System forward design method of nuclear reactor

Abstract

The embodiment of the invention relates to the technical field of nuclear reactors, in particular to a system forward design method of a nuclear reactor. The method comprises the following steps: S1, determining system functions, performance indexes and interface requirements according to a power plant technical scheme; s2, performing system function decomposition and structure configuration according to system functions, performance indexes and interface requirements; s3, carrying out system process principle design according to system function decomposition and structure configuration; s4, performing equipment process design or model selection according to system process principle design; s5, carrying out system process flow design according to a system process principle and equipment process design type selection; s6, system pipeline and plant arrangement is carried out; s7, plant design is carried out; s8, evaluating whether the system design meets the function and performance indexes and interface requirements of the system; and S9, determining a system scheme, a system technology state and an acceptance criterion. The method provided by the embodiment of the invention provides methodological guidance for smooth development of system design of the novel nuclear reactor.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear reactors, and in particular to a system forward design method for a nuclear reactor. Background Art

[0002] This section of content merely provides background information related to the present application and does not necessarily constitute prior art.

[0003] The design of traditional domestic nuclear power plants mostly adopts methods such as "technology introduction" and "reference power plant". As the demand for independence continues to increase, how to carry out forward design of new nuclear reactors has become an urgent problem to be solved. Summary of the invention

[0004] A brief overview of the present application is provided below in order to provide a basic understanding of certain aspects of the present application. It should be understood that this overview is not an exhaustive overview of the present application. It is not intended to identify the key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0005] In response to the above technical problems, the embodiments of the present application provide a system forward design method for a nuclear reactor. The system is determined based on the technical solution of the power plant obtained by analyzing the power supply and heating capacity requirements of the nuclear reactor. The system forward design method includes: S1. According to the technical solution of the power plant, determine the functions and performance indicators and interface requirements of the system; S2. According to the functions and performance indicators and interface requirements of the system, perform system function decomposition and structural configuration of the system, and determine the equipment list of the system configuration; S3. According to the system function decomposition and structural configuration, carry out system process principle design, determine the system process principle diagram, and propose the process design conditions of the system for its equipment; S4. According to the system process principle diagram, carry out equipment process design or selection, determine the equipment working conditions, equipment process parameters, equipment general diagram and the equipment requirements for instrument control and electrical; S5. According to the system process principle diagram, equipment general diagram, system instrumentation and control, and electrical design, determine the system process flow chart containing instrument control points; S6. According to the overall layout and zoning plan of the plant, carry out system pipeline and plant layout, and perform pipeline mechanical analysis and support and hanger design;

[0006] S7. Carry out plant design according to pipeline and system plant layout; S8. Based on the evaluation of equipment function and performance, comprehensively evaluate whether the system design meets the system's functional and performance indicators and interface requirements from the perspective of function and performance; S9. Determine the system plan, system technical status and acceptance criteria, formulate relevant R&D plans, and carry out R&D tests.

[0007] The embodiments of this application are mainly based on the forward design method of system engineering and the design process of chemical system (the design process of nuclear reactor system is similar to that of chemical system), and divide the design and decomposition process into three levels: overall forward design method, system forward design method, and equipment forward design method; and combined with the technical characteristics of new nuclear reactors, a system forward design method of new nuclear reactors is summarized as a methodological guide for the system forward design process. The method provided in the embodiments of this application provides methodological guidance for the smooth implementation of the system design of new nuclear reactors; it is particularly suitable for forward design of many systems with a large number and complex interfaces.

[0008] These and other advantages of the present application will become more apparent through the following detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to further illustrate the above and other advantages and features of the present application, the specific embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. The accompanying drawings together with the following detailed description are included in this specification and form a part of this specification. Elements with the same function and structure are represented by the same reference numerals. It should be understood that these drawings only describe typical examples of the present application and should not be regarded as limiting the scope of the present application.

[0010] Figure 1 It is a flow chart of a method for system forward design of a nuclear reactor according to an embodiment of the present application.

[0011] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0012] Exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the process of developing any such actual implementation in order to achieve the developer's specific goals, such as meeting those constraints related to the system and business, and these constraints may vary from implementation to implementation. In addition, it should be understood that although the development work may be very complex and time-consuming, it is only a routine task for those skilled in the art who benefit from the content of this application.

