Large sodium-cooled fast reactor power station

Abstract

The invention particularly relates to a large sodium-cooled fast reactor power station, which belongs to the technical field of sodium-cooled fast reactors, and comprises a plurality of sodium-cooled fast reactor units and an auxiliary system shared by the sodium-cooled fast reactor units, and each sodium-cooled fast reactor unit comprises a sodium-cooled fast reactor, a main heat transmission system, a power conversion system, an accident waste heat removal system and an energy storage system; the sodium-cooled fast reactor is arranged in a reactor building; the sodium-cooled fast reactor comprises a reactor pit, a containment vessel in the reactor pit and a reactor body in the containment vessel, and is constructed through the following steps that the reactor pit, the containment vessel and the reactor body are constructed in parallel, the reactor body is loaded into the containment vessel after the containment vessel and the reactor body are constructed, the reactor body is modularly manufactured, the containment vessel is a capsule type small steel containment vessel, and the containment vessel is a capsule type small steel containment vessel. The pile pit is built by concrete; and integrally pushing the containment and the reactor body in the containment into a reactor pit. While the nuclear safety and the industrial safety are improved, the economical efficiency of the sodium-cooled fast reactor power station is greatly improved, and the construction period of the sodium-cooled fast reactor power station is greatly shortened.

Description

Technical Field

[0001] The invention relates to the technical field of sodium-cooled fast reactors, in particular to a large-scale sodium-cooled fast reactor power station. Background Art

[0002] Fast reactors are an important direction for the development of advanced nuclear energy, especially sodium-cooled fast reactors. After more than 70 years of development, they have become the fourth-generation advanced nuclear energy technology with the most commercial promotion prospects among the fourth-generation advanced nuclear power reactors. Although the world has accumulated more than 400 reactor-years of sodium-cooled fast reactor operation experience, the currently operating large-scale sodium-cooled fast reactor power plants still have the following problems: due to the low radiation resistance of the fuel assembly cladding material and outer sleeve, the core line power density is low, the fuel consumption is small, the overall volume of the core is large, and the design of the reactor body container is relatively large; the layout of the secondary circuit and other sodium process pipelines and the overall layout of the nuclear island plant are unreasonable, the sodium process pipelines are long, and there are many sodium process rooms; the ventilation system design is complex and the ventilation system is seriously split; the layout of the main control room and the electrical room is unreasonable, and the cable laying is long; these problems have led to a lot of room for improvement in the economy of my country's large-scale sodium-cooled fast reactor power plants. Summary of the invention

[0003] The purpose of the present invention is to provide a large-scale sodium-cooled fast reactor power plant, which, through deep innovative optimization of a traditional sodium-cooled fast reactor power plant, carries out innovative design in terms of the core, the reactor body, the main heat transmission system, the power conversion system and the plant structure, thereby greatly improving the economy of the sodium-cooled fast reactor power plant while improving nuclear safety and industrial safety, and greatly shortening the construction period of the sodium-cooled fast reactor power plant.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: A large sodium-cooled fast reactor power plant comprises a sodium-cooled fast reactor unit and a sodium-cooled fast reactor unit auxiliary system; the sodium-cooled fast reactor unit is used to convert nuclear energy into electrical energy or steam energy, and the sodium-cooled fast reactor unit auxiliary system is used to assist the sodium-cooled fast reactor unit in converting nuclear energy into electrical energy or steam energy; there are multiple sodium-cooled fast reactor units, and the sodium-cooled fast reactor unit auxiliary system is shared by two or each of the sodium-cooled fast reactor units; The sodium-cooled fast reactor unit includes a sodium-cooled fast reactor, a main heat transfer system, a power conversion system, an accident residual heat removal system and an energy storage system; the sodium-cooled fast reactor is used to generate heat energy by nuclear fission; the main heat transfer system is used to transfer the heat energy generated by the sodium-cooled fast reactor to the power conversion system; the power conversion system is used to convert the heat energy generated by the sodium-cooled fast reactor into electrical energy or steam energy; the energy storage system is used to store and release electrical energy; the accident residual heat removal system is used to remove the residual heat of the sodium-cooled fast reactor under the accident condition of the sodium-cooled fast reactor; The sodium-cooled fast reactor is arranged in the reactor building of the nuclear island. The reactor building is an ordinary earthquake-resistant building and is manufactured in a modular manner with a large process room. The sodium-cooled fast reactor includes a reactor pit, a containment vessel in the reactor pit, and a reactor body in the containment vessel. Its construction is completed through the following steps: the construction of the reactor pit, the containment vessel, and the reactor body are carried out in parallel, and after the construction of the containment vessel and the reactor body is completed, the reactor body is installed in the containment vessel. The reactor body is manufactured in a modular manner, the containment vessel is a small capsule-type steel containment vessel, and the reactor pit is built of concrete; the containment vessel and the reactor body in the containment vessel are pushed into the reactor pit as a whole.

[0005] As one of the achievable methods, the containment is divided into an upper container and a lower container; the upper container is a hemispherical container, the lower container is a cylindrical container, and the diameters of the upper container and the lower container are the same; the upper container and the lower container are connected by welding to form the containment, the interiors of the upper container and the lower container are connected, and the welding meets the airtightness requirements of the containment; a detachable top cover is provided on the top of the upper container, and the top cover adopts a mechanical seal; The containment is equipped with personnel and equipment access passages in the reactor hall, which are sealed with sodium fire protection doors. The personnel and equipment access passages are closed during normal operation of the sodium-cooled fast reactor and open during maintenance of the sodium-cooled fast reactor. A sodium leakage receiving and suppression plate is provided at the bottom of the containment vessel, which is used to prevent and mitigate sodium fire accidents and collect and extinguish sodium fires in the reactor pit; a core melt collector is provided at the bottom of the reactor body, which is used to collect and cool molten fuel when the entire core is melted. As one of the feasible ways, the reactor body includes a reactor body container, a reactor body top cover sealed to the top of the reactor body container, a reactor top device sealed to the reactor body top cover, a reactor top shielding device sealed to the reactor body top cover, a sodium pool in the reactor body container, and an intermediate heat exchanger, an independent heat exchanger, a primary sodium pump and a reactor core arranged in the sodium pool; wherein the intermediate heat exchanger and the independent heat exchanger are both manufactured using integrated 3D printing technology; the reactor top shielding device is designed and manufactured in an integrated manner; The internal components of the sodium-cooled fast reactor are made of low-copper and low-phosphorus steel with a phosphorus content of 10 to 1000 ppm and a copper content of 0.1 to 5% to mitigate neutron radiation embrittlement and achieve a design life of the sodium-cooled fast reactor unit of ≥60 years.

[0006] As one of the feasible ways, the core uses radiation-resistant FMS or ODS cladding materials; the inner ring of the core is the active zone, in which the fissile nuclear fuel U-235 undergoes fission reaction to produce fast neutrons; the outer ring of the core is the breeding zone, in which the fissile nuclear fuel U-238 absorbs fast neutrons and is converted into fissile nuclear fuel Pu-239; the content of fissile nuclear fuel Pu-239 in the breeding zone is higher than that in the active zone, so that the power of the fuel assemblies in the active zone and the breeding zone is flattened; The active zone includes an active zone fuel inner zone and an active zone fuel outer zone surrounding the outer periphery of the active zone fuel inner zone; the active zone fuel inner zone is designed to be axially non-uniform, and is axially divided from top to bottom into a first active zone fuel inner zone, an inert fuel zone, and a second active zone fuel inner zone; the active zone fuel inner zone and the breeding zone are each provided with an irradiation zone for isotope production; The breeding ratio in the core is 1; the control rod assembly consists of a regulating control rod assembly and a safety control rod assembly, or a regulating control rod assembly, a safety control rod assembly and a small number of compensating control rod assemblies; the safety control rod assembly is used to control the shutdown of the sodium-cooled fast reactor, the regulating control rod assembly is used to control the power of the sodium-cooled fast reactor, and the compensating control rod assembly is used for the positive reactivity of the sodium-cooled fast reactor; The reactor body top cover is provided with a reactor rotating shield plug; the reactor top equipment includes a control rod drive mechanism; the control rod drive mechanism enters the reactor body container from the rotating shield plug and connects with the corresponding control rod in the core, driving the control rod to insert or extract the fuel assembly; A short fuel rod bundle is combined at the lower end of the control rod; when the control rod is inserted, the control rod is located in the inner area of ​​the fuel in the active zone, introducing negative reactivity; when the control rod is lifted, the short fuel rod bundle at the lower end of the control rod is located in the inner area of ​​the fuel in the active zone, introducing positive reactivity, thereby increasing the value of the control rod.

[0007] As one of the feasible ways, the main heat transfer system is a sodium-sodium-molten salt-water four-circuit structure, including an intermediate heat exchanger, a primary sodium pump, a secondary sodium pump, a sodium-molten salt heat exchanger, a first regulating valve, a second regulating valve, a high-temperature molten salt pump, a low-temperature molten salt pump, a molten salt-water heat exchanger, a high-temperature molten salt tank, a low-temperature molten salt tank, a main feed water pump and a linear Fresnel concentrating system; The sodium pool is filled with primary sodium and is divided into a cold pool and a hot pool by partitions; the reactor core and the intermediate heat exchanger are arranged in the hot pool, and the primary sodium pump is arranged in the cold pool; the primary sodium pump flows the primary sodium in the cold pool through the reactor core and the primary sodium side of the intermediate heat exchanger and then returns it to the cold pool to form a primary loop; The outlet of the secondary circuit sodium side of the intermediate heat exchanger is connected to the secondary circuit sodium pump, the sodium side of the sodium-molten salt heat exchanger and the inlet of the secondary circuit sodium side of the intermediate heat exchanger by pipelines in sequence to form a secondary circuit; in the secondary circuit, the secondary circuit sodium on the secondary circuit sodium side of the intermediate heat exchanger flows through the sodium side of the sodium-molten salt heat exchanger through the secondary circuit sodium pump and is then sent back to the secondary circuit sodium side of the intermediate heat exchanger; The outlet of the molten salt side of the sodium-molten salt heat exchanger is connected to the high-temperature molten salt tank, the second regulating valve, the high-temperature molten salt pump, the molten salt side of the molten salt-water heat exchanger, the low-temperature molten salt tank, the first regulating valve, the low-temperature molten salt pump and the inlet of the molten salt side of the sodium-molten salt heat exchanger by pipelines in sequence, forming a three-circuit circuit; in the three-circuit circuit, the molten salt on the molten salt side of the sodium-molten salt heat exchanger flows through the high-temperature molten salt tank, the molten salt side of the molten salt-water heat exchanger and the low-temperature molten salt tank through the high-temperature molten salt pump, and then is sent back to the molten salt side of the sodium-molten salt heat exchanger through the low-temperature molten salt pump; the pipeline connecting the molten salt side of the sodium-molten salt heat exchanger and the high-temperature molten salt tank is heated by the linear Fresnel concentrating system, and the linear Fresnel concentrating system uses light energy to heat the molten salt in the molten salt pipeline, thereby realizing the coupling of the sodium-cooled fast reactor and light energy; The water side outlet of the molten salt-water heat exchanger is connected to the power conversion system, the main water supply pump and the water side outlet inlet of the molten salt-water heat exchanger by pipelines in sequence, forming four circuits; in the four circuits, the main water supply on the water side of the molten salt-water heat exchanger flows through the power conversion system through the main water supply pump and is then sent back to the water side of the molten salt-water heat exchanger.

[0008] As one of the feasible ways, the power conversion system includes a steam circuit control valve, a power generation circuit control valve, a molten salt superheater, a steam turbine generator, a condenser, a steam user, a power grid user and a power grid main transformer; the water side outlet of the molten salt-water heat exchanger is divided into two routes, one route is sequentially connected to the steam circuit control valve by pipeline, and the other route is sequentially connected to the power generation circuit control valve, the molten salt superheater, the steam turbine generator, the condenser, the main feed water pump and the water side inlet of the molten salt-water heat exchanger by pipeline; the steam turbine generator and the steam user are connected by pipeline, and a check valve is provided on the pipeline connecting the steam turbine generator and the steam user; the power generation outlet of the steam turbine generator is connected to the power grid user through the power grid main transformer; The operation mode of the sodium-cooled fast reactor unit is one or a combination of the solar thermal energy storage mode, the power generation mode and the high-temperature industrial steam supply mode; In the solar thermal energy storage mode, the first regulating valve, the second regulating valve, the steam circuit control valve, the power generation circuit control valve and the check valve are all closed; the sodium-cooled fast reactor operates at full power, the secondary circuit sodium pump and the high-temperature molten salt pump operate at rated power, the low-temperature molten salt pump operates at high power, and the linear Fresnel concentrating system heats the molten salt pipeline; the liquid level of the high-temperature molten salt tank rises, and the liquid level of the low-temperature molten salt tank drops. By adjusting the amount of high and low-temperature molten salt, nuclear energy and light energy are converted into molten salt thermal energy for storage; In power generation mode, the first regulating valve, the second regulating valve, the power generation circuit control valve and the check valve are all open, and the steam circuit control valve is closed; the sodium-cooled fast reactor operates at full power, and the secondary circuit sodium pump, the low-temperature molten salt pump and the high-temperature molten salt pump all operate at rated power; the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged; part of the steam after the steam turbine generator generates electricity is sent to the condenser to condense into condensate, and part is sent to the steam user; the condensate is sent to the water side of the molten salt-water heat exchanger for heat exchange through the main feed water pump, and then sent to the molten salt superheater to be heated into superheated steam and then sent back to the steam turbine generator to generate electricity; In the high-temperature industrial steam supply mode, the first regulating valve, the second regulating valve and the steam circuit control valve are all opened, and the power generation circuit control valve and the check valve are all closed; the sodium-cooled fast reactor operates at full power, and the secondary circuit sodium pump, the low-temperature molten salt pump and the high-temperature molten salt pump all operate at rated power; the liquid levels of the high-temperature molten salt tank and the low-temperature molten salt tank remain unchanged; the main feed water is pumped to the water side of the molten salt-water heat exchanger through the main feed water pump for heat exchange to generate high-temperature industrial steam and send it to the steam users.

