A large sodium-cooled fast reactor power station

Abstract

The present invention specifically relates to a large sodium-cooled fast reactor power station, belonging to the technical field of sodium-cooled fast reactors, and includes a plurality of sodium-cooled fast reactor units and their shared auxiliary systems. The sodium-cooled fast reactor unit includes a sodium-cooled fast reactor, a primary heat transfer system, a power conversion system, an accident residual heat removal system, and an energy storage system; the sodium-cooled fast reactor is arranged in the reactor building; the sodium-cooled fast reactor includes a reactor pit, a containment vessel within the reactor pit, and a reactor core within the containment vessel. The construction is completed through the following steps: constructing the reactor pit, the containment vessel, and the reactor core in parallel, and after the construction of the containment vessel and the reactor core is completed, loading the reactor core into the containment vessel. The reactor core is modularly manufactured, the containment vessel is a capsule-type small steel containment vessel, and the reactor pit is constructed of concrete; the containment vessel and the reactor core within the containment vessel are integrally pushed into the reactor pit. The present invention improves nuclear safety and industrial safety while significantly improving the economy of the sodium-cooled fast reactor power station and significantly shortening the construction period of the sodium-cooled fast reactor power station.

Description

Technical Field

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

[0002] Fast reactors are an important direction for the development of advanced nuclear energy. In particular, sodium-cooled fast reactors have become the most commercially promising fourth-generation advanced nuclear energy technology among the fourth-generation advanced nuclear power reactor types after more than 70 years of development. Although the global cumulative operation experience of sodium-cooled fast reactors has exceeded 400 reactor-years, the currently operating large sodium-cooled fast reactor power stations still have the following problems: due to the low radiation resistance of the fuel assembly cladding material and the outer casing pipe, the low linear power density of the reactor core, the small burnup, the relatively large overall volume of the reactor core, and the relatively large design of the reactor vessel; the layout of sodium process pipelines such as the secondary circuit and the overall layout of the nuclear island building 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 severely split; the layout of the main control room and the electrical room is unreasonable, and the cable laying is long; these problems lead to a large room for improvement in the economy of large sodium-cooled fast reactor power stations in China. Summary of the Invention

[0003] The purpose of the present invention is to provide a large sodium-cooled fast reactor power station, which through a deep and innovative optimization of the traditional sodium-cooled fast reactor power station, conducts innovative designs in aspects such as the reactor core, the reactor vessel, the main heat transfer system, the power conversion system, and the plant structure, while improving nuclear safety and industrial safety, greatly improving the economy of the sodium-cooled fast reactor power station, and greatly shortening the construction period of the sodium-cooled fast reactor power station.

[0004] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0005] A large sodium-cooled fast reactor power station includes a sodium-cooled fast reactor unit and an auxiliary system for the sodium-cooled fast reactor unit; the sodium-cooled fast reactor unit is used to convert nuclear energy into electrical energy or steam energy, and the auxiliary system for the sodium-cooled fast reactor unit is used to assist the sodium-cooled fast reactor unit to convert nuclear energy into electrical energy or steam energy; the number of sodium-cooled fast reactor units is multiple, and the auxiliary system for the sodium-cooled fast reactor unit is two or each sodium-cooled fast reactor unit shares one;

[0006] 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 for nuclear fission to generate heat energy; 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 export the residual heat of the sodium-cooled fast reactor under accident conditions of the sodium-cooled fast reactor;

[0007] 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 large process rooms. The sodium-cooled fast reactor includes a reactor pit, a containment vessel inside the reactor pit, and a reactor core inside the containment vessel. The construction is completed through the following steps: The construction of the reactor pit, the containment vessel, and the reactor core is carried out in parallel. After the construction of the containment vessel and the reactor core is completed, the reactor core is installed into the containment vessel. The reactor core is manufactured modularly, the containment vessel is a capsule-type small steel containment vessel, and the reactor pit is constructed with concrete. The containment vessel and the reactor core inside it are integrally pushed into the reactor pit.

[0008] As one of the achievable ways, the containment vessel 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 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. The interiors of the upper container and the lower container are connected, and the welding meets the airtightness requirements inside the containment vessel. A detachable top cover is provided at the top of the upper container, and the top cover adopts a mechanical seal.

[0009] The containment vessel is provided with passages for personnel and equipment to enter and exit at the position of the reactor hall. The passages for personnel and equipment to enter and exit are sealed with sodium fire protection doors. The passages for personnel and equipment to enter and exit are in a closed state during the normal operation of the sodium-cooled fast reactor. The passages for personnel and equipment to enter and exit are in an open state during the maintenance of the sodium-cooled fast reactor.

[0010] A sodium leakage receiving and suppressing tray is provided at the bottom of the containment vessel to prevent and mitigate sodium fire accidents and collect and extinguish the sodium fire in the reactor pit. A core melting collector is provided at the bottom of the reactor core to collect and cool the molten fuel in the case of full core melting. As one of the achievable ways, the reactor core includes a reactor core container, a reactor core top cover sealed to the top of the reactor core container, reactor top equipment sealed to the reactor core top cover, reactor top shielding equipment sealed to the reactor core top cover, a sodium pool inside the reactor core container, and an intermediate heat exchanger, an independent heat exchanger, a primary sodium pump, and a reactor core arranged in the sodium pool. Among them, both the intermediate heat exchanger and the independent heat exchanger are manufactured using integrated D printing technology. The reactor top shielding equipment is designed and manufactured integrally.

[0011] The materials of the internal components of the sodium-cooled fast reactor adopt low-copper and low-phosphorus steel with a phosphorus mass content of 10 - 1000 ppm and a copper mass content of 0.1 - 5% to slow down neutron irradiation embrittlement and achieve a design life of ≥60 years for the sodium-cooled fast reactor unit.

[0012] As one of the achievable ways, the reactor core adopts radiation-resistant FMS or ODS cladding materials; the inner ring of the reactor core is the active zone, where fission reactions of the fissile nuclear fuel U-235 occur to generate fast neutrons; the outer ring of the reactor core is the breeding zone, where 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 breeding zone is higher than that in the active zone, flattening the power of the fuel assemblies in the active zone and the breeding zone.

[0013] The active zone includes an inner active zone fuel region and an outer active zone fuel region surrounding the inner active zone fuel region; the inner active zone fuel region has an axially non-uniform design and is divided axially from top to bottom into a first inner active zone fuel region, an inert fuel region, and a second inner active zone fuel region; each of the inner active zone fuel region and the breeding zone is provided with an irradiation zone for isotope production.

[0014] The breeding ratio in the reactor core is 1; the control rod assembly consists of an adjustment control rod assembly and a safety control rod assembly, or an adjustment control rod assembly, a safety control rod assembly, and a small amount of compensation control rod assemblies; the safety control rod assembly is used to control the shutdown of the sodium-cooled fast reactor, the adjustment control rod assembly is used to control the power of the sodium-cooled fast reactor, and the compensation control rod assembly is used for the positive reactivity of the sodium-cooled fast reactor.

[0015] The top cover of the reactor body is provided with a reactor rotating shield plug; the top equipment of the reactor includes a control rod drive mechanism; the control rod drive mechanism enters the reactor body container from the rotating shield plug and is connected to the corresponding control rod in the reactor core to drive the control rod to insert into or withdraw from the fuel assembly.

[0016] The lower end of the control rod is combined with a short fuel rod bundle; when the control rod is inserted, the control rod is located in the inner active zone fuel region to introduce negative reactivity; when the control rod is withdrawn, the short fuel rod bundle at the lower end of the control rod is located in the inner active zone fuel region to introduce positive reactivity, thereby increasing the control rod worth.

[0017] As one of the achievable ways, the main heat transfer system has a sodium-sodium-molten salt-water four-loop 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.

[0018] 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 and the intermediate heat exchanger are both arranged in the hot pool, and the primary sodium pump is arranged in the cold pool; the primary sodium pump sends the primary sodium in the cold pool through the primary sodium side of the reactor core and the intermediate heat exchanger and then returns it to the cold pool, forming the primary loop.

[0019] The outlet of the secondary sodium side of the intermediate heat exchanger is sequentially connected by pipelines to the secondary sodium pump, the sodium side of the sodium-salt heat exchanger, and the inlet of the secondary sodium side of the intermediate heat exchanger, forming a secondary loop; in the secondary loop, the secondary sodium in the secondary sodium side of the intermediate heat exchanger flows through the sodium side of the sodium-salt heat exchanger via the secondary sodium pump and then returns to the secondary sodium side of the intermediate heat exchanger;

[0020] The outlet of the molten salt side of the sodium-salt heat exchanger is sequentially connected by pipelines 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-salt heat exchanger, constituting a tertiary loop; in the tertiary loop, the molten salt in the molten salt side of the sodium-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 via the high-temperature molten salt pump, and then returns to the molten salt side of the sodium-salt heat exchanger via the low-temperature molten salt pump; the pipeline connecting the molten salt side of the sodium-salt heat exchanger to the high-temperature molten salt tank is heated by a linear Fresnel concentrating system, and the linear Fresnel concentrating system uses light energy to heat the molten salt in the molten salt pipeline, realizing the coupling of the sodium-cooled fast reactor and light energy;

[0021] The outlet of the water side of the molten salt-water heat exchanger is sequentially connected by pipelines to the power conversion system, the main feed water pump, and the inlet of the outlet of the water side of the molten salt-water heat exchanger, constituting a quaternary loop; in the quaternary loop, the main feed water in the water side of the molten salt-water heat exchanger flows through the power conversion system via the main feed water pump and then returns to the water side of the molten salt-water heat exchanger.

[0022] As one of the achievable 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, steam users, grid users, and a grid main transformer; the outlet of the water side of the molten salt-water heat exchanger is divided into two paths, one path is sequentially connected by pipelines to the steam circuit control valve, and the other path is sequentially connected by pipelines to the power generation circuit control valve, the molten salt superheater, the steam turbine generator, the condenser, the main feed water pump, and the inlet of the water side of the molten salt-water heat exchanger; there is a pipeline connection between the steam turbine generator and the steam users, and a check valve is provided on the pipeline connecting the steam turbine generator and the steam users; the power generation outlet of the steam turbine generator is connected to the grid users through the grid main transformer;

[0023] The operation mode of the sodium-cooled fast reactor unit is a combination of one or more of the solar thermal energy storage mode, the power generation mode, and the high-temperature industrial steam supply mode;

[0024] 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 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;

[0025] In the power generation mode, the first regulating valve, the second regulating valve, the power generation loop control valve and the check valve are all opened, and the steam loop control valve is closed; the sodium-cooled fast reactor operates at full power, and the secondary 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 be condensed into condensate, and part is sent to steam users; the condensate is sent to the water side of the molten salt-water heat exchanger by the main feed water pump for heat exchange, 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.

