Accident condition selection method and system in design stage of new reactor type nuclear power plant

Abstract

The invention discloses a method and a system for selecting accident conditions in a design stage of a new reactor type nuclear power plant. The method comprises the steps of collecting and acquiring design information of the new reactor type nuclear power plant; establishing a conceptual model of the new reactor type nuclear power plant according to the design information and the concept of the nuclear power plant production system; carrying out accident working condition selection analysis based on a production system of the conceptual model and an accident coping system which is determined or considered to be set in an existing design stage to obtain an accident working condition list; iteratively designing and perfecting forms and details of all systems of the conceptual model, and perfecting the conceptual model into a more detailed model; and updating an accident condition list of the conceptual model along with design depth iteration. According to the accident condition selection method, the technical problem of accident condition selection in the early stage of the design stage of the new reactor type nuclear power plant is solved, and in the initial stage of the design of the new reactor type nuclear power plant, the accident condition selection method has no or low requirements on the design depth, is iteratively improved along with the design depth, and provides support for gradual refinement of the design scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plant design, and particularly relates to a method and system for selecting accident conditions during the design stage of a new reactor type nuclear power plant. Background Art

[0002] The accident conditions of a nuclear power plant are conditions that deviate from normal operation, including design basis accidents (DBAs) and design extension accidents (DECs).

[0003] Design basis accidents of a nuclear power plant are not expected to occur during the service life of the nuclear power plant. However, according to the principle of defense in depth, they still need to be considered in the design of the nuclear power plant, that is, design basis accidents are used to determine the performance criteria of safety systems and other safety significant items necessary to control design basis accidents, so as to return the nuclear power plant to a safe state and mitigate the consequences of accidents.

[0004] Design extension conditions of a nuclear power plant are accident conditions not within the scope of design basis accidents of the nuclear power plant. This type of condition may be an initiating event with a very low occurrence frequency but a severity exceeding the coping ability of the corresponding safety system, or an initiating event with a not-so-low occurrence frequency, including multiple failures and resulting in the loss of a certain safety system that performs part of the normal operation function, or a superposition combination of an initiating event expected to occur during the service life of the nuclear power plant and the failure of the safety system functions required for event mitigation. Design extension conditions must be considered in the design of a nuclear power plant, practical prevention and mitigation measures must be set for such accidents, and design extension condition analysis must be carried out.

[0005] The goal of the former is to prevent accident conditions in the nuclear power plant that exceed design basis accidents, or reasonably and feasibly mitigate the consequences of such accident conditions. This may require adding additional safety facilities for design extension conditions, or expanding the capabilities of safety systems, to prevent the occurrence of severe accidents or mitigate the consequences of severe accidents, or maintain the integrity of the containment. The latter is mainly to analyze and demonstrate whether these additional safety facilities for design extension conditions or safety systems with expanded capabilities have the ability to control accident conditions, so as to ensure that the nuclear power plant can enter a controllable state and maintain the containment function, thereby actually eliminating the possibility of the occurrence of nuclear power plant states that lead to early radioactive release or large-scale radioactive release.

[0006] Accident conditions are closely related to the system settings of nuclear power plants. For nuclear power plants with mature reactor types, the design has been relatively solidified. For newly built nuclear power plants adopting mature designs, the content of the accident condition list will not change significantly compared with the reference object. For such nuclear power plants, the selection of accident conditions can be based on engineering judgment, deterministic and probabilistic evaluations to obtain a set of accident condition lists. Engineering judgment mainly refers to engineering practice experience, that is, referring to the existing accident condition lists of nuclear power plants with the same design. This method is applicable to situations where the design is the same as or similar to the reference object. Deterministic evaluation mainly refers to China's nuclear safety guide "Deterministic Safety Analysis of Nuclear Power Plants". This guide gives some design basis accidents and design extension conditions as references. However, this method more selects relatively inclusive conditions from a deterministic perspective, and the reference list given by the guide mainly comes from the designs of previous mature reactor types. Therefore, it is more applicable to designs with a certain foundation or reference scheme. Probabilistic evaluation is mainly based on the probabilistic safety analysis model, quantitatively calculating the occurrence frequencies of various event sequences, and then selecting accident conditions based on the frequencies. Since the probabilistic safety analysis model needs to consider and reflect the systems and equipment required for the nuclear power plant to perform safety functions and conduct analysis layer by layer at different levels, it can be gradually carried out according to the existing design scheme depth and content, but there are also certain requirements for the design depth of newly designed nuclear power plants.

