Reliability probability safety evaluation method of reactor protection system

Abstract

The invention provides a reliability probability safety evaluation method for a reactor protection system, the method is suitable for the reactor protection system, the reactor protection system comprises at least one first subsystem with a redundant card, and the method comprises the following steps: obtaining modeling input information; calculating the probability of a basic event for modeling according to the modeling input information; a fault tree is established according to the modeling input information, the fault tree comprises a card group common cause failure basic event, and the probability of the card group common cause failure basic event is equal to the sum of the probability of a bus failure basic event and the probability of all types of card common cause failure basic events on a signal flow of at least one first subsystem; the failure probability of the reactor protection system is analyzed using the fault tree and the probability of the elementary events.

Description

Technical Field

[0001] This application mainly relates to the field of probabilistic safety assessment technology for nuclear power plant units, and in particular to a method for probabilistic safety assessment of the reliability of a reactor protection system. Background Technology

[0002] The reactor protection system (RPS) is a core component of the safety system of a nuclear power plant, playing a crucial role in ensuring the safe operation of the plant. Therefore, it is necessary to analyze the reliability of the reactor protection system using systematic analysis methods.

[0003] Probabilistic Safety Assessment (PSA) is a risk quantification assessment technique based on probability theory and statistics. PSA for nuclear power plants focuses on the failure probability of the reactor protection system, i.e., the probability that the system will fail to perform its protective actions due to random faults when required. Therefore, PSA analysis of nuclear power plants requires constructing numerous shutdown fault trees and dedicated safety facility-driven fault trees based on signal paths. Furthermore, to ensure high reliability of the reactor protection system, it typically has multiple redundancy sequences, numerous system cabinets, and a large number of cards. This leads to a surge in the modeling workload of the reactor protection system fault trees in PSA models for nuclear power plants, especially in multi-unit / multi-reactor power plants, thus increasing modeling time and scale, and also increasing the computation and analysis time for the reactor protection system's probabilistic safety assessment.

[0004] Therefore, there is an urgent need in this field for a probabilistic safety assessment method for the reliability of reactor protection systems that can effectively reduce the workload of modeling fault trees for reactor protection systems, reduce modeling time and modeling scale, thereby improving the modeling and computational efficiency of probabilistic safety assessment. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a method, electronic equipment, computer storage medium, and computer program product for probabilistic safety evaluation of the reliability of a reactor protection system, which can reduce the workload of modeling the fault tree of the reactor protection system, reduce the modeling time and modeling scale, thereby improving the modeling and calculation efficiency of probabilistic safety evaluation.

[0006] To address the aforementioned technical problems, this application provides a reliability probabilistic safety evaluation method for a reactor protection system, applicable to reactor protection systems. The reactor protection system includes at least one first subsystem with redundant cards. The reliability probabilistic safety evaluation method includes the following steps: acquiring modeling input information; calculating the probability of basic events used for modeling based on the modeling input information; establishing a fault tree based on the modeling input information, wherein the fault tree includes basic events of common-cause failure of card groups, the probability of which is equal to the probability of basic bus failure and the sum of the probabilities of all types of basic events of common-cause failure of cards on the signal flow of the at least one first subsystem; and analyzing the failure probability of the reactor protection system using the fault tree and the probabilities of the basic events.

[0007] In one embodiment of the present invention, the fault tree does not include card failure basic events and card common cause failure basic events of the at least one first subsystem.

[0008] In one embodiment of the present invention, the modeling input information includes modeling requirement data for dedicated security facilities.

[0009] In one embodiment of the present invention, calculating the probability of basic events for modeling based on the modeling input information includes: calculating common card failure basic events for both detectable and undetectable failure modes of the card.

[0010] In one embodiment of the present invention, setting the probability of the basic events used for modeling includes calculating the card unavailability using the following formula: In the formula, For self-diagnosis rate, For regular testing cycles, For card failure rate, This represents the average repair time.

[0011] In one embodiment of the present invention, the unavailability setting of the redundant card is less than 1×10. -4 .

[0012] In one embodiment of the present invention, the reactor protection system includes at least one second subsystem without redundant cards, and the establishment of a fault tree based on the modeling input information includes: establishing card failure basic events and card failure common cause event groups for the at least one second subsystem.

[0013] In one embodiment of the present invention, establishing a fault tree based on the modeling input information includes: establishing a common signal for multiple automatic triggering signals of the reactor protection system.