[0013] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure and / or processing steps closely related to the scheme according to the present application are shown in the accompanying drawings, while other details that are not very relevant to the present application are omitted.

[0014] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the common meanings understood by persons with ordinary skills in the field to which this application belongs.

[0015] In the description of the embodiments of the present application, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0016] System engineering is a theoretical method summarized and practiced in the organization, planning, production, management of large-scale complex engineering or economic activities, as well as the design and development of complex products. System engineering is an engineering application technology that provides a positive design logic thinking method to successfully transform user needs into products. By observing the "overall picture" of the system life cycle, guided by the idea of ​​decomposition-integration, integrating multiple professional technologies, and through the iterative process of analysis-synthesis-experimentation, a system that meets the use requirements and optimizes overall performance is developed.

[0017] The development of new nuclear reactor technology is a large and complex project with complex interfaces, high technical difficulty, long R&D time, large R&D funds, and great risks. It is necessary not only to consider how to carry out the engineering design, but also to plan the corresponding many R&D, testing, and verification projects, and to repeatedly iterate and adjust between engineering design, R&D, testing, and verification. At the same time, it is also necessary to take into account the requirements of quality, safety, progress, investment, etc. This places extremely high demands on engineering technology development and engineering project management.

[0018] At present, classical system engineering theory can hardly guarantee the smooth implementation of new nuclear reactor engineering design.

[0019] The embodiments of the present application provide a system forward design method for a nuclear reactor, which is used to provide methodological guidance for the smooth implementation of system design for a new type of nuclear reactor.

[0020] The system mentioned in the embodiments of the present application is determined based on the technical solution of the power plant obtained by analyzing the power supply and heating capacity requirements of the nuclear reactor.

[0021] like Figure 1 As shown, Figure 1 1 is a flow chart of a method for forward design of a nuclear reactor system according to an embodiment of the present application. The method for forward design of a nuclear reactor system provided by an embodiment of the present application may include steps S1 to S9.

[0022] S1. Determine the system functions, performance indicators and interface requirements based on the power plant technical plan.

[0023] S2. According to the system's functions, performance indicators and interface requirements, the system is decomposed and structured, and the equipment list of the system configuration is determined.

[0024] S3. Based on the system function decomposition and structural configuration, carry out system process principle design, determine the system process principle diagram, and propose the system process design conditions for its equipment.

[0025] S4. According to the system process schematic, carry out equipment process design or selection, determine the equipment operating conditions, equipment process parameters, equipment general diagram and equipment requirements for instrument control electrical.

[0026] S5. Determine the system process flow chart including instrument control points based on the system process schematic, equipment general diagram, system instrumentation and control, and electrical design.

[0027] S6. According to the overall layout and zoning plan of the plant, carry out the system piping and plant layout, and conduct pipeline mechanical analysis and support and hanger design.

[0028] S7. Carry out plant design according to pipeline and system plant layout.

[0029] S8. Based on the evaluation of equipment functions and performance, comprehensively evaluate whether the system design meets the system's functions, performance indicators and interface requirements from the perspective of functions and performance.

[0030] S9. Determine the system plan, system technical status and acceptance criteria, formulate relevant R&D plans, and carry out R&D tests.

[0031] The embodiments of the present application are mainly based on the forward design method of system engineering and the chemical system design process (the nuclear reactor system design process is similar to the chemical system design process), and combined with the technical characteristics of the new nuclear reactor, a system forward design method of a new nuclear reactor is summarized as a methodological guidance for the system forward design process. The method provided in the embodiments of the present application is practiced and summarized in the system design process of the sodium-cooled fast reactor, which can provide methodological guidance for the smooth implementation of the system design of the new nuclear reactor.

[0032] The system forward design method provided in the embodiment of the present application makes the system design input complete and accurate through the above-mentioned steps S1 to S9, makes the system forward design process more logical, helps to reduce the design time, and avoids design rework or design failure due to incomplete design input.

[0033] The above steps S1-S9 are equivalent to the design and decomposition steps in the system forward design. In some embodiments, the system forward design method provided by the embodiment of the present application may also include: S10, integrating and verifying the system.

