A mobile equipment dispatching system for multiple unit accidents in nuclear power plants

Abstract

The present invention belongs to the field of nuclear power simulation technology, and relates to a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant, in which a multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key states and index data; a mobile emergency equipment demand unit establishes mobile emergency equipment demand logic and determines the dispatching plan of mobile emergency equipment according to accident handling procedures and severe accident management guidelines; an accident mitigation simulation unit combines the dispatching demand of mobile emergency equipment on the basis of the initial state of the accident, performs accident simulation and comparative analysis through a severe accident analysis program, and evaluates the accident mitigation result; a mobile emergency equipment dispatching decision unit comprehensively determines the final dispatching decision of mobile equipment under multi-unit accidents. The present invention can avoid the adverse consequences caused by single information decision-making, and better help emergency decision-makers make more reasonable judgments.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power simulation, and in particular relates to a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant. Background Art

[0002] Earthquakes and tsunamis can cause nuclear accidents in nuclear power plants, and tsunamis can flood fixed emergency diesel generators in nuclear power plants, causing the nuclear power plants to lose AC power inside and outside the plants. my country's nuclear power plants that have been built and are under construction are all located in coastal areas. In the face of severe natural disasters, especially natural disasters such as super-large earthquakes and super-large tsunamis, there may be a potential risk of nuclear accidents caused by the loss of power inside and outside the plants.

[0003] In order to ensure the long-term discharge of residual heat from the core and spent fuel pool in the event of a power outage in the entire nuclear power plant, and to ensure the integrity of the second sealing barrier, my country has taken various emergency preparedness measures for nuclear power plants to respond to beyond-design basis accidents, including equipping low-voltage / medium-voltage mobile power supply vehicles, mobile water pump vehicles, fire trucks, etc. These equipment are stored in emergency equipment plants on a daily basis. Emergency equipment plants are generally built at the highest altitude of the plant area to ensure that the equipment is available in the event of floods or tsunamis. There are two types of accident conditions in which the unit needs an emergency low-voltage / medium-voltage power supply vehicle: loss of all external power or about to lose all external power, and the power plant emergency or standby diesel generator cannot be started. There are three main types of accident conditions in which the unit needs a mobile water pump vehicle and a fire truck: loss of make-up water in the primary circuit, loss of make-up water in the secondary circuit, and leakage in the spent fuel pool.

[0004] Based on the above background and current situation, how to timely and reasonably dispatch emergency mobile equipment when an accident occurs in a nuclear power plant unit is an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant. The system can make dispatching decisions on mobile emergency equipment by comprehensively considering various information such as equipment requirements, accident mitigation result comparison, and accident key parameters when accidents occur simultaneously in multiple units of a nuclear power plant and mobile emergency equipment is needed; at the same time, it can avoid adverse consequences caused by single information decision-making and better help emergency decision-makers make more reasonable judgments.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A mobile equipment dispatching system under multi-unit accidents in a nuclear power plant, the system comprising: a multi-unit accident simulation unit, a mobile emergency equipment demand unit, an accident mitigation simulation unit, and a mobile emergency equipment dispatching decision unit; the multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key states and index data; the mobile emergency equipment demand unit establishes mobile emergency equipment demand logic and determines the dispatching plan of mobile emergency equipment according to accident handling procedures and severe accident management guidelines; the accident mitigation simulation unit combines the dispatching demand of mobile emergency equipment on the basis of the initial state of the accident, performs accident simulation and comparative analysis through a severe accident analysis program, and evaluates the accident mitigation result; the mobile emergency equipment dispatching decision unit determines the final mobile equipment dispatching decision under multi-unit accidents by comprehensively considering the key states and index data, mobile emergency equipment demand, and accident mitigation results.

[0008] The multi-unit accident simulation unit is connected to the mobile emergency equipment demand unit; the multi-unit accident simulation unit transmits basic parameter data, key status and index data to the mobile emergency equipment demand unit, and the mobile emergency equipment demand unit determines the accident status according to the basic parameter data, key status and index data transmitted by the multi-unit accident simulation unit; the mobile emergency equipment demand unit determines the scheduling plan of the mobile emergency equipment in combination with the mobile emergency equipment demand logic and basic parameter data.

