local boundary condition list corresponding to each sequence group top gate corresponding to the first event tree. The local boundary condition set of the originating event header of the second event tree includes the corresponding first local boundary condition list. Continue to refer to Figure 4 , event tree A2 has an originating event header IE2, a functional event header FE3, and a functional event header FE4. The originating event header IE2 has its own local boundary condition BC4. The functional event header FE3 has two response conditions, namely response condition FE3 and response condition -FE3, and response condition FE3 has a local boundary condition BC6, and response condition -FE3 has a local boundary condition BC5. The functional event header FE4 also has two response conditions, namely response condition FE4 and response condition -FE4, but the local boundary conditions corresponding to response condition FE2 and response condition -FE2 are both empty, that is, they do not have corresponding local boundary conditions. It can be seen that the sequences from top to bottom in event tree A2 are the first target sequence OA21 corresponding to the branch IE2&-FE3&-FE4, the first target sequence OA22 corresponding to the branch IE2&-FE3&FE4, the first target sequence OA23 corresponding to the branch IE2&FE3&-FE4, and the first target sequence OA24 corresponding to the branch IE2&FE3&FE4. It should be noted that the final states of the four sequences of event tree A2, i.e., consequences 2, are all inputs to the initiating event header of event tree A3, i.e., the above four sequences are all first target sequences. Figure 4 and Figure 5 In step S21, event tree A1 is the first event tree, and event tree A2 is the second event tree. Then, the local boundary condition list containing BC1&BC3 corresponding to event tree A1 is passed to event tree A2, so that the local boundary condition set of the originating event header of event tree A2 includes BC1&BC3&BC4 in sequence; the local boundary condition list containing BC1&BC2 corresponding to event tree A1 is passed to event tree A2, so that the local boundary condition set of the originating event header of event tree A2 includes BC1&BC2&BC4 in sequence. It should be noted that, in this embodiment, each second event tree that receives the local boundary condition list is a copy of the original second event tree. For example, in this embodiment Figure 2The replicas of the event tree A2 include replicas A2-1 and A2-2. In this embodiment, the replicas are not used. Figure 2 The original event tree A2 in the nuclear power accident event tree model A10 is modified to ensure that it does not affect the nuclear power accident event tree model A10.

[0042] Continue to refer to Figure 5 Step S22 is to generate a second local boundary condition list corresponding to each first target sequence of the second event tree for each second event tree corresponding to each first local boundary condition list. The second local boundary condition list sequentially includes the local boundary conditions in the local boundary condition set of the corresponding initiating event header and the local boundary conditions corresponding to each corresponding branch result. Figure 4 , when the first local boundary condition list transmitted by event tree A1 is BC1&BC2, the second local boundary condition list corresponding to the first target sequence OA21 in the replica A2-1 is BC1&BC2&BC4&BC5, the second local boundary condition list corresponding to the first target sequence OA22 is BC1&BC2&BC4&BC5, the second local boundary condition list corresponding to the first target sequence OA23 is BC1&BC2&BC4&BC6, and the second local boundary condition list corresponding to the first target sequence OA24 is BC1&BC2&BC4&BC6 ; When the first local boundary condition list transmitted by event tree A1 is BC1&BC3, the second local boundary condition list corresponding to the first target sequence OA21 in the replica A2-2 is BC1&BC3&BC4&BC5, the second local boundary condition list corresponding to the first target sequence OA22 is BC1&BC3&BC4&BC5, the second local boundary condition list corresponding to the first target sequence OA23 is BC1&BC3&BC4&BC6, and the second local boundary condition list corresponding to the first target sequence OA24 is BC1&BC3&BC4&BC6.

[0043] Continue to refer to Figure 5 Step S23 is to connect the first target sequences with the same second local boundary condition list in the second event tree through an OR gate to form a sequence grouping top gate corresponding to the second event tree. Figure 4When the first local boundary condition list transmitted by event tree A1 is BC1&BC2, there are two sequence grouping top gates, one of which includes the first target sequence OA21 and the first target sequence OA22 whose local boundary condition lists are BC1&BC2&BC4&BC5, and the other sequence grouping top gate DA22 includes the first target sequence OA23 and the first target sequence OA24 whose local boundary condition lists are BC1&BC2&BC4&BC6; when the first local boundary condition list transmitted by event tree A1 is BC1&BC3, there are two sequence grouping top gates DA2, one of which includes the first target sequence OA21 and the first target sequence OA22 whose local boundary condition lists are BC1&BC3&BC4&BC5, and the other sequence grouping top gate DA24 includes the first target sequence OA23 and the first target sequence OA24 whose local boundary condition lists are BC1&BC3&BC4&BC6.