[0026] In the high-temperature industrial steam supply mode, the first regulating valve, the second regulating valve and the steam loop control valve are all opened, and the power generation loop control valve and the check valve are all closed; the sodium-cooled fast reactor operates at full power, and the secondary 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 sent to the water side of the molten salt-water heat exchanger by the main feed water pump for heat exchange to generate high-temperature industrial steam and sent to steam users.

[0027] As one of the realizable ways, the primary frequency modulation and peak shaving of the sodium-cooled fast reactor unit include the power increase and power decrease of the sodium-cooled fast reactor unit; there are the following two modes for the power decrease of the sodium-cooled fast reactor unit:

[0028] In the first mode, the sodium-cooled fast reactor unit maintains the power generation mode, the sodium-cooled fast reactor operates at full power, the secondary sodium pump operates at full power, and continuously takes out the heat of the sodium-cooled fast reactor; the low-temperature molten salt pump operates at rated power, the high-temperature molten salt pump operates at low power, and the main feed water pump operates at low power, so that the total amount of steam is reduced and the output electric power of the steam turbine generator is reduced, thereby realizing the peak shaving of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank rises, and the liquid level of the low-temperature molten salt tank continuously decreases. By adjusting the storage amounts of the high- and low-temperature molten salts, the excess energy generated by the sodium-cooled fast reactor is stored.

[0029] In the second mode, while the sodium-cooled fast reactor unit is in the power generation mode, the high-temperature industrial steam supply mode is synchronously started, and the amount of high-temperature industrial steam supply is controlled by the opening degree of the steam loop control valve, thereby reducing the power generation power of the steam turbine generator and realizing the peak shaving of the sodium-cooled fast reactor unit.

[0030] The operation mode of the power increase of the sodium-cooled fast reactor unit is as follows: the sodium-cooled fast reactor operates at full power, the secondary sodium pump operates at full power, and continuously takes out the heat of the sodium-cooled fast reactor; 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 and the output electric power of the steam turbine generator is increased, realizing the peak shaving of the sodium-cooled fast reactor unit; the liquid level of the high-temperature molten salt tank decreases, and the liquid level of the low-temperature molten salt tank rises. By adjusting the storage amounts of the high- and low-temperature molten salts, the molten salt energy storage is released, the power generation power of the steam turbine generator is increased, and the on-grid power of the sodium-cooled fast reactor unit is increased.

[0031] As one of the feasible ways, the secondary frequency regulation of the sodium-cooled fast reactor unit includes the secondary frequency regulation for power reduction of the sodium-cooled fast reactor unit and the secondary frequency regulation for power increase of the sodium-cooled fast reactor unit;

[0032] Under the secondary frequency regulation for 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, reducing the grid-connected power of the sodium-cooled fast reactor unit, and realizing the secondary frequency regulation for power reduction of the sodium-cooled fast reactor unit;

[0033] 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 discharging, increasing the grid-connected power of the sodium-cooled fast reactor unit, and realizing the secondary frequency regulation for power increase of the sodium-cooled fast reactor unit.

[0034] As one of the feasible ways, the condenser includes an air-cooled radiator and a natural draft cooling tower. The air-cooled radiator is connected to the steam turbine generator through pipelines and is arranged at the bottom or side of the natural draft cooling tower; the steam after the steam turbine generator generates electricity is sent to the air-cooled radiator, and the suction force of the natural draft cooling tower tower body makes the cold air flow through the surface of the air-cooled radiator, causing the steam in the air-cooled radiator to condense into condensate and be sent to the molten salt-water heat exchanger water side through the main feed water pump.

[0035] As one of the feasible ways, the accident residual heat removal system includes an air heat exchanger and an independent heat exchanger; it is used for removing the residual heat of the sodium-cooled fast reactor under accident conditions;

[0036] The air heat exchanger is arranged at the bottom or side of the induced draft chimney and is connected to the induced draft chimney through pipelines; the independent heat exchanger is arranged in the cold pool or hot pool and is connected to the air heat exchanger through pipelines;

[0037] The primary circuit sodium in the cold pool flows through the reactor core and the primary circuit sodium side of the independent heat exchanger and then returns to the cold pool; the secondary circuit sodium on the secondary circuit sodium side of the independent heat exchanger exchanges heat with the primary circuit sodium on the primary circuit 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 circuit sodium side of the independent heat exchanger; the air in the air heat exchanger rises due to heat and is discharged into the atmosphere from the induced draft chimney by using the pressure difference generated by the height difference of the induced draft chimney.

[0038] 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.

[0039] 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.

[0040] 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;

[0041] 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;

[0042] 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;

[0043] 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;

[0044] 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.

[0045] 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;

[0046] A reactor rotating shield plug is provided on the top cover of the reactor vessel body; the in-core refueling system includes a refueling machine and a hoist; the refueling machine is a direct-pull type refueling machine. During in-core refueling, it directly enters the reactor vessel body from the reactor rotating shield plug, and through the circumferential rotation of the reactor rotating shield plug, it realizes full coverage of the fuel assembly jacking positions in the core and the lower working positions of the hoist; the hoist is an inclined hoist. During in-core refueling, it enters the upper or lower working positions in the reactor vessel body from the top cover of the reactor vessel body in an inclined manner; 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-in-core refueling periods;

[0047] The out-of-core refueling system includes a new fuel storage, a new fuel transportation channel, a transfer room, a spent fuel transportation channel, a cleaning room, and a spent fuel storage pool;

[0048] The new fuel storage is arranged on the left side of the reactor building, and the cleaning room and the spent fuel storage pool are arranged on the right side of the reactor building; the new fuel storage is connected to the new fuel transportation channel; the spent fuel transportation channel is connected to the cleaning room; the transfer room is respectively connected to the new fuel transportation channel and the spent fuel transportation channel; the cleaning room and the spent fuel storage pool are connected through a spent fuel transportation water channel;

[0049] A new fuel transfer vehicle is provided on the new fuel transportation channel, and a new fuel transfer connection 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 connection 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;

[0050] A storage container and a preheating box are provided in the new fuel storage; the storage container is used to store new fuel assemblies; a new fuel hanging basket is provided in the preheating box, 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 the new fuel assemblies, and the preheating box cover is used to open or close the preheating box; a cleaning room transfer vehicle, a lead leakage detection well, a lead bath well, and a cleaning well are provided in the cleaning room.

[0051] As one achievable method, in-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:

[0052] Transfer the new fuel assemblies from the storage container in the new fuel storage to the new fuel hanging basket in the preheating box; after the new fuel hanging basket is full of new fuel assemblies, close the preheating box cover to complete the enclosure of the preheating box;

[0053] After preheating the new fuel assemblies in the preheating box to the set temperature, load the new fuel hanging basket into the new fuel transfer vehicle through the new fuel transfer connection device; the new fuel transfer vehicle moves in the new fuel transportation channel to the transfer room, and transfer the new fuel assemblies in the new fuel hanging basket to the hoist barrel through the transfer room transfer vehicle;

[0054] The hoist bucket of the elevator enters the reactor vessel from the top cover of the reactor body and descends along the inclined guide rail to the lower working position. The refueling machine transfers the new fuel assembly from the hoist bucket to the jacking position of the spent fuel assembly that has been unloaded from the reactor core, completing the loading of the new fuel assembly.

[0055] The refueling system discharges the spent fuel assembly, including the following steps:

[0056] The elevator enters the reactor vessel from the top cover of the reactor body and descends along the inclined guide rail to the lower working position; the refueling machine enters the reactor vessel from the rotating shield plug along the vertical guide rail, and reaches the jacking position of the reactor core fuel assembly through the circumferential rotation of the rotating shield plug, extracts the spent fuel assembly at the jacking position of the reactor core fuel assembly and transfers it to the lower working position of the hoist bucket of the elevator.

[0057] The hoist bucket of the elevator ascends along the inclined guide rail to the upper working position; the transfer vehicle in the transfer room enters the upper working position of the hoist bucket of the elevator in the reactor vessel from the top cover of the reactor body, and transfers the spent fuel assembly to the spent fuel hanging basket of the spent fuel transfer vehicle through the spent fuel transfer connection device.

[0058] When the spent fuel hanging basket is full of spent fuel assemblies, the spent fuel transfer vehicle moves along the spent fuel transportation channel to the cleaning room, and the transfer vehicle in the cleaning room hoists the spent fuel hanging basket into the cleaning well for cleaning; after the cleaning of the spent fuel hanging basket is completed, the transfer vehicle in the cleaning room transfers the spent fuel hanging basket to the spent fuel storage pool for temporary storage through the spent fuel transportation water channel.

[0059] If a damaged spent fuel assembly is found in the reactor vessel, when the spent fuel hanging basket is still on the spent fuel transfer vehicle, the transfer vehicle in the cleaning room is used to transfer the damaged spent fuel assembly to the lead bath well for lead bath cleaning. After the lead bath cleaning is completed, it is loaded into a sealed can, and then transferred to the spent fuel storage pool by the transfer vehicle in the cleaning room along the spent fuel transportation water channel through the spent fuel hanging basket.

[0060] If a damaged spent fuel assembly is found during the cleaning process in the cleaning well, after the cleaning is completed, the spent fuel assemblies in the spent fuel hanging basket are transferred to the leakage detection well by the transfer vehicle in the cleaning room for one-by-one detection. The damaged spent fuel assemblies are loaded into sealed cans, and then transferred to the spent fuel storage pool by the transfer vehicle in the cleaning room along the spent fuel transportation water channel through the spent fuel hanging basket.

[0061] As one of the achievable 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 plant-wide technical management layer;

[0062] The process system interface layer includes sensors and actuators; the sensors are installed on the process equipment and are used to detect the process parameters of the process equipment; the actuators are used to control the process according to the control instructions from the automatic control and protection layer.

[0063] The automatic control and protection layer adopts on-site summary control technology to collect process parameters of the process system interface layer; processes and performs logical operations on the process parameters of the process system interface layer, generates control instructions and transmits them to the process system interface layer;

[0064] The operation and management information layer is used to execute tasks, including information support, information diagnosis, recording of process information and operator actions, and controlling the sodium-cooled fast reactor unit through operating equipment;

[0065] The technical management layer is used for the operation management of the sodium-cooled fast reactor power station, and receives information required for the operation management of the sodium-cooled fast reactor power station through network interface devices.