[0009] As one of the feasible ways, the primary frequency regulation and peak regulation of the sodium-cooled fast reactor unit includes the power increase of the sodium-cooled fast reactor unit and the power decrease of the sodium-cooled fast reactor unit. The power decrease of the sodium-cooled fast reactor unit has the following two modes: In the first mode, the sodium-cooled fast reactor unit maintains the power generation mode, the sodium-cooled fast reactor runs at full power, the secondary circuit sodium pump runs at full power, and the heat of the sodium-cooled fast reactor is continuously taken out; the low-temperature molten salt pump runs at rated power, the high-temperature molten salt pump runs at low power, and the main feed water pump runs at low power, so that the total amount of steam is reduced and the output power of the steam turbine generator is reduced, thereby realizing the peak regulation of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank increases, and the liquid level of the low-temperature molten salt tank continues to decrease. By adjusting the high and low temperature molten salt reserves, the excess energy generated by the sodium-cooled fast reactor is stored; In the second mode, the sodium-cooled fast reactor unit starts the high-temperature industrial steam supply mode simultaneously with the power generation mode, and controls the amount of high-temperature industrial steam supply by controlling the opening of the steam loop control valve, thereby reducing the power generation of the steam turbine generator and realizing the peak regulation of the sodium-cooled fast reactor unit. The power increase operation mode of the sodium-cooled fast reactor unit is as follows: the sodium-cooled fast reactor operates at full power, the secondary circuit sodium pump operates at full power, and the heat of the sodium-cooled fast reactor is continuously removed; the high-temperature molten salt pump operates at high power, the low-temperature molten salt pump operates at rated power, and the main feed water pump operates at high power, so that the total amount of steam is increased, the output power of the steam turbine generator is increased, and the peak load of the sodium-cooled fast reactor unit is achieved; the liquid level of the high-temperature molten salt tank is reduced, and the liquid level of the low-temperature molten salt tank is increased. By adjusting the reserves of high and low temperature molten salt, the molten salt energy storage is released, the power generation power of the steam turbine generator is increased, and the online power of the sodium-cooled fast reactor unit is increased.

[0010] As one of the feasible ways, the secondary frequency regulation of the sodium-cooled fast reactor unit includes the secondary frequency regulation of the sodium-cooled fast reactor unit power down and the secondary frequency regulation of the sodium-cooled fast reactor unit power up; Under the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator is synchronously connected to the energy storage system for charging, thereby reducing the online power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit; Under the secondary frequency regulation for power increase of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator is synchronously connected to the energy storage system for discharge, thereby increasing the online power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation for power increase of the sodium-cooled fast reactor unit.

[0011] As one of the feasible ways, the condenser includes an air-cooled radiator and a natural ventilation cooling tower. The air-cooled radiator is connected to the steam turbine generator pipeline and arranged at the bottom or side of the natural ventilation cooling tower. The steam after the steam turbine generator generates electricity is sent to the air-cooled radiator. The suction force of the natural ventilation cooling tower makes the cold air flow through the surface of the air-cooled radiator, so that the steam in the air-cooled radiator condenses to form condensed water, which is sent to the water side of the molten salt-water heat exchanger through the main feed water pump.

[0012] As one of the feasible ways, the accident residual heat removal system includes an air heat exchanger and an independent heat exchanger; used for removing the residual heat of the sodium-cooled fast reactor under the accident condition of the sodium-cooled fast reactor; The air heat exchanger is arranged at the bottom or side of the wind chimney and is connected to the wind chimney pipeline; the independent heat exchanger is arranged in the cold pool or the hot pool and is connected to the air heat exchanger pipeline; The primary sodium in the cold pool flows through the core and the primary sodium side of the independent heat exchanger and then returns to the cold pool; the secondary sodium on the secondary sodium side of the independent heat exchanger undergoes heat exchange with the primary sodium on the primary sodium side of the independent heat exchanger and then enters the air heat exchanger, exchanges heat with the air in the air heat exchanger and then returns to the secondary sodium side of the independent heat exchanger; the air in the air heat exchanger rises due to the heat, and is discharged into the atmosphere from the exhaust chimney using the pressure difference generated by the height difference of the exhaust chimney.

[0013] As one of the feasible ways, the auxiliary system of the sodium-cooled fast reactor unit includes a primary-loop purification system, a secondary-loop purification system, a nitrogen system, an argon system, a vacuum system, a gas heating system, a ventilation system, a refrigeration system, an electrical system, an instrumentation and control system, a refueling system and a fire-fighting system; among which, the primary-loop purification system and the secondary-loop purification system are shared by two sodium-cooled fast reactor units; the nitrogen system, the argon system, the vacuum system, the gas heating system, the ventilation system, the refrigeration system, the electrical system, the instrumentation and control system, the refueling system and the fire-fighting system are shared by each sodium-cooled fast reactor unit.

[0014] As one of the feasible ways, the nitrogen system is used to fill the sodium fire location in the containment with nitrogen when a sodium fire accident occurs, so as to extinguish the sodium fire and mitigate the consequences of the sodium fire accident; the nitrogen system is arranged in the reactor building, including a nitrogen tank, a nitrogen pipeline and a nitrogen valve; the nitrogen tank is used to store nitrogen; the nitrogen tank is connected to the inside of the containment through a nitrogen pipeline, and a nitrogen valve is provided on the nitrogen pipeline; the nitrogen valve receives control instructions from the instrument control system, and controls the charging and discharging of nitrogen from the nitrogen tank into the containment according to the control instructions.

[0015] As one of the achievable methods, the ventilation system is arranged in the reactor building, including a first air inlet duct, a second air inlet duct, an exhaust duct and an air extraction chimney; the air extraction chimney is elevated to the outside of the reactor building; One end of the first air inlet duct is connected to the outside of the reactor building, and the other end is connected to the inside of the containment; the first air inlet duct is provided with an air inlet fan and a first air inlet valve in sequence along the wind direction; one end of the second air inlet duct is connected to the inside of the reactor building outside the containment, and the other end is connected to the inside of the containment; the second air inlet duct is provided with a second air inlet valve; One end of the exhaust duct is connected to the inside of the containment, and the other end is connected to the inside of the exhaust chimney; the exhaust duct is provided with an exhaust valve, a primary filter, a high efficiency filter and an exhaust fan in sequence along the wind direction; The air outside the reactor building enters the containment from the first air inlet duct or the air inside the reactor building enters the containment from the second air inlet duct, and the pressure difference generated by the high head difference drives the gas inside the containment to be discharged from the exhaust duct through the wind chimney overhead to the outside of the reactor building; The first air inlet valve, the second air inlet valve and the exhaust valve are all arranged near the containment and are provided with a fuse device, which automatically fuses and closes when the temperature rises to the set value.

[0016] As one of the feasible ways, the refueling system is arranged in the reactor building of the nuclear island and is used for core refueling, including an in-core refueling system and an out-core refueling system; A reactor rotating shield plug is provided on the top cover of the reactor body; the in-core refueling system includes a refueling machine and a hoist; the refueling machine is a direct-pull refueling machine, which directly pulls into the reactor body container from the reactor rotating shield plug during core refueling, and fully covers the core fuel assembly plug hole and the lower working position of the hoist through the circular rotation of the reactor rotating shield plug; the hoist is an inclined hoist, which tilts into the upper working position or the lower working position in the reactor body container from the top cover of the reactor body during core refueling; a maintenance temporary storage position is provided in the reactor building, and the refueling machine and the hoist are placed in the maintenance temporary storage position during non-core refueling; The off-core refueling system includes a new fuel depot, a new fuel transportation channel, a transfer room, a spent fuel transportation channel, a cleaning room and a spent fuel storage pool; The new fuel depot is arranged on the left side of the reactor building, and the cleaning room and spent fuel storage pool are arranged on the right side of the reactor building; the new fuel depot is connected to the new fuel transportation channel; the spent fuel transportation channel is connected to the cleaning room; the transfer room is connected to the new fuel transportation channel and the spent fuel transportation channel respectively; the cleaning room and the spent fuel storage pool are connected through the spent fuel transportation waterway; A new fuel transfer vehicle is provided on the new fuel transportation channel, and a new fuel transfer coupling device is provided on the new fuel transfer vehicle; a spent fuel transfer vehicle is provided on the spent fuel transportation channel, and a spent fuel transfer coupling device and a spent fuel hanging basket are provided on the spent fuel transfer vehicle; a transfer room transfer vehicle is provided in the transfer room; The new fuel depot is equipped with storage containers and preheating boxes; the storage containers are used to store new fuel assemblies; the preheating box is equipped with a new fuel hanging basket, and a preheating box cover is provided on the top of the preheating box; the new fuel hanging basket is used to store new fuel assemblies, the preheating box is used to heat new fuel assemblies, and the preheating box cover is used to open or close the preheating box; the cleaning room is equipped with a cleaning room transfer vehicle, a lead leakage detection trap, a lead bath trap and a cleaning trap.

[0017] As one of the feasible ways, the core refueling includes loading new fuel assemblies and unloading spent fuel assemblies; the refueling system performs loading of new fuel assemblies, including the following steps: Transferring new fuel assemblies from the storage container of the new fuel depot to the new fuel basket of the preheating box; after the new fuel basket is fully loaded with new fuel assemblies, closing the cover of the preheating box to complete the sealing of the preheating box; After the new fuel assembly in the preheating box is preheated to the set temperature, the new fuel basket is loaded into the new fuel transfer vehicle through the new fuel transfer coupling device; the new fuel transfer vehicle moves to the transfer room in the new fuel transportation channel, and the new fuel assembly in the new fuel basket is transferred to the hoist barrel by the transfer vehicle in the transfer room; The hoist cylinder enters the reactor body container from the reactor body top cover and descends to the lower working position along the inclined guide rail. The refueling machine transfers the new fuel assembly from the hoist cylinder to the insertion position of the spent fuel assembly that has been unloaded from the reactor core, completing the loading of the new fuel assembly. The refueling system unloads the spent fuel assembly, including the following steps: The hoist enters the reactor body container from the reactor body top cover and descends to the lower working position along the inclined guide rail; the material changer enters the reactor body container from the rotating shield plug along the vertical guide rail, and reaches the core fuel assembly insertion hole position through the circumferential rotation of the rotating shield plug, and takes out the spent fuel assembly at the core fuel assembly insertion hole position and transfers it to the lower working position of the hoist barrel; The hoist barrel is lifted to the upper working position along the inclined guide rail; the transfer vehicle in the transfer room enters the upper working position of the hoist barrel in the reactor body container from the top cover of the reactor body, and transfers the spent fuel assembly to the spent fuel basket of the spent fuel transfer vehicle through the spent fuel transfer coupling device; When the spent fuel basket is fully loaded with spent fuel assemblies, the spent fuel transfer vehicle moves along the spent fuel transport channel to the cleaning room, and the cleaning room transfer vehicle lifts the spent fuel basket into the cleaning well for cleaning; after the spent fuel basket is cleaned, the cleaning room transfer vehicle transfers the spent fuel basket to the spent fuel storage pool through the spent fuel transport waterway for temporary storage; If the spent fuel assembly is found to be damaged in the reactor container, the spent fuel basket is still on the spent fuel transfer vehicle. The damaged spent fuel assembly is transferred to the lead bath well by the cleaning room transfer vehicle for lead bath cleaning. After the lead bath cleaning is completed, it is placed in a sealed can and then transferred to the spent fuel storage pool by the cleaning room transfer vehicle along the spent fuel transport waterway via the spent fuel basket. If the spent fuel assembly is found damaged during the cleaning process in the cleaning well, after the cleaning is completed, the spent fuel assembly in the spent fuel basket will be transferred to the leakage detection well for inspection one by one by the cleaning room transfer vehicle. The damaged spent fuel assembly will be placed in a sealed can and then transferred through the spent fuel basket by the cleaning room transfer vehicle along the spent fuel transport waterway to the spent fuel storage pool.

[0018] As one of the feasible ways, the instrument control system is a distributed instrument control system; the instrument control system includes a process system interface layer, an automatic control and protection layer, an operation and management information layer, and a technical management layer for the whole plant; The process system interface layer includes sensors and actuators; sensors are installed on process equipment to detect process parameters of process equipment; actuators are used to control the process according to control instructions from the automatic control and protection layers; The automatic control and protection layer adopts on-site summary control technology to collect the process parameters of the process system interface layer; process and perform logical operations on the process parameters of the process system interface layer, generate control instructions and pass them to the process system interface layer; The operation and management information layer is used to perform tasks, including information support, information diagnosis, recording of process information and operator actions, and controlling the sodium-cooled fast reactor unit through operating equipment; The technical management layer is used for the operation and management of the sodium-cooled fast reactor power plant, and receives the information required for the operation and management of the sodium-cooled fast reactor power plant through the network interface equipment.