[0034] In some embodiments, in step S1, the functional and performance indicators include function, performance, safety, reliability, maintainability, life, economy, and ergonomics.

[0035] In some embodiments, if the system is a superior system of other subordinate systems, the primary functions, performance and interface requirements of the system for the subordinate systems are also proposed in step S2; the primary process design conditions of the system for its subordinate systems are also proposed in step S3; the final functions, performance and interface requirements and final process design conditions of the system for its subordinate systems are also determined in step S9. If the system is a subordinate system of other superior systems, the functions and performance indicators and interface requirements of the system are determined in step S1 according to the technical plan of the power plant and the functions, performance and interface requirements of all superior systems; the system process principle design is also carried out according to the process design conditions proposed by all superior systems in step S3. The embodiments of the present application enable each system to meet the functions, performance and interface requirements of the superior system, making the reactor safer and more reliable.

[0036] In the embodiments of the present application, the subordinate system refers to other systems whose design priority is lower than that of the system currently being designed; the superior system refers to other systems whose design priority is higher than that of the system currently being designed. When designing each system, each system is designed in order from high to low design priority.

[0037] In some embodiments, according to the technical status of the power plant, the power plant is divided into multiple systems with different design priorities. Each system is designed and decomposed in sequence from high to low design priority to determine the system technical status and acceptance criteria corresponding to each system.

[0038] Specifically, if the system is the main system, the system's functions, performance indicators and interface requirements are derived from the power plant's technical plan; if the system is another lower-level system, the system's functions, performance indicators and interface requirements are derived from the power plant's technical plan and all upper-level systems. Specifically, after the system's technical plan is determined, corresponding technical requirements or functions, performance and interface requirements will be proposed to its lower-level systems, equipment, instrumentation, electrical, and public engineering.

[0039] In some embodiments, in step S2, the system function decomposition and structural configuration mainly analyzes what system process support is needed to realize the system function, generally including power, source, path, etc., that is, to analyze the system process principle and configure the corresponding execution equipment. The output of the system function analysis and structural configuration is the system configuration list, system process principle diagram, system requirements for equipment functions, performance and interfaces, system requirements for its subordinate systems functions, performance and interfaces, etc.

[0040] The purpose of the system process principle design in step S3 is to complete the system process principle diagram and propose the system's process design conditions for its equipment and its lower-level systems.

[0041] In some embodiments, step S3 includes: S31. Determine the system operating conditions based on the power plant operating conditions and design benchmarks, and propose requirements for the equipment and lower-level system operating conditions; S32. Carry out steady-state and transient thermal fluid dynamics calculations of the system, give the temperature, pressure, and flow characteristics in the system, and propose system flow resistance, pipe diameter, valve selection, and equipment pressure drop limit requirements; S33. Carry out system insulation and heat dissipation calculations, and propose system heat dissipation, insulation requirements, and electric heating requirements; S34. Complete the system process principle design and determine the system process principle diagram.

[0042] The purpose of equipment process design or selection in step S4 is to determine the equipment process parameters.

[0043] In some embodiments, step S4 includes: S41. Determine the equipment operating condition design according to the system operating condition and equipment design benchmark, and put forward requirements for the lower-level system operating condition; S42. Carry out equipment thermal hydraulic calculations, equipment structural design, determine the equipment structure size, and publish a simplified diagram of the equipment structure; S43. Conduct equipment strength, seismic, stress, and vibration analysis to ensure that the equipment can withstand various operating transients, publish the equipment general drawing, and put forward requirements for the equipment instrumentation and electrical.

[0044] The system process principle design in step S3 and the equipment process design in step S4 are processes of repeated iteration and gradual optimization, with the ultimate goal of achieving optimization of system and equipment process design.

[0045] In some embodiments, step S5 may include: S51. According to the system process schematic diagram and equipment general diagram, combined with the overall layout requirements of the plant, carry out equipment layout and piping design; S52. On the basis of equipment layout and piping design, combined with system instrumentation and electrical design, carry out system layout, and output a system process flow chart containing instrument control points.