[0009] The multi-unit accident simulation unit and the mobile emergency equipment demand unit are respectively connected to the accident mitigation situation simulation unit; the multi-unit accident simulation unit transmits the initial state of the accident to the accident mitigation situation simulation unit, and the mobile emergency equipment demand unit transmits the mobile emergency equipment scheduling demand to the accident mitigation situation simulation unit; the accident mitigation situation simulation unit performs accident simulation calculations on whether to call the equipment based on the initial state of the accident in combination with the mobile emergency equipment scheduling demand through a severe accident analysis program, compares and analyzes the accident mitigation situation of whether the equipment is called per unit time, and evaluates the accident mitigation result.

[0010] The multi-unit accident simulation unit, the mobile emergency equipment demand unit, and the accident mitigation simulation unit are respectively connected to the mobile emergency equipment scheduling decision unit; the multi-unit accident simulation unit transmits key status and index data to the mobile emergency equipment scheduling decision unit, the mobile emergency equipment demand unit transmits the mobile emergency equipment demand to the mobile emergency equipment scheduling decision unit, and the accident mitigation simulation unit transmits the accident mitigation result to the mobile emergency equipment scheduling decision unit. The mobile emergency equipment scheduling decision unit comprehensively determines the final mobile equipment scheduling decision under the multi-unit accident based on the key status and index data, mobile emergency equipment demand, and accident mitigation results.

[0011] The accident model objects established by the multi-unit accident simulation unit include: main circuit thermal-hydraulic modeling, core material and structure modeling, containment compartment division and structure modeling, auxiliary plant modeling, spent fuel pool modeling, dedicated containment facility and system modeling, secondary circuit system and main equipment modeling, and reference unit post-improvement item modeling.

[0012] The basic parameter data include: temperature, pressure, water level, flow rate, and voltage.

[0013] The key status includes: which items in the accident handling procedures and severe accident management guidelines are triggered, which emergency action level is at, and what kind of accident has occurred.

[0014] The indicator data include: core outlet temperature, radioactive material leakage, and hydrogen concentration.

[0015] The beneficial technical effects of the present invention are:

[0016] 1. The present invention provides a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant. It simulates the accident status of multiple units through a severe accident analysis program, designs the emergency mobile equipment demand logic in combination with the nuclear power plant accident handling procedures and severe accident management guidelines, and simulates the accident mitigation situation before and after the emergency mobile equipment of different units is called, thereby achieving the technical effect of dispatching decision-making for mobile emergency equipment.

[0017] 2. The present invention provides a mobile equipment dispatching system for multi-unit accidents in a nuclear power plant. When accidents occur simultaneously in multiple units of a nuclear power plant and mobile emergency equipment is required, the system can make dispatching decisions on mobile emergency equipment by comprehensively considering various information such as equipment requirements, comparison of accident mitigation results, and key accident parameters.

[0018] 3. The mobile equipment dispatching system under multi-unit accidents in nuclear power plants provided by the present invention can avoid adverse consequences caused by single information decision-making and better help emergency decision-makers make more reasonable judgments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A block diagram of a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant provided by the present invention;

[0020] Figure 2 It is a demand logic design diagram of a low-voltage mobile power supply vehicle in an embodiment of the present invention;

[0021] Figure 3 It is a demand logic design diagram of a medium voltage mobile power supply vehicle in an embodiment of the present invention;

[0022] Figure 4 This is a demand logic design diagram for mobile water pump trucks and fire trucks in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] The present invention provides a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant. The system uses a severe accident analysis program to establish an accident model to simulate the initial state of a multi-unit accident, and obtains basic parameter data, key state and index data; and designs corresponding logic based on accident handling procedures and severe accident handling management guidelines to confirm the demand for emergency mobile equipment. Combined with the demand for emergency mobile equipment, the severe accident analysis program is continued to be used to perform simulation comparison and analysis in the initial state of the accident to confirm the optimal accident mitigation plan for dispatching mobile emergency equipment when similar accidents occur in multiple units at the same time; and finally, the above information is combined to complete the decision on dispatching mobile equipment under multi-unit accidents.

[0025] like Figure 1 As shown, the present invention provides a mobile equipment dispatching system under multi-unit accidents in a nuclear power plant, comprising: a multi-unit accident simulation unit, a mobile emergency equipment demand unit, an accident mitigation simulation unit, and a mobile emergency equipment dispatching decision unit.