[0019] As one of the feasible ways, the electrical system includes an off-site electrical system and an on-site electrical system; the off-site electrical system consists of two completely independent power supply lines, which are respectively provided by an off-site power supply through a main transformer and an auxiliary transformer to each sodium-cooled fast reactor unit; the on-site power system consists of a normal power supply system, a reliable power supply system, a reliable diesel engine and a battery energy storage station; The normal power supply system is used to ensure the normal startup, rated power operation and normal shutdown of the sodium-cooled fast reactor unit. The reliable power supply system is used to ensure the normal operation of the sodium-cooled fast reactor unit. The reliable diesel engine provides power to the reliable power supply system when both the normal power supply system and the reliable power supply system lose power; The battery energy storage station realizes secondary frequency regulation of the sodium-cooled fast reactor unit when the sodium-cooled fast reactor unit is operating normally, and supplies power to the normal power supply system when the normal power supply system loses power.

[0020] As one of the possible ways, the battery energy storage station includes energy storage battery packs, energy storage converters, battery management systems, energy management systems, cooling and fire protection systems, and grid-connected interfaces and protection devices; The energy storage battery pack uses lithium-ion batteries as energy storage media to convert electrical energy into chemical energy for storage; the energy storage converter is used to achieve bidirectional conversion between AC and DC, control the charging and discharging process of the energy storage battery pack, and adjust the power output of the energy storage battery pack; The battery management system is used to monitor the voltage, temperature, state of charge and health status of the energy storage battery pack in real time, ensure the safe operation of the energy storage battery pack and optimize the charging and discharging strategy of the energy storage battery pack; the energy management system is used to coordinate the operation of the energy storage system and optimize the charging and discharging plan of the energy storage system through data analysis and algorithms; the cooling and fire protection system is used to maintain the temperature of the energy storage battery pack and activate the fire extinguishing device when the energy storage battery pack is thermally out of control; the grid interface and protection device are used to ensure a safe connection with the power grid.

[0021] As one of the feasible ways, the energy storage system includes a super capacitor, a battery and an energy storage transformer; the power generation outlet of the steam turbine generator is connected to the super capacitor and the battery circuit in sequence through the energy storage transformer; the battery is connected to the battery energy storage station circuit; Under the secondary frequency regulation of the sodium-cooled fast reactor unit, when the grid frequency deviates from the rated value, the energy management system of the battery energy storage station captures the grid frequency deviation signal in real time through sensors, and calculates the amount of power to be supplemented or absorbed based on the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, the frequency regulation timing and output depth of the energy storage system are determined, the allocation factor is optimized, and the power output of the energy storage system is smoothly adjusted; When the normal power supply system loses power, the battery energy storage station transmits a power failure signal to the energy storage system. The energy storage system adjusts the discharge power to the steam turbine generator according to the grid load demand, and discharges to the normal power supply system through the battery energy storage station while ensuring the voltage and frequency stability of the grid, thereby supplying power to the normal power supply system.

[0022] Beneficial technical effects of the present invention: The large-scale sodium-cooled fast reactor power plant of the present invention is innovatively designed in terms of the core, the reactor body, the main heat transmission system, the power conversion system, the plant structure, etc., through deep innovative optimization of the traditional sodium-cooled fast reactor power plant. While improving nuclear safety and industrial safety, the economy of the sodium-cooled fast reactor power plant is greatly improved and the construction period of the sodium-cooled fast reactor power plant is shortened. By optimizing the design of the containment, the technical index requirements that do not require off-site emergency response are met; the sodium-water steam generator and related auxiliary systems are eliminated to eliminate the risk of sodium-water reaction; the in-pile cold trap and the capsule-type containment are adopted, and the radioactive substances are completely contained in the capsule-type small Inside the steel containment, the capsule-type small steel containment can maintain an extremely low radioactive leakage rate, completely eliminating the possibility of large-scale radioactive release from the containment; the use of air-cooled steam turbine generator exhaust steam greatly reduces the requirement for water sources, making the sodium-cooled fast reactor power plant independent of water sources and suitable for inland sites; the use of additional molten salt heat storage function achieves deep peak-shaving capability and has primary frequency regulation; the integration of battery energy storage stations and energy storage systems has good secondary frequency regulation capabilities; the use of passive, modular, fuel-economic, and simplified process configuration design concepts greatly reduces the cost of large-scale sodium-cooled fast reactor power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an embodiment of a large-scale sodium-cooled fast reactor power plant of the present invention; Figure 2 The structure diagram of an embodiment of a sodium-cooled fast reactor is shown; Figure 3 A schematic structural view of an embodiment of a main heat transfer system, a power conversion system and an energy storage system; Figure 4 is a structural schematic diagram of an embodiment of a core; Figure 5 is a structural schematic diagram of an embodiment of an electrical system; Figure 6 The figure is a schematic structural diagram of an embodiment of a material changing system.

[0024] In the figure, 1, sodium-cooled fast reactor; 101, reactor core; 102, core melt collector; 103, reactor body; 104, sodium leakage receiving and suppression plate; 105, reactor top shielding equipment; 106, personnel and equipment access passage; 107, exhaust fan; 108, air extraction chimney; 109, high-efficiency filter; 110, exhaust air valve; 111, first air inlet air valve; 112 second air inlet air valve; 113, nitrogen valve; 114. Nitrogen tank; 115. Air intake fan; 116. Radiation monitor; 117. Containment; 118. Reactor building; 119. Reactor top equipment; 120. Primary filter; 201. Intermediate heat exchanger; 202. Secondary circuit sodium pump; 203. Sodium-molten salt exchanger; 204. Low-temperature molten salt pump; 205. Linear Fresnel focusing system; 206. First regulating valve; 207. Low-temperature molten salt tank; 208, high temperature molten salt tank; 209, second regulating valve; 210, high temperature molten salt pump; 211, molten salt-water heat exchanger; 301, steam circuit control valve; 302, power generation circuit control valve; 303, steam turbine generator; 304, main feed water pump; 305, condenser; 306, check valve; 307, steam user; 308, grid main transformer; 309, grid user; 310 superheater; 401, energy storage transformer; 402, supercapacitor; 403, battery; 501, control rod; 502, control rod upper section; 503, control rod lower section; 504, fuel zone isotope production irradiation zone; 505, breeding zone isotope production irradiation zone; 506, inert fuel zone; 507, first active zone fuel inner zone; 508, active zone fuel outer zone; 509, second active zone fuel inner zone; 510, breeding zone; 601. New fuel depot; 602. Preheating box; 603. New fuel hanging basket; 604. New fuel transfer coupling device; 605. New fuel transfer vehicle; 606. New fuel transportation channel; 607. Spent fuel transportation channel; 608. Spent fuel transfer vehicle; 609. Spent fuel transportation coupling device; 610. Cleaning room; 611. Cleaning trap; 612. Lead bath trap; 613. Leakage detection trap; 615. Spent fuel transportation waterway; 616. Transfer room; 617. Transfer room transfer vehicle; 618. Cleaning room transfer vehicle; 619 Spent fuel hanging basket; 620. Maintenance temporary storage position; 621 Spent fuel storage pool; 701. First off-site power supply; 702. Second off-site power supply; 703. Off-site main transformer ;704, the first external auxiliary transformer;705, the second external auxiliary transformer;706, the first high-voltage plant transformer;707, the second high-voltage plant transformer;708, the first nuclear island normal section;709, the second nuclear island normal section;710, the first conventional island normal section;711, the second conventional island normal section;712, the first nuclear island reliable section;713, the second nuclear island reliable section;714, the battery energy storage station;715, the reliable diesel engine;8, the reactor assembly plant;9, the maintenance plant;10, the spare parts warehouse;11, the dangerous goods warehouse;12, the maintenance temporary storage place;13, the main control room;14, the conventional island;15, the natural ventilation cooling tower;16, the battery energy storage station;17, the fuel regeneration sub-item; 18. Isotope production hot cell. DETAILED DESCRIPTION

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0028] See also Figure 1-6 The present embodiment provides a large-scale sodium-cooled fast reactor power station, including a sodium-cooled fast reactor unit and a sodium-cooled fast reactor unit auxiliary system; the sodium-cooled fast reactor unit is used to convert nuclear energy into electrical energy or steam energy, and the sodium-cooled fast reactor unit auxiliary system is used to assist the sodium-cooled fast reactor unit in converting nuclear energy into electrical energy or steam energy; there are multiple sodium-cooled fast reactor units, and the sodium-cooled fast reactor unit auxiliary system is shared by two or each sodium-cooled fast reactor unit; the thermal power of the sodium-cooled fast reactor unit is 1500-3800MW, and the electric power is 600-1500MW.

[0029] In this embodiment, as one of the feasible ways, the sodium-cooled fast reactor unit includes a sodium-cooled fast reactor 1, a main heat transmission system, a power conversion system, an accident waste heat removal system and an energy storage system; the sodium-cooled fast reactor 1 is used to generate heat energy by nuclear fission; the main heat transmission system is used to transfer the heat energy generated by the sodium-cooled fast reactor 1 to the power conversion system; the power conversion system is used to convert the heat energy generated by the sodium-cooled fast reactor 1 into electrical energy or steam energy; the energy storage system is used to store and release electrical energy; the accident waste heat removal system is used to extract the waste heat of the sodium-cooled fast reactor 1 under the accident condition of the sodium-cooled fast reactor 1.

[0030] In this embodiment, as one of the feasible ways, the sodium-cooled fast reactor 1 is arranged in the reactor building 118 of the nuclear island, without considering the impact of external events; the reactor building 118 is an ordinary earthquake-resistant building, which is manufactured in a large process room modularly; The sodium-cooled fast reactor 1 includes a reactor pit, a containment vessel 117 in the reactor pit, and a reactor body 103 in the containment vessel 117, and is constructed by the following steps: The construction of the reactor pit, the containment 117 and the reactor body 103 is carried out in parallel, and after the construction of the containment 117 and the reactor body 103 is completed, the reactor body 103 is loaded into the containment 117; the reactor pit is arranged below the ground of the reactor building 118 and is constructed of concrete; the reactor body 103 is modularly manufactured and is assembled in the reactor body assembly plant 8 of the nuclear island and then sent to the ground of the reactor building 118; the containment 117 is a capsule-type small steel containment, which is fully welded from a steel plate with a thickness of 40 mm and is welded on the ground of the reactor building 118 of the nuclear island; The containment shell 117 and the stack body 103 inside the containment shell 117 are pushed into the stack pit as a whole.

[0031] After the manufacture of the reactor body 103 and the containment vessel 117 is completed, they are first placed on the ground of the reactor building 118, so that the reactor body 103 can be put into the containment vessel 117 and then pushed into the reactor pit as a whole. The construction of the reactor pit, the containment vessel 117 and the reactor body 103 is carried out in parallel, and after the construction of the containment vessel 117 and the reactor body 103 is completed, the reactor body 103 is put into the containment vessel 117, which greatly shortens the main line construction period of the sodium-cooled fast reactor power plant.

[0032] Containment 117 is a small capsule-type steel containment vessel, which is fully welded from 40mm thick steel plates. Due to its small size and good sealing, it can ensure the effective containment of radioactive gas leakage from the reactor body 103 and eliminate the possibility of radioactive gas release into the environment, thereby achieving the cancellation of off-site emergencies.

[0033] In view of the fact that all items related to nuclear safety are contained in the containment vessel 117, the safety of the sodium-cooled fast reactor power plant can be ensured by ensuring the earthquake resistance and safety of the containment vessel 117. In addition to the containment vessel, the reactor building 118 is an industrial building with a mature design and a simple structure. The earthquake resistance level only needs to meet conventional earthquake resistance requirements, which can greatly reduce the civil construction cost of the reactor building 118.

[0034] In this embodiment, as one of the achievable ways, the containment vessel 117 is divided into an upper container and a lower container; the upper container is a hemispherical container, the lower container is a cylindrical container, and the diameters of the upper container and the lower container are the same; the upper container and the lower container are connected by welding to form the containment vessel 117, the interiors of the upper container and the lower container are connected, and the welding meets the airtightness requirements of the interior of the containment vessel 117; in order to provide convenience for the subsequent operation and maintenance of the sodium-cooled fast reactor 1, a detachable top cover is provided on the top of the upper container, the top cover adopts a mechanical seal, and the upper container can be opened as a whole from the top; The containment 117 is provided with a personnel and equipment access passage 106 at the reactor hall, and the personnel and equipment access passage 106 is sealed with a sodium fire protection door; during normal operation of the sodium-cooled fast reactor 1, the personnel and equipment access passage 106 is in a closed state; during maintenance of the sodium-cooled fast reactor 1, the personnel and equipment access passage 106 is in an open state, and operation and maintenance personnel and small equipment can enter and exit through the passage; The containment vessel 117 contains the entire reactor body 103, and can realize the containment barrier function of the sodium-cooled fast reactor 1. Since the sodium-cooled fast reactor 1 is a low-pressure system, the pressure in the containment vessel 117 will not increase significantly under any operating conditions, so the containment vessel 117 does not need to withstand high pressure. A sodium leakage receiving and suppression plate 104 is provided at the bottom of the containment vessel 117 to prevent and mitigate sodium fire accidents and collect and extinguish sodium fires in the reactor pit; a core melt collector 102 is provided at the bottom of the reactor body 103 to ensure that even if the entire core 101 melts, all molten fuel will be collected and cooled, without having to worry about a large sodium fire after the reactor body 103 is melted.