[0014] In one embodiment of the present invention, building a fault tree based on the modeling input information includes: pre-constructing at least one fault subtree of a specific pattern, and invoking the corresponding fault subtree when the specific pattern is selected.

[0015] This application also proposes an electronic device comprising: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the method described above.

[0016] This application also proposes a computer storage medium storing computer program code that, when executed by a processor, implements the method described above.

[0017] This application also proposes a computer program product including computer program code, which, when executed by one or more processors, implements the steps of the method described above.

[0018] Compared with the prior art, this application has the following advantages:

[0019] This application unifies the bus failure basic event and all types of card common cause failure events on the signal flow of the first subsystem with redundant cards into a card group common cause failure basic event, and uses a pre-built fault subtree of a specific pattern to serve the call of the corresponding fault subtree during fault tree modeling, thereby reasonably simplifying the fault tree modeling of the reactor protection system, reducing the modeling time and modeling scale, and thus improving the modeling and calculation efficiency of the reliability probabilistic safety analysis of the reactor protection system. Attached Figure Description

[0020] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings:

[0021] Figure 1 This is a flowchart of a reactor protection system reliability probabilistic safety evaluation method according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of a general automatic-driven fault subtree for a dedicated safety facility constructed according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of a general manually driven fault subtree for a dedicated safety facility constructed according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of a dedicated safety facility driven fault tree constructed according to an embodiment of this application;

[0025] Figure 5This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0027] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0028] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0029] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely 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. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0030] This application uses flowcharts to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed precisely in sequence. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from them. This application is applicable not only to probabilistic safety assessments during the operational phase of nuclear power plants, but also to probabilistic safety assessments during the preliminary design and construction design phases of nuclear power plants.

[0031] Figure 1 This is a flowchart of a probabilistic safety evaluation method for the reliability of a reactor protection system according to an embodiment of this application. Now refer to... Figure 1 The diagram illustrates a probabilistic safety evaluation method for the reliability of a reactor protection system according to this application.

[0032] In step 101, obtain the modeling input information.

[0033] In this step, the modeling input information obtained includes the reactor protection system specification and the modeling requirements data for dedicated safety facilities. The reactor protection system specification includes numerical and non-numerical data such as the hardware architecture, software logic, and performance parameters of the reactor protection system. Dedicated safety facilities include, but are not limited to, valves and circuit breakers, and their modeling requirements data can be derived from the system specifications of the relevant dedicated safety facilities.

[0034] In some embodiments, the acquired modeling input information also includes system reliability data and power supply reliability data. System reliability data includes system self-diagnostic rate, periodic testing cycle, mean time to repair (MTBL), and card failure rate. System reliability data and power supply reliability data can use general data, such as NUREG / CR-6928, GJB 299C, and the China Nuclear Power Plant Equipment Reliability Data Report, or can refer to reliability data from similar reactor protection system platforms. In other embodiments, the acquired modeling input information also includes signal flow graphs and human error data.

[0035] In step 102, the probabilities of the basic events used for modeling are calculated based on the modeling input information.

[0036] In this step, based on the modeling input information obtained in step 101, the probabilities of the basic events used for modeling are calculated. Basic events, as the base events of the fault tree, are the smallest indivisible units in the fault tree; the probability of a basic event is its probability of occurrence. The basic events calculated in this step for modeling include card failure basic events and card common-cause failure basic events, but are not limited to these two types of basic events.

[0037] Specifically, card failures are categorized into two modes: detectable failures and undetectable failures. Detectable failures are self-diagnosed faults with short recovery times; undetectable failures are faults diagnosed through periodic manual testing with long recovery times. For both modes of card failure, the failure probability is quantified using only a single basic card failure event. This step calculates the probability of this basic event to concisely and accurately model the card failure state in the reactor protection system.

[0038] In some embodiments, the probability of a card failure basic event can be calculated using a card unavailability calculation formula. The card unavailability calculation formula is:

[0039] ,

[0040] In the formula, For self-diagnosis rate, For regular testing cycles, For card failure rate, This represents the average repair time. The failure rate of the card is also considered. Typically provided by the manufacturer, the reliability prediction rate can be calculated using reliability prediction methods based on electronic equipment reliability prediction standards. Optionally, the failure rate of the card can be calculated using reliability prediction methods according to GJB 299C. .