[0066] As one possible implementation, 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 each sodium-cooled fast reactor unit is powered by off-site power sources through main transformers and auxiliary transformers respectively; the on-site power system consists of a normal power supply system, a reliable power supply system, reliable diesel engines and a battery energy storage station;

[0067] The normal power supply system supplies power to the electrical equipment for ensuring the normal startup, rated power operation and normal shutdown of the sodium-cooled fast reactor unit; the reliable power supply system supplies power to the electrical equipment for maintaining the normal operation of the sodium-cooled fast reactor unit;

[0068] The reliable diesel engines supply power to the reliable power supply system when both the normal power supply system and the reliable power supply system lose power;

[0069] The battery energy storage station realizes secondary frequency regulation of the sodium-cooled fast reactor unit during the normal operation of the sodium-cooled fast reactor unit, and supplies power to the normal power supply system when the normal power supply system loses power.

[0070] As one possible implementation, the battery energy storage station 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 connection interface and protection device;

[0071] Among them, the energy storage battery pack uses lithium-ion batteries as the energy storage medium to store electrical energy by converting it into chemical energy; the energy storage converter is used to realize the bidirectional conversion between alternating current and direct current, control the charging and discharging process of the energy storage battery pack, and adjust the power output of the energy storage battery pack;

[0072] The battery management system is used to monitor the voltage, temperature, state of charge and health state of the energy storage battery pack in real time, ensuring the safe operation of the energy storage battery pack and optimizing the charge and discharge strategies of the energy storage battery pack; the energy management system is used to overall arrange and dispatch the operation of the energy storage system, and optimize the charge and discharge 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 gets thermally out of control; the grid connection interface and protection device are used to ensure a safe connection to the grid.

[0073] As one achievable way, the energy storage system includes a super capacitor, a storage battery and an energy storage transformer; the power generation outlet of the steam turbine generator is sequentially connected to the super capacitor and the storage battery circuit through the energy storage transformer; the storage battery is connected to the storage battery energy storage station circuit;

[0074] 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 storage battery energy storage station captures the grid frequency deviation signal in real time through sensors, calculates the power quantity to be supplemented or absorbed according to the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, determines the frequency regulation timing and output depth of the energy storage system, optimizes the distribution factor, and smoothly adjusts the power output of the energy storage system;

[0075] When the normal power supply system loses power, the storage battery energy storage station transmits the signal of the loss of power of the normal power supply system to the energy storage system, and 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 storage battery energy storage station while ensuring the voltage and frequency stability of the grid, supplying power to the normal power supply system.

[0076] The beneficial technical effects of the present invention:

[0077] The large sodium-cooled fast reactor power station of the present invention, through in-depth revolutionary optimization of the traditional sodium-cooled fast reactor power station, conducts innovative designs in aspects such as the reactor core, reactor vessel, primary heat transfer system, power conversion system, and plant structure. While improving nuclear safety and industrial safety, it significantly enhances the economy of the sodium-cooled fast reactor power station and shortens the construction period of the sodium-cooled fast reactor power station; by optimizing the containment design, it meets the technical index requirements of not requiring off-site emergency; the sodium-water steam generator and related auxiliary systems are cancelled to eliminate the risk of sodium-water reaction; an in-core cold trap and a capsule-type containment are adopted, and radioactive substances are completely contained within the small capsule-type steel containment. The small capsule-type steel containment can maintain an extremely low radioactive leakage rate and completely eliminate the possibility of large-scale radioactive release from the containment; air is used to cool the exhaust steam of the turbogenerator, greatly reducing the requirement for water sources, making the sodium-cooled fast reactor power station independent of water sources and suitable for inland sites; an additional molten salt heat storage function is adopted to achieve deep peak shaving capacity and have primary frequency modulation; a battery energy storage station and an energy storage system are integrated to have good secondary frequency modulation capabilities; design concepts such as passive, modular, fuel economy, and simplified process configuration are adopted to significantly reduce the cost of the large sodium-cooled fast reactor power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a schematic structural view of an embodiment of the large sodium-cooled fast reactor power station of the present invention;

[0079] Figure 2 It is a schematic structural view of an embodiment of a sodium-cooled fast reactor;

[0080] Figure 3 It is a schematic structural view of an embodiment of the primary heat transfer system, power conversion system, and energy storage system;

[0081] Figure 4 It is a schematic structural view of an embodiment of the reactor core;

[0082] Figure 5 It is a schematic structural view of an embodiment of the electrical system;

[0083] Figure 6 It is a schematic structural view of an embodiment of the refueling system.

[0084] In the figure, 1 is a sodium-cooled fast reactor; 101 is the reactor core; 102 is the core melt collector; 103 is the reactor vessel; 104 is the sodium leakage receiving and suppressing disk; 105 is the reactor top shielding equipment; 106 is the access passage for personnel and equipment; 107 is the exhaust fan; 108 is the chimney for drawing air; 109 is the high-efficiency filter; 110 is the exhaust air valve; 111 is the first inlet air valve; 112 is the second inlet air valve; 113 is the nitrogen valve; 114 is the nitrogen tank; 115 is the inlet air fan; 116 is the radiation monitor; 117 is the containment; 118 is the reactor building; 119 is the reactor top equipment; 120 is the primary filter; 201 is the intermediate heat exchanger; 202 is the secondary sodium pump; 203 is the sodium-molten salt exchanger; 204 is the low-temperature molten salt pump; 205 is the linear Fresnel concentrating system; 206 is the first regulating valve; 207 is the low-temperature molten salt tank; 208 is the high-temperature molten salt tank; 209 is the second regulating valve; 210 is the high-temperature molten salt pump; 211 is the molten salt-water heat exchanger; 301 is the steam circuit control valve; 302 is the power generation circuit control valve; 303 is the steam turbine generator; 304 is the main feed water pump; 305 is the condenser; 306 is the check valve; 307 is the steam user; 308 is the main transformer of the power grid; 309 is the power grid user; 310 is the superheater; 401 is the energy storage transformer; 402 is the super capacitor; 403 is the storage battery; 501 is the control rod; 502 is the upper section of the control rod; 503 is the lower section of the control rod; 504 is the fuel area isotope production irradiation area; 505 is the breeding area isotope production irradiation area; 506 is the inert fuel area; 507 is the inner area of the fuel in the first active area; 508 is the outer area of the fuel in the active area; 509 is the inner area of the fuel in the second active area; 510 is the breeding area.

[0085] 601, New fuel storage; 602, Preheating box; 603, New fuel hanging basket; 604, New fuel transfer connection device; 605, New fuel transfer vehicle; 606, New fuel transportation channel; 607, Spent fuel transportation channel; 608, Spent fuel transfer vehicle; 609, Spent fuel transfer connection device; 610, Cleaning room; 611, Cleaning trap; 612, Lead bath trap; 613, Leak detection trap; 615, Spent fuel transportation water channel; 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, First off-site auxiliary transformer; 705, Second off-site auxiliary transformer; 706, First high-voltage station service transformer; 707, Second high-voltage station service transformer; 708, First nuclear island normal section; 709, Second nuclear island normal section; 710, First conventional island normal section; 711, Second conventional island normal section; 712, First nuclear island reliable section; 713, Second nuclear island reliable section; 714, Battery energy storage station; 715, Reliable diesel engine; 8, Reactor body assembly workshop; 9, Maintenance workshop; 10, Spare parts warehouse; 11, Dangerous goods warehouse; 12, Maintenance temporary storage position; 13, Main control room; 14, Conventional island; 15, Natural draft cooling tower; 16, Battery energy storage station; 17, Fuel regeneration sub-item;

[0086] 18, Isotope production hot cell. Detailed implementation manners

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "provided with" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0088] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0089] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

[0090] See Figure 1-6 , this embodiment provides a large sodium-cooled fast reactor power station, including a sodium-cooled fast reactor unit and an auxiliary system for the sodium-cooled fast reactor unit; the sodium-cooled fast reactor unit is used to convert nuclear energy into electrical energy or steam energy, and the auxiliary system for the sodium-cooled fast reactor unit 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 auxiliary system for the sodium-cooled fast reactor unit is either two or each sodium-cooled fast reactor unit shares one; the thermal power of the sodium-cooled fast reactor unit is between 1500 and 3800 MW, and the electrical power is between 600 and 1500 MW.

[0091] In this embodiment, as one of the realizable ways, the sodium-cooled fast reactor unit includes a sodium-cooled fast reactor 1, a primary heat transfer 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 through nuclear fission; the primary heat transfer 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.

[0092] In this embodiment, as one of the realizable ways, the sodium-cooled fast reactor 1 is arranged in the reactor building 118 of the nuclear island without considering the influence of external events; the reactor building 118 is an ordinary seismic-resistant building and is manufactured in a large process room modularization.

[0093] The sodium-cooled fast reactor 1 includes a reactor pit, a containment 117 in the reactor pit, and a reactor core 103 in the containment 117, and is constructed through the following steps:

[0094] Carry out the construction of the reactor pit, the containment 117, and the reactor core 103 in parallel, and after the construction of the containment 117 and the reactor core 103 is completed, install the reactor core 103 into the containment 117; the reactor pit is arranged below the ground of the reactor building 118 and is constructed with concrete; the reactor core 103 is modularly manufactured and is sent to the ground of the reactor building 118 after being assembled in the reactor core assembly building 8 of the nuclear island; the containment 117 is a capsule-type small steel containment and is fully welded with steel plates with a thickness of 40 mm and is welded on the ground of the reactor building 118 of the nuclear island.

[0095] Push the containment 117 and the reactor core 103 inside the containment 117 as a whole into the reactor pit.

[0096] After the reactor vessel body 103 and the containment 117 are manufactured, they are first located on the floor of the reactor building 118, which facilitates the subsequent overall pushing of the reactor vessel body 103 into the containment 117 after it is loaded into the containment 117. The construction of the reactor pit, the containment 117 and the reactor vessel body 103 is carried out in parallel. After the construction of the containment 117 and the reactor vessel body 103 is completed, the reactor vessel body 103 is loaded into the containment 117, which significantly shortens the main construction period of the sodium-cooled fast reactor power station.

[0097] The containment 117 is a capsule-type small steel containment, which is entirely welded and manufactured from steel plates with a thickness of 40 mm. Due to its small volume and good sealing performance, it can effectively contain the radioactive gas leakage of the reactor vessel body 103, eliminate the possibility of radioactive gas being released into the environment, and thus achieve the cancellation of off-site emergency response.