[0035] The containment shell 117 of the present invention separates the functions of containing radioactive materials and resisting external events of the traditional containment shell according to the inherent safety of the sodium-cooled fast reactor 1. The entire containment shell 117 is located inside the reactor building 118, and there is no need to consider the impact of external events. The containment shell 117 plays a sealing function of isolating radioactive materials after an accident. The containment shell 117 is located inside the reactor building 118, which greatly simplifies the structure of the containment shell 117, makes the structure size of the containment shell 117 smaller, and greatly reduces the difficulty of design and manufacturing. The sealing performance of the containment shell 117 can be more effectively guaranteed, and the cost of the containment shell 117 can be greatly reduced, while the safety and economy of the sodium-cooled fast reactor power station are improved.

[0036] In this embodiment, as one of the achievable ways, the stack body 103 includes a stack body container, a stack body top cover sealed to the top of the stack body container, a stack top device 119 sealed to the stack body top cover, a stack top shielding device 105 sealed to the stack body top cover, a sodium pool in the stack body 103 container, and an intermediate heat exchanger 201, an independent heat exchanger, a primary sodium pump and a core 101 arranged in the sodium pool; wherein the intermediate heat exchanger 201 and the independent heat exchanger are both manufactured by integrated 3D printing technology; the stack top shielding device 105 is designed and manufactured in an integrated manner; The internal component material of the sodium-cooled fast reactor 1 is low-copper and low-phosphorus steel with a phosphorus content of 10 to 1000 ppm and a copper content of 0.1 to 5% to mitigate neutron irradiation embrittlement and achieve a design life of the sodium-cooled fast reactor unit of ≥60 years.

[0037] In this embodiment, as one of the feasible ways, the core 101 uses FMS or ODS cladding material with a radiation resistance level of 200 dPA, so that the core 101 refueling cycle is 18 to 24 months; the core 101 damage frequency CDF is less than 1×10 -6 1 / pile·year, large radioactive material release frequency LRF<1×10 -6 1 / pile·year; The inner circle of the core 101 is the active zone, in which the fissile nuclear fuel U-235 undergoes fission reaction to produce fast neutrons; the outer circle of the core 101 is the breeder zone 510, in which the fissile nuclear fuel U-238 absorbs fast neutrons and is converted into the fissile nuclear fuel Pu-239; the content of the fissile nuclear fuel Pu-239 in the breeder zone 510 is higher than that in the active zone, so as to flatten the neutron flux and flatten the power of the fuel assemblies in the active zone and the breeder zone 510; The active zone includes an active zone fuel inner zone and an active zone fuel outer zone 508 surrounding the outer periphery of the active zone fuel inner zone; the active zone fuel inner zone is designed to be axially non-uniform, and is axially divided from top to bottom into a first active zone fuel inner zone 507, an inert fuel zone 506, and a second active zone fuel inner zone 509, so that the sodium cavitation coefficient is close to 0; the active zone fuel inner zone and the breeding zone 510 are each provided with an irradiation zone for isotope production; The proliferation ratio in the core 101 is 1; the control rod assembly is composed of a regulating control rod assembly and a safety control rod assembly, or a regulating control rod assembly, a safety control rod assembly and a small number of compensating control rod assemblies; the safety control rod assembly is used to control the shutdown of the sodium-cooled fast reactor 1, the regulating control rod assembly is used to control the power of the sodium-cooled fast reactor 1, and the compensating control rod assembly is used for the positive reactivity of the sodium-cooled fast reactor 1; The reactor body top cover is provided with a reactor rotating shield plug; the reactor top equipment includes a control rod driving mechanism; the control rod driving mechanism enters the reactor body container from the rotating shield plug and connects with the corresponding control rod in the core 101, driving the control rod to insert or extract the fuel assembly; A short fuel rod bundle is combined at the lower end of the control rod; when the control rod is inserted, the control rod is located in the inner area of ​​the fuel in the active zone, introducing negative reactivity; when the control rod is lifted, the short fuel rod bundle at the lower end of the control rod is located in the inner area of ​​the fuel in the active zone, introducing positive reactivity, thereby increasing the value of the control rod.

[0038] The proliferation ratio in the reactor core 101 of the present invention is 1.0, a small number of compensating control rod assemblies are cancelled or retained, and the positive reactivity introduced by the proliferation characteristics of the fissile nuclear fuel U-238 is used to compensate for the burnup reactivity loss during the operation of the sodium-cooled fast reactor 1, thereby reducing the positive backup reactivity in the early stage of the operation life of the sodium-cooled fast reactor 1, improving the operation safety of the sodium-cooled fast reactor 1, and fundamentally reducing or even avoiding the risk of instantaneous supercriticality of the sodium-cooled fast reactor 1; a small number of compensating control rod assemblies are cancelled or retained, reducing the number of openings of the reactor rotating shield plug, and improving the reliability of the primary circuit boundary operation.

[0039] In a conventional sodium-cooled fast reactor, the sodium in the primary circuit plays a certain role in neutron reflection. Therefore, when the sodium in the primary circuit is lost, the core usually experiences a positive cavitation effect, that is, the reactivity increases. The present invention optimizes the reactivity and reduces the sodium cavitation effect by adjusting the distribution of the fuel area and the non-fuel area in the active area.

[0040] The core 101 design of the present invention can reduce the number of components in a sodium-cooled fast reactor, flatten the power of the core 101, reduce the sodium cavitation positive reaction coefficient, improve the safety of the core 101, reduce the size of the core 101 and thus reduce the diameter of the reactor body container, while taking into account the isotope production capacity.

[0041] In this embodiment, as one of the achievable methods, the main heat transfer system is a sodium-sodium-molten salt-water four-circuit structure, including an intermediate heat exchanger 201, a primary sodium pump, a secondary sodium pump 202, a sodium-molten salt heat exchanger 203, a first regulating valve 206, a second regulating valve 209, a high-temperature molten salt pump 210, a low-temperature molten salt pump 204, a molten salt-water heat exchanger 211, a high-temperature molten salt tank 208, a low-temperature molten salt tank 207, a main feed water pump 304 and a linear Fresnel focusing system 205; The sodium pool is filled with primary sodium and is divided into a cold pool and a hot pool by a partition; the reactor core 101 and the intermediate heat exchanger 201 are both arranged in the hot pool, and the primary sodium pump is arranged in the cold pool; the primary sodium pump flows the primary sodium in the cold pool through the reactor core 101 and the primary sodium side of the intermediate heat exchanger 201 and then returns it to the cold pool to form a primary loop; The outlet of the secondary circuit sodium side of the intermediate heat exchanger 201 is connected to the secondary circuit sodium pump 202, the sodium side of the sodium-molten salt heat exchanger 203 and the inlet of the secondary circuit sodium side of the intermediate heat exchanger 201 by pipelines in sequence to form a secondary circuit; in the secondary circuit, the secondary circuit sodium on the secondary circuit sodium side of the intermediate heat exchanger 201 flows through the sodium side of the sodium-molten salt heat exchanger 203 through the secondary circuit sodium pump 202 and is then sent back to the secondary circuit sodium side of the intermediate heat exchanger 201; The outlet of the molten salt side of the sodium-molten salt heat exchanger 203 is connected to the high-temperature molten salt tank 208, the second regulating valve 209, the high-temperature molten salt pump 210, the molten salt side of the molten salt-water heat exchanger 211, the low-temperature molten salt tank 207, the first regulating valve 206, the low-temperature molten salt pump 204 and the inlet of the molten salt side of the sodium-molten salt heat exchanger 203, forming a three-circuit circuit; in the three-circuit circuit, the molten salt on the molten salt side of the sodium-molten salt heat exchanger 203 flows through the high-temperature molten salt pump 210 After passing through the high-temperature molten salt tank 208, the molten salt side of the molten salt-water heat exchanger 211 and the low-temperature molten salt tank 207, the low-temperature molten salt pump 204 returns to the molten salt side of the sodium-molten salt heat exchanger 203; the pipeline connecting the molten salt side of the sodium-molten salt heat exchanger 203 and the high-temperature molten salt tank 208 is heated by the linear Fresnel concentrating system 205, and the linear Fresnel concentrating system 205 uses light energy to heat the molten salt in the molten salt pipeline, thereby realizing the coupling of the sodium-cooled fast reactor 1 with light energy; The water side outlet of the molten salt-water heat exchanger 211 is connected to the power conversion system, the main water supply pump 304 and the water side outlet inlet of the molten salt-water heat exchanger 211 by pipelines in sequence, forming four circuits; in the four circuits, the main water supply on the water side of the molten salt-water heat exchanger 211 flows through the power conversion system through the main water supply pump 304 and is then sent back to the water side of the molten salt-water heat exchanger 211.

[0042] In a traditional sodium-cooled fast reactor power plant, the main heat transfer system is a sodium-sodium-water three-circuit structure, including an intermediate heat exchanger and a sodium-water heat exchanger. Compared with a traditional large-scale fast reactor power plant, the large-scale fast reactor power plant of the present invention introduces a sodium-molten salt heat exchanger 203 and a molten salt-water heat exchanger 211 into the main heat transfer system, cancels the sodium-water heat exchanger, eliminates the possibility of sodium-water reaction caused by sodium-water contact, and greatly reduces the industrial safety risk of the sodium-cooled fast reactor; in addition, a high-temperature molten salt tank 208 and a low-temperature molten salt tank 207 are introduced into the main heat transfer system, and the main heat transfer system realizes the energy storage function, which is convenient for subsequent sodium-cooled fast reactor units to participate in the peak load regulation of the power grid.

[0043] In this embodiment, as one of the achievable ways, the power conversion system includes a steam loop control valve 301, a power generation loop control valve 302, a molten salt superheater 310, a steam turbine generator 303, a condenser 305, a steam user 307, a power grid user 309 and a power grid main transformer 308; the water side outlet of the molten salt-water heat exchanger 211 is divided into two routes, one route is sequentially connected to the steam loop control valve 301 by pipeline, and the other route is sequentially connected to the power generation loop control valve 302, the molten salt superheater 310, the steam turbine generator 303, the condenser 305, the main feed water pump 304 and the water side inlet of the molten salt-water heat exchanger 211 by pipeline; the steam turbine generator 303 is connected to the steam user 307 by pipeline, and a check valve 306 is provided on the pipeline connecting the steam turbine generator 303 and the steam user 307; the power generation outlet of the steam turbine generator 303 is connected to the power grid user 309 through the power grid main transformer 308; The operation mode of the sodium-cooled fast reactor unit is one or a combination of the solar thermal energy storage mode, the power generation mode and the high-temperature industrial steam supply mode; In the solar thermal energy storage mode, the first regulating valve 206, the second regulating valve 209, the steam loop control valve 301, the power generation loop control valve 302 and the check valve 306 are all closed; the sodium-cooled fast reactor 1 operates at full power, the secondary loop sodium pump 202 and the high-temperature molten salt pump 210 operate at rated power, the low-temperature molten salt pump 204 operates at high power, and the linear Fresnel focusing system 205 heats the molten salt pipeline; the liquid level of the high-temperature molten salt tank 208 rises, and the liquid level of the low-temperature molten salt tank 207 drops. By adjusting the amount of high and low temperature molten salt, nuclear energy and light energy are converted into molten salt thermal energy for storage; In the power generation mode, the first regulating valve 206, the second regulating valve 209, the power generation loop control valve 302 and the check valve 306 are all opened, and the steam loop control valve 301 is closed; the sodium-cooled fast reactor 1 operates at full power, and the secondary loop sodium pump 202, the low-temperature molten salt pump 204 and the high-temperature molten salt pump 210 all operate at rated power; the liquid levels of the high-temperature molten salt tank 208 and the low-temperature molten salt tank 207 remain unchanged; the steam from the steam turbine generator 303 after power generation is partially sent to the condenser 305 to condense into condensed water, and partially sent to the steam user; the condensed water is sent to the water side of the molten salt-water heat exchanger 211 by the main feed water pump 304 for heat exchange, and then sent to the molten salt superheater 310 to be heated into superheated steam and then sent back to the steam turbine generator 303 for power generation; In the high-temperature industrial steam supply mode, the first regulating valve 206, the second regulating valve 209 and the steam loop control valve 301 are all opened, and the power generation loop control valve 302 and the check valve 306 are all closed; the sodium-cooled fast reactor 1 operates at full power, and the secondary loop sodium pump 202, the low-temperature molten salt pump 204 and the high-temperature molten salt pump 210 all operate at rated power; the liquid levels of the high-temperature molten salt tank 208 and the low-temperature molten salt tank 207 remain unchanged; the main feed water is sent to the water side of the molten salt-water heat exchanger 211 through the main feed water pump 304 for heat exchange to generate high-temperature industrial steam and send it to the steam user 307.

[0044] The power conversion system of the present invention adopts a superheated steam cycle, and the power generation efficiency is greater than 40%; the steam after the steam turbine generator 303 generates electricity is cooled by air, and no longer relies on a large amount of water, which is suitable for sodium-cooled fast reactor power plants built in inland arid areas.

[0045] The main heat transmission system of the present invention cooperates with the power conversion system to realize the coupling of nuclear energy, solar energy and energy storage. It has various operation modes, and the solar thermal energy storage mode, power generation mode and high-temperature industry have deep frequency modulation and peak regulation capabilities without sacrificing the output of the sodium-cooled fast reactor unit, thereby greatly improving the economy.