[0026] The multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key states and indicator data; the mobile emergency equipment demand unit establishes the mobile emergency equipment demand logic and determines the scheduling plan for mobile emergency equipment according to the accident handling procedures and severe accident management guidelines; the accident mitigation simulation unit combines the scheduling needs of mobile emergency equipment on the basis of the initial state of the accident, performs accident simulation and comparative analysis through a severe accident analysis program, and evaluates the accident mitigation results; the mobile emergency equipment scheduling decision unit determines the final mobile equipment scheduling decision under multi-unit accidents based on key states and indicator data, mobile emergency equipment needs, and accident mitigation results.

[0027] The multi-unit accident simulation unit is connected to the mobile emergency equipment demand unit, the accident mitigation simulation unit, and the mobile emergency equipment dispatch decision unit. The multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key state and index data. The multi-unit accident simulation unit transmits the basic parameter data, key state and index data to the mobile emergency equipment demand unit; transmits the initial state of the accident to the accident mitigation simulation unit; and transmits the key state and index data to the mobile emergency equipment dispatch decision unit.

[0028] The multi-unit accident simulation unit uses severe accident analysis procedures to model and simulate the relevant systems of nuclear power plants. The modeling objects mainly include thermal hydraulic modeling of the main circuit, modeling of core materials and structures, containment compartment division and structure modeling, modeling of auxiliary buildings, modeling of spent fuel pools, modeling of dedicated containment facilities and systems, modeling of secondary circuit systems and major equipment, and modeling of reference unit post-improvement items; the calculation simulation includes severe accident phenomena such as steam generation, core overheating and melting, cladding oxidation and hydrogen generation, pressure vessel failure, reaction of core melt and concrete, combustion of combustible gases, and release of fission products.

[0029] Obtain data related to the modeling object (design information, plant layout, valve or pump start and stop logic diagram, etc.) and model the simulation object by filling in the input card. The parameters that need to be filled in for modeling include control parameters (time control, integral control, drawing control, output list, etc.), modeling parameters (physical parameters and structural parameters of modeling objects such as core, main loop, steam generator, containment, and dedicated safety facilities), event parameters (define the actual event logic that needs to be built, such as when the pressure of the pressurizer is lower than 10MPa, the operation event of opening the residual heat removal system), etc.

[0030] The input card after modeling is calculated and output using the severe accident analysis program. The output results are arranged in time sequence. The output content includes log files, event files, data files, etc. The details are as follows:

[0031] Log file: records all parameter values ​​changed in the input card, newly added operation logic, file output format, and some important results after the program operation is completed.

[0032] Event file: records in detail the event codes that have changed and the events that occurred during the entire simulation process.

[0033] Data file: records in detail the changes of various physical quantities with events during the entire simulation process.

[0034] Taking the large breach superimposed injection failure and spray failure accident as an example, any stage in the accident process 2-7 can be used as the initial state of the accident. The entire accident process is as follows:

[0035] 1) 300 seconds ago, the reactor was operating at full power and in a steady state;

[0036] 2) At 300s, assume that a cold pipe section of a loop is sheared and fractured, and the inner diameter of the cold pipe section is 0.6985m;

[0037] 3) The high and low pressure injection system is assumed to fail;

[0038] 4) The injection box is normal, and the injection port is located between the rupture and the cold section nozzle;

[0039] 5) When the pressure difference between the primary circuit and the containment is greater than 0.1MPa, the injection water cannot be injected into the pressure vessel, but flows out directly from the breach. When the pressure difference between the primary circuit and the containment is less than 0.1MPa, 10% of the injection flow can enter the pressure vessel, and 90% of the injection flow still flows out directly from the breach.

[0040] 6) Failure of containment spray system;

[0041] 7) The containment vessel began to leak after 24 hours.

[0042] The mobile emergency equipment demand unit is connected to the accident mitigation simulation unit and the mobile emergency equipment dispatch decision unit. The mobile emergency equipment demand unit establishes the mobile emergency equipment demand logic according to the accident handling procedures and severe accident management guidelines; judges the accident status according to the basic parameter data, key status and indicator data transmitted by the multi-unit accident simulation unit; and determines the dispatch plan of the mobile emergency equipment in combination with the mobile emergency equipment demand logic and basic parameter data. The mobile emergency equipment demand unit transmits the mobile emergency equipment dispatch demand to the accident mitigation simulation unit; and transmits the mobile emergency equipment demand to the mobile emergency equipment dispatch decision unit.