[0098] Since all items related to nuclear safety are contained within the containment 117, the safety of the sodium-cooled fast reactor power station can be ensured by ensuring the seismic resistance and safety of the containment 117. Except for the containment, the reactor building 118 is an industrial building with mature design and simple structure, and its seismic design category only needs to meet the requirements of conventional seismic resistance, which can greatly reduce the civil engineering cost of the reactor building 118.

[0099] In this embodiment, as one of the realizable ways, the containment 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 117, and the interiors of the upper container and the lower container are connected. The welding meets the internal airtightness requirements of the containment 117; to provide convenience for the subsequent operation and maintenance of the sodium-cooled fast reactor 1, a detachable top cover is provided at the top of the upper container, the top cover adopts mechanical seal, and the upper container can be opened integrally from the top;

[0100] The containment 117 is provided with a personnel and equipment access passage 106 at the position of the reactor hall, and the personnel and equipment access passage 106 is sealed with a sodium fire protection door; the personnel and equipment access passage 106 is in a closed state during the normal operation of the sodium-cooled fast reactor 1; the personnel and equipment access passage 106 is in an open state during the maintenance of the sodium-cooled fast reactor 1, and operation and maintenance personnel and small equipment can enter and exit through this passage;

[0101] The containment 117 entirely contains the reactor vessel 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 inside the containment 117 will not be significantly increased under any operating conditions, so the containment 117 does not need to withstand high pressure;

[0102] At the bottom of the containment vessel 117, there is a sodium leakage receiving and suppressing tray 104, which is used to prevent and mitigate sodium fire accidents, collect and extinguish the sodium fire in the reactor pit; at the bottom of the reactor vessel 103, there is a core melt collector 102 to ensure that even if the entire core 101 melts, the molten fuel will be completely collected and cooled, without considering the large sodium fire after the reactor vessel 103 is melted through.

[0103] For the containment vessel 117 of the present invention, according to the inherent safety of the sodium-cooled fast reactor 1, the functions of containing radioactive substances and withstanding external events of the traditional containment vessel are separated. The entire containment vessel 117 is located inside the reactor building 118, without considering the influence of external events. The containment vessel 117 plays a sealing function to isolate radioactive substances after an accident, and since the containment vessel 117 is located inside the reactor building 118, the structure of the containment vessel 117 is greatly simplified, making the structural dimensions of the containment vessel 117 smaller, significantly reducing the design and manufacturing difficulties, being able to more effectively ensure the sealing performance of the containment vessel 117, greatly reducing the cost of the containment vessel 117, and at the same time improving the safety and economy of the sodium-cooled fast reactor power station.

[0104] In this embodiment, as one feasible way, the reactor vessel 103 includes a reactor vessel container, a reactor vessel top cover sealed to the top of the reactor vessel container, a top equipment 119 sealed to the reactor vessel top cover, a top shielding equipment 105 sealed to the reactor vessel top cover, a sodium pool inside the reactor vessel 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; among them, both the intermediate heat exchanger 201 and the independent heat exchanger are manufactured using the integrated 3D printing technology; the top shielding equipment 105 adopts an integrated design and manufacturing.

[0105] The internals materials of the sodium-cooled fast reactor 1 adopt low-copper and low-phosphorus steel with a phosphorus mass content of 10 - 1000 ppm and a copper mass content of 0.1 - 5% to slow down neutron irradiation embrittlement and achieve a design life of ≥60 years for the sodium-cooled fast reactor unit.

[0106] In this embodiment, as one feasible way, the core 101 adopts FMS or ODS cladding materials with a radiation resistance level of 200 dPA to achieve a core 101 refueling cycle of 18 - 24 months; the core 101 damage frequency CDF < 1×10 -6 1 / reactor·year, and the large radioactive substance release frequency LRF < 1×10 -6 1 / reactor·year;

[0107] The inner ring of the core 101 is the active zone, where fission reactions occur in the fissile nuclear fuel U-235, generating fast neutrons; the outer ring of the core 101 is the breeding zone 510, where the fissile nuclear fuel U-238 in the breeding zone 510 absorbs fast neutrons and is converted into the fissile nuclear fuel Pu-239; the content of the fissile nuclear fuel Pu-239 in the breeding 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 breeding zone 510.

[0108] The active zone includes the inner active zone fuel area and the outer active zone fuel area 508 surrounding the inner active zone fuel area; the inner active zone fuel area is designed with axial non-uniformity, and is axially divided into the first inner active zone fuel area 507, the inert fuel area 506, and the second inner active zone fuel area 509 from top to bottom, so that the sodium void coefficient is close to 0; each of the inner active zone fuel area and the breeding zone 510 is provided with an irradiation zone for isotope production.

[0109] The breeding ratio in the core 101 is 1; the control rod assembly consists of an adjustment control rod assembly and a safety control rod assembly, or an adjustment control rod assembly, a safety control rod assembly, and a small number of compensation control rod assemblies; the safety control rod assembly is used to control the shutdown of the sodium-cooled fast reactor 1, the adjustment control rod assembly is used to control the power of the sodium-cooled fast reactor 1, and the compensation control rod assembly is used for the positive reactivity of the sodium-cooled fast reactor 1.

[0110] The reactor vessel top cover is provided with a reactor rotating shield plug; the top equipment of the reactor includes a control rod drive mechanism; the control rod drive mechanism enters the reactor vessel from the rotating shield plug and is connected to the corresponding control rod in the core 101 to drive the control rod to insert into or withdraw from the fuel assembly.

[0111] The lower end of the control rod is combined with a short fuel rod bundle; when the control rod is inserted, the control rod is located in the inner active zone fuel area to introduce negative reactivity; when the control rod is withdrawn, the short fuel rod bundle at the lower end of the control rod is located in the inner active zone fuel area to introduce positive reactivity, thereby increasing the control rod worth.

[0112] The breeding ratio in the core 101 of the present invention is 1.0. By canceling or retaining a small number of compensation control rod assemblies, the positive reactivity introduced by the breeding 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, reducing the positive reserve reactivity at the initial 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 prompt supercritical risk of the sodium-cooled fast reactor 1; canceling or retaining a small number of compensation control rod assemblies reduces the number of openings in the reactor rotating shield plug and improves the reliability of the operation of the primary circuit boundary.

[0113] In a traditional sodium-cooled fast reactor, the primary circuit sodium plays a certain role in neutron reflection. Therefore, when the primary circuit sodium is lost, a positive void coefficient effect usually occurs in the reactor core, that is, the reactivity increases. The present invention optimizes the reactivity and reduces the sodium void coefficient effect by adjusting the distribution of the fuel region and the non-fuel region in the active region.

[0114] The core 101 design of the present invention can reduce the number of components in the sodium-cooled fast reactor, flatten the power of the core 101, reduce the positive reactivity coefficient of the sodium void, improve the safety of the core 101, reduce the size of the core 101 and thus reduce the diameter of the reactor vessel, and at the same time take into account the isotope production capacity.

[0115] In this embodiment, as one of the realizable ways, the main heat transfer system is a sodium-sodium-molten salt-water four-circuit structure, including an intermediate heat exchanger 201, a primary circuit sodium pump, a secondary circuit 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 concentrating system 205;

[0116] The sodium pool is filled with primary circuit sodium and is divided into a cold pool and a hot pool by a partition; the core 101 and the intermediate heat exchanger 201 are both arranged in the hot pool, and the primary circuit sodium pump is arranged in the cold pool; the primary circuit sodium pump sends the primary circuit sodium in the cold pool back to the cold pool after flowing through the primary circuit sodium sides of the core 101 and the intermediate heat exchanger 201, forming a primary circuit;

[0117] The outlet of the secondary circuit sodium side of the intermediate heat exchanger 201 is connected in sequence through pipelines 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, forming 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 then is sent back to the secondary circuit sodium side of the intermediate heat exchanger 201;

[0118] The molten salt side outlet of the sodium-molten salt heat exchanger 203 is sequentially connected by pipelines to the high-temperature molten salt tank 208, the second regulating valve 209, the high-temperature molten salt pump 210, the molten salt-water heat exchanger 211 on the molten salt side, the low-temperature molten salt tank 207, the first regulating valve 206, the low-temperature molten salt pump 204 and the molten salt side inlet of the sodium-molten salt heat exchanger 203, forming a three-loop; in the three-loop, the molten salt on the molten salt side of the sodium-molten salt heat exchanger 203 flows 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 through the high-temperature molten salt pump 210, and then is sent back to the molten salt side of the sodium-molten salt heat exchanger 203 through the low-temperature molten salt pump 204; 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, realizing the coupling of the sodium-cooled fast reactor 1 and light energy;

[0119] The water side outlet of the molten salt-water heat exchanger 211 is sequentially connected by pipelines to the power conversion system, the main feed water pump 304 and the water side inlet of the molten salt-water heat exchanger 211 outlet, forming a four-loop; in the four-loop, the main feed water on the water side of the molten salt-water heat exchanger 211 flows through the power conversion system through the main feed water pump 304 and then is sent back to the water side of the molten salt-water heat exchanger 211.

[0120] In a traditional sodium-cooled fast reactor power station, the main heat transfer system is a sodium-sodium-water three-loop structure, including an intermediate heat exchanger and a sodium-water heat exchanger. Compared with a traditional large fast reactor power station, in the large fast reactor power station of the present invention, a sodium-molten salt heat exchanger 203 and a molten salt-water heat exchanger 211 are introduced into the main heat transfer system, the sodium-water heat exchanger is cancelled, the possibility of sodium-water reaction caused by sodium-water contact is eliminated, and the industrial safety risk of the sodium-cooled fast reactor is greatly reduced; 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 an energy storage function, which is convenient for the subsequent sodium-cooled fast reactor unit to participate in power grid peak shaving.

[0121] In this embodiment, as one of the realizable ways, the power conversion system includes 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 path is sequentially connected by pipelines to the steam circuit control valve 301, and one path is sequentially connected by pipelines to the power generation circuit 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; a pipeline is connected between the steam turbine generator 303 and the steam user 307, 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;

[0122] The operation modes of the sodium-cooled fast reactor unit are one or a combination of several of the solar thermal energy storage mode, the power generation mode, and the high-temperature industrial steam supply mode;

[0123] 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 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 concentrating 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 heat energy for storage;

[0124] 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 open, and the steam circuit control valve 301 is closed; the sodium-cooled fast reactor 1 operates at full power, and the secondary 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 after the steam turbine generator 303 does work to generate electricity is sent to the condenser 305 to be condensed into condensate, and part is sent to steam users; the condensate 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 to do work and generate electricity;

[0125] 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 open, 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 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 by the main feed water pump 304 to generate high-temperature industrial steam and send it to the steam user 307.