[0046] In this embodiment, as one of the achievable methods, the primary frequency regulation and peak regulation of the sodium-cooled fast reactor unit includes power increase of the sodium-cooled fast reactor unit and power decrease of the sodium-cooled fast reactor unit; There are two modes for reducing the power of sodium-cooled fast reactor units: In the first mode, the sodium-cooled fast reactor unit maintains the power generation mode, the sodium-cooled fast reactor 1 operates at full power, the secondary circuit sodium pump 202 operates at full power, and the heat of the sodium-cooled fast reactor 1 is continuously taken out; the low-temperature molten salt pump 204 operates at rated power, the high-temperature molten salt pump 210 operates at low power, and the main feed water pump 304 operates at low power, so that the total amount of steam is reduced, and the output power of the steam turbine generator 303 is reduced, thereby realizing the peak regulation of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank 208 increases, and the liquid level of the low-temperature molten salt tank 207 continues to decrease, and the excess energy generated by the sodium-cooled fast reactor 1 is stored by adjusting the high and low temperature molten salt reserves; In the second mode, the sodium-cooled fast reactor unit starts the high-temperature industrial steam supply mode while in the power generation mode, and controls the amount of high-temperature industrial steam supply by the opening of the steam loop control valve 301, thereby reducing the power generation power of the steam turbine generator 303 and realizing the peak regulation of the sodium-cooled fast reactor unit; The power increase operation mode of the sodium-cooled fast reactor unit is as follows: the sodium-cooled fast reactor operates at full power, the secondary circuit sodium pump 202 operates at full power, and the heat of the sodium-cooled fast reactor 1 is continuously taken out; the high-temperature molten salt pump 210 operates at high power, the low-temperature molten salt pump 204 operates at rated power, and the main feed water pump 304 operates at high power, so that the total amount of steam is increased, the output power of the steam turbine generator 303 is increased, and the peak load of the sodium-cooled fast reactor unit is realized; the liquid level of the high-temperature molten salt tank 208 is reduced, and the liquid level of the low-temperature molten salt tank 207 is increased. By adjusting the reserves of high and low temperature molten salts, the molten salt energy storage is released, the power generation power of the steam turbine generator 303 is increased, and the online power of the sodium-cooled fast reactor unit is increased.

[0047] In this embodiment, as one of the achievable methods, the secondary frequency regulation of the sodium-cooled fast reactor unit includes the secondary frequency regulation of the sodium-cooled fast reactor unit power down regulation and the secondary frequency regulation of the sodium-cooled fast reactor unit power up regulation; Under the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator 303 is synchronously connected to the energy storage system for charging, thereby reducing the online power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit; Under the secondary frequency regulation for increasing the power of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator 303 is synchronously connected to the energy storage system for discharge, thereby increasing the online power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation for increasing the power of the sodium-cooled fast reactor unit.

[0048] The sodium-cooled fast reactor unit of the present invention can adopt a single solar thermal energy storage mode, a power generation mode or a high-temperature industrial steam supply mode, or a combination of multiple modes. By controlling the operating power of the low-temperature molten salt pump 204, the high-temperature molten salt pump 210 and the main feed water pump 304 and the opening of the steam circuit control valve 301 and the power generation circuit control valve 302, the steam amount to the steam turbine generator 303 is adjusted, thereby controlling the power generation power of the steam turbine generator 303.

[0049] In this embodiment, as one of the feasible methods, the condenser 305 includes an air-cooled radiator and a natural ventilation cooling tower 15. The air-cooled radiator is connected to the steam turbine generator 303 by pipeline, and the air-cooled radiator is arranged at the bottom or side of the natural ventilation cooling tower 15. The steam generated by the steam turbine generator 303 is sent to the air-cooled radiator, and the suction force of the tower of the natural ventilation cooling tower 15 causes the cold air to flow through the surface of the air-cooled radiator, so that the steam in the air-cooled radiator condenses to form condensed water, which is sent to the water side of the molten salt-water heat exchanger 211 through the main feed water pump 304.

[0050] In this embodiment, as one of the achievable methods, the accident waste heat removal system includes an air heat exchanger and an independent heat exchanger; used for removing waste heat from the sodium-cooled fast reactor 1 under the accident condition of the sodium-cooled fast reactor 1; The air heat exchanger is arranged at the bottom or side of the air extraction chimney 108 and is connected to the air extraction chimney 108 pipeline; the independent heat exchanger is arranged in the cold pool or the hot pool and is connected to the air heat exchanger pipeline; The primary sodium in the cold pool flows through the core 101 and the primary sodium side of the independent heat exchanger and then returns to the cold pool; the secondary sodium on the secondary sodium side of the independent heat exchanger undergoes heat exchange with the primary sodium on the primary sodium side of the independent heat exchanger and then enters the air heat exchanger, undergoes heat exchange with the air in the air heat exchanger and then returns to the secondary sodium side of the independent heat exchanger; the air in the air heat exchanger rises due to the heat, and is discharged from the air extraction chimney 108 into the atmosphere by using the pressure difference generated by the height difference of the air extraction chimney 108.

[0051] In the present embodiment, as one of the technical implementation modes, the auxiliary system of the sodium-cooled fast reactor unit includes a primary-loop purification system, a secondary-loop purification system, a nitrogen system, an argon system, a vacuum system, a gas heating system, a ventilation system, a refrigeration system, an electrical system, an instrumentation and control system, a refueling system and a fire-fighting system; wherein, the primary-loop purification system and the secondary-loop purification system are shared by two sodium-cooled fast reactor units; the nitrogen system, the argon system, the vacuum system, the gas heating system, the ventilation system, the refrigeration system, the electrical system, the instrumentation and control system, the refueling system and the fire-fighting system are shared by each sodium-cooled fast reactor unit to save construction costs.

[0052] The primary circuit purification system is used to extract part of the primary circuit sodium from the primary circuit, and then send it back to the primary circuit after purification treatment to maintain the purity and quality of the primary circuit sodium. The secondary circuit purification system is used to extract part of the secondary circuit sodium from the secondary circuit, and then send it back to the secondary circuit after purification treatment to maintain the purity and quality of the secondary circuit sodium. The nitrogen system is used to fill nitrogen into the sodium fire position when a sodium fire accident occurs to extinguish the sodium fire and mitigate the consequences of the sodium fire accident. The argon system is used to fill argon into the surface of the sodium pool in the reactor body container to prevent the primary circuit sodium in the sodium pool from reacting with oxygen or moisture in the air. The vacuum system is used to maintain the vacuum environment before argon is filled into the surface of the sodium pool in the reactor body container. The gas heating system is used to preheat the reactor body container before filling the sodium pool to ensure that the liquid sodium can flow and transfer heat normally. The ventilation system is used to maintain the air quality in the reactor building 118 to prevent the sodium from reacting with oxygen and moisture in the air. The refrigeration system is used to cool the equipment of the sodium-cooled fast reactor unit. The electrical system is used to provide power for the operation of the sodium-cooled fast reactor unit and the auxiliary system of the sodium-cooled fast reactor unit. The instrumentation and control system is used to monitor and control the operating status of the sodium-cooled fast reactor unit and the auxiliary system of the sodium-cooled fast reactor unit. The refueling system is used for refueling of core 101. The fire protection system is used for fire detection, alarm and extinguishing of the sodium-cooled fast reactor unit. The sodium-cooled fast reactor unit auxiliary system ensures the safe and stable operation of the sodium-cooled fast reactor unit 1.

[0053] In this embodiment, as one of the feasible ways, the nitrogen system is used to fill the sodium fire position of the containment with nitrogen when a sodium fire accident occurs, so as to extinguish the sodium fire and alleviate the consequences of the sodium fire accident; the nitrogen system is arranged in the reactor building 118, including a nitrogen tank 114, a nitrogen pipeline and a nitrogen valve 113; the nitrogen tank 114 is used to store nitrogen; the nitrogen tank 114 is connected to the inside of the containment 117 through a nitrogen pipeline, and a nitrogen valve 113 is provided on the nitrogen pipeline; the nitrogen valve 113 receives the control command of the instrument control system, and controls the charging and discharging of nitrogen from the nitrogen tank 114 to the containment 117 according to the control command. As a defense-in-depth measure, the nitrogen system can perform fire extinguishing operations for sodium fires of different scales.

[0054] In this embodiment, as one of the achievable ways, the ventilation system is arranged in the reactor building 118, including a first air inlet duct, a second air inlet duct, an exhaust duct and an air extraction chimney 108; the air extraction chimney 108 is elevated to the outside of the reactor building 118; One end of the first air inlet duct is connected to the outside of the reactor building 118, and the other end is connected to the inside of the containment 117; the first air inlet duct is provided with an air inlet fan 115 and a first air inlet valve 111 in sequence along the wind direction; one end of the second air inlet duct is connected to the inside of the reactor building 118 outside the containment 117, and the other end is connected to the inside of the containment 117; the second air inlet duct is provided with a second air inlet valve 112; One end of the exhaust duct is connected to the interior of the containment 117, and the other end is connected to the interior of the exhaust chimney 108; the exhaust duct is provided with an exhaust valve 110, a primary filter 120, a high efficiency filter 109 and an exhaust fan 107 in sequence along the wind direction; The air outside the reactor building 118 enters the containment vessel 117 from the first air inlet duct or the air inside the reactor building 118 enters the containment vessel 117 from the second air inlet duct. The pressure difference generated by the high head difference drives the gas inside the containment vessel 117 to be discharged from the exhaust duct through the chimney 108 to the outside of the reactor building 118. The first air inlet valve 111, the second air inlet valve 112 and the exhaust valve 110 are all arranged near the containment vessel 117 and are provided with a fuse device which automatically fuses and closes when the temperature rises to a set value.

[0055] When the sodium-cooled fast reactor 1 is operating normally, the first air inlet valve 111, the air inlet fan 115, the exhaust air valve 110 and the exhaust air fan 107 are all opened, and the ventilation system discharges the gas in the containment 117 to the outside through an overhead, and maintains a micro-negative pressure state of 100 pa in the containment, ensuring that the gas flows from the reactor building 118 to the containment 117, and preventing a very small amount of radioactive material released by the sodium-cooled fast reactor 1 from entering the reactor building 118, so as not to affect the operation of the sodium-cooled fast reactor 1 and the safety of personnel. The radiation monitor 116 in the containment 117 monitors the radioactivity level of the environment in the containment 117 in real time, and when the radioactivity level of the environment in the containment 117 exceeds the set value, the first air inlet valve 111, the second air inlet valve 112 and the exhaust air valve 110 are triggered to close, and the containment 117 enters an isolated state.

[0056] When a design basis accident of a small amount of radioactive leakage occurs in the sodium-cooled fast reactor 1, most of the radioactive materials are contained in the reactor body container. At this time, the second air inlet valve 112, the exhaust air valve 110, the primary filter 120 and the high-efficiency filter 109 are opened, and the natural circulation driving force of the air extraction chimney 108 drives the internal gas circulation of the containment 117 to cool the internal equipment and maintain the necessary equipment functions.

[0057] When a very low probability beyond-design basis accident occurs in the sodium-cooled fast reactor 1, such as a hypothetical core 101 disintegration accident, the radioactive material in the reactor body container leaks into the containment 117 through the core melting collector 102. When the radiation monitor 116 in the containment 117 detects radioactive anomalies, the first air inlet valve 111, the second air inlet valve 112 and the exhaust valve 110 are triggered to close. At this time, the containment 117 is in an isolated state, which can effectively prevent the leakage of radioactive materials into the environment and affect the environment and personnel. After the containment 117 is sealed for a period of time, the short-lived radioactive materials with a large proportion of the radioactive materials decay, and only a small amount of long-lived radioactive materials remain. At this time, the isolation state of the containment 117 can be intermittently released, and the natural circulation of the exhaust chimney 108 or the low-flow operation of the exhaust fan 107 can be used to filter the gas in the containment 117 and then controllably discharge it from a high altitude to prevent the disordered ground source discharge of radioactive materials, and maintain the temperature in the containment 117 at a level where personnel can enter and intervene. If a sodium fire occurs in the containment vessel 117, the nitrogen system is activated to extinguish the sodium fire first.

[0058] The passive post-accident ventilation system reduces the demand for safety-level power load and improves the safety and economy of the sodium-cooled fast reactor 1.

[0059] In this embodiment, as one of the achievable methods, the refueling system is arranged in the reactor building 118 of the nuclear island, and is used for refueling the core 101, including an in-core refueling system and an out-core refueling system; A reactor rotating shield plug is provided on the top cover of the reactor body; the in-core refueling system includes a refueling machine and a hoist; the refueling machine is a direct-pull refueling machine, during the refueling of the core 101, the refueling machine enters the reactor body container in a direct-pull manner from the reactor rotating shield plug, and the reactor rotating shield plug is rotated in a circle to achieve full coverage of the core fuel assembly insertion position and the lower working position of the hoist; the hoist is an inclined hoist, during the refueling of the core 101, the refueling machine enters the upper working position or the lower working position in the reactor body container in an inclined manner from the top cover of the reactor body; a maintenance temporary storage position 620 is provided in the reactor building 118, and the refueling machine and the hoist are placed in the maintenance temporary storage position 620 during non-core refueling; The off-core refueling system includes a new fuel depot 601, a new fuel transportation channel 606, a transfer room, a spent fuel transportation channel, a cleaning room 610 and a spent fuel storage pool 621; The new fuel depot 601 is arranged on the left side of the reactor building 118, and the cleaning room 610 and the spent fuel storage pool 621 are arranged on the right side of the reactor building 118; the new fuel depot 601 is connected to the new fuel transportation channel 606; the spent fuel transportation channel is connected to the cleaning room 610; the transfer room is connected to the new fuel transportation channel 606 and the spent fuel transportation channel respectively; the cleaning room 610 and the spent fuel storage pool are connected through the spent fuel transportation waterway; A new fuel transfer vehicle 605 is provided on the new fuel transport passage 606, and a new fuel transfer coupling device 604 is provided on the new fuel transfer vehicle 605; a spent fuel transfer vehicle 608 is provided on the spent fuel transport passage, and a spent fuel transfer coupling device 609 and a spent fuel hanging basket are provided on the spent fuel transfer vehicle 608; a transfer room transfer vehicle is provided in the transfer room; A storage container and a preheating box 602 are provided in the new fuel depot 601; the storage container is used to store new fuel assemblies; a new fuel hanging basket 603 is provided in the preheating box 602, a preheating box 602 cover is provided on the top of the preheating box 602, the new fuel hanging basket 603 is used to store new fuel assemblies, the preheating box 602 is used to heat new fuel assemblies, and the preheating box 602 cover is used to open or close the preheating box 602; a cleaning room transfer vehicle 618, a lead leakage detection trap 613, a lead bath trap 612 and a cleaning trap 611 are provided in the cleaning room 610.