[0044] The above has described the process of obtaining the top gates of each sequence group of the current event tree in step 133. In this embodiment, the joint solution result includes the joint solution sub-results of each different local boundary condition list of the corresponding event tree, wherein each sequence group top gate of the first event tree is the joint solution sub-result of the first event tree. Figure 3 and Figure 6 , in step S133, for the first event tree and the second event tree connected in sequence in the event tree chain, according to the joint solution result of the first event tree and the top gates of each sequence grouping of the second event tree, the process 300 of obtaining the joint solution result of the second event tree includes the following steps. Step S31 is to perform a top gate for each sequence grouping of the second event tree, and determine the local boundary condition list in the first event tree contained in the sequence grouping top gate as the target local boundary condition list. Step S32 is to perform a top gate for each sequence grouping of the second event tree, and connect the joint solution sub-result corresponding to the target local boundary condition list in the first event tree with the sequence grouping top gate of the second event tree through an AND gate to obtain a joint solution sub-result of the second event tree. Exemplarily, further referring to Figure 4When event tree A2 is used as the second event tree, the sequence grouping top gate DA11 and the sequence grouping top gate DA21 form a joint solution sub-result by connecting with the gate, the sequence grouping top gate DA11 and the sequence grouping top gate DA22 form a joint solution sub-result by connecting with the gate, the sequence grouping top gate DA12 and the sequence grouping top gate DA23 form a joint solution sub-result by connecting with the gate, and the sequence grouping top gate DA12 and the sequence grouping top gate DA24 form a joint solution sub-result by connecting with the gate. Therefore, the joint solution result of event tree A2 contains 4 joint solution sub-results. It should be noted that when the event tree chain is unlinked using the existing technology, the four sequences of the first target sequence OA11 to the first target sequence OA14 need to form a sequence chain with the four sequences of the first target sequence OA21 to the first target sequence OA24 respectively, that is, the joint solution result corresponding to event tree A2 contains 16 sequence chains. It can be seen that this embodiment can compress and merge a large number of repeated structures in the event tree chain, reduce the information redundancy of the joint solution results, provide accurate data for subsequent calculations, and improve computing efficiency. It should be noted that this application does not limit the number of response situations corresponding to the function event header, that is, in other embodiments of this application, a function event header can contain more than two response situations, so that the corresponding event tree has more branches. In addition, the same local boundary condition list means that the local boundary conditions arranged in sequence in the local boundary condition list correspond to each other. For example, for Figure 4 In event tree A1, when response case -FE1 has local boundary condition BC2, and the local boundary condition corresponding to response case FE1 is empty, and response case -FE2 has local boundary condition BC2, and the local boundary condition corresponding to response case FE2 is empty, the local boundary condition lists corresponding to the first target sequence corresponding to branches IE1&-FE1&FE2 and the first target sequence corresponding to branches IE1&-FE1&FE2 are both BC1&BC2, so the above two first target sequences are included in the same sequence grouping top gate. It can be understood that, referring to Figure 4 The process of obtaining the corresponding joint solution result of the above event tree A2 can sequentially obtain the joint solution results corresponding to each event tree connected in sequence in the event tree chain, and then obtain the first joint solution result of the first target event tree corresponding to the event tree chain.