[0126] For the power conversion system of the present invention, the power conversion system adopts a superheated steam cycle, and the power generation efficiency is greater than 40%; the steam after the steam turbine generator 303 does work to generate electricity is air-cooled, no longer relying on a large amount of water sources, and is suitable for sodium-cooled fast reactor power stations built in arid inland areas.

[0127] The main heat transfer system of the present invention cooperates with the power conversion system to realize the coupling of nuclear energy, light energy, and energy storage. The operation modes are diverse. The solar thermal energy storage mode, the power generation mode, and high-temperature industry have the capabilities of deep frequency modulation and peak shaving, without sacrificing the output of the sodium-cooled fast reactor unit, and greatly improving the economy.

[0128] In this embodiment, as one of the realizable ways, the primary frequency regulation and peak shaving of the sodium-cooled fast reactor unit include the power increase and power decrease of the sodium-cooled fast reactor unit.

[0129] There are the following two modes for the power decrease of the sodium-cooled fast reactor unit:

[0130] 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 sodium pump 202 operates at full power, continuously taking out the heat of the sodium-cooled fast reactor 1; 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, reducing the total amount of steam and decreasing the output electric power of the steam turbine generator 303, thereby achieving peak shaving of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank 208 rises, and the liquid level of the low-temperature molten salt tank 207 continuously decreases. By adjusting the storage amounts of high- and low-temperature molten salts, the excess energy generated by the sodium-cooled fast reactor 1 is stored.

[0131] In the second mode, while the sodium-cooled fast reactor unit is in the power generation mode, the high-temperature industrial steam supply mode is synchronously activated, and the amount of high-temperature industrial steam supply is controlled by the opening degree of the steam circuit control valve 301, thereby reducing the power generation power of the steam turbine generator 303 and achieving peak shaving of the sodium-cooled fast reactor unit.

[0132] 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 sodium pump 202 operates at full power, continuously taking out the heat of the sodium-cooled fast reactor 1; 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, increasing the total amount of steam and increasing the output electric power of the steam turbine generator 303, achieving peak shaving of the sodium-cooled fast reactor unit; the liquid level of the high-temperature molten salt tank 208 decreases, and the liquid level of the low-temperature molten salt tank 207 rises. By adjusting the storage amounts of high- and low-temperature molten salts, the molten salt energy storage is released, increasing the power generation power of the steam turbine generator 303 and increasing the grid-connected power of the sodium-cooled fast reactor unit.

[0133] In this embodiment, as one of the realizable ways, the secondary frequency regulation of the sodium-cooled fast reactor unit includes the secondary frequency regulation of the power decrease of the sodium-cooled fast reactor unit and the secondary frequency regulation of the power increase of the sodium-cooled fast reactor unit.

[0134] In the secondary frequency regulation of the power decrease 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, reducing the grid-connected power of the sodium-cooled fast reactor unit and achieving the secondary frequency regulation of the power decrease of the sodium-cooled fast reactor unit.

[0135] In the secondary frequency regulation of the 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 303 is synchronously connected to the energy storage system for discharging, increasing the grid-connected power of the sodium-cooled fast reactor unit and achieving the secondary frequency regulation of the power increase of the sodium-cooled fast reactor unit.

[0136] The sodium-cooled fast reactor unit of the present invention can adopt a single solar thermal energy storage mode, power generation mode or 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, high-temperature molten salt pump 210 and main feed water pump 304, as well as the opening degrees of the steam circuit control valve 301 and power generation circuit control valve 302, the steam flow rate to the steam turbine generator 303 is adjusted, thereby controlling the power generation power of the steam turbine generator 303.

[0137] In this embodiment, as one of the achievable ways, the condenser 305 includes an air-cooled radiator and a natural draft cooling tower 15. The air-cooled radiator is connected to the steam turbine generator 303 through pipelines and is arranged at the bottom or side of the natural draft cooling tower 15. The steam after the steam turbine generator 303 generates power is sent to the air-cooled radiator. The suction force of the tower barrel of the natural draft cooling tower 15 causes cold air to flow through the surface of the air-cooled radiator, causing the steam in the air-cooled radiator to condense into condensate, which is sent to the water side of the molten salt-water heat exchanger 211 through the main feed water pump 304.

[0138] In this embodiment, as one of the achievable ways, the accident residual heat removal system includes an air heat exchanger and an independent heat exchanger, which is used for removing the residual heat of the sodium-cooled fast reactor 1 under accident conditions of the sodium-cooled fast reactor 1.

[0139] The air heat exchanger is arranged at the bottom or side of the induced draft chimney 108 and is connected to the induced draft chimney 108 through pipelines; the independent heat exchanger is arranged in the cold pool or hot pool and is connected to the air heat exchanger through pipelines.

[0140] 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 exchanges heat 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 is heated and rises, and uses the pressure difference generated by the height difference of the induced draft chimney 108 to be discharged into the atmosphere from the induced draft chimney 108.

[0141] In this embodiment, as one of the technical implementation ways, the auxiliary system of the sodium-cooled fast reactor unit includes a primary circuit purification system, a secondary circuit 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 instrument control system, a refueling system and a fire protection system. Among them, the primary circuit purification system and the secondary circuit purification system are shared by two sodium-cooled fast reactor units; the nitrogen system, argon system, vacuum system, gas heating system, ventilation system, refrigeration system, electrical system, instrument control system, refueling system and fire protection system are all shared by each sodium-cooled fast reactor unit to save construction costs.

[0142] The primary circuit purification system is used to extract a part of the primary circuit sodium from the primary circuit, and after purification treatment, it is returned to the primary circuit to maintain the purity and quality of the primary circuit sodium. The secondary circuit purification system is used to extract a part of the secondary circuit sodium from the secondary circuit, and after purification treatment, it is returned to the secondary circuit to maintain the purity and quality of the secondary circuit sodium. The nitrogen gas system is used to fill nitrogen gas at the sodium fire location in case of a sodium fire accident to extinguish the sodium fire and mitigate the consequences of the sodium fire accident. The argon gas system is used to fill argon gas on the surface of the sodium pool in the reactor vessel 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 filling argon gas on the surface of the sodium pool in the reactor vessel. The gas heating system is used to preheat the inside of the reactor vessel before filling sodium into the sodium pool to ensure the normal flow and heat transfer of liquid sodium. The ventilation system is used to maintain the air quality in the reactor building 118 and prevent 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 systems of the sodium-cooled fast reactor unit. The I&C system is used to monitor and control the operating status of the sodium-cooled fast reactor unit and the auxiliary systems of the sodium-cooled fast reactor unit. The refueling system is used for refueling the core 101. The fire protection system is used for fire detection, alarm and extinguishment of the sodium-cooled fast reactor unit. The auxiliary systems of the sodium-cooled fast reactor unit ensure the safe and stable operation of the sodium-cooled fast reactor unit 1.

[0143] In this embodiment, as one of the realizable ways, the nitrogen gas system is used to fill nitrogen gas at the sodium fire location in the containment in case of a sodium fire accident to extinguish the sodium fire and mitigate the consequences of the sodium fire accident; the nitrogen gas system is arranged in the reactor building 118 and includes a nitrogen gas tank 114, nitrogen gas pipelines and nitrogen gas valves 113; the nitrogen gas tank 114 is used to store nitrogen gas; the nitrogen gas tank 114 is connected to the inside of the containment 117 through nitrogen gas pipelines, and nitrogen gas valves 113 are provided on the nitrogen gas pipelines; the nitrogen gas valves 113 receive control instructions from the instrument control system and control the charging and discharging of nitrogen gas from the nitrogen gas tank 114 into the containment 117 according to the control instructions. As a defense-in-depth measure, the nitrogen gas system can carry out fire extinguishing operations for sodium fires of different scales.

[0144] In this embodiment, as one of the realizable ways, the ventilation system is arranged in the reactor building 118 and includes a first air inlet pipeline, a second air inlet pipeline, an exhaust pipeline and a chimney 108; the chimney 108 is elevated to the outside of the reactor building 118;

[0145] One end of the first air inlet pipeline is connected to the outside of the reactor building 118, and the other end is connected to the inside of the containment 117; an air inlet fan 115 and a first air inlet valve 111 are successively provided on the first air inlet pipeline along the wind direction; one end of the second air inlet pipeline 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; a second air inlet valve 112 is provided on the second air inlet pipeline;

[0146] 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;

[0147] 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.

[0148] 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.

[0149] 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 relative pressure 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.

[0150] 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.

[0151] When a beyond-design-basis accident with an extremely low probability occurs in the sodium-cooled fast reactor 1, such as a hypothetical accident of the core 101 disintegration, the radioactive substances in the reactor vessel leak into the containment 117 through the core meltdown collector 102. When the radiation monitor 116 in the containment 117 detects abnormal radioactivity, it triggers the closing of the first intake air valve 111, the second intake air valve 112, and the exhaust air valve 110. At this time, the containment 117 is in an isolated state, which can effectively prevent the leakage of radioactive substances into the environment and affect the environment and personnel. After the containment 117 is sealed for a period of time, the short-lived radioactive substances with a larger share in the radioactive substances decay, and only a small amount of long-lived radioactive substances remain. At this time, the isolation state of the containment 117 can be intermittently released, and the natural circulation of the chimney 108 or the small-flow operation of the exhaust fan 107 is used to filter the gas in the containment 117 and discharge it controllably at a high altitude, preventing the disorderly ground-source emission of radioactive substances and maintaining the temperature in the containment 117 at the level where personnel can enter for intervention. If a sodium fire occurs in the containment 117, the nitrogen system is started to extinguish the sodium fire first.

[0152] The passive post-accident ventilation system reduces the demand for safety-class electrical loads and improves the safety and economy of the sodium-cooled fast reactor 1.