[0043] In the event of an accident, the accident handling procedures (for design basis accidents) and the severe accident management guidelines (for severe accidents) have corresponding handling measures for low evaporator water level and low primary circuit water level. Mobile emergency equipment will be dispatched in the relevant handling measures. For example, the mitigation measure for low primary circuit water level in the severe accident management guidelines is to inject water into the reactor coolant system. During the process of injecting water into the reactor coolant system, it is necessary to call a mobile water pump truck for water injection. At this time, the mobile emergency equipment demand logic (calling a mobile water pump truck for water injection) is established through the severe accident management guidelines (the low primary circuit water level requires water injection into the reactor coolant system).

[0044] The basic parameter data include temperature, pressure, water level, flow, voltage and other parameters. According to the accident handling procedures, by comparing the evaporator pressure, primary circuit pressure and containment pressure, it can be determined whether it is a primary circuit large rupture accident or a secondary circuit pipeline rupture accident in the containment, and then the corresponding accident can be handled according to the regulations.

[0045] When an accident occurs, the accident handling procedures (for design basis accidents) and severe accident management guidelines (for severe accidents) are used to confirm the handling measures for different accidents and the required mobile emergency equipment. The basic parameter data is used to determine what type of accident has occurred (such as a primary circuit major rupture accident or a secondary circuit pipeline rupture accident in the containment) and the consequences of the corresponding accident. The demand for mobile emergency equipment (what kind of mobile emergency equipment is needed for what kind of accident) and basic parameter data (to determine the type of accident, the stage of the accident process, and the harm caused by the consequences of the accident) are used to determine the dispatch plan for mobile emergency equipment.

[0046] The accident mitigation simulation unit is connected to the mobile emergency equipment dispatch decision unit. Based on the initial state of the accident and the dispatch requirements of the mobile emergency equipment, the accident mitigation simulation unit performs accident simulation calculations on whether to call the equipment through the severe accident analysis program, compares and analyzes the accident mitigation situation of whether to call the equipment within a unit time, and evaluates the accident mitigation results. The accident mitigation results are transmitted to the mobile emergency equipment dispatch decision unit.

[0047] Taking the large breach superimposed with injection failure and spray failure as an example, the whole accident process is as follows:

[0048] 1) 300 seconds ago, the reactor was operating at full power and in a steady state;

[0049] 2) At 300s, assume that a cold pipe section of a loop is sheared and fractured, and the inner diameter of the cold pipe section is 0.6985m;

[0050] 3) The high and low pressure injection system is assumed to fail;

[0051] 4) The injection box is normal, and the injection port is located between the rupture and the cold section nozzle;

[0052] 5) When the pressure difference between the primary circuit and the containment is greater than 0.1MPa, the injection water cannot be injected into the pressure vessel, but flows out directly from the breach. When the pressure difference between the primary circuit and the containment is less than 0.1MPa, 10% of the injection flow can enter the pressure vessel, and 90% of the injection flow still flows out directly from the breach.

[0053] 6) Failure of containment spray system;

[0054] 7) The containment vessel began to leak after 24 hours.

[0055] At stage 6 of the accident, the high and low pressure injection system and the containment spray system had already failed, and the primary circuit water level gradually dropped. After it dropped to the point where the core was exposed, the core temperature began to rise. The mitigation measure for the low primary circuit water level in the severe accident management guidelines is to inject water into the reactor coolant system. During the process of injecting water into the reactor coolant system, it is necessary to call a mobile water pump truck for water injection. At this time, the operation of calling a mobile water pump truck for water injection was carried out in accordance with the severe accident management guidelines, and the core was re-flooded for cooling, protecting the safety of the core. Compare the accident mitigation situations in the two cases of calling a mobile water pump truck (core re-flooding) and not calling a mobile water pump truck (exposed core temperature rise). (Simulated through severe accident analysis program)

[0056] The closer the core outlet temperature, radioactive material leakage, hydrogen concentration and other parameters are to normal values, the better the accident mitigation effect will be if the subcriticality, core cooling, secondary heat sink, primary circuit water loading, primary circuit integrity and containment integrity functions are maintained (or satisfied for a longer period of time). Whether the subcriticality, core cooling, secondary heat sink, primary circuit water loading, primary circuit integrity and containment integrity functions are satisfied is determined based on the symptom-oriented accident handling procedures (SEOP). For example, if the core cooling function is satisfied when the core outlet temperature is less than 650°C and the core outlet subcooling is greater than 20°C.