[0046] In step S6, according to the overall layout and zoning plan of the plant, the system piping and plant layout are carried out, and the pipeline mechanical analysis and support and hanger design are performed. In some embodiments, step S6 includes: steps S61 to S63. S61. Carry out system piping and plant layout, determine the equipment layout diagram, process piping layout diagram, main cable layout diagram, main ventilation duct layout diagram, and other piping layout diagrams. S62. Carry out system piping mechanical analysis, issue a system piping mechanical analysis report, and propose adjustment requirements for the system layout. S63. Carry out support and hanger design, and determine the support and hanger position diagram.

[0047] In some embodiments, in step S7, the plant design is carried out according to the pipeline and system plant layout, the floor response spectrum, concrete structure, steel structure, general plan and transportation are determined, and funding for civil engineering and ventilation utilities is provided.

[0048] In some embodiments, in step S9, the system technical status items and their acceptance criteria include but are not limited to the system functions, performances, and physical characteristics defined in the "System Design Requirements", "System Process Schematics", "System Operating Conditions Description", "System Process Flowchart", "System Layout Diagram", "Equipment Design Requirements", and "System Acceptance Criteria".

[0049] In step S9, the steps of determining the system solution, system technical status and acceptance criteria may include: S20001, conducting a demand analysis on the system; S20002, determining the system technical requirement definition based on the demand analysis results; S20003, conducting a functional analysis of the system based on the system technical requirement definition; S20004, based on the functional analysis results, carrying out system solution trade-offs and design, and proposing research and development items; S20005, determining the system technical status and its acceptance criteria based on the system solution.

[0050] In some embodiments, in step S20004, based on the functional analysis results, the system technical indicators are decomposed downward, and the corresponding equipment to implement these functions and performance indicators and interface requirements is configured to form multiple system technical solutions; multiple technical solutions are weighed and compared to weigh out the best system technical solution; relevant R&D plans are formulated, and R&D experiments are carried out.

[0051] In some embodiments, in step S20005, the design is carried out according to the best system technical solution, and the functions, performance indicators and interface requirements corresponding to the system technical solution are decomposed into the equipment; the system technical status and its acceptance criteria are proposed.

[0052] In some embodiments, the system forward design method provided in the embodiments of the present application may also include: S101, conducting a demand analysis on the power supply and heating capacity requirements of the nuclear reactor, and determining multiple systems included in the power plant based on the functional logical relationship between the systems, and the multiple systems have different design priorities; S102, designing and decomposing multiple systems in sequence using steps S1 to S9 in order of design priority from high to low; S103, after step S102, integrating and verifying each system in sequence in order of design priority from low to high.

[0053] The embodiments of the present application analyze the power and heat supply capacity requirements of the nuclear reactor, and divide the power plant into multi-level systems according to the functional logical relationship between the systems, so that the process of forward design of the system is more logical and helps to reduce the design time.

[0054] In some embodiments, a demand analysis is performed on the power supply and heating capacity demand of the nuclear reactor to determine the technical status of the power plant and its acceptance criteria; wherein, in the technical status of the power plant, the power plant is divided into multiple systems. After all system verifications are completed, the power plant can be verified for the technical status of the power plant and its acceptance criteria to ensure that the technical status and acceptance criteria of the power plant are met.

[0055] In some embodiments, multiple systems with different design priorities include: a main system, a dedicated safety system, a primary auxiliary system, a secondary auxiliary system, and a tertiary auxiliary system, and the design priorities of the main system, the dedicated safety system, the primary auxiliary system, the secondary auxiliary system, and the tertiary auxiliary system are reduced in sequence. Among them, the main system carries the basic functions of nuclear heat generation, main heat transmission, steam power conversion, and even power generation.

[0056] The dedicated safety system carries dedicated safety functions such as overpressure protection and waste heat removal on the basis of the inherent safety of the main system. The first-level auxiliary system is an auxiliary system that directly supports the main system and the dedicated safety system. The second-level auxiliary system is a non-process auxiliary system, which is an auxiliary system of the main system, the dedicated safety system and the first-level auxiliary system. The third-level auxiliary system is a non-process auxiliary system, which is an auxiliary system that provides support for the whole plant system and equipment. The embodiment of the present application divides the power plant into the above-mentioned 5-level system, which makes the process of forward design of the system more logical and helps to reduce the design time.