[0153] In this embodiment, as one of the realizable ways, 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-of-core refueling system;

[0154] A reactor rotating shield plug is provided on the top cover of the reactor vessel; 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, it directly enters the reactor vessel from the reactor rotating shield plug and realizes full coverage of the fuel assembly jacking positions in the core and the lower working positions of the hoist through the circumferential rotation of the reactor rotating shield plug; the hoist is an inclined hoist. During the refueling of the core 101, it enters the upper or lower working positions inside the reactor vessel from the top cover of the reactor vessel in an inclined manner; a maintenance storage position 620 is provided in the reactor building 118, and the refueling machine and the hoist are placed in the maintenance storage position 620 during non-core refueling periods;

[0155] The out-of-core refueling system includes a new fuel storage 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;

[0156] The new fuel storage 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 storage 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 respectively connected to the new fuel transportation channel 606 and the spent fuel transportation channel; the cleaning room 610 and the spent fuel storage pool are connected through the spent fuel transportation water channel;

[0157] The new fuel transportation channel 606 is provided with a new fuel transfer vehicle 605, and the new fuel transfer vehicle 605 is provided with a new fuel transfer coupling device 604; the spent fuel transportation channel is provided with a spent fuel transfer vehicle 608, and the spent fuel transfer vehicle 608 is provided with a spent fuel transfer coupling device 609 and a spent fuel hanging basket; a transfer room transfer vehicle is arranged in the transfer room;

[0158] The new fuel storage 601 is provided with a storage container and a preheating box 602; the storage container is used for storing new fuel assemblies; the preheating box 602 is provided with a new fuel hanging basket 603, the top of the preheating box 602 is provided with a cover plate 602 of the preheating box, the new fuel hanging basket 603 is used for storing new fuel assemblies, the preheating box 602 is used for heating new fuel assemblies, and the cover plate 602 of the preheating box is used to open or close the preheating box 602; the cleaning room 610 is provided with a cleaning room transfer vehicle 618, a lead leakage detection trap 613, a lead bath trap 612 and a cleaning trap 611.

[0159] In this embodiment, as one of the realizable ways, refueling of the reactor 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:

[0160] Transfer the new fuel assemblies from the storage container in the new fuel storage 601 to the new fuel hanging basket 603 in the preheating box 602; after the new fuel hanging basket 603 is full of new fuel assemblies, close the cover plate 602 of the preheating box 602 to complete the enclosure of the preheating box 602;

[0161] After preheating the new fuel assemblies in the preheating box 602 to the set temperature, load the new fuel hanging basket 603 into the new fuel transfer vehicle 605 through the new fuel transfer coupling device 604; the new fuel transfer vehicle 605 moves in the new fuel transportation channel 606 to the transfer room 616, and transfers the new fuel assemblies in the new fuel hanging basket 603 to the lifting machine barrel through the transfer room transfer vehicle 617;

[0162] The lifting machine barrel enters the reactor vessel from the top cover of the reactor body and descends along the inclined guide rail to the lower working position, and the refueling machine transfers the new fuel assemblies from the lifting barrel to the jacking position of the reactor core 101 where the spent fuel assemblies have been unloaded, completing the loading of the new fuel assemblies;

[0163] The refueling system performs unloading of spent fuel assemblies, including the following steps:

[0164] The hoist enters the reactor vessel from the top cover of the reactor body and descends along the inclined guide rail to the lower working position; the refueling machine enters the reactor vessel from the rotating shield plug along the vertical guide rail, and reaches the position of the fuel assembly socket of the reactor core 101 through the circumferential rotation of the rotating shield plug, takes out the spent fuel assembly at the position of the fuel assembly socket of the reactor core 101 and transports it to the lower working position of the hoist bucket.

[0165] The hoist bucket is lifted along the inclined guide rail to the upper working position; the transfer vehicle 617 in the transfer chamber enters the upper working position of the hoist bucket in the reactor vessel from the top cover of the reactor body, and transfers the spent fuel assembly to the spent fuel hanging basket 619 of the spent fuel transfer vehicle 608 through the spent fuel transfer coupling device 609.

[0166] When the spent fuel hanging basket 619 is full of spent fuel assemblies, the spent fuel transfer vehicle 608 moves along the spent fuel transportation channel to the cleaning chamber 610, and the transfer vehicle 618 in the cleaning chamber lifts the spent fuel hanging basket 619 into the cleaning well 611 for cleaning; after the cleaning of the spent fuel hanging basket 619 is completed, the transfer vehicle 618 in the cleaning chamber transfers the spent fuel hanging basket 619 to the spent fuel storage pool 621 through the spent fuel transportation water channel 615 for temporary storage.

[0167] If it is found that the spent fuel assembly is damaged in the reactor vessel, when the spent fuel hanging basket 619 is still on the spent fuel transfer vehicle 608, the transfer vehicle 618 in the cleaning chamber is used to transfer the damaged spent fuel assembly to the lead bath well 612 for lead bath cleaning. After the lead bath cleaning is completed, it is loaded into a sealed can, and then transferred to the spent fuel storage pool 621 by the transfer vehicle 618 along the spent fuel transportation water channel 615 through the spent fuel hanging basket 619.

[0168] If it is found that the spent fuel assembly is damaged during the cleaning process in the cleaning well 611, after the cleaning is completed, the spent fuel assembly in the spent fuel hanging basket 619 is transferred to the leakage detection well 613 by the transfer vehicle 618 in the cleaning chamber for one-by-one detection. The damaged spent fuel assembly is loaded into a sealed can, and then transferred to the spent fuel storage pool 621 by the transfer vehicle 618 along the spent fuel transportation water channel 615 through the spent fuel hanging basket 619.

[0169] In the traditional sodium-cooled fast reactor 1, a new fuel assembly conversion barrel is used as an essential transfer device in the path of the new fuel assembly entering the reactor, and at the same time as a preheating device for the new fuel assembly before entering the reactor. When a large number of in-core fuel assemblies are refueled, the preheating and cooling of the new fuel assembly conversion barrel will greatly extend the overhaul period of the unit. The present invention preheats a batch of new fuel assemblies 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 at the same time removes the configuration of the new fuel assembly conversion barrel.

[0170] In the sodium-cooled fast reactor unit of the present invention, the refueling machine is a direct drive refueling machine. Compared with the traditional rotary loop refueling machine, the new fuel transportation channel 606 and the spent fuel transportation channel 607 in the form of a through-type straight long strip are more suitable for the unified management of multiple sodium-cooled fast reactor units, reducing the construction period of the barrel loading and transportation of new fuel assemblies and spent fuel assemblies, enabling the maximum possible compression of the refueling period, and at the same time removing the conversion barrels for new fuel assemblies and spent fuel assemblies and related auxiliary supporting systems.

[0171] In the traditional sodium-cooled fast reactor unit, high requirements for the installation accuracy of the refueling system equipment are used to achieve high requirements for the positioning accuracy between the conversions of the refueling system equipment during the transfer process of the fuel assemblies. In the sodium-cooled fast reactor unit of the present invention, the high requirements for the installation accuracy of the refueling system equipment during the transfer process of the fuel assemblies are greatly reduced, and the high requirements for the installation accuracy of the refueling system equipment are transformed into requirements for the control accuracy of the positioning between the conversions of the refueling system equipment, greatly reducing the installation difficulty of the refueling system equipment and the risk of difficulty in realizing the refueling process due to the installation of the refueling system equipment and the deviation of the civil construction.

[0172] In the present invention, the new fuel basket 603 is used for overall heating and transfer of the new fuel assemblies, and the spent fuel basket 619 is used for overall lifting and cleaning of the spent fuel assemblies, reducing the transfer cycle of the fuel assemblies through modular design.

[0173] In the refueling system of the present invention, the spent fuel assemblies are cleaned by a waterless cleaning device in the cleaning chamber 610. Compared with the traditional steam cleaning method, the risk of sodium-water reaction and excessive hydrogen content is reduced, and at the same time, a series of monitoring devices such as hydrogen meters and hydrogen-oxygen alkali measuring devices are removed.

[0174] In this embodiment, as one possible implementation method, the instrument control system is a distributed instrument control system;

[0175] The instrument control system includes a process system interface layer, an automatic control and protection layer, an operation and management information layer, and a plant-wide technical management layer;

[0176] The process system interface layer includes sensors and actuators; the sensors are installed on the process equipment and are used to detect the process parameters of the process equipment; the actuators are used to control the process according to the control instructions from the automatic control and protection layer.

[0177] The automatic control and protection layer adopts field summary control technology, which is used to collect the process parameters of the process system interface layer; process the process parameters of the process system interface layer and perform logical operations, and generate control instructions to be transmitted to the process system interface layer.

[0178] The operation and management information layer is used to execute tasks, including information support, information diagnosis, recording of process information and operator actions, and control of the sodium-cooled fast reactor unit through operating equipment; the operation and management information layer includes the main control room 13 and the standby control room;

[0179] The technical management layer is used for the operation management of the sodium-cooled fast reactor power station. It receives the information required for the operation management of the sodium-cooled fast reactor power station through network interface devices, enabling the managers of the sodium-cooled fast reactor power station to understand the operating conditions of the sodium-cooled fast reactor power station.

[0180] In this embodiment, as one of the achievable ways, the automatic control and protection layer includes a safety-class digital control system and a non-safety-class digital control system;

[0181] The safety-class digital control system is a safety-class DCS that has been verified and validated, including the sodium-cooled fast reactor 1 protection system, the sodium-cooled fast reactor 1 post-accident monitoring system, and the nuclear instrumentation system;

[0182] The non-safety-class digital control system adopts the mature bus control technology of modern industry, combines the AI technology and 5G technology developed in recent years, and adopts the domestic mature non-safety-class DCS and PLC, taking into account the advancement of technology while meeting the requirements of safety, maturity, and stability.

[0183] For the auxiliary systems of the sodium-cooled fast reactor unit, especially the auxiliary systems of the conventional island and the nuclear island, 5G systems are arranged in the relevant plants. Through wireless network and field bus technologies, drawing on the mature and advanced experience in industrial fields such as large-scale chemical industry, petrochemical industry, and thermal power generation, a 5G system network constructed by modern intelligent instruments is fully utilized to achieve wireless communication network connection between people, systems, and equipment, and to real-time master the system equipment status of the auxiliary systems of the sodium-cooled fast reactor unit. Robots are used for inspection in some places, greatly reducing the workload of manual inspection, improving the accuracy of equipment monitoring at the same time, and being beneficial to equipment management during the engineering construction and operation stages. In view of the inherent safety of the sodium-cooled fast reactor 1, the safety-class DCS is optimized, and the control of some auxiliary systems in the nuclear island is adjusted to non-safety-class, while retaining the sodium-cooled fast reactor 1 protection, the sodium-cooled fast reactor 1 post-accident monitoring, and the nuclear measurement instrumentation system as safety-class. 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, ensuring the safety, reliability, flexibility, and economy of the operation of the sodium-cooled fast reactor power station.

[0184] In this embodiment, as one of the achievable ways, 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 power is supplied to each sodium-cooled fast reactor unit by the off-site power source through the main transformer and the auxiliary transformer respectively; 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;

[0185] The normal power supply system supplies power to the electrical equipment for ensuring the normal startup, rated power operation, and normal shutdown of the sodium-cooled fast reactor unit; the reliable power supply system supplies power to the electrical equipment for maintaining the normal operation of the sodium-cooled fast reactor unit.