[0007] For nuclear power plants with new reactor types, due to the lack of reference objects and the unclear setting of various systems in the early stage of the design phase, the use of the above various methods will be greatly restricted in the early stage of the design phase.

[0008] The existing patent CN114842994A discloses a method for accident diagnosis design of a fast reactor nuclear power plant, including: (1) Based on the accident procedure document list, eliminating the procedure documents not applicable to the procedures guided by the accident diagnosis strategy to form a procedure list guided by the accident diagnosis strategy; (2) On the basis of the procedure list guided by the accident diagnosis strategy, sorting the accident procedures; and forming accident diagnosis strategy entry symptom information based on the entry symptom information of the accident procedures according to the screening principle as the criterion for judging whether to start executing the accident diagnosis strategy; (3) According to the sorted procedure list guided by the accident diagnosis strategy and the accident diagnosis strategy entry symptom information, formulating the operation process of the accident diagnosis strategy.

[0009] The existing patent CN111627583A discloses a method for selecting confirmation conditions of the best recovery accident guidelines for symptom - oriented nuclear power plants, including: screening to obtain a first list of conditions including the first DBA condition that poses the greatest challenge to the safety of the nuclear power plant unit; determining the first best recovery guidelines according to the first list of conditions; obtaining a second list of conditions including the second DBA condition according to the second best recovery guidelines; and merging the first list of conditions and the second list of conditions to obtain a list of confirmation conditions for the best recovery guidelines. This method solves the technical problem of the difficulty in establishing screening principles in the screening work of confirmation conditions for symptom - oriented EOP best recovery guidelines.

[0010] In summary, the above two existing patents do not solve the problems of how to select accident conditions and how to set various systems in new reactor type nuclear power plants in the prior art. Summary of the Invention

[0011] Based on the above - mentioned technical problems, the object of the present invention is to propose a method and system for selecting accident conditions in the design stage of a new reactor type nuclear power plant, to solve the problem that the selection of accident conditions in a new reactor type nuclear power plant in the prior art is greatly restricted due to the lack of reference objects and the lack of clarity on how to set various systems in the early stage of its design stage.

[0012] To achieve the above object, the present invention proposes a method and system for selecting accident conditions in the design stage of a new reactor type nuclear power plant. This method has no or low requirements for the design depth in the analysis initial stage, can be iteratively improved with the design depth, and provides support for the gradual refinement of the design scheme. The specific technical solutions are as follows:

[0013] A method for selecting accident conditions in the design stage of a new reactor type nuclear power plant, the method comprising the following steps:

[0014] S1. Obtain the design information of the new reactor type nuclear power plant;

[0015] S2. Establish a conceptual model of the new reactor type nuclear power plant according to the design information;

[0016] S3. Conduct accident condition selection analysis based on the conceptual model to determine the list of accident conditions;

[0017] S4. Iteratively design the conceptual model of the new reactor type nuclear power plant;

[0018] S5. Conduct accident condition selection analysis for the iteratively designed conceptual model to update the list of accident conditions.

[0019] Further, in step S1, the design information includes one or a combination of multiple information such as the design purpose, usage scenario, fuel type, and coolant type of the new reactor type nuclear power plant.

[0020] Further, in step S2, a conceptual model of the new reactor type nuclear power plant is established according to the obtained design information and the concept of the nuclear power plant production system.

[0021] Further, in step S2, the production system of the conceptual model includes a core that generates energy and a closed primary loop, a steam generator that generates steam and a closed secondary loop, and a steam turbine generator that generates electricity.

[0022] Further, in step S3, for the production system in the conceptual model and the accident response systems that have been determined or considered to be set in the existing design stage, an accident condition selection analysis is carried out in combination with the identified initiating events to determine the initial accident condition list.

