Method and device for implementing successful channel of safety function of nuclear power plant and storage medium
By using an artificial intelligence decision support system and a target tree-success tree-state tree model, the problem of incomplete emergency response of offshore floating nuclear power platforms in extreme environments has been solved. It provides a rapid safety function recovery channel and improves the emergency response capabilities of operators and the safety of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2022-12-12
- Publication Date
- 2026-06-23
AI Technical Summary
In extreme environments, when floating nuclear power platforms at sea face unexpected events, existing safety operating procedures are incomplete, operators' emergency response capabilities are insufficient, human error is easily caused, leading to increased safety risks, and there is a lack of effective emergency response strategies and systematic procedural guidance.
An artificial intelligence-based operation guidance decision support system is adopted. Through the target tree-success tree-state tree model, a hierarchical functional coupling structure of "target-function-task-implementation means" for nuclear power plants is established. The system identifies the current operating conditions, formulates emergency response task objectives, generates key safety function recovery channels, and provides emergency operation support for operators.
It enables rapid emergency response to nuclear power plants in extreme environments, reduces the consequences of accidents, improves operators' emergency response capabilities, ensures safe recovery of the plant, and optimizes emergency response task planning.
Smart Images
Figure CN115983629B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of nuclear safety analysis, and specifically relates to a method, apparatus, computer equipment, and storage medium for realizing the safety function success channel of a nuclear power plant. Background Technology
[0002] Even with high design standards, strict operational safety regulations, and multi-layered defense, unexpected events may still occur under extreme environmental and operational conditions, exceeding the existing system's safety protection, accident mitigation, and response capabilities. In particular, in the absence of effective emergency management strategies and systematic procedural guidance, the key to achieving flexible safety for nuclear power plants lies in how to adopt appropriate emergency response strategies to regulate nuclear power plants to a safe operating state and effectively avoid human error events in the process.
[0003] As a special type of marine nuclear power plant, the floating nuclear power platform is characterized by high efficiency, flexibility, and economy. However, it is a very large and complex dynamic system involving numerous system components, various initiating events, scenario sequences, and dynamic changes in time-series variables. The natural and social environmental characteristics it faces are also more severe, making it difficult to find corresponding mitigation measures and contingency plans for all possible potential failure events. Especially when facing unexpected events in extreme operating environments (such as the impact of typhoons, tsunamis, collisions, and other complex and severe sea conditions on the floating platform), existing conservative safety assumptions, operating procedures, and guidelines may no longer meet the requirements. Operators may be in a blind control scenario. Coupled with the urgency of the current mission, operators will have to adopt more flexible response methods, posing a significant challenge to their emergency response capabilities. The operation process will involve a huge workload and mental stress, making human error more likely and endangering the safety of the nuclear power plant.
[0004] Therefore, it is crucial and urgent to equip marine nuclear power plants with an artificial intelligence-based operation guidance and decision support system to address potential extreme operating scenarios and unexpected events (covering normal operation transients and design basis accident conditions). This system would assist operators in planning or constructing a set of effective emergency response strategies in a timely manner based on the current operating scenario and environmental conditions of the nuclear power plant, even without procedural guidance. Combined with operator emergency preparedness training, this would improve the successful and effective intervention and handling of extreme and abnormal conditions, restore the nuclear power plant to a safe state, and ensure the effective achievement of mission objectives.
[0005] Currently, my country's research and development of offshore floating nuclear power platforms is still in the prototype reactor conceptual design and development stage. A systematic and unified set of norms and standards has not yet been established, and related technology research and development and safe operating procedures are not yet mature and complete. The current approach mainly involves learning from and drawing on advanced technologies and experiences from Russia, the United States, and other countries. In recent years, while research on emergency safety management technologies for sudden events has received considerable attention, much of this research is based on emergency response mechanisms and process management for sudden events, primarily concentrated in areas such as public health, urban safety, aerospace, petrochemicals, and offshore platforms. Technological innovations in emergency response mission planning and successful path planning for the restoration of safety functions in nuclear power plants under extreme operating conditions are relatively rare. Summary of the Invention
[0006] This invention addresses the practical technical challenge of incomplete operational response procedures for floating nuclear power platforms in extremely unfamiliar and complex operating environments when dealing with unexpected events. By employing reasoning and analysis through an artificial intelligence-based operational guidance decision support system, it provides a method, device, computer equipment, and storage medium for successfully implementing safety functions in nuclear power plants. This enables the planning of emergency response tasks and the identification of their implementation methods, thereby quickly guiding operators to restore and mitigate safety functions and reduce the harmful consequences of accidents.
[0007] The first objective of this invention is to provide a method for successfully implementing the safety functions of a nuclear power plant.
[0008] The second objective of this invention is to provide a device for achieving a successful channel for safety functions in a nuclear power plant.
[0009] A third objective of this invention is to provide a computer device.
[0010] A fourth objective of this invention is to provide a storage medium.
[0011] The first objective of this invention can be achieved by adopting the following technical solution:
[0012] A method for achieving a successful safety function pathway in a nuclear power plant, the method comprising:
[0013] Based on the overall design principles and functional structure design characteristics of nuclear power plants, a hierarchical functional coupling structure model of nuclear power plants, namely "goal-function-task-implementation means", is established based on the goal tree-success tree-state tree.