[0060] In this embodiment, as one of the achievable methods, the refueling of the core 101 includes loading of new fuel assemblies and unloading of spent fuel assemblies; the refueling system performs loading of new fuel assemblies, including the following steps: Transfer new fuel assemblies from the storage container of the new fuel depot 601 to the new fuel basket 603 of the preheating box 602; after the new fuel basket 603 is fully loaded with new fuel assemblies, close the cover of the preheating box 602 to complete the sealing of the preheating box 602; After the new fuel assembly in the preheating box 602 is preheated to the set temperature, the new fuel basket 603 is loaded into the new fuel transfer vehicle 605 through the new fuel transfer coupling device 604; the new fuel transfer vehicle 605 moves to the transfer chamber 616 in the new fuel transportation channel 606, and the new fuel assembly in the new fuel basket 603 is transferred to the elevator barrel through the transfer chamber transfer vehicle 617; The hoist cylinder enters the reactor body container from the reactor body top cover and descends to the lower working position along the inclined guide rail. The refueling machine transfers the new fuel assembly from the hoist cylinder to the insertion position of the spent fuel assembly that has been unloaded from the reactor core 101, completing the loading of the new fuel assembly. The refueling system unloads the spent fuel assembly, including the following steps: The hoist enters the reactor body container from the reactor body top cover and descends to the lower working position along the inclined guide rail; the material changer enters the reactor body container from the rotating shield plug along the vertical guide rail, and reaches the core 101 fuel assembly insertion hole position through the circumferential rotation of the rotating shield plug, and takes out the spent fuel assembly at the core 101 fuel assembly insertion hole position and transfers it to the lower working position of the hoist barrel; The hoist barrel is lifted to the upper working position along the inclined guide rail; the transfer room transfer vehicle 617 enters the upper working position of the hoist barrel in the reactor body container from the reactor body top cover, and transfers the spent fuel assembly to the spent fuel basket 619 of the spent fuel transfer vehicle 608 through the spent fuel transfer coupling device 609; When the spent fuel basket 619 is fully loaded with spent fuel assemblies, the spent fuel transfer vehicle 608 moves along the spent fuel transport channel to the cleaning room 610, and the spent fuel basket 619 is hoisted into the cleaning well 611 by the cleaning room transfer vehicle 618 for cleaning; after the spent fuel basket 619 is cleaned, the cleaning room transfer vehicle 618 transfers the spent fuel basket 619 to the spent fuel storage pool 621 for temporary storage through the spent fuel transport waterway 615; If the spent fuel assembly is found to be damaged in the reactor body container, the spent fuel basket 619 is still on the spent fuel transfer vehicle 608, and the damaged spent fuel assembly is transferred to the lead bath well 612 by the cleaning room transfer vehicle 618 for lead bath cleaning. After the lead bath cleaning is completed, the spent fuel assembly is placed in a sealed can, and then transferred to the spent fuel storage pool 621 by the cleaning room transfer vehicle 618 along the spent fuel transport waterway 615 via the spent fuel basket 619; If the spent fuel assembly is found damaged during the cleaning process in the cleaning well 611, after the cleaning is completed, the spent fuel assembly in the spent fuel basket 619 is transferred to the leakage detection well 613 for inspection one by one by the cleaning room transfer vehicle 618, and the damaged spent fuel assembly is placed in a sealed can, and then transferred through the spent fuel basket 619 by the cleaning room transfer vehicle 618 along the spent fuel transport waterway 615 to the spent fuel storage pool 621.

[0061] In the conventional sodium-cooled fast reactor 1, the new fuel assembly conversion barrel is used as an indispensable transfer device in the path of the new fuel assembly entering the stack, and at the same time as a preheating device before the new fuel assembly enters the stack. The preheating and cooling of the new fuel assembly conversion barrel when the fuel assembly in the stack is replaced in batches will greatly extend the overhaul period of the unit. The present invention preheats the new fuel assembly in batches through the preheating box 602, ensures the continuity of the new fuel assembly loading, reduces the loading main line period of the sodium-cooled fast reactor unit overhaul, and eliminates the configuration of the new fuel assembly conversion barrel.

[0062] The sodium-cooled fast reactor unit of the present invention has a direct-drive material changer. Compared with the traditional rotary loop material changer, the straight and long new fuel transportation channel 606 and the spent fuel transportation channel 607 are more suitable for the unified management of multiple sodium-cooled fast reactor units, reducing the construction period of barrel-type loading and transportation of new fuel assemblies and spent fuel assemblies, and can achieve the maximum possible compression of the material change period. At the same time, the new fuel assembly and spent fuel assembly conversion barrels and related auxiliary supporting systems are eliminated.

[0063] In the conventional sodium-cooled fast reactor unit, the high requirements for the installation accuracy of the refueling system equipment are met during the transportation of the fuel assemblies to achieve the high requirements for the positioning accuracy between the conversion of the refueling system equipment. The sodium-cooled fast reactor unit of the present invention greatly reduces the high requirements for the installation accuracy of the refueling system equipment during the transportation of the fuel assemblies, and converts the high requirements for the installation accuracy of the refueling system equipment into the control accuracy requirements for the positioning between the conversion of the refueling system equipment, which greatly reduces the difficulty of installing the refueling system equipment and the risk of difficulty in realizing the refueling process due to deviations in the installation of the refueling system equipment and civil construction.

[0064] In the present invention, new fuel assemblies are heated and transported as a whole using the new fuel basket 603, and spent fuel assemblies are hoisted and cleaned as a whole using the spent fuel basket 619, thereby reducing the fuel assembly transport cycle through modular design.

[0065] In the refueling system of the present invention, the waterless cleaning device in the cleaning chamber 610 cleans the spent fuel assembly, which reduces the risk of sodium-water reaction and excessive hydrogen content compared to the traditional water vapor cleaning method, and eliminates the need for a series of monitoring devices such as hydrogen meters and hydrogen-oxygen-alkali measuring devices.

[0066] In this embodiment, as one of the achievable methods, the instrument control system is a distributed instrument control system; The instrument control system includes the process system interface layer, the automatic control and protection layer, the operation and management information layer, and the plant-wide technical management layer; The process system interface layer includes sensors and actuators; sensors are installed on process equipment to detect process parameters of process equipment; actuators are used to control the process according to control instructions from the automatic control and protection layers; The automatic control and protection layer adopts on-site summary control technology to collect the process parameters of the process system interface layer; process and perform logical operations on the process parameters of the process system interface layer, generate control instructions and pass them to the process system interface layer; The operation and management information layer is used to perform tasks, including information support, information diagnosis, recording of process information and operator actions, and controlling the sodium-cooled fast reactor unit through operating equipment; the operation and management information layer includes the main control room 13 and the backup control room; The technical management layer is used for the operation and management of the sodium-cooled fast reactor power plant. It receives the information required for the operation and management of the sodium-cooled fast reactor power plant through the network interface equipment, so that the managers of the sodium-cooled fast reactor power plant can understand the operating status of the sodium-cooled fast reactor power plant.

[0067] In this embodiment, as one of the achievable methods, the automatic control and protection layer includes a safety-level digital control system and a non-safety-level digital control system; The safety-level digital control system is a verified and confirmed safety-level DCS, including the sodium-cooled fast reactor 1 protection system, the sodium-cooled fast reactor 1 post-accident monitoring system and the nuclear instrument system; The non-safety-grade digital control system adopts the mature bus control technology of modern industry, combined with the AI ​​technology and 5G technology developed in recent years, and adopts the domestic mature non-safety-grade DCS and PLC, while meeting the safety, maturity and stability, taking into account the advanced technology.

[0068] For the auxiliary systems of sodium-cooled fast reactor units, especially the auxiliary systems of conventional islands and nuclear islands, 5G systems are arranged in relevant plant buildings. Through wireless network and field bus technology, the mature and advanced experience in large-scale chemical, petrochemical, thermal power and other industrial fields is learned, and the 5G system network constructed by modern intelligent instruments is fully adopted to realize the wireless communication network connection between people, systems and equipment, and to grasp the system equipment status of the auxiliary system of sodium-cooled fast reactor units in real time; robot inspection is used in some places, which greatly reduces the workload of manual inspection, and at the same time improves the accuracy of equipment monitoring, which is conducive to equipment management in engineering construction and operation stages. In view of the inherent safety of sodium-cooled fast reactor 1, the safety-level DCS is optimized, and the control of some auxiliary systems of the nuclear island is adjusted to the non-safety level, and the sodium-cooled fast reactor 1 protection, sodium-cooled fast reactor 1 post-accident monitoring, nuclear measurement instrument system, etc. are retained as safety levels. In the sodium-cooled fast reactor power station of the present invention, the instrument control system adopts a mature and advanced distributed instrument control system, which ensures the safety, reliability, flexibility and economy of the operation of the sodium-cooled fast reactor power station.

[0069] In this embodiment, as one of the achievable modes, the electrical system includes an off-site electrical system and an on-site electrical system; the off-site electrical system is composed of two completely independent power supply lines, and the off-site power supply provides power to each sodium-cooled fast reactor unit through a main transformer and an auxiliary transformer; the on-site power system is composed of a normal power supply system, a reliable power supply system, a reliable diesel engine 715 and a battery energy storage station 714; The normal power supply system is used to ensure the normal startup, rated power operation and normal shutdown of the sodium-cooled fast reactor unit. The reliable power supply system is used to ensure the normal operation of the sodium-cooled fast reactor unit. Reliable diesel engine 715 is an independent medium-voltage reliable AC power source in the sodium-cooled fast reactor power plant, which supplies power to the reliable power supply system when both the normal power supply system and the reliable power supply system lose power; The battery energy storage station 714 realizes secondary frequency regulation of the sodium-cooled fast reactor unit when the sodium-cooled fast reactor unit operates normally, and supplies power to the normal power supply system when the normal power supply system loses power.

[0070] The sodium-cooled fast reactor 1 has passive inherent safety. Under accident conditions, the heat of the sodium-cooled fast reactor 1 can be transferred to the intermediate heat exchanger 201 through the natural circulation of the sodium-cooled fast reactor 1 in the reactor and to the air heat exchanger through the independent heat exchanger. The air heat exchanger transfers the heat of the sodium-cooled fast reactor 1 to the atmosphere through the wind extraction chimney 108 to extract the heat of the sodium-cooled fast reactor 1, thereby realizing the extraction of residual heat of the sodium-cooled fast reactor 1 under accident conditions. At the same time, the safety of the sodium-cooled fast reactor 1 does not rely on power supply, and only one reliable diesel engine is used to protect the operation of important equipment under accident conditions.

[0071] In this embodiment, as one of the achievable methods, the battery energy storage station 714 includes an energy storage battery pack, an energy storage converter, a battery management system, an energy management system, a cooling and fire protection system, and a grid-connected interface and protection device; Among them, the energy storage battery pack uses lithium-ion batteries as energy storage media to convert electrical energy into chemical energy for storage; The energy storage converter is used to realize the bidirectional conversion between AC and DC, control the charging and discharging process of the energy storage battery pack, and adjust the power output of the energy storage battery pack; The battery management system is used to monitor the voltage, temperature, state of charge and health status of the energy storage battery pack in real time to ensure the safe operation of the energy storage battery pack and optimize the charging and discharging strategy of the energy storage battery pack; The energy management system is used to coordinate the operation of the energy storage system and optimize the charging and discharging plan of the energy storage system through data analysis and algorithms; The cooling and fire fighting system is used to maintain the temperature of the energy storage battery pack stable, prevent thermal runaway, and activate the fire extinguishing device when the energy storage battery pack thermal runaway; Grid-connected interfaces and protection devices include circuit breakers, isolation transformers and surge protectors to ensure safe connection to the grid.

[0072] In this embodiment, as one of the achievable methods, the energy storage system includes a super capacitor 402, a battery 403 and an energy storage transformer 401; the power generation outlet of the steam turbine generator 303 is connected to the super capacitor 402 and the battery 403 in turn through the energy storage transformer 401; the battery 403 is connected to the battery energy storage station 714 in circuit; Under the secondary frequency regulation of the sodium-cooled fast reactor unit, when the grid frequency deviates from the rated value, the energy management system of the battery energy storage station 714 captures the grid frequency deviation signal in real time through sensors, and calculates the amount of power to be supplemented or absorbed based on the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, the frequency regulation timing and output depth of the energy storage system are determined, the allocation factor is optimized, and the power output of the energy storage system is smoothly adjusted to quickly respond to grid frequency fluctuations; When the normal power supply system loses power, the battery energy storage station 714 transmits a normal power supply system power failure signal to the energy storage system. The energy storage system adjusts the discharge power to the steam turbine generator 303 according to the grid load demand, and discharges to the normal power supply system through the battery energy storage station 714 while ensuring the voltage and frequency stability of the grid, thereby supplying power to the normal power supply system.