[0023] Further, in step S3, analyze the requirements of the initiating event for safety functions, and the measures required or existing to perform the corresponding functions at different defense levels.

[0024] Further, in step S3, if the impact of the initiating event can be eliminated through "prevention and control", but in the case of the failure of "prevention and control", the continuous development of the initiating event will cause damage to the reactor type, then the combination of the initiating event and the failed "prevention and control" is used as the design basis accident condition;

[0025] If the impact of the initiating event cannot be eliminated through "prevention and control", then the initiating event is directly used as the design basis accident condition;

[0026] For the situation of the failure of "prevention and control" and the situation where the impact of the initiating event cannot be eliminated through "prevention and control", set measures to mitigate the development of the accident condition, and use the combination of the above two design basis accident conditions and the failure of the measures as the design extension accident condition.

[0027] Further, in step S3, all combinations of potential initiating events and subsequent event developments are screened and merged to obtain the accident condition list of the conceptual model of the new reactor type nuclear power plant.

[0028] Further, in step S4, iteratively design the conceptual model of the new reactor type nuclear power plant to improve the specific forms and details of each system of the new reactor type nuclear power plant.

[0029] Further, in step S4, an adjustment, pressure control and protection system for the primary coolant inventory, and / or an additional heat removal system, and / or a secondary loop flow control, pressure control and protection system are added on the basis of the conceptual model.

[0030] Further, in step S5, for the conceptual model after iterative design, the method in step S3 is used to carry out accident condition selection analysis, and the accident condition list is updated according to the analysis results.

[0031] The present invention also provides an accident condition selection device for the design stage of a new reactor type nuclear power plant, which is used for the accident condition selection method in the design stage of the new reactor type nuclear power plant, and includes:

[0032] An information acquisition module, configured to acquire the design information of the new reactor type nuclear power plant;

[0033] A model establishment module, configured to establish a conceptual model of the new reactor type nuclear power plant according to the design information;

[0034] An accident analysis module, configured to conduct accident condition analysis on the conceptual model of the new reactor type nuclear power plant to determine the accident condition list of the new reactor type nuclear power plant;

[0035] An iterative design module, configured to perform iterative design on the conceptual model of the new reactor type nuclear power plant;

[0036] A list output module, configured to update and output the accident condition list according to the analysis result of the accident analysis module.

[0037] Based on the above technical solutions, the present invention has at least the following beneficial effects:

[0038] 1. The present invention provides an accident condition selection method and system for the design stage of a new reactor type nuclear power plant. This accident condition selection method solves the technical problem of accident condition selection in the early stage of the design stage of the new reactor type nuclear power plant, making it possible to carry out a complete and systematic accident condition selection work in the design stage of the new reactor type nuclear power plant.

[0039] 2. The present invention provides an accident condition selection method and system for the design stage of a new reactor type nuclear power plant. There is no requirement or a low requirement for the design depth at the initial stage of the design of the new reactor type nuclear power plant, and it can be iteratively improved with the design depth, and provides support for the gradual refinement of the design scheme.

[0040] 3. The present invention provides an accident condition selection method and system for the design stage of a new reactor type nuclear power plant, and proposes a hierarchical principle. First, a conceptual model of the new reactor type nuclear power plant is established, accident condition selection analysis is carried out, and then each link of the production system in the conceptual model is gradually designed and improved, and the accident condition list is improved.

[0041] 4. The present invention provides an accident condition selection method and system for the design stage of a new reactor type nuclear power plant, which has good versatility. It can perform accident condition selection analysis according to the production system of the conceptual model of a specific new reactor type nuclear power plant, combined with the initiating event, to obtain the accident condition list, and iteratively improve the accident condition list with the design depth. Brief Description of the Drawings

[0042] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments of the invention and their descriptions are used to explain the invention and do not unduly limit the invention. In the drawings:

[0043] Figure 1 FIG. is a schematic flow chart of a method for selecting accident conditions in the design stage of a new reactor type nuclear power plant proposed by the present invention;

[0044] Figure 2 FIG. is a schematic diagram of the preliminary established conceptual model of a new reactor type nuclear power plant in an embodiment of the present invention;

[0045] Figure 3 FIG. is a schematic diagram of the gradually improved conceptual model of a new reactor type nuclear power plant in an embodiment of the present invention;

[0046] Figure 4 FIG. is a schematic structural diagram of a system for selecting accident conditions in the design stage of a new reactor type nuclear power plant proposed by the present invention.

