Active circulation type solution type reactor system

Abstract

The present invention discloses an active circulation type solution type reactor system, and relates to the technical field of nuclear reactor design, the active circulation type solution type reactor system comprises: a loop fuel circulation system, which is respectively connected with a fuel solution outlet and a fuel solution inlet of a reactor core through a loop pipeline; along the conveying direction of the primary loop pipeline, the primary loop fuel circulation system comprises a heat exchanger, a solid impurity filtering unit and a gas-water separation unit which are sequentially connected in series, and an isotope separation and radioactive waste disposal unit which is connected to the primary loop pipeline in parallel; the primary-loop fuel circulation system further comprises a fuel solution circulation unit. By adopting the scheme, the fuel solution flows in the circulating system, and a series of on-line operations such as fission, impurity removal and target isotope extraction of the fuel solution are respectively realized in each subsystem of the flowing path, so that the reactor system can continuously run on line, the economical efficiency can be improved, and the performance of the reactor can be improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor design technology, and more specifically to an active circulation solution reactor system. Background Technology

[0002] A solution-type reactor is a homogeneous reactor that uses an acidic aqueous solution containing fissile nuclides (i.e., fuel solution) as fuel. Unlike traditional reactors, solution-type reactors do not have solid fuel assembly structures; the acidic aqueous solution in the reactor core serves as both fuel and moderator, and is uniformly distributed. Solution-type reactors have advantages such as inherent high safety, simple fuel manufacturing, and convenient loading and unloading, making them particularly suitable for special applications such as the production of medical isotopes.

[0003] Existing molten metal reactors typically employ a boiler-like structure as their core container. The molten fuel remains static within the container. During reactor operation, natural convection occurs due to the heat released from the nuclear fuel. Cooling pipes connect the core container to the outside environment, and circulating water removes the fission heat generated in the core. During operation, fragments from fuel fission bombard water molecules, and nitric acid molecules continuously produce hydrogen and oxygen gases, nitrogen-containing gases, and radioactive gases. This introduces negative reactivity into the reactor and leads to core instability and changes in the chemical composition of the molten fuel solution. Furthermore, molten metal reactors generally have relatively low power outputs; currently in service, none exceed 50kW. Besides the aforementioned instability factors, simply increasing the core volume to a 1:1 height-to-diameter ratio would result in uncontrollable backup reactivity.

[0004] Existing molten metal reactors primarily operate under a mode of shutdown and offline fuel reprocessing after a period of operation. Reactor operation and fuel reprocessing are sequential and independent; therefore, the reactor cannot operate during the fuel reprocessing phase. Due to the short operating cycle, the molten metal needs to be transferred once per cycle, increasing operating costs. Furthermore, fuel is lost during transfer, increasing the risk of radioactive material leakage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention aims to provide an active circulation solution-type reactor system. By using this solution, a series of online operations, such as fuel solution fission, impurity removal, and target isotope extraction, are achieved in each subsystem along the flow path. This allows the reactor system to operate continuously online, improving both economic efficiency and reactor performance.

[0006] This invention is achieved through the following technical solution:

[0007] An active circulation solution-type reactor system includes:

[0008] The primary loop fuel cycle system is connected to the fuel solution outlet and fuel solution inlet of the reactor core via primary loop pipelines. Along the transport direction of the primary loop pipelines, the primary loop fuel cycle system includes a heat exchanger, a solid impurity filtration unit and a gas-liquid separation unit connected in series, as well as an isotope separation and radioactive waste disposal unit connected in parallel to the primary loop pipelines.

[0009] The primary loop fuel cycle system also includes a fuel solution cycle unit, which is used to provide solution cycle power in the primary loop.

[0010] The heat exchanger is used for heat exchange with the fuel solution; the solid impurity filtration unit is used to remove solid impurities from the fuel solution; the gas-liquid separation unit is used to discharge gas from the fuel solution; the isotope separation and radioactive waste disposal unit is used to continuously or periodically draw out a portion of the fuel solution from the primary loop pipeline to extract the required radioactive isotopes and separate fission products, and can return the extracted and separated fuel solution to the primary loop pipeline.