[0014] By analyzing the process characteristics and functional tasks of nuclear power plant operation, we can clarify the operational purpose and functional requirements of nuclear power plant system equipment under different operating conditions, determine the system input and related process parameter characterization range under specific or variable operating conditions, and establish discrimination criteria under different operating conditions.
[0015] Based on the aforementioned discrimination criteria, identify the current operating condition of the nuclear power plant; under the current operating condition, determine the integrity or damage status of the nuclear power plant's safety functions based on the monitoring feedback of key safety parameters, and formulate corresponding emergency response task objectives.
[0016] Based on the emergency response mission planning objectives and the monitoring inputs of system equipment availability and process parameter status, a set of successful recovery channels for key safety functions is generated through reverse deduction using the hierarchical functional coupling structure model of the nuclear power plant, which consists of "objective-function-task-implementation means".
[0017] Based on the generated set of successful channels, the system's security level is classified by combining security function associations, and the optimal successful channel is determined, providing auxiliary support for operators' emergency operations.
[0018] Furthermore, the target tree-success tree-state tree is a multi-level structured model representation of the target-function-physical structure of a nuclear power plant, comprising three parts: the target tree model, the success tree model, and the state tree model, wherein:
[0019] The target tree model is obtained by hierarchically decomposing the targets at each level, and is used to describe the realization association and supporting relationship of the targets at each level, including the overall safety target layer of the nuclear power plant, the safety function target layer, the functional task target layer, and the sub-targets of each level.
[0020] The success tree model is constructed by extracting the interactive behavior features between physical structures / systems / equipment and process parameter variables, and is used to describe the channels and means for achieving the target function;
[0021] The state tree model estimates the safety functions and safety target states of nuclear power plants based on key safety parameters, thereby supporting emergency response task planning. The key safety parameters are external correlation representations of the safety functions and safety target states of nuclear power plants. Based on the alarm level definition of key safety parameters, the model achieves multi-state division of safety functions.
[0022] Furthermore, based on the hierarchical functional structure of "target-function-process-system equipment-support system" in the target tree-success tree-state tree model, a success path planning knowledge base is obtained, which constitutes the reasoning basis for successful path planning for the restoration or mitigation of safety functions of nuclear power plants. The success path planning knowledge base is an integrated expression of knowledge on the design and operation process of nuclear power plant systems with multi-target, multi-parameter, multi-state, and multi-task control.
[0023] The safety objectives of a nuclear power plant are mapped and correlated through safety functional states, including six major safety functions: reactivity control, core heat removal, primary loop heat removal, reactor coolant load integrity, reactor coolant pressure boundary integrity, and containment integrity. The realization relationship between the nuclear power plant safety objectives and the major safety functional states is an all-inclusive AND relationship.
[0024] The safety functional status of a nuclear power plant is characterized by monitoring key safety parameters, including nuclear power, reactor coolant boric acid concentration, core outlet temperature, steam generator water level, steam generator pressure, pressurizer water level, primary loop system pressure, containment pressure, and containment radioactivity. These key safety parameters are the minimum set of parameters that characterize the safety status of a nuclear power plant.
[0025] The monitoring of the key safety parameters establishes the indirect correlation and influence between the safety functional status of the nuclear power plant and the functional task control objectives. The functional task control objectives of the nuclear power plant are determined based on the exceedance of safety functional characterization parameters, and the functional task control objectives and the exceedance of safety functional characterization parameters form an inverse influence relationship.
[0026] The functional objectives are achieved through the frontier system, which is the system that directly executes the security functions. The availability and executability of the frontier system are constrained by its auxiliary support system and access conditions, thus forming a conditional dependency relationship.
[0027] Furthermore, the monitoring of the critical safety function status of nuclear power plants connects the upper-level safety objectives with the lower-level success pathways, aiming to establish a multi-functional, in-depth defense safety target monitoring perspective and formulate emergency response requirements and objectives based on the monitoring results of the safety function status. The critical safety function status of nuclear power plants is determined by combining the system process parameter exceeding the limit and the intelligent alarm classification system, thereby helping the main control room operator to quickly and reliably make situation judgments and emergency operation responses under normal operating conditions, especially abnormal operating conditions.
[0028] The classification of key safety function states of the nuclear power plant is based on a flexible implementation of two-state, multi-state, and near-continuous states. Among them, two-state means that the safety function state only considers two situations: integrity and damage. Multi-state is determined according to the alarm classification of the nuclear power plant. Near-continuous state is an extreme extension of the multi-level threshold alarm of process parameters, which can be compatible with the existing graded alarm system of nuclear power plants, and the clear process parameter value indication facilitates the formulation of specific operation response plans.
[0029] Furthermore, the successful channel refers to the specific operational mode for achieving functional task objectives, and is a combined expression of the cutting-edge system for achieving security functions, its auxiliary support system, and access conditions;
[0030] The planning of successful pathways under emergency operation conditions is guided by the goal of achieving the safety objectives of nuclear power plants. Based on the preliminary set of potential successful pathway candidates determined by the monitoring of the critical safety function status of nuclear power plants and the orientation of mission objectives, and combined with the monitoring feedback of the availability status of physical structures and the judgment of system access conditions, the plan further determines the executable successful pathways that are suitable for the current scenario.