[0047] Reference numerals: 1, reactor core; 2, steam generator; 3, main pump; 4, high-pressure heater; 5, main feed water pump; 6, low-pressure heater; 7, condensate pump; 8, deaerator; 9, condenser; 10, high-pressure cylinder; 11, steam-water separation and reheating; 12, low-pressure cylinder; 13, generator; 14, pressurizer; 15, primary coolant inventory regulation pipeline; 16, main feed water flow control valve; 17, safety valve; 18, atmosphere valve; 100, primary production system; 200, secondary production system; 300, primary coolant inventory regulation, pressure control and protection system; 400, additional heat removal system; 500, secondary flow control, pressure control and protection system. Detailed embodiments

[0048] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The following further describes the present invention in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present invention.

[0050] Embodiment 1

[0051] To solve the problem that the selection of accident conditions for a new reactor type nuclear power plant in the prior art is greatly limited due to the lack of reference objects and the unclear setting of various systems in the early stage of its design stage. The present invention proposes a method and system for selecting accident conditions in the design stage of a new reactor type nuclear power plant.

[0052] To achieve the above object, refer to Figure 1As shown in the figure, this embodiment proposes a method for selecting accident conditions in the design stage of a new reactor type nuclear power plant. The method specifically includes the following steps:

[0053] S1. Obtain the design information of the new reactor type nuclear power plant;

[0054] Specifically, for a newly designed nuclear power plant, neither the production system during normal operation nor the safety system dedicated to accident response has been clearly defined. However, there is still some information that is necessarily clear. This information mainly includes one or more of the design purpose, usage scenario, possible fuel type, and coolant type of the new reactor type nuclear power plant. Collecting and obtaining the above design information of the new reactor type nuclear power plant can be used for the establishment of the conceptual model of the new reactor type nuclear power plant and the development of subsequent design work.

[0055] S2. Establish a conceptual model of the new reactor type nuclear power plant according to the design information;

[0056] Specifically, since the production system of the new reactor type nuclear power plant directly serves the production function and design goal of the nuclear power plant, and the accident response system serves the safety of the production function, in principle, the design of the production system should be earlier than the design of the accident response system. Before the concept or initial design of the production system is established, the identification and selection of accident conditions lack the most basic analysis object. For a nuclear power plant in the early stage of the design stage, although the design of its production system may still be unclear in terms of specific form and details, its overall concept should be relatively easy to clarify. For example, whether it is necessary to rely on the phase change of the medium during the process of energy transfer and conversion.

[0057] Therefore, according to the collected design information of the new reactor type nuclear power plant and the concept of the production system, establish a conceptual model of the new reactor type nuclear power plant in the form of a process flow diagram. The production system in the conceptual model of the new reactor type nuclear power plant may include a reactor core that generates energy, a closed primary loop, a steam generator that generates steam, a closed secondary loop, and a steam turbine generator that generates electricity.

[0058] S3. Conduct accident condition selection analysis based on the conceptual model to determine the accident condition list in the design stage of the new reactor type nuclear power plant;

[0059] Specifically, in the order from upstream to downstream of the new reactor type nuclear power plant, according to the production system in the conceptual model and the accident response system that has been determined or considered to be set in the current design stage, combined with the identified initiating events, analyze the requirements of the initiating events for safety functions, as well as the measures that need to be or already exist to perform corresponding functions at different defense levels, and determine the accident condition list. The specific analysis method is as follows:

[0060] For some initiating events, the impact of the initiating event can be eliminated through "prevention and control". However, in the case where "prevention and control" fails, it is considered that the continued development of the initiating event will cause core damage. The combination of the initiating event and the failed "prevention and control" is taken as the design basis accident condition (potential DBA).