[0011] In existing technologies, the fuel solution remains static in the container, leading to problems such as unstable core operation and changes in the chemical composition of the solution. Furthermore, adopting an operation mode of shutting down the reactor and processing the fuel offline after a period of operation increases operating costs, causes fuel loss during transfer, and increases the risk of radioactive material leakage. Therefore, this invention provides an active circulation solution-type reactor system. This solution allows the fuel solution to flow within a circulation system, enabling a series of online operations such as fuel solution fission, impurity removal, and target isotope extraction in each subsystem along the flow path. This allows the reactor system to operate continuously online, improving both economic efficiency and reactor performance. Specifically, the system includes a primary loop fuel circulation system connected to the fuel solution outlet and fuel solution inlet of the reactor core via primary loop piping to form a circulating fuel solution. The fuel solution circulation unit comprises one or more circulation pumps and valves connected in series in the primary loop to provide circulation power. In actual operation, after the fuel solution inside the reactor core undergoes a fission reaction, producing radioactive isotopes and heat, the fuel solution enters a heat exchanger through the fuel solution outlet. The heat exchanger discharges the fission heat, and the fuel solution after heat exchange enters a solid impurity filtration unit to remove solid impurities from the fuel solution. Subsequently, it enters a gas-liquid separation unit to separate the gas and liquid in the fuel solution, and the liquid is discharged into the downstream primary loop pipeline for subsequent operations. If the isotope separation and radioactive waste disposal unit can be used to continuously or periodically extract a portion of the fuel solution from the primary loop for the extraction of usable radioactive isotopes and the separation of fission products such as rare earth metals, the neutron poison in the fuel solution can be reduced. The isotope separation and radioactive waste disposal unit can be connected to the primary loop via valves, allowing the fuel solution in the primary loop to be exported for processing in a timely manner to produce radioactive isotopes, separate radioactive waste, and return the remaining fuel solution to the primary loop. After a series of operations, the processed fuel solution can enter the reactor core from the fuel solution inlet to continue the reaction, forming a circulation channel. It can also perform a series of online operations on the fuel solution, such as impurity removal and target isotope extraction, enabling the reactor system to operate continuously online.

[0012] In the aforementioned scheme, the isotope separation and radioactive waste disposal unit includes isotope separation and purification devices, radioactive waste separation, extraction and storage devices, and radioactive waste disposal devices, which can operate independently as needed. The solid impurity filtration system, which uses porous materials and bubbling to remove solid impurities from the fuel solution, is connected in series in a single loop.

[0013] Further optimization involves recombining hydrogen and oxygen gas to generate water. The gas-water separation unit includes a gas-water separation device and a hydrogen-oxygen gas recombination device. The gas-water separation device discharges the gas phase from the fuel solution, while the hydrogen-oxygen gas recombination device recombines the hydrogen and oxygen gas in the gas phase to generate water, which is then transported to the primary loop. In this design, the gas-water separation unit includes a gas-water separation device for separating the gas generated in the reactor core from the fuel solution, a hydrogen-oxygen gas recombination device, and an external exhaust gas treatment device. The inlet of this unit is connected to the primary loop. The gas-water mixture of the fuel solution enters through the inlet and has two types of outlets: one is the gas outlet after gas-water separation, which is directly connected to the exhaust gas treatment device, through which radioactive gases generated in the reactor core and unrecombined hydrogen and oxygen gas enter the exhaust gas treatment device; the other is the liquid outlet, which is connected to the primary loop, through which the remaining fuel solution and the water generated after hydrogen-oxygen gas recombination re-enter the primary loop.

[0014] To further optimize the process and prevent the risk of hydrogen explosion, several gas-liquid separation units are sequentially arranged in parallel and at least one gas-liquid separation unit is arranged in series along the downstream conveying direction of the solid impurity filtration unit. In this design, at the outlet of the solid impurity filtration unit, several gas-liquid separation units are first connected in parallel. The liquid outlets of these parallel gas-liquid separators converge into a primary loop and then enter the at least one gas-liquid separation unit in series. The parallel gas-liquid separation units effectively disperse hydrogen and oxygen gases, preventing the risk of hydrogen explosion. Furthermore, the series-connected gas-liquid separation units more effectively remove gaseous impurities. Additionally, the multi-stage gas-liquid separation units are all arranged downstream of the heat exchanger, effectively reducing the loss of water in the fuel solution as vapor.

[0015] For further optimization, to collect and treat the separated waste gas, the primary loop fuel cycle system also includes a waste gas treatment device. The gas outlet of each gas-liquid separation unit is connected to the waste gas treatment device via a waste gas conveying pipeline. Multiple gas-liquid separation units can share a single waste gas treatment device.

[0016] Further optimization is needed. After the entire reactor system has been operating for a period of time, due to the consumption of fissile nuclides and the accumulation of non-separable fission products, k eff To ensure continuous system operation, the primary loop fuel cycle system further includes a nuclear fuel handling unit. This unit stores fresh fuel solution and is located before the fuel solution inlet. A first transfer pump delivers the fresh fuel solution into the primary loop piping. In this design, the nuclear fuel handling unit stores unused fresh fuel solution and can transfer it from the reactor core inlet section of the primary loop into the fuel loading mechanism within the reactor vessel.