[0057] The mobile emergency equipment dispatch decision unit comprehensively considers key status and indicator data, mobile emergency equipment demand, and accident mitigation results to determine the final mobile equipment dispatch decision under multi-unit accidents.

[0058] By obtaining key status and indicator data, mobile emergency equipment demand, and accident mitigation results, we can combine the above information to make a comprehensive judgment and determine the final mobile equipment scheduling decision under multi-unit accidents.

[0059] Among them, through the key status, we can obtain which items in the accident handling procedures and severe accident management guidelines have been triggered, what emergency action level is at, what kind of accident has occurred, etc.; through the indicator data, we can obtain information such as the core outlet temperature, radioactive material leakage, hydrogen concentration, etc.; through the demand for mobile emergency equipment, we can obtain which mobile emergency equipment is needed in the current accident (which of the low-voltage mobile power supply vehicle, medium-voltage mobile power supply vehicle, mobile water pump vehicle, and fire truck are needed); through the accident mitigation results, we can obtain the comparison of indicator data such as the core outlet temperature, radioactive material leakage, and hydrogen concentration when using mobile emergency equipment and not using mobile emergency equipment. Finally, based on the above information, we consider how to reasonably allocate limited mobile emergency equipment to each unit in the case of a multi-unit accident under unit time (unit time refers to the time that the mobile emergency equipment can be used continuously, such as the time that the mobile power supply vehicle can continuously supply power, and the time that the mobile water pump vehicle or fire truck can continuously inject water), so as to minimize the overall harm.

[0060] In a specific implementation, basic parameter data include: temperature, pressure, water level, flow, voltage; key states include: which items in the accident handling procedures and severe accident management guidelines are triggered, what emergency action level is at, and what type of accident has occurred; indicator data include: core outlet temperature, radioactive material leakage, hydrogen concentration, etc.; accident handling procedures such as H3.1-RRA of the M310 unit EOP procedure is not connected when the entire plant is shut down; severe accident management guidelines such as SAG-3 in the M310 unit SAMG-injection of water into the reactor coolant system.

[0061] In another specific implementation, the unit time refers to the continuous use time of the mobile emergency equipment, such as the continuous power supply time of the mobile power supply vehicle, the continuous water injection time of the mobile water pump vehicle or the fire truck. Whether to call for equipment to mitigate the accident includes: the comparison of the core outlet temperature, radioactive material leakage, hydrogen concentration and other indicators when using the mobile emergency equipment and when not using the mobile emergency equipment.

[0062] The present invention can make dispatching decisions on mobile emergency equipment by integrating multiple information such as equipment requirements, accident mitigation result comparison, and accident key parameters when multiple units in a nuclear power plant have accidents at the same time and need mobile emergency equipment. At the same time, it can avoid adverse consequences caused by single information decision-making and better help emergency decision-makers make more reasonable judgments.

[0063] Example 1 Multi-unit accident simulation unit

[0064] The multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key states and indicator data.

[0065] The accident models established by the multi-unit accident simulation unit include: main circuit thermal-hydraulic modeling, core material and structure modeling, containment compartment division and structure modeling, auxiliary plant modeling, spent fuel pool modeling, dedicated containment facility and system modeling, secondary circuit system and main equipment modeling, and reference unit post-improvement item modeling.

[0066] The established accident model can simulate accidents such as power outage of the entire plant (calling a mobile power supply vehicle), water loss in the primary / secondary circuit (calling a mobile water pump vehicle), etc., and can realize the simulation from steady state to baseline accident and finally to severe accident scenario. When simulating accidents, each unit accident needs to be simulated separately. Some parameters of the simulation calculation of the severe accident analysis program are shown in Table 1. Table 1 gives a partial list of parameters.