[0031] Based on the feasible successful channels in the current scenario, and referring to the security function association to implement the security level classification of the system, the optimal successful channel is determined; wherein, the system includes structures, systems, and components;
[0032] The functional task objectives are determined in reverse based on the over-limit status of the safety function characterization associated parameters, so as to achieve the regulation of key safety parameters and the restoration of safety functions.
[0033] Furthermore, based on the system security level, the channels for successfully restoring security functions that meet the needs of the current scenario are prioritized and displayed. The higher the security level of the system associated with the security function, the higher it is ranked.
[0034] For each successful recovery of a safety function channel, emergency operation guidance is provided to operators through dynamic flow design and human-machine interface display.
[0035] Furthermore, the operating condition judgment criteria are determined with reference to the standard operating state definition of the nuclear power plant in the nuclear power plant technical specifications; wherein, the standard operating state refers to the operating state of the nuclear power plant corresponding to the combination of core reactivity, reactor power level, reactor coolant average temperature, and pressurizer pressure parameters.
[0036] The step of identifying the current operating condition of the nuclear power plant according to the discrimination criterion includes:
[0037] Based on the parameter fluctuations or temporary alarms exceeding thresholds introduced during the switching of operating modes of the nuclear power plant, the characteristic changes of the parameter set are extracted, and the feature pattern recognition algorithm is used to accurately identify different operating conditions of the nuclear power plant; wherein, the feature pattern recognition algorithm is based on the standard operating state definition of the nuclear power plant and the monitoring of its characteristic parameters.
[0038] Furthermore, the feature pattern recognition algorithm is based on a mapping relationship model between standard operating states and process parameters. It combines real-time data input of process state parameters, extracts mapping-related variables one by one to determine parameter limits, and filters them through a funnel-style multi-layer filter to finally determine and guide the operating state and working mode.
[0039] The second objective of this invention can be achieved by adopting the following technical solution:
[0040] A device for achieving a structured and successful pathway for safety functions in a nuclear power plant, the device comprising:
[0041] The hierarchical functional coupling structure model building unit is used to establish a hierarchical functional coupling structure model of the nuclear power plant based on the overall design criteria and functional structure design characteristics of the nuclear power plant, and on the basis of the target tree-success tree-state tree.
[0042] The operating condition discrimination criterion establishment unit is used to clarify the operating purpose and functional target requirements of nuclear power plant system equipment under different operating conditions by analyzing the process characteristics and functional task decomposition of nuclear power plant operating conditions, determine the system input status and related process parameter characterization range under specific or variable operating conditions, and establish discrimination criteria under different operating condition modes.
[0043] The emergency response task objective determination unit is used to identify the current operating condition of the nuclear power plant according to the discrimination criteria; under the current operating condition, based on the monitoring feedback of key safety parameters, determine the integrity or damage status of the safety function of the nuclear power plant, and formulate corresponding emergency response task objectives.
[0044] The successful channel set generation unit is used to generate a set of executable successful channels for the recovery of key safety functions by back-deriving from the hierarchical functional coupling structure model of the nuclear power plant’s “target-function-task-implementation means”, based on the mission objective requirements, the available status of system equipment and the monitoring input of process parameters, and the planning objectives of the emergency response mission.
[0045] The optimal success channel determination unit is used to determine the optimal success channel based on the generated success channel set and the security function association to classify the system's security level, thus providing auxiliary support for operator emergency operations.
[0046] The third objective of this invention can be achieved by adopting the following technical solution:
[0047] A terminal device includes a processor and a memory for storing a processor-executable program, wherein when the processor executes the program stored in the memory, it implements the above-described method for successfully implementing the safety function channel of a power unit.
[0048] The fourth objective of this invention can be achieved by adopting the following technical solution:
[0049] A storage medium storing a program, which, when executed by a processor, implements the above-mentioned method for successfully implementing the safety function channel of a power unit.
[0050] The present invention has the following advantages over the prior art:
[0051] 1. The method for realizing the successful channel of safety functions of nuclear power plants provided by the present invention can realize the integrated expression of the knowledge of nuclear power plant system design and operation process control with multiple objectives, multiple parameters, multiple states, and multiple tasks through the target tree-success tree-state tree model. Based on the existing monitoring of key safety parameters of nuclear power plants, the key safety function states of nuclear power plants are defined and divided in detail by combining intelligent alarm classification of system process parameters. It can optimize the state-oriented emergency response task planning from the comprehensive perspective of the urgency of task execution and the severity of the consequences of the event.
[0052] 2. The automatic identification method for operating conditions of nuclear power plants provided by the present invention is based on the analysis of the characteristics of the nuclear power plant operation process and the extraction of feature parameters under different operating conditions. It achieves accurate identification of operating conditions through parameter monitoring and system operation event triggering control, thereby realizing task planning for specific operating conditions.
[0053] 3. The method for optimizing and evaluating the implementation channels of safety functions in nuclear power plants provided by this invention determines the optimal successful channels based on the safety level classification of the safety function-related implementation system, highlighting the importance of different successful channels to the implementation of safety functions, and providing clearer guidance and direction for mitigating accident consequences. Attached Figure Description
[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0055] Figure 1 This is a flowchart of the successful implementation method of the structured safety function channel of the nuclear power plant according to Embodiment 1 of the present invention.
[0056] Figure 2 This is the framework for achieving the safety function objectives of a nuclear power plant according to Embodiment 1 of the present invention.
[0057] Figure 3 This is the coupled and related structural model of the nuclear power plant target tree-success tree-state tree in Embodiment 1 of the present invention.