[0186] The reliable diesel engine 715 is an independent medium-voltage reliable AC power source in the sodium-cooled fast reactor power station, and supplies power to the reliable power supply system when both the normal power supply system and the reliable power supply system lose power.

[0187] The battery energy storage station 714 realizes the secondary frequency modulation of the sodium-cooled fast reactor unit during the normal operation of the sodium-cooled fast reactor unit, and supplies power to the normal power supply system when the normal power supply system loses power.

[0188] The sodium-cooled fast reactor 1 has passive inherent safety. Under accident conditions, only the heat of the sodium-cooled fast reactor 1 needs to be transferred to the intermediate heat exchanger 201 through natural circulation in the reactor and the heat of the sodium-cooled fast reactor 1 through natural circulation outside the reactor is transferred to the air heat exchanger through an independent heat exchanger, and the air heat exchanger transfers the heat of the cold fast reactor 1 to the atmosphere through the induced draft chimney 108 to export the heat of the sodium-cooled fast reactor 1, realizing the residual heat removal of the sodium-cooled fast reactor 1 under accidents. At the same time, the safety of the sodium-cooled fast reactor 1 does not depend on the power supply, and only one reliable diesel engine is used to protect the operation of important equipment under accident conditions.

[0189] In this embodiment, as one of the realizable ways, 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 connection interface and protection device;

[0190] Among them, the energy storage battery pack uses lithium-ion batteries as the energy storage medium and stores electrical energy by converting it into chemical energy;

[0191] The energy storage converter is used to realize the bidirectional conversion between alternating current and direct current, control the charge and discharge process of the energy storage battery pack, and adjust the power output of the energy storage battery pack;

[0192] The battery management system is used to monitor the voltage, temperature, state of charge, 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 charge and discharge strategy of the energy storage battery pack;

[0193] The energy management system is used to overall dispatch the operation of the energy storage system and optimize the charge and discharge plan of the energy storage system through data analysis and algorithms;

[0194] The cooling and fire protection system is used to maintain the temperature stability of the energy storage battery pack, prevent thermal runaway, and start the fire extinguishing device when the energy storage battery pack has thermal runaway;

[0195] The grid connection interface and protection device includes a circuit breaker, an isolation transformer, and a surge protector, and is used to ensure the safe connection with the power grid.

[0196] In this embodiment, as one of the feasible ways, the energy storage system includes 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 sequentially connected to the super capacitor 402 and the storage battery 403 through the energy storage transformer 401; the storage battery 403 is connected to the battery energy storage station 714 in an electrical circuit;

[0197] 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 a sensor, calculates the power quantity to be supplemented or absorbed according to the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, determines the frequency regulation timing and output depth of the energy storage system, optimizes the distribution factor, and smoothly adjusts the power output of the energy storage system to quickly respond to the grid frequency fluctuation;

[0198] When the normal power supply system loses power, the battery energy storage station 714 transmits a signal of power loss of the normal power supply system to the energy storage system, and the energy storage system adjusts the discharge power to the steam turbine generator 303 according to the grid load demand, and discharges power to the normal power supply system through the battery energy storage station 714 while ensuring the voltage and frequency stability of the grid, so as to supply power to the normal power supply system.

[0199] The energy storage system is integrated with the battery energy storage station 714, while meeting the energy storage and secondary frequency regulation functions of the sodium-cooled fast reactor unit, ensuring the safety and reliability of the battery energy storage station 714.

[0200] In this embodiment, as one of the feasible ways, the nuclear island is also provided with a maintenance workshop 9, a spare parts warehouse 10, a dangerous goods warehouse 11, a fuel regeneration item 17 and an isotope production hot cell 18; among them, the maintenance workshop 9 is used for the equipment maintenance of the sodium-cooled fast reactor unit; the spare parts warehouse 10 is used for the storage of spare parts of the sodium-cooled fast reactor unit; the dangerous goods warehouse 11 is used for the storage of dangerous chemicals of the sodium-cooled fast reactor unit, the fuel regeneration item 17 is used for the reprocessing of spent fuel and the manufacture of new fuel, and the isotope production hot cell 18 is used for the extraction, purification and packaging of radioactive isotopes.

[0201] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A large sodium-cooled fast reactor power station, comprising a sodium-cooled fast reactor unit and an auxiliary system for the sodium-cooled fast reactor unit; characterized in that, The sodium-cooled fast reactor unit is used to convert nuclear energy into electric energy or steam energy, and the auxiliary system of the sodium-cooled fast reactor unit is used to assist the sodium-cooled fast reactor unit in converting nuclear energy into electric energy or steam energy; there are multiple sodium-cooled fast reactor units, and the auxiliary system of the sodium-cooled fast reactor unit is shared by two or each sodium-cooled fast reactor unit; The sodium-cooled fast reactor unit includes a sodium-cooled fast reactor (1), a primary heat transfer system, a power conversion system, an accident residual heat removal system, and an energy storage system; the sodium-cooled fast reactor (1) is used for nuclear fission to generate heat energy; the primary heat transfer 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 electric energy or steam energy; the energy storage system is used to store and release electric energy; the accident residual heat removal system is used to remove the residual heat of the sodium-cooled fast reactor (1) under accident conditions; The sodium-cooled fast reactor (1) is arranged in the reactor building (118) of the nuclear island. The reactor building (118) is an ordinary seismic-resistant building and is manufactured in a large process room modular manner; the sodium-cooled fast reactor (1) includes a reactor pit, a containment vessel (117) in the reactor pit, and a reactor core body (103) in the containment vessel (117), and the construction is completed through the following steps: Carry out the construction of the reactor pit, the containment vessel (117), and the reactor core body (103) in parallel, and after the construction of the containment vessel (117) and the reactor core body (103) is completed, install the reactor core body (103) into the containment vessel (117); push the containment vessel (117) and the reactor core body (103) inside the containment vessel (117) into the reactor pit as a whole; the reactor core body (103) is manufactured modularly, the containment vessel (117) is a capsule structure made of all-welded steel plates, and the reactor pit is made of concrete; The primary 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 concentrating 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 sends the primary sodium in the cold pool through the primary sodium sides of the reactor core (101) and the intermediate heat exchanger (201) and then sends it back to the cold pool to form a primary loop; The outlet of the secondary sodium side of the intermediate heat exchanger (201) is connected in sequence through pipelines to the secondary sodium pump (202), the sodium side of the sodium-molten salt heat exchanger (203), and the inlet of the secondary sodium side of the intermediate heat exchanger (201) to form a secondary loop; The sodium - molten salt heat exchanger (203) is connected in series on the molten salt side outlet to the high - temperature molten salt tank (208), the second regulating valve (209), the high - temperature molten salt pump (210), the molten salt - water heat exchanger (211) molten salt side, the low - temperature molten salt tank (207), the first regulating valve (206), the low - temperature molten salt pump (204) and the sodium - molten salt heat exchanger (203) molten salt side inlet, forming a three - loop; the pipeline connecting the sodium - molten salt heat exchanger (203) molten salt side 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, 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 in series to the power conversion system, the main feed water pump (304) and the water side outlet inlet of the molten salt - water heat exchanger (211), forming a four - loop.

2. The large sodium-cooled fast reactor power station according to claim 1, characterized in that The containment vessel (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 vessel (117), and the interiors of the upper container and the lower container are in communication, and the welding meets the internal airtightness requirements of the containment vessel (117); a detachable top cover is provided at the top of the upper container, and the top cover uses mechanical seals; The containment vessel (117) is provided with a personnel and equipment access passage (106) at the reactor hall location, and the personnel and equipment access passage (106) is sealed with sodium fire - resistant doors; the personnel and equipment access passage (106) is in a closed state during the normal operation of the sodium - cooled fast reactor (1); the personnel and equipment access passage (106) is in an open state during the maintenance of the sodium - cooled fast reactor (1); A sodium leakage receiving and suppressing tray (104) is provided at the bottom of the containment vessel (117); a core melting collector (102) is provided at the bottom of the reactor body (103).

3. The large sodium-cooled fast reactor power station according to claim 1, wherein, The reactor body (103) includes a reactor body container, a reactor body top cover sealed to the top of the reactor body container, a top - mounted equipment (119) sealed to the reactor body top cover, a top - mounted shielding equipment (105) sealed to the reactor body top cover, a sodium pool inside the reactor body (103) container, and an intermediate heat exchanger (201), an independent heat exchanger, a primary loop sodium pump and a core (101) arranged in the sodium pool; among them, both the intermediate heat exchanger (201) and the independent heat exchanger are manufactured using integrated 3D printing technology; the top - mounted shielding equipment (105) is integrally manufactured; the in - core component materials of the sodium - cooled fast reactor (1) use low - copper and low - phosphorus steel.

4. The large sodium-cooled fast reactor power station according to claim 3, characterized in that, The core (101) uses radiation - resistant FMS or ODS cladding materials; the inner ring of the core (101) is the active zone, and the fissile nuclear fuel U - 235 in the active zone undergoes fission reactions to generate fast neutrons; the outer ring of the core (101) is the breeding zone (510), and the fissile nuclear fuel U - 238 in the breeding zone (510) absorbs fast neutrons and is converted into fissile nuclear fuel Pu - 239; the content of fissile nuclear fuel Pu - 239 in the breeding zone (510) is higher than that in the active zone, flattening the power of the fuel assemblies in the active zone and the breeding zone (510); The active region includes an inner active-region fuel zone and an outer active-region fuel zone (508) surrounding the inner active-region fuel zone; the inner active-region fuel zone is designed with axial non-uniformity and is axially divided into a first inner active-region fuel zone (507), an inert fuel zone (506), and a second inner active-region fuel zone (509) from top to bottom; each of the inner active-region fuel zone and the breeding zone (510) is provided with an irradiation zone for isotope production; The multiplication ratio within 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 vessel top cover is provided with a reactor rotating shield plug; the top equipment of the reactor includes a control rod drive mechanism; the control rod drive mechanism enters the reactor vessel from the rotating shield plug and is connected to the corresponding control rod in the core (101) to drive the control rod to insert into or withdraw from the fuel assembly; The lower end of the control rod is combined with a short fuel rod bundle; when the control rod is inserted, the control rod is located in the inner active-region fuel zone to introduce negative reactivity; when the control rod is withdrawn, the short fuel rod bundle at the lower end of the control rod is located in the inner active-region fuel zone to introduce positive reactivity, thereby increasing the control rod worth. The power conversion system includes 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 grid user (309), and a grid main transformer (308); the water-side outlet of the molten salt - water heat exchanger (211) is divided into two paths, one path is connected in sequence through pipelines to the steam circuit control valve (301), and the other path is connected in sequence through pipelines to the power generation circuit 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); the steam turbine generator (303) is connected through pipelines to the steam user (307), 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 grid user (309) through the grid main transformer (308); 5. The large sodium-cooled fast reactor power station according to claim 1, characterized in that, The operating modes of the sodium-cooled fast reactor unit are one or a combination of several 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 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 concentrating 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 amounts of high- and low-temperature molten salt, nuclear energy and solar energy are converted into molten salt heat 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 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 after the steam turbine generator (303) does work and generates electricity is sent to the condenser (305) to be condensed into condensate, and part is sent to steam users; the condensate 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) to do work and generate electricity; 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 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) by the main feed water pump (304) for heat exchange to generate high-temperature industrial steam and sent to the steam user (307).