[0067] Table 1 Parameter list

[0068]

[0069]

[0070] Example 2 Mobile emergency equipment demand unit

[0071] The mobile emergency equipment demand unit establishes demand logic according to the accident handling procedures and severe accident management guidelines, and adopts multiple parameter multiple verification methods for relevant important input parameters to make the logical judgment results more real and reliable. Taking a nuclear power base as an example, there are 4 types of mobile emergency equipment in the base, including medium-voltage mobile power supply trucks, low-voltage mobile power supply trucks, mobile water pump trucks, and fire trucks. The information of mobile emergency equipment is shown in Table 2.

[0072] Table 2 Mobile emergency equipment information table

[0073]

[0074] Taking the whole plant power outage when H3.1-RRA of the M310 unit EOP regulation is not connected as an example, the logic information of the low-voltage mobile power supply vehicle demand is shown in Table 3, and the logic design is as follows: Figure 2 shown.

[0075] When the accident procedure H3.1 is triggered, the voltage of 0GEW002MU1 and 0GEW002MU2 is less than 400KV; the voltage of 9LGR001MU1 and 9LGR001MU2 is less than 176KV; when 9LLS507KS and 2LNE005SY are equal to 1, a low-voltage mobile power supply vehicle is called.

[0076] Table 3 Low-voltage mobile power vehicle demand logic information table

[0077]

[0078] The logic information required for the medium voltage mobile power supply vehicle is shown in Table 4. The logic design is as follows: Figure 3 shown.

[0079] When the accident procedure H3.1 is triggered, the voltage of 0GEW002MU1 and 0GEW002MU2 is less than 400KV; the voltage of 9LGR001MU1 and 9LGR001MU2 is less than 176KV; the voltage of 1LHP404MU1, 1LHQ404MU1, 0LHS404MU1, 2LHP404MU1, 2LHQ404MU1 is less than 5280V, and the medium-voltage mobile power supply vehicle is called.

[0080] Table 4 Requirement logic information table of medium voltage mobile power vehicle

[0081]

[0082] Taking SAG-3 in the SAMG of the M310 unit - water injection into the reactor coolant system as an example, the demand logic information of the mobile water pump truck and the fire truck is shown in Table 5. The logic design is as follows: Figure 4 shown.

[0083] When Severe Accident Management Guidelines SAG-3 is triggered, a mobile water pump truck or fire truck is called in.

[0084] Table 5 Logic information table of mobile water pump truck and fire truck demand

[0085]

[0086] Example 3 Accident Mitigation Simulation Unit

[0087] Through the multi-unit accident simulation unit, the initial state of the accident was obtained, and the basic parameter data, key status and indicator data were acquired. On this basis, the accident was further simulated in combination with the demand for mobile emergency equipment, and the accident relief situation per unit time was compared between the two cases of whether the equipment was called or not.

[0088] Taking the whole plant power outage when H3.1-RRA of the M310 unit EOP regulations is not connected as an example, when the two off-site power supplies and the emergency diesel generator in the plant are lost, the LLS can operate until the temporary power supply is intervened (about 6 hours), that is, except for the power loss, the loss of other functions of the power plant is not considered. After the mobile power supply is connected, it replaces the LLS and uses a 380V low-voltage mobile power supply to power the LLS001AR to provide power for the water pressure test pump and the main pump shaft seal water to ensure the integrity of the primary circuit pressure boundary. At the same time, the instruments monitoring the important parameters of the core can also be powered. The core heat relies on the steam-driven auxiliary feedwater pump to supply water to the steam generator. The steam generated by the steam generator is discharged to the atmosphere to take out the heat. The water volume of the primary circuit is maintained by the water pressure test pump (through shaft seal injection or top-up). When the mobile power supply cannot be connected, the water level of the steam generator continues to decrease until it dries up. After losing the secondary circuit heat sink, the core water level also continues to decrease until the core is exposed. Then the core temperature begins to rise and the situation continues to deteriorate. Compare the accident mitigation situations of whether the equipment is called upon during the time when the mobile power vehicle provides continuous power, and determine the optimal accident mitigation plan for the dispatch of mobile emergency equipment when similar accidents occur in multiple units at the same time. The parameters that need to be focused on include: core outlet temperature, radioactive material leakage, and hydrogen concentration.