[0058] Figure 4 This is a diagram illustrating the monitoring of safety objectives and safety function status of a nuclear power plant according to Embodiment 1 of the present invention.
[0059] Figure 5 This is the automatic identification algorithm for the operating mode of a nuclear power plant in Embodiment 1 of the present invention.
[0060] Figure 6 This is a screenshot of the normal power operation mode recognition of a nuclear power plant according to Embodiment 1 of the present invention.
[0061] Figure 7 The image shows the identification screen of the normal cold shutdown mode of the nuclear power plant in Embodiment 1 of the present invention.
[0062] Figure 8 This is a structural block diagram of the device for successfully implementing the structured safety function of a nuclear power plant according to Embodiment 2 of the present invention.
[0063] Figure 9 This is a structural block diagram of the computer device according to Embodiment 3 of the present invention. Detailed Implementation
[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be understood that the specific embodiments described are merely used to explain this application and are not intended to limit this application.
[0065] Example 1:
[0066] like Figure 1 As shown in the figure, this embodiment provides a method for implementing a structured success channel for the safety functions of a power unit. The following sections will describe each part in detail.
[0067] (I) Construction of the target tree-success tree model.
[0068] Ensuring the integrity of all safety functions is a prerequisite for achieving the safety and availability objectives of a nuclear power plant. If any safety function is compromised, the safety objectives of the nuclear power plant will be threatened. In such cases, it is necessary to seek appropriate means of restoring or mitigating these safety functions to bring the nuclear power plant back into a normal and safe operating state. (See Appendix) Figure 2 The critical safety functions of a nuclear power plant, prioritized by importance, are categorized into six main safety functions: reactivity control, core heat removal, primary coolant removal, reactor coolant load integrity, reactor coolant pressure boundary integrity, and containment integrity. Each critical safety function encompasses multiple implementation methods, also known as the success pathways for achieving the safety function, used to maintain the overall safety objectives of the nuclear power plant. See Appendix [Appendix] for a list of the systems associated with the critical safety functions of a nuclear power plant and the components of their success pathways. Figure 3 .
[0069] (1) Reactivity control.
[0070] The purpose of reactivity control is to adjust reactor power, flatten core power distribution, or quickly and safely shut down the reactor while maintaining an appropriate shutdown depth under different operating conditions, ensuring reactor operation and shutdown safety. This is characterized by whether the reactor is controllable, and its key safety function parameters include reactor power and coolant boron concentration. Reactor power control mainly involves the reactor protection system and rod control system; the adjustment and control of coolant boron concentration is mainly achieved through the coupling and correlation of the reactor coolant system, safety injection system, chemical and volume control system, reactor boron and water supply system, and their auxiliary support systems (such as equipment cooling water system, power supply system, air compression system, lubrication system, etc.).
[0071] (2) Core heat removal.
[0072] The purpose of core heat removal is to effectively transfer the heat released from the nuclear fission reaction in the core to the reactor coolant system loop, ensuring that the core temperature remains below the peak temperature of the fuel rod cladding and preventing core meltdown. Core heat removal primarily involves coolant temperature control, with the core outlet temperature reflecting the core's heat removal capability. A high core outlet temperature leads to a decrease in the reactor coolant's undercooling, causing core vaporization and jeopardizing the effective release of core heat. The reactor coolant temperature control objective is mainly achieved through the reactor coolant system, residual heat removal system, safety injection system, main steam system, and steam bypass system.
[0073] (3) Heat removal from the primary loop.
[0074] The purpose of primary loop heat removal is to further transfer the heat released from the reactor core into the primary coolant to the secondary loop system via steam generators (heat sinks) to achieve power production. The steam generator not only acts as a heat exchanger, transferring heat from the primary coolant to the secondary feedwater, but also serves as a crucial component of the reactor coolant pressure boundary. Therefore, the key characteristic parameters of the primary loop heat removal safety function status are primarily reflected in the monitoring and control of steam generator pressure and steam generator water level. Steam generator pressure control is mainly achieved through the main steam system and steam venting system, while steam generator water level control is achieved through the main feedwater system and auxiliary feedwater system.
[0075] (4) Integrity of reactor coolant loading.
[0076] Reactor coolant charge control is a crucial component of ensuring the integrity of the primary coolant circuit. Coolant mismatch will cause pressure changes in the primary coolant operating system, and a continuous decrease in coolant charge may lead to fuel element deviation from nucleation boiling or even core exposure, thereby jeopardizing reactor safety. The integrity of the reactor coolant charge is manifested in the monitoring of pressurizer and pressure vessel water levels to determine whether the primary coolant charge meets requirements under normal operating and accident conditions. Depending on the amount of reactor coolant charge under different operating conditions, the successful implementation of safety functions includes various pathways such as charging, draining, boric acid injection, and safety injection. Related systems include the reactor coolant system, the chemical and volume control system / reactor boron and water supply system, and the safety injection system.
[0077] (5) Integrity of reactor coolant pressure boundary.
[0078] The reactor coolant system, acting as the reactor's second safety barrier, serves to remove heat from the core while also isolating radioactive materials. Reactor operation relies on a pressurizer to maintain the primary coolant circuit pressure within a normal range. Excessive pressure can lead to equipment or pipeline damage, while insufficient pressure may cause the primary coolant water to vaporize, hindering core heat removal. As the name suggests, the integrity of the reactor coolant pressure boundary is primarily achieved through pressurizer pressure control, and related systems include the pressure safety system.