[0045] Continue to refer to Figure 7 The nuclear power accident event tree model analysis method 100 of this embodiment further includes the following steps. Step S14 is to parse the second target event tree to obtain a second joint solution result of the second target event tree in response to determining that the input of the initiating event header of the second target event tree in the target event tree does not contain the consequences of other event trees. For example, referring to Figure 2When event tree A6 and event tree A1 are target event trees, since the input of the originating event header of event tree A1 and event tree A6 does not contain the consequences of other event trees, event tree A1 and event tree A6 are both second target event trees. Figure 8 , step S14 includes the following sub-steps. Step S141 is to determine each second target sequence in the second target event tree, and the final state of the second target sequence is the target consequence. Step S142 is to connect the second target sequences with the same local boundary condition list in the second target event tree through an OR gate to form a corresponding sequence grouping top gate. Step S143 is to connect each sequence grouping top gate of the second target event tree through an OR gate to obtain a second joint solution result. It can be understood that step S142 is the same as the process of obtaining the sequence grouping top gate of the first event tree in the event tree chain in step S132 above, and will not be repeated here. Step S15 is to connect all the first joint solution results and the second joint solution results through an OR gate to obtain a joint solution total result corresponding to the target consequence. Among them, the first joint solution result contains at least one first target sequence, and the second joint solution result contains at least one second target sequence. Step S16 is to assign the joint solution total result to obtain the model to be quantified based on the global boundary conditions of the nuclear power accident event tree model and the local boundary conditions in the local boundary condition lists corresponding to the joint solution total result. Further reference Figure 9, step S16 includes the following sub-steps. Step S161 is to copy the original model structure of each corresponding header for each first target sequence and second target sequence in each joint solution result. Among them, the header is the initiating event header or functional event header corresponding to the first target sequence or the second target sequence. In this embodiment, in step S161, not only the original model structure of the input of each header (i.e., basic event or gate) is copied, but all node elements in the copied structure are traversed downward. If it is a gate, the gate is copied and replaced. Step S162 is to assign values ​​to the nodes in the copied original model structure according to the header boundary condition list corresponding to the header for each copied original model structure to obtain the model to be quantified. Among them, the header boundary condition list sequentially includes the local boundary conditions corresponding to each header from the initiating event header in the first target sequence or the second target sequence corresponding to the header in the local boundary condition list to the header, as well as the global boundary conditions. Step S162 of this embodiment further includes replacing the event in the node with the value corresponding to the event in the header boundary condition list when the event in the node is the same as the event in the header boundary condition list. Specifically, when multiple local boundary conditions in the header boundary condition list all contain the same event, the value corresponding to the event in the last local boundary condition is used as the value corresponding to the event in the header boundary condition list; when at least one local boundary condition and a global boundary condition in the header boundary condition list both contain the same event, the value corresponding to the event in the global boundary condition is used as the value corresponding to the event in the header boundary condition list; when the values ​​corresponding to the event in the local boundary condition or the global boundary condition in the header boundary condition list contain both logical values ​​of true and logical values ​​of false, the logical value of true is used as the value corresponding to the event in the local boundary condition or the global boundary condition, thereby not excluding negative responses corresponding to the header, that is, conservatively assessing the risk in the nuclear power accident event tree model A10, thereby improving the reliability of the model to be quantified. In this embodiment, if a local boundary condition A in the header boundary condition list nests another local boundary condition B, then the boundary conditions contained in the local boundary condition B are used as part of the boundary conditions of the local boundary condition A. In this embodiment, the header boundary condition list processes each local boundary condition in sequence first, and then processes the global boundary condition, so that the global boundary condition has the highest priority among all boundary conditions. In addition, after assigning values ​​to the nodes in the copied original model structure according to the header boundary condition list corresponding to the header, step S162 of this embodiment also transfers the influence of each assigned node in sequence from bottom to top according to the Boolean logic relationship, thereby obtaining the model to be quantified.

[0046] For the assignment process of step S16 above, Figure 10 For example, Figure 9As shown on the left, the original model structure for a response scenario corresponding to the input of a functional event header FE1 in a certain sequence of joint solutions is shown. This original model structure includes a fault tree with a gate structure FT1. Conditions A and B affect whether the response scenario corresponding to fault tree FT1 occurs. When the header boundary condition list corresponding to functional event header FE1 includes a local boundary condition BC1, and local boundary condition BC1 includes boundary condition A = True, after the gate structure FT1 of the fault tree is copied to obtain gate structure D-FT1, condition A in gate structure D-FT1 is assigned to True based on local boundary condition BC1. It can be understood that after gate structure D-FT1 is assigned, the Boolean logic relationship and gate structure determine whether to propagate the node's influence. For example, if gate structure D-FT1 is an OR gate and the node corresponding to A is set to True, the influence is further propagated upward, that is, gate structure D-FT1 is assigned to True. By sequentially propagating the influence of the assigned nodes, the model size can be further reduced, resulting in a more concise model to be quantified and improving subsequent computational efficiency.

[0047] Continue to refer to Figure 6 Step S17 is to perform a quantitative analysis on the quantified model to obtain the accident frequency corresponding to the target consequence. It is understandable that the quantitative analysis in step S17 is not the focus of this application, so it will not be explained in detail.

[0048] An embodiment of the present application also proposes a method such as Figure 11 The electronic device 400 is shown. Figure 10 The electronic device 400 shown includes a memory 41 and a processor 42. The memory 41 is used to store instructions that can be executed by the processor 42. The processor 42 is used to execute the instructions to implement the nuclear power accident event tree model analysis method described above.