[0089] Example 4 Mobile emergency equipment dispatch unit

[0090] After completing the multi-unit accident simulation, mobile emergency equipment requirements, and accident mitigation simulation, decisions can be made by comparing key parameter indicators, equipment requirements, and accident mitigation results.

[0091] When accidents occur in multiple units and the number of emergency mobile equipment required is greater than the actual number, the present invention can comprehensively evaluate the severity of accidents occurring in different units and the degree of demand for emergency mobile equipment by the units, provide information comparison, and assist emergency decision-makers in dispatching and commanding.

[0092] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant, characterized in that: The system comprises: a multi-unit accident simulation unit, a mobile emergency equipment demand unit, an accident mitigation simulation unit, and a mobile emergency equipment dispatch decision unit; the multi-unit accident simulation unit establishes an accident model through a severe accident analysis program, simulates and calculates the initial state of each unit accident, and obtains basic parameter data, key states and index data; the mobile emergency equipment demand unit establishes the mobile emergency equipment demand logic and determines the dispatch plan of the mobile emergency equipment according to the accident handling procedures and severe accident management guidelines; the accident mitigation simulation unit conducts accident simulation and comparative analysis based on the initial state of the accident and the dispatch demand of the mobile emergency equipment through a severe accident analysis program, and evaluates the accident mitigation results; the mobile emergency equipment dispatch decision unit determines the final dispatch decision of the mobile equipment under the multi-unit accident by combining the key states and index data, the mobile emergency equipment demand, and the accident mitigation results; The multi-unit accident simulation unit and the mobile emergency equipment demand unit are respectively connected to the accident mitigation situation simulation unit; the multi-unit accident simulation unit transmits the initial state of the accident to the accident mitigation situation simulation unit, and the mobile emergency equipment demand unit transmits the mobile emergency equipment scheduling demand to the accident mitigation situation simulation unit; the accident mitigation situation simulation unit performs accident simulation calculations on whether to call the equipment based on the initial state of the accident in combination with the mobile emergency equipment scheduling demand through a severe accident analysis program, compares and analyzes the accident mitigation situation of whether the equipment is called per unit time, and evaluates the accident mitigation result.

2. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant according to claim 1, characterized in that: The multi-unit accident simulation unit is connected to the mobile emergency equipment demand unit; the multi-unit accident simulation unit transmits basic parameter data, key status and index data to the mobile emergency equipment demand unit, and the mobile emergency equipment demand unit determines the accident status according to the basic parameter data, key status and index data transmitted by the multi-unit accident simulation unit; the mobile emergency equipment demand unit determines the scheduling plan of the mobile emergency equipment in combination with the mobile emergency equipment demand logic and basic parameter data.

3. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant according to claim 1, characterized in that: The multi-unit accident simulation unit, the mobile emergency equipment demand unit, and the accident mitigation simulation unit are respectively connected to the mobile emergency equipment scheduling decision unit; the multi-unit accident simulation unit transmits key status and index data to the mobile emergency equipment scheduling decision unit, the mobile emergency equipment demand unit transmits the mobile emergency equipment demand to the mobile emergency equipment scheduling decision unit, and the accident mitigation simulation unit transmits the accident mitigation result to the mobile emergency equipment scheduling decision unit. The mobile emergency equipment scheduling decision unit comprehensively determines the final mobile equipment scheduling decision under the multi-unit accident based on the key status and index data, mobile emergency equipment demand, and accident mitigation results.

4. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant according to claim 1, characterized in that: The accident model objects established by the multi-unit accident simulation unit include: main circuit thermal-hydraulic modeling, core material and structure modeling, containment compartment division and structure modeling, auxiliary plant modeling, spent fuel pool modeling, dedicated containment facility and system modeling, secondary circuit system and main equipment modeling, and reference unit post-improvement item modeling.

5. The mobile equipment dispatching system for multiple unit accidents in a nuclear power plant according to claim 1, characterized in that: The basic parameter data include: temperature, pressure, water level, flow rate, and voltage.

6. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant according to claim 1, characterized in that: The key status includes: which items in the accident handling procedures and severe accident management guidelines are triggered, which emergency action level is at, and what kind of accident has occurred.

7. A mobile equipment dispatching system for multi-unit accidents in a nuclear power plant according to claim 1, characterized in that: The indicator data include: core outlet temperature, radioactive material leakage, and hydrogen concentration.

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