[0079] (6) Integrity of containment.
[0080] The containment vessel is the last line of defense against nuclear fuel fission products and primary loop radioactive materials entering the environment. When a primary loop system rupture occurs inside the containment vessel, high-temperature, high-pressure steam forces the temperature and pressure within the containment vessel to rise, releasing radioactive materials. Accordingly, the integrity of the containment vessel is primarily reflected in the monitoring of pressure and radioactivity levels within the containment vessel. Excessive containment pressure directly threatens the integrity of the containment vessel, requiring the effective reduction of pressure and temperature through the containment spray system to ensure the integrity of the third safety barrier. High levels of radioactivity in the containment vessel indicate that the second safety barrier has failed, necessitating timely isolation of the containment vessel entrances and exits; the relevant implementation system mainly refers to the containment isolation system.
[0081] (ii) Monitoring the status of key safety functions.
[0082] This embodiment will take the reactive change response under a uniform boron dilution accident in a nuclear power plant as an example to specifically illustrate the method for achieving a successful safety function channel in a nuclear power plant provided by the present invention.
[0083] Accident scenario assumptions: Assume that the reactor is operating at full power at the beginning of its service life (310℃, 15.5MPa, BOL, 100%FP), the regulating rod group (R rod group) is in the middle of the regulating zone, and the reactor coolant charge is constant, that is, the charging flow and the discharge flow are in dynamic balance.
[0084] In the event of a boron dilution accident, the reactor will first trigger a high neutron flux alarm. The control rod assembly will then be lowered. When the control rod assembly reaches its lower limit, a low-low position alarm will be triggered. If the positive reactivity introduced by boron dilution cannot be compensated by the control rods at this point, the system will issue an over-temperature / over-power ΔT alarm, subsequently triggering the reactor protection system for an emergency shutdown. Simultaneously, the reactor protection system will send a boron dilution isolation signal to the chemistry and volume control system, switching the charging pump suction port from the volume control tank to the refueling tank. This allows concentrated boric acid to be injected into the core via the safety injection line. After a period of concentrated boric acid conditioning, the operator is allowed to switch the charging pump suction port back to the chemistry and volume control system based on the reset isolation signal to prevent excessive boration of the reactor coolant.
[0085] Based on the above analysis of the accident response process, the key alarms related to boron dilution accidents can be summarized as follows: high neutron flux alarm, abnormal boric acid concentration alarm, low and low-low control rod insertion limit alarms, axial flux deviation alarm, and over-temperature / over-power ΔT alarm. Among these, the parameter alarms related to reactivity control safety functions mainly involve the monitoring of nuclear power and boron concentration; while the over-temperature / over-power ΔT alarm reflects the impairment of the core heat removal safety function, which, if not mitigated in time, may lead to a deviating nucleation boiling crisis.
[0086] Based on the classification and grading principles of intelligent alarm systems for nuclear power plants, the monitoring of critical safety function status can be achieved through the attached... Figure 4 The multi-layered, three-dimensional hexagonal view shown represents the overall safety objective of the nuclear power plant. The six corners correspond to the status of each critical safety function, with the hierarchical structure determined by the intelligent alarm system of the nuclear power plant, each marked with a different color. To illustrate the implementation process, this embodiment references a common four-level alarm system used in nuclear power plants, consistently representing the overall safety objective status based on the most severely compromised state among the various safety functions. In practical applications, the color representation of functional states can be adjusted according to the actual intelligent alarm system design of the nuclear power plant.
[0087] (iii) Identification of operating conditions.
[0088] Based on the assumed operating conditions and parameter ranges in section (I), including nuclear power level, primary loop pressure, primary loop average temperature, subcriticality, control rod group and shutdown rod group locations, a multi-parameter pattern recognition algorithm is used (see Appendix). Figure 5 This enables automatic identification of the power operation mode and shutdown mode of the nuclear power plant. The results of the operation mode identification are shown in the figure. Figure 6 and sign Figure 7 .
[0089] (iv) Success path planning.
[0090] like Figure 1 As shown, based on the back-deductive analysis of the target tree-success tree-state tree coupled model, the main implementation methods of reactivity control include control rod control and boric acid control. Control rod control primarily achieves rapid reactivity control, and the associated implementation systems involve the rod control and position system and the reactor protection system, classifying it as a Level I safety system. Slow reactivity regulation is mainly achieved through boric acid control, and the associated implementation systems include the reactor coolant system, the safety injection system, and the chemical and volume control system / reactor boron and water replenishment system. Among these, the safety injection system, as an important dedicated safety facility, is connected to the reactor coolant pressure boundary. In the event of a boron dilution accident, it primarily performs boron dilution isolation and emergency concentrated boric acid replenishment functions, classifying it as a Level II system. The chemical and volume control system, as a major auxiliary system of the primary loop, is also connected to the reactor coolant pressure boundary, primarily achieving boron and water replenishment under normal operating conditions, also classifying it as a Level II safety system. The reactor boron and water replenishment system, as an auxiliary support system for the chemical and volume control system, is a Level III safety system.