[0041] The card unavailability calculation formula can simultaneously model the impact of factors such as random failure, self-diagnosis, mean time to repair, and periodic test cycle on the failure probability of the card, so as to comprehensively quantify the detectable failure and undetectable failure of the card.

[0042] For redundantly designed cards, such as analog input / output cards, digital input / output cards, logic cards / processors, and communication cards, their unavailability should be set to less than 1×10^6. -4 If the unavailability of redundant design cards does not meet this requirement, the unavailability of redundant design cards should be reduced by adjusting parameters such as the periodic testing cycle, thereby controlling the probability of card failure basic events.

[0043] Furthermore, because the probability of a card failure due to a common cause is much greater than the probability of a card failure due to an independent cause in the total probability of card failure due to a common cause, this application only calculates the probability of a card failure due to a common cause as a basic event for the card failure due to a common cause, without considering the probability of a card failure due to an independent cause. In some embodiments, this can be achieved by... The factor model multiplies the probability of the basic event of card failure by... The factor yields the probability of the basic event of common cause failure of the card. Among them, Factors can be estimated based on fundamental standards in the field of functional safety, such as IEC 61508, to quickly model the basic events of common-cause failure of card components. Optionally, The factor value is 0.02.

[0044] In some embodiments, step 102 further includes calculating the probabilities of basic failure events and common cause failure events of electrical equipment based on the modeling input information. For example, electrical equipment includes manual switches, circuit breakers, relays, sensors, etc. The probabilities of basic failure events of electrical equipment can be calculated using common data such as NUREG / CR-6928 and the China Nuclear Power Plant Equipment Reliability Data Report. Fault Tree Analysis (FTA) has various calculation models for common cause failures (CCF). Therefore, basic common cause failure events of electrical equipment can be modeled and calculated by setting up common cause event groups; that is, the probability of a basic common cause failure event of electrical equipment is equal to the sum of the probability of independent failure of electrical equipment and the probability of common cause failure of electrical equipment. The probability of independent failure of electrical equipment is derived from the probability of basic failure events of electrical equipment, and the common cause parameter quantifies the share of common cause failures among similar equipment to obtain the probability of common cause failure of electrical equipment, thereby calculating the probability of basic common cause failure events of electrical equipment. Optionally, common cause parameters can be obtained from common cause failure study reports such as NUREG / CR-5497, which use general data.

[0045] In some embodiments, step 102 further includes calculating the probabilities of software common-cause failure basic events, bus failure basic events, manual-driven indication failure basic events, and manual-driven sensor common-cause failure basic events based on the modeling input information, and calculating the probabilities of these basic events based on expert judgment. Optionally, the reactor protection system is implemented using Field Programmable Gate Array (FPGA) technology, eliminating the need for modeling and calculating the probabilities of software common-cause failure basic events.

[0046] In step 103, a fault tree is built based on the modeling input information.

[0047] In this step, based on the modeling input information obtained in step 101, including but not limited to the reactor protection system specification and the modeling requirement data for dedicated safety facilities, a shutdown fault tree for the reactor protection system and a fault tree for the dedicated safety facilities are established.

[0048] The reactor protection system includes at least one first subsystem with redundant cards, such as a data acquisition and processing subsystem, a conformal logic subsystem, and an equipment control and optimization subsystem. In this step, basic events for common-cause failures of the card group are established for the first subsystem to simplify modeling of the redundant cards in the first subsystem. Specifically, the probability of a basic event for a common-cause failure of the card group is equal to the probability of a basic bus failure calculated in step 102 plus the sum of all types of basic events for common-cause failures of the card group on the signal flow of the first subsystem. Furthermore, based on the causal relationships in the modeling input information obtained in step 101, corresponding logic gates are assigned to the basic events for common-cause failures of the card group. A basic event for a common-cause failure of the card group is an envelope value, which simplifies modeling while covering all card failure states. Therefore, in some embodiments, it is not necessary to model the basic events for card failures and basic events for common-cause failures of the card group in the first subsystem as bottom event nodes of the fault tree. In other embodiments, based on the requirements of fine-grained analysis, different types of card common cause failure basic events and bus failure basic events are established as child nodes, and card group common cause failure basic events are established as parent nodes of the aforementioned two child nodes. The child nodes are then connected to the parent nodes by logic gates corresponding to predetermined connection relationships, thereby improving the applicability of this application.