[0017] Further optimization, to control the pressure and volume in the primary loop, the primary loop fuel cycle system also includes a volume control unit. This volume control unit is connected to the primary loop pipeline downstream of the fuel solution circulation unit and is used to control the liquid phase volume ratio in the primary loop pipeline. In this design, the volume control unit is used to feed fuel solution from the reactor core inlet section of the primary loop into and extract it from the fuel loading mechanism in the reactor vessel. The volume control unit includes a storage tank for storing used fuel solution, and the tank contains a pressure control device. The volume control unit can measure and adjust the pressure in the primary loop to ensure that the liquid phase space in the primary loop occupies more than 97%.

[0018] To further optimize the system and ensure volume balance in the primary loop, the solution storage chamber inside the volume control unit is connected to the inlet of the isotope separation and radioactive waste disposal unit via a second transfer pump. In this design, the volume control unit can transport an equal amount of spent fuel solution to the isotope separation and radioactive waste disposal unit for processing via the second transfer pump, thus ensuring volume balance in the primary loop.

[0019] Further optimization, to facilitate rapid discharge of molten fuel in accident conditions, includes a safety tank in the primary loop fuel circulation system. This safety tank is located directly below the molten fuel inlet of the reactor core and connected to the primary loop piping via valves. Opening the valves allows all molten fuel in the primary loop to flow into the safety tank under gravity. In this design, the tank is located below the reactor core. In the event of a severe accident in the reactor system, all fuel in the primary loop can flow into the safety tank under gravity, maintaining a subcritical state. The valves can be used for emergency opening in accident conditions.

[0020] Further optimization, to increase capacity, involves multiple safety tanks, each connected to the primary loop pipeline; the total volume of the safety tanks is at least 1.5 times the total volume of all fuel solutions in the primary loop. Specifically, there are at least three safety tanks, each remaining in a subcritical state when filled with new fuel solution.

[0021] For further optimization, the primary loop fuel cycle system also includes a fission product disposal device for collecting and processing radioactive waste, and the fission product outlet of the isotope separation and radioactive waste disposal unit is connected to the fission product disposal device.

[0022] Further optimization includes a secondary cooling circulation system to achieve a cooling circulation loop. The secondary cooling circulation system includes a final heat sink and a secondary circulation pump. The cooling medium outlet of the final heat sink is connected to the cooling medium inlet of the heat exchanger via a secondary pipeline and the secondary circulation pump to deliver a low-temperature cooling medium. The cooling medium outlet of the heat exchanger is connected to the cooling medium inlet of the final heat sink to deliver a high-temperature cooling medium after heat exchange.

[0023] The dual-loop cooling circulation system can use a closed-loop circulation loop with liquid cooling medium or an open-loop circulation loop with gaseous cooling medium.

[0024] When a closed-loop circulation system using liquid cooling medium is adopted, the secondary loop cooling circulation system further includes a heat exchange medium storage tank, which is used to replenish cooling water into the secondary loop pipeline through a fourth delivery pump.

[0025] The heat exchanger is a multi-tube convection radiator.

[0026] In this scheme, the secondary loop cooling circulation system includes a nuclear heat transfer unit, which includes a primary loop heat exchange section, a secondary loop, a heat exchanger, and a circulation pump that drives the flow of the heat exchange medium. The primary loop heat exchange section consists of multiple branch pipes connected in series in the primary loop main pipeline. The heat exchanger can be a container that encloses the aforementioned branch pipes, with sufficient space inside the container for the cooling medium to pass through. The heat exchanger is connected in series in the secondary loop. The secondary loop adopts a closed-loop circulation loop with liquid coolant or an open-loop circulation pipeline with gaseous cooling medium. The cooling medium is driven through the heat exchanger by a power device (such as a circulation pump) to achieve heat exchange between the primary and secondary loops. If the secondary loop adopts a closed-loop circulation loop with liquid coolant, it also includes a heat exchange medium storage tank for storing the heat exchange medium.

[0027] In actual operation, the secondary loop cooling circulation system operates at atmospheric pressure. If water is used as the cooling medium, the low-temperature cooling water flows through the heat exchanger driven by the secondary loop circulation pump. The fission heat generated in the reactor core heats the cooling water. The high-temperature cooling water passes through the final heat sink, and its temperature decreases before returning to the heat exchanger via the secondary loop pipeline, thus completing the cycle. The lost cooling water is replenished by the heat exchange medium storage tank.

[0028] Further optimization, as a specific structure of the reactor core, the reactor core includes a main reactor vessel, which includes a core conduit and an outer wall. An annular space is formed between the core conduit and the outer wall and is filled with a neutron reflector. The fuel solution inlet c is located at the bottom of the core conduit, and several fuel solution outlets d are circumferentially opened on the upper part of the core conduit, all of which are connected to the primary loop. In this design, the reactor core includes a main reactor vessel for controlling nuclear fuel fission and generating isotopes and fission heat, and a reactor control system for controlling core reactivity. The main reactor vessel includes a spaced-apart outer wall and a core confining tube, forming a sealed annular space between them. This space is filled with water or materials such as graphite, beryllium metal, or beryllium oxide as a neutron reflector. The interior of the core confining tube is the core active zone, with an opening at the bottom connecting to the primary coolant loop. The top of the core confining tube is sealed, and multiple openings at its upper part connect to the primary coolant loop. Furthermore, the reactor core also includes a reactivity control system located within the core active zone for regulating nuclear fuel fission. This system includes a drive mechanism for moving control rods, control rods distributed within the core active zone, and their channels.