[0091] Therefore, assuming system availability and that all access conditions are met, the reactive control strategy and successful pathway implementation method under a boron dilution accident mainly include three types: 1) rapid reactive control of control rods; 2) boron dilution isolation function and emergency boron operation performed by dedicated safety facilities; and 3) conventional boron replenishment. Specific implementation methods are detailed in Appendix 1. Among these, the rod control and position system and the reactor protection system have the highest safety levels and are therefore prioritized as the primary implementation method in successful pathway planning, followed by the safety injection channel, and finally the capacity system charging pipeline. The actual operational response process under a boron dilution accident has also effectively verified the rationality and correctness of the successful pathway planned in this embodiment.
[0092] Table 1 Successful pathway planning under boron dilution accidents
[0093]
[0094] Example 2:
[0095] like Figure 8As shown, this embodiment provides a structured success channel implementation device for the safety functions of a nuclear power plant. The device includes a hierarchical functional coupling structure model establishment unit 801, an operating condition discrimination criterion establishment unit 802, an emergency response task target determination unit 803, a success channel set generation unit 804, and an optimal success channel determination unit 805, wherein:
[0096] The hierarchical functional coupling structure model building unit 801 is used to build a hierarchical functional coupling structure model of the nuclear power plant based on the overall design criteria and functional structure design characteristics of the nuclear power plant, and on the basis of the target tree, success tree and state tree.
[0097] The operating condition discrimination criterion establishment unit 802 is used to clarify the operating purpose and functional target requirements of the nuclear power plant system equipment under different operating conditions through the process characteristics and functional task decomposition analysis of the operating conditions of the nuclear power plant, determine the system input status and the characterization range of related process parameters under specific or variable operating conditions, and establish discrimination criteria under different operating condition modes.
[0098] The emergency response task objective determination unit 803 is used to identify the current operating condition of the nuclear power plant according to the discrimination criteria; under the current operating condition, based on the monitoring feedback of key safety parameters, determine the integrity or damage status of the safety function of the nuclear power plant, and formulate corresponding emergency response task objectives.
[0099] Success channel set generation unit 804 is used to generate a set of executable success channels for key safety function recovery based on the planning objectives of the emergency response task, the monitoring input of the availability status of system equipment and the status of process parameters, and the hierarchical functional coupling structure model of the nuclear power plant’s “objective-function-task-implementation means” through reverse deduction.
[0100] The optimal success channel determination unit 805 is used to determine the optimal success channel based on the generated success channel set and the security function association to classify the system's security level, thus providing auxiliary support for operator emergency operations.
[0101] The specific implementation of each module in this embodiment can be found in Embodiment 1 above, and will not be repeated here. It should be noted that the device provided in this embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure can be divided into different functional modules to complete all or part of the functions described above.
[0102] Example 3:
[0103] This embodiment provides a computer device, which can be a computer, such as... Figure 9 As shown, the system bus 401 connects a processor 402, a memory, an input device 403, a display 404, and a network interface 405. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium 406 and internal memory 407. The non-volatile storage medium 406 stores the operating system, computer programs, and a database. The internal memory 407 provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. When the processor 402 executes the computer programs stored in the memory, it implements the successful implementation method of the nuclear power plant safety function structured channel of Embodiment 1, as follows:
[0104] Based on the overall design principles and functional structure design characteristics of nuclear power plants, a hierarchical functional coupling structure model of nuclear power plants, namely "goal-function-task-implementation means", is established based on the goal tree-success tree-state tree.
[0105] By analyzing the process characteristics and functional tasks of nuclear power plant operation, we can clarify the operational purpose and functional requirements of nuclear power plant system equipment under different operating conditions, determine the system input and related process parameter characterization range under specific or variable operating conditions, and establish discrimination criteria under different operating conditions.
[0106] Based on the aforementioned discrimination criteria, identify the current operating condition of the nuclear power plant; under the current operating condition, determine the integrity or damage status of the nuclear power plant's safety functions based on the monitoring feedback of key safety parameters, and formulate corresponding emergency response task objectives.
[0107] Based on the emergency response mission planning objectives and the monitoring inputs of system equipment availability and process parameter status, a set of successful recovery channels for key safety functions is generated through reverse deduction using the hierarchical functional coupling structure model of the nuclear power plant, which consists of "objective-function-task-implementation means".
[0108] Based on the generated set of successful channels, the system's security level is classified by combining security function associations, and the optimal successful channel is determined, providing auxiliary support for operators' emergency operations.
[0109] Example 4:
[0110] This embodiment provides a storage medium, which is a computer-readable storage medium, storing a computer program. When the computer program is executed by a processor, it implements the method for successfully implementing the structured safety function channel of a nuclear power plant as described in Embodiment 1 above, as follows:
[0111] Based on the overall design principles and functional structure design characteristics of nuclear power plants, a hierarchical functional coupling structure model of nuclear power plants, namely "goal-function-task-implementation means", is established based on the goal tree-success tree-state tree.
[0112] By analyzing the process characteristics and functional tasks of nuclear power plant operation, we can clarify the operational purpose and functional requirements of nuclear power plant system equipment under different operating conditions, determine the system input and related process parameter characterization range under specific or variable operating conditions, and establish discrimination criteria under different operating conditions.
[0113] Based on the aforementioned discrimination criteria, identify the current operating condition of the nuclear power plant; under the current operating condition, determine the integrity or damage status of the nuclear power plant's safety functions based on the monitoring feedback of key safety parameters, and formulate corresponding emergency response task objectives.