[0057] Specifically, step S102 may include: S1021. According to the technical status of the power plant, design and decompose the main system, and determine the functions, performance and interface requirements of the main system for the dedicated safety system, the first-level auxiliary system, the second-level auxiliary system, and the third-level auxiliary system; S1022. According to the technical status of the power plant and the main system for the functions, performance and interface requirements of the dedicated safety system, design and decompose the dedicated safety system, and determine the functions, performance and interface requirements of the dedicated safety system for the first-level auxiliary system, the second-level auxiliary system, and the third-level auxiliary system; S1023. According to the technical status of the power plant, the main system and the dedicated safety system for the functions, performance and interface requirements of the first-level auxiliary system Interface requirements, design and decompose the primary auxiliary system, and determine the functions, performance and interface requirements of the primary auxiliary system for the secondary and tertiary auxiliary systems; S1024, according to the technical status of the power plant, the functions, performance and interface requirements of the main system, dedicated safety system, and primary auxiliary system for the secondary auxiliary system, design and decompose the secondary auxiliary system, and determine the functions, performance and interface requirements of the secondary auxiliary system for the tertiary auxiliary system; S1025, according to the technical status of the power plant, the functions, performance and interface requirements of the main system, dedicated safety system, primary auxiliary system, and secondary auxiliary system for the tertiary auxiliary system, design and decompose the tertiary auxiliary system. Through this setting, the designed power plant can be safer and more stable.

[0058] In step S103, the third-level auxiliary system, the second-level auxiliary system, the first-level auxiliary system, the dedicated safety system, and the main system may be integrated and verified in sequence.

[0059] The embodiments of the present application divide the design and decomposition process into three levels: overall forward design method, system forward design method, and equipment forward design method, based on classical system engineering.

[0060] The embodiment of the present application further refines the system-level technology development process on the basis of the forward design of the new nuclear reactor, and summarizes the system forward design method of the embodiment of the present application, namely the "five-stage nine-step" method. The system technology development is carried out in accordance with the "five stages" of main system design and phased evaluation, dedicated safety system design and phased evaluation, first-level auxiliary system design and phased evaluation, second-level auxiliary system design and phased evaluation, and third-level auxiliary system design and phased evaluation. The system function and performance indicators and interface requirements are determined, the system function decomposition and structural configuration, the system process principle design, equipment process design or selection, the system process flow design, pipeline and plant layout, plant design, phased evaluation, and determination of system technical status items and their acceptance criteria are carried out in sequence. The system forward design method of the nuclear reactor provided in the embodiment of the present application can provide methodological guidance for the smooth development of the system design of the new nuclear reactor; it is particularly suitable for forward design of many systems with a large number and complex interfaces.

[0061] Regarding the embodiments of the present application, it should also be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other to obtain new embodiments.

[0062] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A system forward design method for a nuclear reactor, characterized in that: The system is determined based on a power plant technical solution obtained by analyzing the power supply and heat supply capacity requirements of the nuclear reactor, and the method includes: S1. Determine the functions, performance indicators and interface requirements of the system according to the technical plan of the power plant; S2. According to the functions and performance indicators and interface requirements of the system, perform system function decomposition and structural configuration of the system, and determine the equipment list of the system configuration; S3. According to the system function decomposition and structural configuration, carry out system process principle design, determine the system process principle diagram, and propose the system process design conditions for its equipment; S4. According to the system process principle diagram, carry out equipment process design or selection, determine the equipment working conditions, equipment process parameters, equipment general diagram and equipment requirements for instrument control electrical; S5. Determine the system process flow chart including instrument control points according to the system process principle diagram, the equipment general diagram, system instrumentation and control, and electrical design; S6. Carry out system piping and plant layout according to the overall plant layout and zoning plan, and conduct pipeline mechanical analysis and support and hanger design; S7. Carry out plant design according to pipeline and system plant layout; S8. Based on the evaluation of equipment functions and performance, comprehensively evaluate whether the system design meets the functional and performance indicators and interface requirements of the system from the perspective of functions and performance; S9. Determine the system plan, system technical status and acceptance criteria, formulate relevant R&D plans, and carry out R&D tests.