[0049] In addition, the present application also proposes a computer-readable medium storing computer program code, which implements the aforementioned nuclear power accident event tree model analysis method when executed by a processor.

[0050] It should be noted that the combined solution results described above already include data related to the target consequences of the nuclear power accident event tree model A10. Therefore, subsequent analysis and processing of the combined solution results can be used to obtain conclusions related to the target consequences or achieve corresponding objectives. Therefore, it can be understood that this application does not limit the specific use of the combined solution results.

[0051] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely examples and do not limit the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and revisions to the present application. Such modifications, improvements, and revisions are suggested in the present application and remain within the spirit and scope of the exemplary embodiments of the present application.

[0052] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0053] Some aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor can be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs...), smart cards, and flash memory devices (e.g., cards, sticks, key drives...).

[0054] A computer-readable medium may include a propagated data signal embodying computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, etc., or a suitable combination thereof. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transmit the program for use. The program code on the computer-readable medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above.

[0055] Similarly, it should be noted that, in order to simplify the description of this application and thus facilitate understanding of one or more embodiments of the application, the foregoing description of the embodiments of this application sometimes combines multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, the features of an embodiment may be fewer than all the features of the individual embodiments disclosed above.

[0056] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A method for analyzing a nuclear power accident event tree model, wherein the nuclear power accident event tree model comprises a plurality of event trees, each event tree comprising an originating event header and at least one functional event header, each event tree comprising one or more sequences, each sequence comprising branch results for the at least one functional event header, wherein at least one branch result is associated with a list of local boundary conditions, and the final state of each sequence is a consequence of the corresponding event tree, wherein the final state of the sequence is the branch result of the last functional event header corresponding to the sequence, the method comprising the following steps: Taking one or more event trees corresponding to target consequences in the nuclear power accident event tree model as target event trees; In response to determining that the input of the initiating event header of the first target event tree in the target event trees includes consequences of other event trees, determining an event tree chain corresponding to the first target event tree, the event tree chain including a plurality of event trees sequentially connected in the nuclear power accident model, and the last event tree in the event tree chain being the first target event tree; The event tree chain is disassociated to obtain a first disassociated result of the first target event tree, wherein when parsing each event tree in the event tree chain, the sequences with the same local boundary condition list are connected through an OR gate to form a sequence grouping top gate.

2. The nuclear power accident event tree model analysis method according to claim 1, characterized in that: The step of delinking the event tree chain to obtain a first delinked result of the first target event tree further includes: Determine each first target sequence of each event tree in the event tree chain, wherein the final state of the first target sequence is the input of the originating event header of the next event tree sequentially connected to the event tree where the first target sequence is located; Connecting the first target sequences with the same local boundary condition list in the first event tree of the event tree chain through an OR gate to form the corresponding sequence grouping top gate, and using each sequence grouping top gate of the first event tree as a joint solution result of the first event tree; For the second event tree to the last event tree in the event tree chain, each of the sequence grouping top gates of the current event tree is combined with the joint solution result of the previous event tree to obtain the joint solution result of the current event tree, wherein the joint solution result of the last event tree is the first joint solution result.

3. The nuclear power accident event tree model analysis method according to claim 2, characterized in that: For a first event tree and a second event tree sequentially connected in the event tree chain, the step of obtaining each of the sequence group top gates corresponding to the second event tree includes: Passing each first local boundary condition list to the second event tree respectively, wherein the first local boundary condition list is the local boundary condition list corresponding to each sequence group top gate corresponding to the first event tree, and the local boundary condition set of the initiating event header of the second event tree includes the corresponding first local boundary condition list; For each of the second event trees corresponding to the first local boundary condition lists, a second local boundary condition list corresponding to each of the first target sequences of the second event tree is generated, wherein the second local boundary condition list sequentially includes the local boundary conditions in the local boundary condition set of the corresponding initiating event header and the local boundary conditions corresponding to each of the branch results; The first target sequences with the same second local boundary condition list in the second event tree are connected through an OR gate to form the sequence grouping top gate corresponding to the second event tree.