[0114] Based on the emergency response mission planning objectives and the monitoring inputs of system equipment availability and process parameter status, a set of successful recovery channels for key safety functions is generated through reverse deduction using the hierarchical functional coupling structure model of the nuclear power plant, which consists of "objective-function-task-implementation means".
[0115] Based on the generated set of successful channels, the system's security level is classified by combining security function associations, and the optimal successful channel is determined, providing auxiliary support for operators' emergency operations.
[0116] It should be noted that the computer-readable storage medium in this embodiment can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.
Claims
1. A method for successfully implementing a structured pathway for safety functions in a nuclear power plant, characterized in that, The method includes: Based on the overall design principles and functional structure design characteristics of nuclear power plants, a hierarchical functional coupling structure model of nuclear power plants, namely "goal-function-task-implementation means", is established based on the goal tree-success tree-state tree. By analyzing the characteristics and functional tasks of nuclear power plant operating conditions, the operational purpose and functional requirements of the nuclear power plant system equipment under different operating conditions are clarified. The system input status and the range of related process parameters under specific or variable operating conditions are determined, and discrimination criteria under different operating conditions are established. The discrimination criteria are determined with reference to the definition of the standard operating state of the nuclear power plant in the nuclear power plant technical specifications. The standard operating state includes the nuclear power plant operating state corresponding to the combination of core reactivity, reactor power level, reactor coolant average temperature, and pressurizer pressure parameters. Based on parameter fluctuations or temporary alarms exceeding thresholds introduced during the switching of operating modes of a nuclear power plant, characteristic changes in the parameter set are extracted, and a feature pattern recognition algorithm is used to accurately identify different operating conditions of the nuclear power plant. Under the current operating condition, based on the monitoring feedback of key safety parameters, the integrity or damage status of the safety function of the nuclear power plant is determined, and corresponding emergency response task objectives are formulated. The feature pattern recognition algorithm is based on the standard operating state definition of the nuclear power plant and the monitoring of its characteristic parameters. Based on the emergency response mission objectives and the monitoring inputs of system equipment availability and process parameter status, a set of successful recovery channels for key safety functions is generated through reverse deduction using the hierarchical functional coupling structure model of the nuclear power plant, which is based on the mission objective requirements and the availability status of system equipment and process parameters. Based on the generated set of successful channels, the system's security level is classified by combining security function associations, and the optimal successful channel is determined, providing auxiliary support for operators' emergency operations. The target tree-success tree-state tree is a multi-level structured model representation of the target-function-physical structure of a nuclear power plant, comprising three parts: a target tree model, a success tree model, and a state tree model. The target tree model is obtained by hierarchically decomposing the targets at each level, and is used to describe the realization association and supporting relationship of the targets at each level, including the overall safety target layer of the nuclear power plant, the safety function target layer, the functional task target layer, and the sub-targets of each level. The success tree model is constructed by extracting the interactive behavior features between physical structures / systems / equipment and process parameter variables, and is used to describe the channels and means for achieving the target function; The state tree model estimates the safety functions and safety target states of nuclear power plants based on key safety parameters, thereby supporting emergency response task planning. The key safety parameters are external correlation representations of the safety functions and safety target states of nuclear power plants. Based on the alarm level definition of key safety parameters, the model achieves multi-state division of safety functions.
2. The method for achieving a structured and successful pathway for the safety functions of a nuclear power plant according to claim 1, characterized in that, Based on the hierarchical functional structure of "target-function-process-system equipment-support system" in the target tree-success tree-state tree model, a success path planning knowledge base is obtained, which constitutes the reasoning basis for the success path planning of nuclear power plant safety function recovery or mitigation. The success path planning knowledge base is an integrated expression of the knowledge of nuclear power plant system design and operation process of multi-target, multi-parameter, multi-state, and multi-task control. The safety objectives of a nuclear power plant are mapped and correlated through safety functional states, including six major safety functions: reactivity control, core heat removal, primary loop heat removal, reactor coolant load integrity, reactor coolant pressure boundary integrity, and containment integrity. The realization relationship between the nuclear power plant safety objectives and the major safety functional states is an all-inclusive "AND" relationship. The safety functional status of a nuclear power plant is characterized by monitoring key safety parameters, including nuclear power, reactor coolant boric acid concentration, core outlet temperature, steam generator water level, steam generator pressure, pressurizer water level, primary loop system pressure, containment pressure, and containment radioactivity. These key safety parameters are the minimum set of parameters that characterize the safety status of a nuclear power plant. The monitoring of the key safety parameters establishes the indirect correlation and influence between the safety functional status of the nuclear power plant and the functional task control objectives. The functional task control objectives of the nuclear power plant are determined based on the exceedance of safety functional characterization parameters, and the functional task control objectives and the exceedance of safety functional characterization parameters form an inverse influence relationship. The functional objectives are achieved through the frontier system, which is the system that directly executes the security functions. The availability and executability of the frontier system are constrained by its auxiliary support system and access conditions, thus forming a conditional dependency relationship.