[0049] The reactor protection system also includes at least one second subsystem without redundant cards, such as a safety-level optimization module subsystem. This second subsystem can be directly used to trigger the action of dedicated safety facilities. In step 102, basic card failure events and common-cause event groups for card failures are established for the second subsystem. Specifically, based on the predetermined connection relationships of the second subsystem in the modeling input information obtained in step 101, the corresponding logic gate connections between the second subsystem failure and the basic card failure events and common-cause event groups are set. The failure probability of the common-cause event group is equal to the sum of the card's independent failure probability and the card's common-cause failure probability. Optionally, the card's independent failure probability is the probability of the basic card failure event calculated in step 102, and the card's common-cause failure probability is the probability of the basic card failure event calculated in step 102.

[0050] To ensure the high reliability of the reactor protection system, reactor shutdown and different dedicated safety facilities are triggered by different signal combinations. In step 103, a universal signal is established, eliminating the need to analyze signal combinations under different operating conditions, thus simplifying signal modeling. Specifically, establishing a universal signal includes establishing signal sensor events and signal voting logic gates, with the signal sensor events and sequential failure parent events connected causally through the signal voting logic gates. The signal sensor events can be the basic sensor failure events calculated in step 102. Optionally, based on fine-grained analysis requirements, multiple universal signals can be established, with each signal modeling its corresponding signal sensor and signal voting logic, thereby improving the applicability of this application.

[0051] In step 103, based on the modeling input information obtained in step 101, at least one fault subtree for a specific pattern is pre-constructed. The modeling input information provides the basis for top-down decomposition and refinement of the fault subtree for the specific pattern. The fault subtree is decomposed and refined to indivisible basic events so that the failure states of all relevant components in the reactor protection system can be modeled into the fault subtree. The constructed fault subtree for the specific pattern includes a general automatic-driven fault subtree and a general manual-driven fault subtree to cover fault tree modeling of reactor protection system failures that are only automatic, only manual, and both automatic and manual driven.

[0052] Furthermore, the general automatic drive fault subtree, from top to bottom, includes the failure causal logic involved in the predetermined connection relationships in the modeling input information obtained in step 101, such as card failure causal logic, sensor failure causal logic, and drive signal failure causal logic. Based on these failure causal logics, the top event of the general automatic drive fault subtree is further decomposed and refined to basic events, with the upper-level event and the refined lower-level event connected by logic gates. Basic events include the basic events used for modeling calculated in step 102. In some embodiments, the general automatic drive fault subtree includes a general automatic drive fault subtree for reactor shutdown and a general automatic drive fault subtree for dedicated safety facilities. Because the dedicated safety facility requires power support, the general automatic drive fault subtree for dedicated safety facilities also includes power failure causal logic in addition to the aforementioned causal logic.

[0053] Figure 2This is a general, automatically driven fault subtree for a dedicated safety facility constructed in one embodiment. The dedicated, general automatically driven fault subtree is set as the top event, which is connected to the intermediate events of drive signal failure, the basic events of card group common-cause failure, and the basic events of software common-cause failure via a logical "OR gate." The logical "OR gate" indicates that the occurrence of any failure event will lead to the occurrence of the top event. The basic events of card group common-cause failure and software common-cause failure are indivisible base events in the fault subtree, and their probabilities are the probabilities of the corresponding basic events calculated in step 102, to simplify modeling. The intermediate events of drive signal failure are connected to the intermediate events of sequence A, sequence B, sequence C, and sequence D signal failure shown in the figure via signal voting logic gates. It can be understood that the number of intermediate events of sequence signal failure and the signal voting logic gates are determined by the signal flow graph in the modeling input information obtained in step 101. Each sequence signal failure intermediate event is further decomposed and refined into sensor failure basic events and UPS distribution panel power failure basic events, which are connected by a logic "OR gate". The probabilities of both sensor failure basic events and UPS distribution panel power failure basic events are calculated in step 102. In some embodiments, since the reactor protection system is implemented using FPGA technology, the common cause failure basic events in the automatic driving fault subtree do not require modeling software.