[0073] The energy storage system is integrated with the battery energy storage station 714 to ensure the safety and reliability of the battery energy storage station 714 while meeting the energy storage and secondary frequency regulation functions of the sodium-cooled fast reactor unit.

[0074] In this embodiment, as one of the feasible ways, the nuclear island is also provided with a maintenance plant 9, a spare parts warehouse 10, a hazardous goods warehouse 11, a fuel regeneration project 17 and an isotope production hot chamber 18; wherein, the maintenance plant 9 is used for the maintenance of equipment of the sodium-cooled fast reactor unit; the spare parts warehouse 10 is used for the storage of spare parts and spare parts of the sodium-cooled fast reactor unit; the hazardous goods warehouse 11 is used for the storage of hazardous chemicals of the sodium-cooled fast reactor unit, the fuel regeneration project 17 is used for the post-processing of spent fuel and the manufacture of new fuel, and the isotope production hot chamber 18 is used for the extraction, purification and packaging of radioactive isotopes.

[0075] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A large sodium-cooled fast reactor power plant, comprising a sodium-cooled fast reactor unit and a sodium-cooled fast reactor unit auxiliary system; characterized in that: The sodium-cooled fast reactor unit is used to convert nuclear energy into electrical energy or steam energy, and the sodium-cooled fast reactor unit auxiliary system is used to assist the sodium-cooled fast reactor unit in converting nuclear energy into electrical energy or steam energy; there are multiple sodium-cooled fast reactor units, and the sodium-cooled fast reactor unit auxiliary system is shared by two or each sodium-cooled fast reactor unit; The sodium-cooled fast reactor unit comprises a sodium-cooled fast reactor (1), a main heat transmission system, a power conversion system, an accident residual heat removal system and an energy storage system; the sodium-cooled fast reactor (1) is used to generate heat energy by nuclear fission; the main heat transmission system is used to transfer the heat energy generated by the sodium-cooled fast reactor (1) to the power conversion system; the power conversion system is used to convert the heat energy generated by the sodium-cooled fast reactor (1) into electrical energy or steam energy; the energy storage system is used to store and release electrical energy; the accident residual heat removal system is used to remove the residual heat of the sodium-cooled fast reactor (1) under accident conditions of the sodium-cooled fast reactor (1); The sodium-cooled fast reactor (1) is arranged in a reactor building (118) of a nuclear island. The reactor building (118) is a common earthquake-resistant building and is manufactured in a modular manner using a large process room. The sodium-cooled fast reactor (1) includes a reactor pit, a containment vessel (117) in the reactor pit, and a reactor body (103) in the containment vessel (117). The construction is completed by the following steps: The construction of the reactor pit, the containment vessel (117) and the reactor body (103) is carried out in parallel, and after the construction of the containment vessel (117) and the reactor body (103) is completed, the reactor body (103) is loaded into the containment vessel (117); the containment vessel (117) and the reactor body (103) in the containment vessel (117) are pushed into the reactor pit as a whole; the reactor body (103) is manufactured in a modular manner, the containment vessel (117) is a capsule-type structure made of fully welded steel plates, and the reactor pit is constructed of concrete.

2. The large-scale sodium-cooled fast reactor power plant according to claim 1, characterized in that: The containment shell (117) is divided into an upper container and a lower container; the upper container is a hemispherical container, and the lower container is a cylindrical container; the upper container and the lower container are connected by welding to form the containment shell (117), the interiors of the upper container and the lower container are connected, and the welding meets the internal airtightness requirements of the containment shell (117); a detachable top cover is provided on the top of the upper container, and the top cover adopts a mechanical seal; The containment (117) is provided with a personnel and equipment access passage (106) at the reactor hall position, and the personnel and equipment access passage (106) is sealed by a sodium fire protection door; during normal operation of the sodium-cooled fast reactor (1), the personnel and equipment access passage (106) is in a closed state; during maintenance of the sodium-cooled fast reactor (1), the personnel and equipment access passage (106) is in an open state; A sodium leakage receiving and suppression plate (104) is provided at the bottom of the containment vessel (117); and a core melting collector (102) is provided at the bottom of the reactor body (103).

3. The large-scale sodium-cooled fast reactor power plant according to claim 1, characterized in that: The reactor body (103) comprises a reactor body container, a reactor body top cover sealed to the top of the reactor body container, a reactor top device (119) sealed to the reactor body top cover, a reactor top shielding device (105) sealed to the reactor body top cover, a sodium pool in the reactor body (103) container, and an intermediate heat exchanger (201), an independent heat exchanger, a primary circuit sodium pump and a reactor core (101) arranged in the sodium pool; wherein the intermediate heat exchanger (201) and the independent heat exchanger are both manufactured using integrated 3D printing technology; the reactor top shielding device (105) is manufactured in an integrated manner; and the internal component material of the sodium-cooled fast reactor (1) is low-copper and low-phosphorus steel.

4. The large-scale sodium-cooled fast reactor power plant according to claim 3, characterized in that: The core (101) is made of radiation-resistant FMS or ODS cladding material; the inner ring of the core (101) is an active zone, in which fissile nuclear fuel U-235 undergoes fission reaction to produce fast neutrons; the outer ring of the core (101) is a breeder zone (510), in which fissile nuclear fuel U-238 absorbs fast neutrons and is converted into fissile nuclear fuel Pu-239; the content of fissile nuclear fuel Pu-239 in the breeder zone (510) is higher than that in the active zone, so that the power of fuel assemblies in the active zone and the breeder zone (510) is flattened; The active zone includes an active zone fuel inner zone and an active zone fuel outer zone (508) surrounding the outer periphery of the active zone fuel inner zone; the active zone fuel inner zone is designed to be axially non-uniform, and is axially divided from top to bottom into a first active zone fuel inner zone (507), an inert fuel zone (506) and a second active zone fuel inner zone (509); the active zone fuel inner zone and the breeding zone (510) are each provided with an irradiation zone for isotope production; The proliferation ratio in the core (101) is 1; the control rod assembly consists of a regulating control rod assembly and a safety control rod assembly, or a regulating control rod assembly, a safety control rod assembly and a small number of compensating control rod assemblies; the reactor body top cover is provided with a reactor rotating shield plug; the reactor top equipment includes a control rod driving mechanism; the control rod driving mechanism enters the reactor body container from the rotating shield plug and connects with the corresponding control rod in the core (101), driving the control rod to insert or withdraw the fuel assembly; A short fuel rod bundle is combined at the lower end of the control rod; when the control rod is inserted, the control rod is located in the inner area of ​​the fuel in the active zone, introducing negative reactivity; when the control rod is lifted, the short fuel rod bundle at the lower end of the control rod is located in the inner area of ​​the fuel in the active zone, introducing positive reactivity, thereby increasing the value of the control rod.

5. The large-scale sodium-cooled fast reactor power plant according to claim 3, characterized in that: The main heat transfer system is a sodium-sodium-molten salt-water four-loop structure, including an intermediate heat exchanger (201), a primary sodium pump, a secondary sodium pump (202), a sodium-molten salt heat exchanger (203), a first regulating valve (206), a second regulating valve (209), a high-temperature molten salt pump (210), a low-temperature molten salt pump (204), a molten salt-water heat exchanger (211), a high-temperature molten salt tank (208), a low-temperature molten salt tank (207), a main feed water pump (304) and a linear Fresnel focusing system (205); The sodium pool is filled with primary sodium and is divided into a cold pool and a hot pool by a partition; the reactor core (101) and the intermediate heat exchanger (201) are both arranged in the hot pool, and the primary sodium pump is arranged in the cold pool; the primary sodium pump flows the primary sodium in the cold pool through the reactor core (101) and the primary sodium side of the intermediate heat exchanger (201) and then returns it to the cold pool to form a primary loop; The outlet of the secondary circuit sodium side of the intermediate heat exchanger (201) is connected to the secondary circuit sodium pump (202), the sodium side of the sodium-molten salt heat exchanger (203) and the inlet of the secondary circuit sodium side of the intermediate heat exchanger (201) in sequence through pipelines to form a secondary circuit; The outlet of the molten salt side of the sodium-molten salt heat exchanger (203) is connected to the high-temperature molten salt tank (208), the second regulating valve (209), the high-temperature molten salt pump (210), the molten salt side of the molten salt-water heat exchanger (211), the low-temperature molten salt tank (207), the first regulating valve (206), the low-temperature molten salt pump (204) and the inlet of the molten salt side of the sodium-molten salt heat exchanger (203) through pipelines in sequence, forming a three-circuit loop; the pipeline connecting the molten salt side of the sodium-molten salt heat exchanger (203) and the high-temperature molten salt tank (208) is heated by the linear Fresnel concentrating system (205), and the linear Fresnel concentrating system (205) uses light energy to heat the molten salt in the molten salt pipeline, thereby realizing the coupling of the sodium-cooled fast reactor (1) and light energy; The water side outlet of the molten salt-water heat exchanger (211) is connected to the power conversion system, the main water supply pump (304) and the water side outlet inlet of the molten salt-water heat exchanger (211) in sequence through pipelines, forming a four-circuit loop.

6. The large-scale sodium-cooled fast reactor power plant according to claim 5, characterized in that: The power conversion system comprises a steam circuit control valve (301), a power generation circuit control valve (302), a molten salt superheater (310), a steam turbine generator (303), a condenser (305), a steam user (307), a power grid user (309) and a power grid main transformer (308); the water side outlet of the molten salt-water heat exchanger (211) is divided into two paths, one of which is connected to the steam circuit control valve (301) in sequence through a pipeline, and the other is connected to the power generation circuit control valve (302), the molten salt superheater (310) in sequence through a pipeline. The salt superheater (310), the steam turbine generator (303), the condenser (305), the main feed water pump (304) and the water side inlet of the molten salt-water heat exchanger (211); the steam turbine generator (303) and the steam user (307) are connected by a pipeline, and a check valve (306) is provided on the pipeline connecting the steam turbine generator (303) and the steam user (307); the power generation outlet of the steam turbine generator (303) is connected to the power grid user (309) through the power grid main transformer (308); The operation mode of the sodium-cooled fast reactor unit is one or a combination of the solar thermal energy storage mode, the power generation mode and the high-temperature industrial steam supply mode; In the solar thermal energy storage mode, the first regulating valve (206), the second regulating valve (209), the steam circuit control valve (301), the power generation circuit control valve (302) and the check valve (306) are all closed; the sodium-cooled fast reactor (1) operates at full power, the secondary circuit sodium pump (202) and the high-temperature molten salt pump (210) operate at rated power, the low-temperature molten salt pump (204) operates at high power, and the linear Fresnel focusing system (205) heats the molten salt pipeline; the liquid level of the high-temperature molten salt tank (208) rises, and the liquid level of the low-temperature molten salt tank (207) drops. By adjusting the amount of high and low temperature molten salt, nuclear energy and light energy are converted into molten salt thermal energy for storage; In the power generation mode, the first regulating valve (206), the second regulating valve (209), the power generation circuit control valve (302) and the check valve (306) are all opened, and the steam circuit control valve (301) is closed; the sodium-cooled fast reactor (1) operates at full power, and the secondary circuit sodium pump (202), the low-temperature molten salt pump (204) and the high-temperature molten salt pump (210) all operate at rated power; the liquid levels of the high-temperature molten salt tank (208) and the low-temperature molten salt tank (207) remain unchanged; part of the steam generated by the steam turbine generator (303) after power generation is sent to the condenser (305) to be condensed into condensate, and part of the steam is sent to the steam user; the condensate is sent to the water side of the molten salt-water heat exchanger (211) through the main feed water pump (304) for heat exchange, and then sent to the molten salt superheater (310) to be heated into superheated steam and then sent back to the steam turbine generator (303) for power generation; In the high-temperature industrial steam supply mode, the first regulating valve (206), the second regulating valve (209) and the steam circuit control valve (301) are all opened, and the power generation circuit control valve (302) and the check valve (306) are all closed; the sodium-cooled fast reactor (1) operates at full power, and the secondary circuit sodium pump (202), the low-temperature molten salt pump (204) and the high-temperature molten salt pump (210) all operate at rated power; the liquid levels of the high-temperature molten salt tank (208) and the low-temperature molten salt tank (207) remain unchanged; the main feed water is sent to the water side of the molten salt-water heat exchanger (211) through the main feed water pump (304) for heat exchange to generate high-temperature industrial steam and send it to the steam user (307).

7. The large-scale sodium-cooled fast reactor power plant according to claim 6, characterized in that: The primary frequency regulation and peak regulation of sodium-cooled fast reactor units include power increase and power decrease of sodium-cooled fast reactor units. There are two modes for power decrease of sodium-cooled fast reactor units: In the first mode, the sodium-cooled fast reactor unit maintains a power generation mode, the sodium-cooled fast reactor (1) operates at full power, the secondary circuit sodium pump (202) operates at full power, and the heat of the sodium-cooled fast reactor (1) is continuously removed; the low-temperature molten salt pump (204) operates at rated power, the high-temperature molten salt pump (210) operates at low power, and the main feed water pump (304) operates at low power, so that the total amount of steam is reduced and the output power of the steam turbine generator (303) is reduced, thereby achieving peak load regulation of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank (208) increases, and the liquid level of the low-temperature molten salt tank (207) continues to decrease, and the excess energy generated by the sodium-cooled fast reactor (1) is stored by adjusting the high and low temperature molten salt reserves; In the second mode, the sodium-cooled fast reactor unit is in power generation mode while simultaneously starting the high-temperature industrial steam supply mode, and the amount of high-temperature industrial steam supply is controlled by the opening of the steam loop control valve (301), thereby reducing the power generation power of the steam turbine generator (303) and realizing peak regulation of the sodium-cooled fast reactor unit; The power increase operation mode of the sodium-cooled fast reactor unit is as follows: the sodium-cooled fast reactor is operated at full power, the secondary circuit sodium pump (202) is operated at full power, and the heat of the sodium-cooled fast reactor (1) is continuously taken out; the high-temperature molten salt pump (210) is operated at high power, the low-temperature molten salt pump (204) is operated at rated power, and the main feed water pump (304) is operated at high power, so that the total amount of steam is increased, the output power of the steam turbine generator (303) is increased, and the peak load of the sodium-cooled fast reactor unit is realized; the liquid level of the high-temperature molten salt tank (208) is reduced, and the liquid level of the low-temperature molten salt tank (207) is increased. By adjusting the storage of high and low temperature molten salt, the molten salt energy storage is released, the power generation power of the steam turbine generator (303) is increased, and the online power of the sodium-cooled fast reactor unit is increased.