[0061] For another part of the initiating events, the impact of the initiating event cannot be eliminated through "prevention and control", and then it is directly taken as the design basis accident condition (potential DBA).

[0062] For the case where "prevention and control" fails and the case where the impact of the initiating event cannot be eliminated through "prevention and control", special measures are considered to be set up to mitigate the development of the accident condition, prevent its continued development from causing core damage, and the combination of the previous event sequence and the failure of these special measures is taken as the new design extension accident condition (potential DEC).

[0063] The overall logic of the above analysis method is: first determine the design basis accident condition, then set up measures to mitigate its development. If the set measures also fail, it enters the design extension accident condition. For any one of the above two design basis accident conditions, measures need to be set up to mitigate its development. The superposition of any one of the design basis accident conditions and the failure of the set measures is taken as the design extension accident condition.

[0064] After that, all combinations of potential initiating events and subsequent event developments are screened and merged according to whether the event developments are similar, whether the functional requirements are similar, and the severity. That is: similar ones can be merged. If among several similar situations, the severity of situation A can envelope other situations, then situation A can be used to represent these several similar situations.

[0065] The accident condition list at the design stage of the new reactor type nuclear power plant is initially determined through the above accident condition analysis method. The analysis of the accident condition list can be recorded using the analysis table shown in Table 1.

[0066] Table 1: Analysis Table for Selecting Accident Conditions of the Concept Model

[0067]

[0068]

[0069] S4. Iteratively design and improve each system in the initial concept model;

[0070] Specifically, as the design work progresses, the specific forms and details of various systems in the nuclear power plant gradually become clear and enriched. Based on the conceptual model of the new reactor type nuclear power plant, the conceptual model of the new reactor type nuclear power plant is designed and improved, including the specific forms and details of each part of the system. For example, a coolant inventory regulation device, a pressure control and protection system, and an additional heat removal system are added to the primary circuit, and a flow control device and a pressure control and protection system are added to the secondary circuit. The conceptual model of the new reactor type nuclear power plant is improved into a more detailed design model.

[0071] S5. Conduct accident condition analysis for the improved conceptual model, update the accident condition list until the design of the new reactor type nuclear power plant is completed.

[0072] Specifically, for each system of the designed and improved conceptual model, the accident condition selection method such as in step S3 is used to conduct accident condition selection analysis, and the accident condition list of the new reactor type nuclear power plant is updated according to the analysis results until the design of the new reactor type nuclear power plant is completed.

[0073] Finally, an example is given to illustrate the practical application of an accident condition selection method in the design stage of a new reactor type nuclear power plant proposed in this embodiment.

[0074] S1. Collect and obtain the design information of the new reactor type nuclear power plant: The new reactor type nuclear power plant is designed to provide civil electricity, intended to be connected to a large power grid, and light water is considered as the moderator and coolant.

[0075] S2. According to the existing design information, further consider using a pressurized water reactor design, that is, the energy transfer and conversion process of "the energy-producing reactor core and the closed primary circuit + the steam generator that generates steam and the closed secondary circuit + the steam turbine generator that generates electricity". For this process and the most important production system, a conceptual model of the new reactor type nuclear power plant is established in the form of a process flow diagram.

[0076] Refer to Figure 2 As shown, the conceptual model of the new reactor type nuclear power plant includes the primary circuit production system 100 and the secondary circuit production system 200. The primary circuit production system 100 includes the reactor core 1, the steam generator 2, and the main pump 3. The secondary circuit production system 200 includes the high-pressure heater 4, the main feed water pump 5, the low-pressure heater 6, the condensate pump 7, the deaerator 8, the condenser 9, the high-pressure cylinder 10, the moisture separator reheater 11, the low-pressure cylinder 12, and the generator 13. The above only includes the most important production system process, retains the necessary heat sink interfaces, but does not limit the form of the heat sink, nor does it include other support systems and auxiliary systems such as power supply and gas supply, and does not involve systems dedicated to accident response, and is applicable to the early stage of the design of pressurized water reactor nuclear power plants.