[0054] Furthermore, constructing a general manually driven fault subtree includes the failure causal logic involved in the predetermined connection relationships in the modeling input information obtained in step 101, such as: indication failure causal logic, card failure causal logic, sensor failure causal logic, human error causal logic, and software failure causal logic. Based on these failure causal logics, the top event of the general manually driven fault subtree is further decomposed and refined to basic events, with the upper-level event and the refined lower-level event connected by logic gates. Basic events include the basic events used for modeling calculated in step 102. In some embodiments, the general manually driven fault subtree includes a general manually driven fault subtree for reactor shutdown and a general manually driven fault subtree for dedicated safety facilities. In other embodiments, since reactor shutdown requires manual switch operation and the reactor shutdown manual switch is isolated from the reactor shutdown automatic switch, the general manually driven fault subtree for reactor shutdown also includes reactor shutdown switch failure causal logic.

[0055] Figure 3This is a general manually driven fault subtree for a dedicated safety facility constructed in one embodiment. This general manually driven fault subtree is set as the top event and is connected via a logic OR gate to the indicator failure basic event, the card group common cause failure basic event, the software common cause failure basic event, and the sensor common cause failure basic event. The aforementioned basic events are indivisible bottom events in the fault subtree, and their probabilities are the probabilities of the corresponding basic events calculated in step 102. In some embodiments, the simultaneous failure of indicator signals from multiple instrumentation and control systems in the reactor protection system is modeled as an indicator failure basic event in the general manually driven fault subtree of the dedicated safety facility to simplify modeling. In other embodiments, the simultaneous failure of sensors of indicator signals from multiple instrumentation and control systems in the reactor protection system is modeled as a sensor common cause failure basic event in the general manually driven fault subtree of the dedicated safety facility to simplify modeling.

[0056] Based on pre-built fault subtrees of specific patterns, the corresponding fault subtree is invoked when a specific pattern is selected in the fault tree construction. Specifically, for different top failure events in reactor protection systems that are only automatic, only manual, automatic, and manually driven, where each top failure event includes the automatically driven failure causal logic and the manually driven failure causal logic that caused the top failure event, the corresponding pre-built fault subtree of specific patterns is invoked when constructing the fault tree for the top failure event to quickly build the fault tree. The fault tree depends on the specific design of the reactor protection system; in some embodiments, the fault tree includes a shutdown fault tree and a dedicated safety facility fault tree. This application can improve the modeling and computational efficiency of probabilistic safety analysis of reactor protection system reliability by reasonably simplifying fault tree modeling of reactor protection systems, reducing modeling time and modeling scale.

[0057] Figure 4This is a schematic diagram of a dedicated safety facility drive fault tree constructed in one embodiment. The top event of the fault tree is set as "RPS failed to trigger pneumatic valve XXX to open". This top event is connected via an OR gate to the intermediate events of RPS manual drive failure, the basic event of UPS distribution panel BSA01 power failure, and the intermediate events of RPS safety level optimization module failure. The basic event of UPS distribution panel BSA01 power failure is an indivisible base event of this fault tree, and its probability is calculated in step 102. The RPS safety level optimization module is a second subsystem without redundant cards. In this step, its corresponding card failure basic events and card failure common cause event groups are established and connected to the intermediate events of the RPS safety level optimization module via logic gates. The intermediate events of RPS drive failure are connected via AND gates to the dedicated general automatic drive fault subtree and the intermediate events of RPS manual drive failure. The dedicated general automatic drive fault subtree calls and transfers to the general automatic drive fault subtree of the dedicated safety facility pre-constructed in this step. Furthermore, the intermediate events of RPS manual drive failure are connected to a dedicated general manual drive fault subtree and the basic events of operator error via a logic OR gate. The dedicated general manual drive fault subtree calls and transfers to the general manual drive fault subtree of the dedicated safety facility pre-built in this step. The basic events of operator error are the basic events calculated in step 102, and their probabilities have been calculated in step 102 based on the modeling input information. In some embodiments, if a certain drive function needs to consider different personnel errors under multiple conditions, the basic events of operator error can be refined into operator error fault subtrees and connected to the corresponding fault trees through logic gates, thereby refining the causal logic of personnel error in the fault trees.

[0058] In step 104, the probability values ​​of the basic events calculated in step 102 are used to establish the fault tree in step 103 and the probability values ​​of the basic events are assigned to the corresponding bottom events in the fault tree. The probability of the top event in the fault tree is calculated from bottom to top to analyze the failure probability of the reactor protection system.