8. The large-scale sodium-cooled fast reactor power plant according to claim 6, characterized in that: Secondary frequency regulation of sodium-cooled fast reactor units, including secondary frequency regulation for power down regulation of sodium-cooled fast reactor units and secondary frequency regulation for power up regulation of sodium-cooled fast reactor units; Under the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator (303) is synchronously connected to the energy storage system for charging, thereby reducing the on-grid power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit; Under the secondary frequency regulation for increasing the power of the sodium-cooled fast reactor unit, the sodium-cooled fast reactor unit maintains the power generation mode, and the power generation outlet of the steam turbine generator (303) is synchronously connected to the energy storage system for discharge, thereby increasing the online power of the sodium-cooled fast reactor unit and realizing the secondary frequency regulation for increasing the power of the sodium-cooled fast reactor unit.

9. The large-scale sodium-cooled fast reactor power plant according to claim 6, characterized in that: The condenser (305) comprises an air-cooling radiator and a natural ventilation cooling tower (15); the air-cooling radiator is connected to the steam turbine generator (303) through a pipeline, and the air-cooling radiator is arranged at the bottom or side of the natural ventilation cooling tower (15); the steam generated by the steam turbine generator (303) is sent to the air-cooling radiator, and the suction force of the natural ventilation cooling tower (15) causes cold air to flow through the surface of the air-cooling radiator, so that the steam in the air-cooling radiator condenses to form condensed water, which is sent to the water side of the molten salt-water heat exchanger (211) through the main feed water pump (304).

10. The large-scale sodium-cooled fast reactor power plant according to claim 3, characterized in that: The accident residual heat removal system comprises an air heat exchanger and an independent heat exchanger; and is used for removing residual heat of a sodium-cooled fast reactor (1) under an accident condition of the sodium-cooled fast reactor (1); The air heat exchanger is arranged at the bottom or side of the air extraction chimney (108) and is connected to the pipeline of the air extraction chimney (108); the independent heat exchanger is arranged in the cold pool or the hot pool and is connected to the air heat exchanger pipeline; The primary sodium in the cold pool flows through the core (101) and the primary sodium side of the independent heat exchanger and then returns to the cold pool; the secondary sodium on the secondary sodium side of the independent heat exchanger undergoes heat exchange with the primary sodium on the primary sodium side of the independent heat exchanger and then enters the air heat exchanger, undergoes heat exchange with the air in the air heat exchanger and then returns to the secondary sodium side of the independent heat exchanger; the air in the air heat exchanger rises due to the heat and is discharged from the air extraction chimney (108) into the atmosphere using the pressure difference generated by the height difference of the air extraction chimney (108).

11. The large-scale sodium-cooled fast reactor power plant according to claim 3, characterized in that: The auxiliary systems of the sodium-cooled fast reactor units include a primary-loop purification system, a secondary-loop purification system, a nitrogen system, an argon system, a vacuum system, a gas heating system, a ventilation system, a refrigeration system, an electrical system, an instrumentation and control system, a refueling system and a fire-fighting system; among them, the primary-loop purification system and the secondary-loop purification system are shared by two sodium-cooled fast reactor units; the nitrogen system, the argon system, the vacuum system, the gas heating system, the ventilation system, the refrigeration system, the electrical system, the instrumentation and control system, the refueling system and the fire-fighting system are shared by each sodium-cooled fast reactor unit.

12. The large-scale sodium-cooled fast reactor power plant according to claim 11, characterized in that: The nitrogen system is used to fill nitrogen into the sodium fire position of the containment when a sodium fire accident occurs, so as to extinguish the sodium fire and alleviate the consequences of the sodium fire accident; the nitrogen system is arranged in the reactor building (118), and comprises a nitrogen tank (114), a nitrogen pipeline and a nitrogen valve (113); the nitrogen tank (114) is used to store nitrogen; the nitrogen tank (114) is connected to the inside of the containment (117) through a nitrogen pipeline, and a nitrogen valve (113) is provided on the nitrogen pipeline; the nitrogen valve (113) receives a control instruction from an instrument control system, and controls the filling and discharge of nitrogen from the nitrogen tank (114) into the containment (117) according to the control instruction.

13. The large-scale sodium-cooled fast reactor power plant according to claim 11, characterized in that: The ventilation system is arranged in the reactor building (118), and includes a first air inlet duct, a second air inlet duct, an exhaust duct, and an air extraction chimney (108); the air extraction chimney (108) is elevated to the outside of the reactor building (118); One end of the first air inlet duct is in communication with the outside of the reactor building (118), and the other end is in communication with the inside of the containment shell (117); an air inlet fan (115) and a first air inlet valve (111) are sequentially arranged on the first air inlet duct along the wind direction; one end of the second air inlet duct is in communication with the inside of the reactor building (118) outside the containment shell (117), and the other end is in communication with the inside of the containment shell (117); a second air inlet valve (112) is arranged on the second air inlet duct; One end of the exhaust duct is in communication with the interior of the containment (117), and the other end is in communication with the interior of the exhaust chimney (108); an exhaust air valve (110), a primary filter (120), a high efficiency filter (109), and an exhaust fan (107) are sequentially arranged on the exhaust duct along the wind direction; The air outside the reactor building (118) enters the containment vessel (117) from the first air inlet duct or the air inside the reactor building (118) enters the containment vessel (117) from the second air inlet duct, and the pressure difference generated by the high head difference drives the gas inside the containment vessel (117) to be discharged from the exhaust duct through the overhead chimney (108) to the outside of the reactor building (118); The first air inlet valve (111), the second air inlet valve (112) and the exhaust valve (110) are all arranged near the containment vessel (117) and are provided with a fuse device which automatically fuses and closes when the temperature rises to a set value.

14. The large-scale sodium-cooled fast reactor power plant according to claim 11, characterized in that: The refueling system is arranged in the reactor building (118) of the nuclear island and is used for refueling the core (101), including an in-core refueling system and an out-core refueling system; A reactor rotating shield plug is provided on the top cover of the reactor body; the in-core refueling system comprises a refueling machine and a hoist; the refueling machine is a direct-pull type refueling machine, and during the refueling of the core (101), the refueling machine enters the reactor body container in a direct-pull manner from the reactor rotating shield plug, and the reactor rotating shield plug is rotated in a circle to achieve full coverage of the core fuel assembly insertion hole position and the lower working position of the hoist; the hoist is an inclined hoist, and during the refueling of the core (101), the refueling machine enters the upper working position or the lower working position in the reactor body container in an inclined manner from the top cover of the reactor body; a maintenance temporary storage position (620) is provided in the reactor building (118), and the refueling machine and the hoist are placed in the maintenance temporary storage position (620) during non-core refueling; The off-core refueling system includes a new fuel depot (601), a new fuel transportation channel (606), a transfer room (616), a spent fuel transportation channel (607), a cleaning room (610) and a spent fuel storage pool (621); The new fuel depot (601) is arranged on the left side of the reactor building (118), and the cleaning room (610) and the spent fuel storage pool (621) are arranged on the right side of the reactor building (118); the new fuel depot (601) is connected to the new fuel transportation channel (606); the spent fuel transportation channel (607) is connected to the cleaning room (610); the transfer room (616) is connected to the new fuel transportation channel (606) and the spent fuel transportation channel (607) respectively; the cleaning room (610) and the spent fuel storage pool (621) are connected through the spent fuel transportation waterway (615); A new fuel transfer vehicle (605) is provided on the new fuel transport passage (606), and a new fuel transfer coupling device (604) is provided on the new fuel transfer vehicle (605); a spent fuel transfer vehicle (608) is provided on the spent fuel transport passage (607), and a spent fuel transfer coupling device (609) and a spent fuel hanging basket (619) are provided on the spent fuel transfer vehicle (608); a transfer room transfer vehicle (617) is provided in the transfer room (616); A storage container and a preheating box (602) are provided in the new fuel depot (601); the storage container is used to store new fuel assemblies; a new fuel hanging basket (603) is provided in the preheating box (602); a preheating box (602) cover is provided on the top of the preheating box (602); the new fuel hanging basket (603) is used to store new fuel assemblies; the preheating box (602) is used to heat new fuel assemblies; and the preheating box (602) cover is used to open or close the preheating box (602); and a cleaning room transfer vehicle (618), a lead leakage detection trap (613), a lead bath trap (612), and a cleaning trap (611) are provided in the cleaning room (610).

15. The large-scale sodium-cooled fast reactor power plant according to claim 11, characterized in that: The instrument control system is a distributed instrument control system, including the process system interface layer, automatic control and protection layer, operation and management information layer, and the whole plant technical management layer; The process system interface layer includes sensors and actuators; sensors are installed on process equipment to detect process parameters of process equipment; The actuator is used to control the process according to the control instructions from the automatic control and protection layer; The automatic control and protection layer adopts on-site summary control technology to collect process parameters of the process system interface layer; Process the process parameters and perform logical operations on the process system interface layer, generate control instructions and pass them to the process system interface layer; The operation and management information layer is used to perform tasks, including information support, information diagnosis, recording of process information and operator actions, and controlling the sodium-cooled fast reactor unit through operating equipment; The technical management layer is used for the operation and management of the sodium-cooled fast reactor power plant, and receives the information required for the operation and management of the sodium-cooled fast reactor power plant through the network interface equipment.

16. The large-scale sodium-cooled fast reactor power plant according to claim 11, characterized in that: The electrical system includes an off-site electrical system and an on-site electrical system; the off-site electrical system consists of two completely independent power supply lines, and the off-site power supply provides power to each sodium-cooled fast reactor unit through a main transformer and an auxiliary transformer; the on-site power system consists of a normal power supply system, a reliable power supply system, a reliable diesel engine (715) and a battery energy storage station (714); the normal power supply system is used to supply power to electrical equipment that ensures normal startup, rated power operation and normal shutdown of the sodium-cooled fast reactor unit; the reliable power supply system is used to supply power to electrical equipment that maintains the normal operation of the sodium-cooled fast reactor unit; the reliable diesel engine (715) supplies power to the reliable power supply system when both the normal power supply system and the reliable power supply system lose power; the battery energy storage station (714) realizes secondary frequency modulation of the sodium-cooled fast reactor unit when the sodium-cooled fast reactor unit is operating normally, and supplies power to the normal power supply system when the normal power supply system loses power.

17. The large sodium-cooled fast reactor power plant according to claim 16, characterized in that: The battery energy storage station (714) comprises an energy storage battery pack, an energy storage converter, a battery management system, an energy management system, a cooling and fire protection system, and a grid connection interface and protection device; Among them, the energy storage battery pack is used to convert electrical energy into chemical energy for storage; the energy storage inverter is used to realize the bidirectional conversion of AC and DC, control the charging and discharging process of the energy storage battery pack, and adjust the power output of the energy storage battery pack; the battery management system is used to monitor the voltage, temperature, charge state and health state of the energy storage battery pack in real time, ensure the safe operation of the energy storage battery pack and optimize the charging and discharging strategy of the energy storage battery pack; the energy management system is used to coordinate the operation of the energy storage system and optimize the charging and discharging plan of the energy storage system through data analysis and algorithms; the cooling and fire protection system is used to maintain the temperature stability of the energy storage battery pack and activate the fire extinguishing device when the energy storage battery pack is thermally out of control; the grid-connected interface and protection device are used to ensure a safe connection with the power grid.

18. The large-scale sodium-cooled fast reactor power plant according to claim 17, characterized in that: The energy storage system comprises a super capacitor (402), a storage battery (403) and an energy storage transformer (401); the power generation outlet of the steam turbine generator (303) is connected to the super capacitor (402) and the storage battery (403) circuit in sequence through the energy storage transformer (401); the storage battery (403) is connected to the storage battery energy storage station (714) circuit; Under the secondary frequency regulation of the sodium-cooled fast reactor unit, when the grid frequency deviates from the rated value, the energy management system of the battery energy storage station (714) captures the grid frequency deviation signal in real time through sensors, and calculates the amount of power to be supplemented or absorbed based on the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, the frequency regulation timing and output depth of the energy storage system are determined, the allocation factor is optimized, and the power output of the energy storage system is smoothly adjusted; When the normal power supply system loses power, the battery energy storage station (714) transmits a normal power supply system power failure signal to the energy storage system. The energy storage system adjusts the discharge power to the steam turbine generator (303) according to the load demand of the power grid, and discharges power to the normal power supply system through the battery energy storage station (714) while ensuring the stability of the voltage and frequency of the power grid, thereby supplying power to the normal power supply system.

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