3. The method for achieving a structured and successful pathway for the safety functions of a nuclear power plant according to claim 2, characterized in that, The critical safety function status of the nuclear power plant is determined by combining the system process parameter exceeding the limit and the intelligent alarm classification system, thereby helping the main control room operator to quickly and reliably make situation judgments and emergency operation responses under normal and abnormal operating conditions. The classification of key safety function states of the nuclear power plant is based on a flexible implementation of two-state, multi-state, and near-continuous states. Among them, two-state means that the safety function state only considers two situations: integrity and damage. Multi-state is determined according to the alarm classification of the nuclear power plant. Near-continuous state is an extreme extension of the multi-level threshold alarm of process parameters, which can be compatible with the existing graded alarm system of nuclear power plants, and the clear process parameter value indication facilitates the formulation of specific operation response plans.
4. The method for achieving a structured and successful pathway for the safety functions of a nuclear power plant according to claim 3, characterized in that, The successful channel refers to the specific operational mode for achieving functional task objectives. It is a combined expression of the cutting-edge system for achieving safety functions, its auxiliary support system, and access conditions. The planning of successful pathways under emergency operating conditions is guided by the goal of achieving the safety objectives of nuclear power plants. Through automatic identification of operating conditions and the preliminary selection of potential successful pathways based on the monitoring of the damage to the critical safety functions of nuclear power plants and the guidance of mission objectives, combined with the monitoring feedback of the availability status of the physical structure and the judgment of system access conditions, the executable successful pathways that are suitable for the current scenario are further determined. Based on the available successful channels in the current scenario and referring to the security level classification of security function implementation methods, determine the optimal successful channel. The functional task objectives are determined in reverse based on the over-limit status of the associated parameters representing the safety functions, so as to achieve the regulation of key safety parameters and the restoration of safety functions.
5. The method for successfully implementing the structured safety function pathway of a nuclear power plant according to claim 4, characterized in that, Based on the system security level, the channels for successful recovery of security functions that meet the needs of the current scenario are prioritized and displayed. The higher the security level of the system associated with the security function, the higher it is ranked. For each successful recovery of a safety function channel, emergency operation guidance is provided to operators through dynamic flow design and human-machine interface display.
6. The method for achieving a structured and successful pathway for the safety functions of a nuclear power plant according to claim 1, characterized in that, The feature pattern recognition algorithm is based on a mapping relationship model between standard operating states and process parameters. It combines real-time data input of process state parameters, extracts mapping-related variables one by one to determine parameter limits, and filters them through a funnel-style multi-layer filter to finally determine and guide the operating state and working mode.
7. A device for achieving a structured and successful pathway for the safety functions of a nuclear power plant, characterized in that, The device includes: The hierarchical functional coupling structure model building unit is used to build a hierarchical functional coupling structure model of the nuclear power plant based on the overall design criteria and functional structure design characteristics of the nuclear power plant, and on the basis of the target tree-success tree-state tree. The operating condition discrimination criterion establishment unit is used to clarify the operating purpose and functional target requirements of the nuclear power plant system equipment under different operating conditions through process characteristics and functional task decomposition analysis of the nuclear power plant's operating conditions, determine the system input status and related process parameter characterization range under specific or variable operating conditions, and establish discrimination criteria under different operating condition modes. The discrimination criteria are determined with reference to the standard operating state definition of the nuclear power plant in the nuclear power plant technical specifications. The standard operating state includes the nuclear power plant operating state corresponding to the combination of core reactivity, reactor power level, reactor coolant average temperature, and pressurizer pressure parameters. The emergency response task objective determination unit is used to extract characteristic changes of the parameter set based on parameter fluctuations or temporary alarms exceeding thresholds introduced during the switching of operating conditions of the nuclear power plant, and to accurately identify different operating conditions of the nuclear power plant through a feature pattern recognition algorithm. Under the current operating condition, based on the monitoring feedback of key safety parameters, it determines the integrity or damage status of the safety function of the nuclear power plant and formulates corresponding emergency response task objectives. The feature pattern recognition algorithm is based on the standard operating state definition of the nuclear power plant and the monitoring of its characteristic parameters. The successful channel set generation unit is used to generate a set of executable successful channels for the recovery of key safety functions by reverse deduction from the hierarchical functional coupling structure model of the nuclear power plant, based on the mission objective requirements and the monitoring input of the system equipment availability status and process parameter status, in accordance with the mission objective requirements and the monitoring input of the system equipment availability status and process parameter status. The optimal success channel determination unit is used to determine the optimal success channel based on the generated success channel set and the security function association to classify the system's security level, thus providing auxiliary support for operator emergency operations. The target tree-success tree-state tree is a multi-level structured model representation of the target-function-physical structure of a nuclear power plant, comprising three parts: a target tree model, a success tree model, and a state tree model. The target tree model is obtained by hierarchically decomposing the targets at each level, and is used to describe the realization association and supporting relationship of the targets at each level, including the overall safety target layer of the nuclear power plant, the safety function target layer, the functional task target layer, and the sub-targets of each level. The success tree model is constructed by extracting the interactive behavior features between physical structures / systems / equipment and process parameter variables, and is used to describe the channels and means for achieving the target function; The state tree model estimates the safety functions and safety target states of nuclear power plants based on key safety parameters, thereby supporting emergency response task planning. The key safety parameters are external correlation representations of the safety functions and safety target states of nuclear power plants. Based on the alarm level definition of key safety parameters, the model achieves multi-state division of safety functions.
8. A storage medium storing a program, characterized in that, When the program is executed by the processor, it implements the method for achieving a structured success channel for the safety functions of a nuclear power plant as described in any one of claims 1-6.