[0059] An embodiment of this application also proposes a method such as Figure 5 The electronic device 20 shown. According to Figure 5 The electronic device 20 may include an internal communication bus 21, a processor 22, a read-only memory (ROM) 23, a random access memory (RAM) 24, and a communication port 25. When used in a personal computer, the electronic device may also include a hard disk 26.

[0060] The internal communication bus 21 enables data communication between components of the electronic device 20. The processor 22 can make judgments and issue prompts. In some embodiments, the processor 22 may consist of one or more processors. The communication port 25 enables data communication between the electronic device 20 and external devices. In some embodiments, the electronic device 20 can send and receive information and data from a network through the communication port 25.

[0061] Electronic device 20 may also include different forms of program storage units and data storage units, such as hard disk 26, read-only memory (ROM) 23, and random access memory (RAM) 24, capable of storing various data files used for computer processing and / or communication, as well as possible program instructions executed by processor 22. The processor executes these instructions to implement the main parts of the reliability probabilistic safety evaluation method for reactor protection systems as described above. The results of processor processing are transmitted to user equipment via a communication port and displayed on a user interface.

[0062] In another aspect, this application also proposes a computer-readable medium storing computer program code, which, when executed by a processor, implements the reliability probabilistic safety evaluation method for the reactor protection system described above.

[0063] In addition, this application also proposes a computer program product, including computer program code, which, when executed by one or more processors, can implement the steps in the above-described reliability probabilistic safety evaluation method for reactor protection systems.

[0064] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0065] Some aspects of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may 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. Furthermore, aspects of this application may manifest as computer products residing in one or more computer-readable media, including 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, magnetic tapes, etc.), optical discs (e.g., compressed CDs, digital multifunction DVDs, etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0066] A computer-readable medium may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and so on, or suitable combinations thereof. A computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signals, or similar media, or any combination of the above media.

[0067] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0068] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0069] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0070] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.

Claims

1. A method for probabilistic safety evaluation of the reliability of a reactor protection system, characterized in that, Applicable to reactor protection systems, the reactor protection system including at least one first subsystem with redundant cards, the reliability probabilistic safety evaluation method includes the following steps: Obtain modeling input information; The probabilities of the basic events used for modeling are calculated based on the modeling input information; A fault tree is established based on the modeling input information, wherein the fault tree includes card group common cause failure basic events, and the probability of the card group common cause failure basic event is equal to the probability of the bus failure basic event and the sum of the probabilities of all types of card common cause failure basic events on the signal flow of the at least one first subsystem. The failure probability of the reactor protection system is analyzed using the fault tree and the probability of the basic events.

2. The method as described in claim 1, characterized in that, The fault tree does not include card failure basic events and card common cause failure basic events of the at least one first subsystem.

3. The method as described in claim 1, characterized in that, The modeling input information includes modeling requirements data for dedicated security facilities.

4. The method as described in claim 1, characterized in that, The probability of basic events used for modeling is calculated based on the modeling input information, including: calculating common card failure basic events for both detectable and undetectable failure modes of the card.

5. The method as described in claim 4, characterized in that, Setting the probabilities of the basic events used for modeling includes calculating card unavailability using the following formula: ， In the formula, For self-diagnosis rate, For regular testing cycles, For card failure rate, This represents the average repair time.

6. The method as described in claim 5, characterized in that, The unavailability setting for redundant cards is less than 1×10. -4 .

7. The method as described in claim 1, characterized in that, The reactor protection system includes at least one second subsystem without redundant cards. Establishing a fault tree based on the modeling input information includes: establishing card failure basic events and card failure common cause event groups for the at least one second subsystem.

8. The method as described in claim 1, characterized in that, Building a fault tree based on the modeling input information includes: establishing a common signal for at least one automatic trigger signal of the reactor protection system.

9. The method as described in claim 1, characterized in that, Building a fault tree based on the modeling input information includes: pre-constructing at least one fault subtree for a specific pattern, and invoking the corresponding fault subtree when the specific pattern is selected.

10. An electronic device, comprising: Memory is used to store instructions that can be executed by the processor; as well as A processor for executing the instructions to implement the method as described in any one of claims 1-9.

11. A computer storage medium storing computer program code, said computer program code implementing the method as claimed in any one of claims 1-9 when executed by a processor.

12. A computer program product comprising computer program code, wherein when the computer program code is executed by one or more processors, the one or more processors implement the steps of the method as described in any one of claims 1-9.

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