6. The large sodium-cooled fast reactor power station according to claim 5, characterized in that, The primary frequency regulation and peak shaving of the sodium-cooled fast reactor unit include the power increase of the sodium-cooled fast reactor unit and the power decrease of the sodium-cooled fast reactor unit; there are the following two modes for the power decrease of the sodium-cooled fast reactor unit: 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 sodium pump (202) operates at full power, continuously taking out the heat of the sodium-cooled fast reactor (1); 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, reducing the total amount of steam, and the output electric power of the steam turbine generator (303) is reduced, so as to realize the peak shaving of the sodium-cooled fast reactor unit; at this time, the liquid level of the high-temperature molten salt tank (208) rises, and the liquid level of the low-temperature molten salt tank (207) continuously decreases. By adjusting the storage amounts of high- and low-temperature molten salts, the excess energy generated by the sodium-cooled fast reactor (1) is stored; In the second mode, while the sodium-cooled fast reactor unit is in the power generation mode, the high-temperature industrial steam supply mode is synchronously started, and the amount of high-temperature industrial steam supply is controlled by the opening degree of the steam loop control valve (301), so as to reduce the power generation power of the steam turbine generator (303) and realize the peak shaving of the sodium-cooled fast reactor unit; The power-up operation mode of the sodium-cooled fast reactor unit is as follows: The sodium-cooled fast reactor operates at full power, the secondary-loop sodium pump (202) operates at full power, continuously taking out the heat of the sodium-cooled fast reactor (1); 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, increasing the total steam volume and raising the output electric power of the steam turbine generator (303) to achieve peak shaving of the sodium-cooled fast reactor unit; the liquid level of the high-temperature molten salt tank (208) decreases, and the liquid level of the low-temperature molten salt tank (207) increases. By adjusting the storage of high- and low-temperature molten salts, the molten salt energy storage is released, increasing the power generation power of the steam turbine generator (303) and raising the grid-connected power of the sodium-cooled fast reactor unit.

7. The large sodium-cooled fast reactor power station according to claim 5, characterized in that The secondary frequency regulation of the sodium-cooled fast reactor unit includes the secondary frequency regulation of power reduction and the secondary frequency regulation of power increase of the sodium-cooled fast reactor unit; 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, reducing the grid-connected power of the sodium-cooled fast reactor unit to achieve the secondary frequency regulation of power reduction of the sodium-cooled fast reactor unit; Under the secondary frequency regulation of 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 (303) is synchronously connected to the energy storage system for discharging, increasing the grid-connected power of the sodium-cooled fast reactor unit to achieve the secondary frequency regulation of power increase of the sodium-cooled fast reactor unit.

8. The large sodium-cooled fast reactor power station according to claim 5, characterized in that The condenser (305) includes an air-cooled radiator and a natural draft cooling tower (15). The air-cooled radiator is connected to the steam turbine generator (303) through pipelines and is arranged at the bottom or side of the natural draft cooling tower (15); the steam after the steam turbine generator (303) does work and generates electricity is sent to the air-cooled radiator, and the suction force of the tower barrel of the natural draft cooling tower (15) makes the cold air flow through the surface of the air-cooled radiator, causing the steam in the air-cooled radiator to condense into condensate and be sent to the water side of the molten salt-water heat exchanger (211) through the main feed water pump (304).

9. The large sodium-cooled fast reactor power station according to claim 3, characterized in that, The accident residual heat removal system includes an air heat exchanger and an independent heat exchanger; it is used for removing the residual heat of the sodium-cooled fast reactor (1) under accident conditions of the sodium-cooled fast reactor (1); The air heat exchanger is arranged at the bottom or side of the induced draft chimney (108) and is connected to the induced draft chimney (108) through pipelines; the independent heat exchanger is arranged in the cold pool or hot pool and is connected to the air heat exchanger through pipelines; The primary-loop sodium in the cold pool flows through the reactor core (101) and the primary-loop sodium side of the independent heat exchanger and then returns to the cold pool; the secondary-loop sodium on the secondary-loop sodium side of the independent heat exchanger exchanges heat with the primary-loop sodium on the primary-loop 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-loop sodium side of the independent heat exchanger; the air in the air heat exchanger is heated and rises, and using the pressure difference generated by the height difference of the induced draft chimney (108), it is discharged into the atmosphere from the induced draft chimney (108).

10. The large sodium-cooled fast reactor power station 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.

11. The large sodium-cooled fast reactor power station according to claim 10, 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 a 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 of 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.

12. The large sodium-cooled fast reactor power station according to claim 10, wherein 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.

13. The large sodium-cooled fast reactor power station according to claim 10, wherein The refueling system is arranged in the reactor building (118) of the nuclear island and is used for refueling the core (101), and includes 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 vessel body; the in-reactor refueling system includes a refueling machine and a hoist; the refueling machine is a direct-pull refueling machine, and during the refueling of the reactor core (101), it directly enters the reactor vessel body from the reactor rotating shield plug and realizes full coverage of the fuel assembly jacking positions in the reactor core and the lower working positions of the hoist through the circumferential rotation of the reactor rotating shield plug; the hoist is an inclined hoist, and during the refueling of the reactor core (101), it enters the upper or lower working positions inside the reactor vessel body in an inclined manner from the top cover of the reactor vessel body; a maintenance storage position (620) is provided in the reactor building (118), and the refueling machine and the hoist are placed at the maintenance storage position (620) during non-core refueling periods; The out-of-reactor refueling system includes a fresh fuel storage (601), a fresh 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 fresh fuel storage (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 fresh fuel storage (601) is connected to the fresh fuel transportation channel (606); the spent fuel transportation channel (607) is connected to the cleaning room (610); the transfer room (616) is respectively connected to the fresh fuel transportation channel (606) and the spent fuel transportation channel (607); the cleaning room (610) and the spent fuel storage pool (621) are connected through a spent fuel transportation water channel (615); A fresh fuel transfer vehicle (605) is provided on the fresh fuel transportation channel (606), and a fresh fuel transfer connection device (604) is provided on the fresh fuel transfer vehicle (605); a spent fuel transfer vehicle (608) is provided on the spent fuel transportation channel (607), and a spent fuel transfer connection 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 fresh fuel storage (601); the storage container is used for storing fresh fuel assemblies; a fresh fuel hanging basket (603) is provided in the preheating box (602), a cover plate of the preheating box (602) is provided on the top of the preheating box (602), the fresh fuel hanging basket (603) is used for storing fresh fuel assemblies, the preheating box (602) is used for heating fresh fuel assemblies, and the cover plate of the preheating box (602) is used for opening or closing the preheating box (602); a cleaning room transfer vehicle (618), a lead leakage detection well (613), a lead bath well (612), and a cleaning well (611) are provided in the cleaning room (610).

14. The large sodium-cooled fast reactor power station according to claim 10, wherein The instrumentation control system is a distributed instrumentation control system, including a process system interface layer, an automatic control and protection layer, an operation and management information layer, and a plant-wide technical management layer; The process system interface layer includes sensors and actuators; the sensors are installed on the process equipment and are used for detecting the process parameters of the process equipment; The actuators are used for controlling the process according to the control instructions from the automatic control and protection layer; The automatic control and protection layer adopts field summary control technology and is used for collecting the process parameters of the process system interface layer; Process and perform logical operations on the process parameters of the process system interface layer, and generate control instructions to be transmitted to the process system interface layer; The operation and management information layer is used to execute tasks, including information support, information diagnosis, recording of process information and operator actions, and control of the sodium-cooled fast reactor unit through operating equipment; The technical management layer is used for the operation management of the sodium-cooled fast reactor power station, and receives the information required for the operation management of the sodium-cooled fast reactor power station through network interface devices.

15. The large sodium-cooled fast reactor power station according to claim 10, 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 the main transformer and the auxiliary transformer respectively; 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 supplies power to the electrical equipment for ensuring the normal start-up, rated power operation and normal shutdown of the sodium-cooled fast reactor unit; the reliable power supply system supplies power to the electrical equipment for maintaining 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 during the normal operation of the sodium-cooled fast reactor unit, and supplies power to the normal power supply system when the normal power supply system loses power.

16. The large sodium-cooled fast reactor power station according to claim 15, characterized in that, 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 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 converter is used to realize the bidirectional conversion of alternating current and direct current, control the charge and discharge 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 state of the energy storage battery pack in real time, ensure the safe operation of the energy storage battery pack and optimize the charge and discharge strategy of the energy storage battery pack; the energy management system is used to overall coordinate and dispatch the operation of the energy storage system, and optimize the charge and discharge 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 start the fire extinguishing device when the energy storage battery pack has a thermal runaway; the grid connection interface and protection device is used to ensure a safe connection to the power grid.

17. The large sodium-cooled fast reactor power station according to claim 16, characterized in that, 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 in sequence with the super capacitor (402) and the battery (403) through the energy storage transformer (401); the battery (403) is connected to the battery energy storage station (714) in an electrical circuit; Under the secondary frequency modulation 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, calculates the power quantity to be supplemented or absorbed according to the captured grid frequency deviation amplitude and the preset control strategy; at the same time, based on the grid sensitivity analysis, determines the frequency modulation timing and output depth of the energy storage system, optimizes the distribution factor, and smoothly adjusts the power output of the energy storage system; When the normal power supply system loses power, the battery energy storage station (714) transmits a signal indicating the loss of power in the normal power supply system 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 while ensuring the stability of the grid voltage and frequency, discharges power to the normal power supply system through the battery energy storage station (714) to supply power to the normal power supply system.

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