2. The method according to claim 1, characterized in that In the step S1, the function and performance indicators include function, performance, safety, reliability, maintainability, life, economy, and ergonomics.

3. The method according to claim 1, characterized in that If the system is a superior system of other subordinate systems, then in step S2, the primary function, performance and interface requirements of the system for its subordinate systems are also proposed; in step S3, the primary process design conditions of the system for its subordinate systems are also proposed; in step S9, the final function, performance and interface requirements and final process design conditions of the system for its subordinate systems are also determined; If the system is a subordinate system of other superior systems, then in step S1, the functions and performance indicators and interface requirements of the system are determined according to the technical solution of the power plant and the functions, performance and interface requirements of all superior systems; In the S3 step, the system process principle design is also carried out according to the process design conditions proposed by all upper-level systems.

4. The method according to claim 1, characterized in that: The S3 step includes: S31. Determine the system operating conditions based on the power plant operating conditions and design benchmarks, and propose requirements for the equipment and lower-level system operating conditions; S32. Carry out steady-state and transient thermal fluid dynamics calculations of the system, give the temperature, pressure, and flow characteristics in the system, and propose system flow resistance, pipe diameter, valve selection, and equipment pressure drop limit requirements; S33. Carry out system insulation and heat dissipation calculations, and propose system heat dissipation, insulation requirements, and electric heating requirements; S34, completing the system process principle design and determining the system process principle diagram.

5. The method according to claim 4, characterized in that The S4 step includes: S41. Determine the equipment operating condition design based on the system operating conditions and equipment design benchmarks, and put forward requirements for the lower-level system operating conditions; S42. Carry out equipment thermal hydraulic calculation, equipment structure design, determine equipment structure dimensions, and publish equipment structure diagram; S43. Conduct equipment strength, seismic, stress, and vibration analysis to ensure that the equipment can withstand various operating transients, publish the equipment general drawing, and put forward requirements for the equipment's instrumentation and electrical systems.

6. The method according to claim 1, characterized in that The S6 step includes: S61. Arrange the system pipelines and plant, and determine the equipment layout, process pipeline layout, main cable layout, main ventilation pipeline layout, and other pipeline layout; S62. Conduct system piping mechanical analysis, issue a system piping mechanical analysis report, and propose adjustment requirements for system layout; S63. Design the supports and hangers and determine the positions of the supports and hangers.

7. The method according to claim 1, characterized in that Step S5 includes: S51. Carry out equipment layout and piping design according to the system process principle diagram and the equipment general diagram and in combination with the overall layout requirements of the plant; S52. Based on the equipment layout and piping design, combined with system instrumentation and control and electrical design, carry out system layout and output the system process flow chart.

8. The method according to claim 1, characterized in that The method further comprises: S101, analyzing the power supply and heating capacity requirements of the nuclear reactor, and determining multiple systems included in the power plant according to the functional logical relationship between the systems, wherein the multiple systems have different design priorities; S102, designing and decomposing the multiple systems in order of design priority from high to low by using steps S1 to S9; S103. After step S102, each system is integrated and verified in order of design priority from low to high.

9. The method according to claim 8, characterized in that The multiple systems with different design priorities include: a main system, a dedicated safety system, a primary auxiliary system, a secondary auxiliary system, and a tertiary auxiliary system, wherein the design priorities of the main system, the dedicated safety system, the primary auxiliary system, the secondary auxiliary system, and the tertiary auxiliary system are decreased in sequence; Among them, the main system carries out the basic functions of nuclear heat generation, main heat transmission, steam power conversion and even power generation; The dedicated safety system carries the dedicated safety functions of overpressure protection and residual heat removal on the basis of the inherent safety of the main system; The primary auxiliary system is an auxiliary system that directly supports the main system and the dedicated safety system; The secondary auxiliary system is a non-process auxiliary system, which is an auxiliary system of the main system, the dedicated safety system and the primary auxiliary system; The third-level auxiliary system is a non-process auxiliary system, which is an auxiliary system that provides support for the entire plant system and equipment.

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