[0077] S3. Conduct accident scenario selection and analysis based on the conceptual model of the new reactor type nuclear power plant: In the order from upstream to downstream, divide the production system of the conceptual model into the core that generates energy, the closed primary loop, the steam generator that generates steam, the closed secondary loop, and the steam turbine generator that generates electricity.

[0078] Take the closed primary loop as an example for illustration. For the closed primary loop, one of the identified initiating events is "rupture of the primary loop pipeline". Conduct accident scenario selection and analysis for this initiating event, analyze the requirements of this initiating event for safety functions, as well as the measures that are required or already available to perform corresponding functions at different defense levels. The corresponding list of accident scenarios obtained is as follows:

[0079] Table 2: List of accident scenarios for the closed primary loop in the conceptual model

[0080]

[0081] For other systems in the conceptual model, also adopt the above-mentioned same method for accident scenario selection and analysis to obtain the corresponding list of accident scenarios, and finally obtain the list of accident scenarios for the conceptual model.

[0082] S4. Based on the conceptual model of the new reactor type nuclear power plant, iteratively design and improve each subsystem of the production system to better maintain the operation of the production system and the safety of the reactor, including the specific forms and details of each subsystem, and perfect the conceptual model of the new reactor type nuclear power plant into a more detailed model. The improved conceptual model is shown in Figure 3 As shown, on the basis of the conceptual model in step S2, a primary loop coolant inventory regulation, pressure control and protection system 300, an additional primary loop heat removal system 400, and a secondary loop flow control, pressure control and protection system 500 are added. Among them, the primary loop coolant inventory regulation, pressure control and protection system 300 includes a pressurizer 14, a safety valve above the pressurizer 14, and a primary loop water inventory regulation pipeline 15, and the pressure control and protection system 500 includes a main feed water flow control valve 16, a safety valve 17, and an atmospheric valve 18.

[0083] S5. For the improved parts of each subsystem of the production system in the iteratively designed conceptual model, adopt the method in step S3 to conduct accident scenario selection and analysis, and iteratively update the list of accident scenarios according to the analysis results. Among them, for the closed primary loop, the iteratively updated list of accident scenarios is shown in the following table.

[0084] Table 3: List of accident scenarios for the closed primary loop in the conceptual model

[0085]

[0086]

[0087] For each newly added link in the conceptual model after iterative design, the same accident condition selection and analysis method described above can be adopted to update the corresponding accident condition list until the design of the new reactor type nuclear power is completed.

[0088] Embodiment 2

[0089] This embodiment proposes an accident condition selection system in the design stage of a new reactor type nuclear power plant. Refer to Figure 4 As shown, the system includes: an information acquisition module, a model establishment module, an accident analysis module, an iterative design module, and an accident output module. The functions of each module will be introduced in detail below.

[0090] The information acquisition module is used to acquire the design information of the new reactor type nuclear power plant.

[0091] Specifically, the design information of the new reactor type nuclear power plant includes one or a combination of the following information: the design purpose, usage scenario, fuel type, and coolant type of the new reactor type nuclear power plant.

[0092] The model establishment module is used to establish a conceptual model corresponding to the new reactor type nuclear power plant according to the design information.

[0093] Specifically, the model establishment module is used to establish a conceptual model of the new reactor type nuclear power plant in the form of a process flow diagram according to the design information and the concept of the production system of the nuclear power plant.

[0094] The accident analysis module is used to conduct accident condition analysis on the conceptual model of the new reactor type nuclear power plant to determine the accident condition list of the new reactor type nuclear power plant.

[0095] Specifically, the accident analysis module is used to analyze the requirements of the initiating event for safety functions and the measures required or already available to perform corresponding functions at different defense levels, based on the production system in the conceptual model and the accident response systems that have been determined or considered to be set in the current design stage, and to determine the accident condition list.

[0096] The iterative design module is used to perform iterative design on the conceptual model of the new reactor type nuclear power plant.

[0097] The list output module is used to update the accident condition list according to the analysis results of the accident analysis module and output the final accident condition list of the new reactor type nuclear power plant.