4. The nuclear power accident event tree model analysis method according to claim 2, characterized in that: The joint solution result includes joint solution sub-results corresponding to different local boundary condition lists of the event tree, wherein each of the sequence grouping top gates of the first event tree is the joint solution sub-result of the first event tree. For the first event tree and the second event tree sequentially connected in the event tree chain, the step of obtaining the joint solution result of the second event tree according to the joint solution result of the first event tree and each of the sequence grouping top gates of the second event tree includes: For each of the sequence grouping top gates of the second event tree, determining the local boundary condition list in the first event tree included in the sequence grouping top gate as a target local boundary condition list; For each of the sequence grouping top gates of the second event tree, the joint solution sub-result corresponding to the target local boundary condition list in the first event tree is connected to the sequence grouping top gate of the second event tree through an AND gate to obtain a joint solution sub-result of the second event tree.

5. The nuclear power accident event tree model analysis method according to claim 1, characterized in that: The method further comprises: In response to determining that the input of the originating event header of the second target event tree in the target event tree does not include consequences of other event trees, parsing the second target event tree to obtain a second joint solution result of the second target event tree; All of the first joint solution results and the second joint solution results are connected through an OR gate to obtain a joint solution total result corresponding to the target consequence.

6. The nuclear power accident event tree model analysis method according to claim 5, characterized in that: The step of parsing the second target event tree to obtain a second joint solution result of the second target event tree further includes: determining each second target sequence in the second target event tree, wherein the final state of the second target sequence is the target consequence; Connecting the second target sequences with the same local boundary condition list in the second target event tree through an OR gate to form the corresponding sequence grouping top gate; The sequence group top gates of the second target event tree are connected through an OR gate to obtain the second joint solution result.

7. The nuclear power accident event tree model analysis method according to claim 5, characterized in that: The method further comprises: Assigning a value to the joint solution overall result according to the global boundary condition of the nuclear power accident event tree model and the local boundary conditions in the local boundary condition lists corresponding to the joint solution overall result to obtain a model to be quantified; The model to be quantified is quantitatively analyzed to obtain the accident frequency corresponding to the target consequence.

8. The nuclear power accident event tree model analysis method according to claim 7, characterized in that: The first joint solution result includes at least one first target sequence, the second joint solution result includes at least one second target sequence, and the step of assigning a value to the joint solution total result to obtain a model to be quantified according to the global boundary conditions of the nuclear power accident event tree model and the local boundary conditions in the local boundary condition lists corresponding to the joint solution total result further includes: For each of the first target sequence and the second target sequence in each of the joint solution results, copy the original model structure of each corresponding header, where the header is the initiating event header or the functional event header corresponding to the first target sequence or the second target sequence; For each copied original model structure, assign values ​​to the nodes in the copied original model structure according to the header boundary condition list corresponding to the header to obtain the model to be quantified, The header boundary condition list sequentially includes the local boundary conditions corresponding to each header from the initiating event header to the header in the first target sequence or the second target sequence corresponding to the header in the local boundary condition list, and the global boundary conditions.

9. The nuclear power accident event tree model analysis method according to claim 8, characterized in that: The local boundary condition and the global boundary condition each include at least one event and a corresponding value, wherein the event is a basic event or a room-shaped event, and the value is a logical value. The step of assigning values ​​to nodes in the copied original model structure according to the header boundary condition list corresponding to the header further includes: When the event in the node is identical to the event in the header boundary condition list, the event in the node is replaced with the value corresponding to the event in the header boundary condition list.

10. The nuclear power accident event tree model analysis method according to claim 9, characterized in that: The method further includes, when a plurality of the local boundary conditions in the header boundary condition list all contain the same event, using the value corresponding to the event in the last local boundary condition as the value corresponding to the event in the header boundary condition list; When at least one of the local boundary conditions and the global boundary condition in the header boundary condition list both contain the same event, the value corresponding to the event in the global boundary condition is used as the value corresponding to the event in the header boundary condition list; When the values ​​corresponding to the event in the local boundary condition or the global boundary condition in the header boundary condition list have both logical values ​​of true and logical values ​​of false, the logical value of true is used as the value corresponding to the event in the local boundary condition or the global boundary condition.

11. The nuclear power accident event tree model analysis method according to claim 10, characterized in that: The method further includes, after assigning values ​​to nodes in the copied original model structure according to the header boundary condition list corresponding to the header: The influence of each assigned node is transmitted sequentially from bottom to top according to the Boolean logic relationship.

12. An electronic device comprising: a memory for storing instructions executable by the processor; and a processor, configured to execute the instructions to implement the nuclear power accident event tree model analysis method according to any one of claims 1 to 11.

13. A computer-readable medium storing computer program code, wherein when executed by a processor, the computer program code implements the nuclear power accident event tree model analysis method according to any one of claims 1 to 11.

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