[0098] It should be understood that the description of the accident condition selection system in the design stage of a new reactor type nuclear power plant is consistent with the description of the embodiment of the accident condition selection method in the design stage of a new reactor type nuclear power plant corresponding to it. Therefore, this embodiment will not be elaborated here.

[0099] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0100] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0101] The logic and / or steps represented in the flowchart or described otherwise herein, for example, can be considered as a definite sequence of executable instructions for implementing logical functions, which can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus or device), or used in combination with these instruction execution systems, apparatus or devices.

[0102] Without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A method for selecting accident conditions in the design phase of a new reactor type nuclear power plant, characterized in that: The method comprises the following steps: S1. Obtain design information of new reactor type nuclear power plant; S2. Establish a conceptual model of a new reactor type nuclear power plant based on design information; S3. Carry out accident condition selection analysis based on the conceptual model and determine the accident condition list; S4. Iterative design of a conceptual model for a new reactor type nuclear power plant; S5. Carry out accident condition selection analysis for the conceptual model after iterative design and update the accident condition list.

2. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 1, characterized in that: In step S1, the design information includes a combination of one or more information of the design purpose, usage scenario, fuel type and coolant type of the new reactor type nuclear power plant.

3. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 1, characterized in that: In step S2, a conceptual model of a new reactor type nuclear power plant is established based on the acquired design information and the concept of a nuclear power plant production system.

4. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 3 is characterized in that: In step S2, the production system of the conceptual model includes a reactor core and a closed primary loop for generating energy, a steam generator and a closed secondary loop for generating steam, and a steam turbine generator for generating electricity.

5. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 1, characterized in that: In step S3, for the production system in the conceptual model and the accident response system that has been determined or considered to be set up in the current design stage, an accident condition selection analysis is performed in combination with the identified initiating events to determine the initial accident condition list.

6. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 5, characterized in that: In step S3, the requirements of the initiating event on the security function and the required or existing measures for executing the corresponding functions at different defense levels are analyzed.

7. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 6 is characterized in that: In step S3, if the impact of the initiating event can be eliminated by "prevention and control", but if the "prevention and control" fails, the continued development of the initiating event will cause reactor damage, the combination of the initiating event and the failed "prevention and control" will be used as the design basis accident condition; If the impact of the initiating event cannot be eliminated through "prevention and control", the initiating event shall be directly used as the design basis accident condition; In the event of failure of "prevention and control" and the inability to eliminate the impact of the initiating event through "prevention and control", measures are set to mitigate the development of accident conditions, and the combination of the above two design basis accident conditions and the failure of measures is used as the design extended accident condition.

8. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 7 is characterized in that: In step S3, all combinations of potential initiating events and subsequent event developments are screened and merged to obtain a list of accident conditions for the conceptual model of the new reactor type nuclear power plant.

9. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 1, characterized in that: In step S4, the conceptual model of the new reactor type nuclear power plant is iteratively designed to improve the specific form and details of each production system of the new reactor type nuclear power plant.

10. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 9, characterized in that: In step S4, a primary circuit coolant charge adjustment, pressure control and protection system, and / or an additional heat removal system, and / or a secondary circuit flow control, pressure control and protection system are added on the basis of the conceptual model.

11. The method for selecting accident conditions in the design phase of a new reactor type nuclear power plant according to claim 8, characterized in that: In step S5, for the conceptual model after iterative design, the accident condition selection analysis is performed using the method in step S3, and the accident condition list is updated according to the analysis results.

12. A system for selecting accident conditions in the design phase of a new reactor type nuclear power plant, used to implement the method for selecting accident conditions in the design phase of a new reactor type nuclear power plant as claimed in any one of claims 1 to 11, characterized in that: include: Information acquisition module, used to obtain design information of new reactor type nuclear power plant; Model building module, used to build a conceptual model of a new reactor type nuclear power plant based on design information; The accident analysis module is used to analyze the accident conditions of the conceptual model of the new reactor type nuclear power plant and determine the accident condition list of the new reactor type nuclear power plant; Iterative design module, used to iteratively design the conceptual model of a new reactor type nuclear power plant; The list output module is used to update and output the accident condition list according to the analysis results of the accident analysis module.

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