[0029] As a redundancy scheme, the fuel solution in this scheme is a uranyl nitrate solution with a U-235 enrichment of 20%; the reactor power is 500kW; the reactor control system consists of 7 bundles of silver-indium-chromium control rods with a diameter of 2.5cm and a drive mechanism; the reflector layer is 20cm thick beryllium oxide; the outer wall and the core shroud are made of stainless steel.

[0030] Secondly, the isotope separation and radioactive waste disposal unit preferably uses a continuous online processing method to treat the fuel solution, with a branch flow rate of approximately 1% of the primary loop flow rate. The final heat sink is a small cooling tower.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] 1. This invention provides an active circulation solution-type reactor system that controls the reactor core to enable a continuous and controllable nuclear fission reaction in the fuel solution to produce usable isotopes. The fuel solution is transported by a primary loop fuel solution circulation system, and the fuel solution passes through a nuclear heat transfer unit to remove fission heat and lower its temperature. A gas-liquid separation unit removes non-recombinable gaseous components from the fuel solution. A solid impurity filtration unit removes solid impurities from the fuel solution. A radioactive waste separation and radioactive waste disposal unit purifies and collects usable isotopes for the production of isotope products. Fission products (mainly neutron poisons) are extracted from the primary loop and disposed of. The remaining fuel solution is returned to the primary loop to continue the above cycle. Through the above steps, the reactor core, heat sink, reprocessing system, fuel and solution addition system can be connected in series in the form of a circulation loop. By making the fuel solution flow in the circulation system, a series of online operations such as fuel solution fission, fission waste (such as Xe) and impurity removal, target isotope extraction, and new fuel addition can be realized in each subsystem of the flow path. This allows the reactor system to operate continuously online, which can improve both economic efficiency and reactor performance.

[0033] 2. The present invention provides an active circulation solution-type reactor system that can control the flow rate of the fuel solution in the primary loop by adjusting the primary loop fuel solution circulation system, thereby reducing the gas content in the reactor core container, the probability of agglomeration to form large bubbles and the uneven distribution, and effectively suppressing the instability of the reactor core caused by bubbles. Therefore, compared with traditional solution reactors, it can increase the core volume, reduce the nuclear fuel enrichment, and increase the reactor power.

[0034] 3. The present invention provides an active circulation solution reactor system that employs multi-stage gas-water separation to gradually recombine hydrogen and oxygen gas, remove gaseous fission products, and improve the safety factor; and removes fission products and improves neutron economy by performing gas-water separation, solid impurity filtration, and online reprocessing of fuel solution in the primary loop.

[0035] 4. The present invention provides an active circulation solution-type reactor system that enables continuous operation of the reactor without reactor shutdown by adding new fuel solution online and reprocessing old fuel solution online, thereby improving economic efficiency; it can also reduce the reactor's backup reactivity and improve safety.

[0036] 5. The present invention provides an active circulation solution reactor system in which the primary loop and the reprocessing loop can operate independently. The reactor power level can be adjusted by the control system according to factors such as reprocessing requirements and capacity, and has high operational flexibility. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0038] Figure 1 This is a schematic diagram of the overall process of the solution-type reactor system provided by the present invention;

[0039] Figure 2 This is a schematic diagram of the reactor core structure provided by the present invention.

[0040] The attached diagram shows the markings and corresponding component names:

[0041] 1-Reactor core; 2-Heat exchanger; 3-Solid impurity filtration unit; 4-Gas-liquid separation unit; 5-Nuclear fuel handling unit; 6-Volume control unit; 7-Isotope separation and radioactive waste disposal unit; 8-Safety container; 9-Fuel solution circulation unit; 10-Heat exchange medium storage tank; 11-Secondary loop circulation pump; 12-Final heat sink; 13-Waste gas treatment device; 14-Fission product treatment device; 15-Primary loop piping; 16-Secondary loop piping; 17-Waste gas delivery piping; 18-First delivery pump; 19-Second delivery pump; 20-Third delivery pump; 21-Fourth delivery pump; 22-Reactor control unit; a-Reactor active zone; b-Reflector layer; c-Fuel solution inlet; d-Fuel solution outlet; e-Control rod drive mechanism; f-Control rod. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0043] Example 1: This Example 1 provides an active circulation solution-type reactor system, such as... Figure 1 As shown, it includes:

[0044] The primary loop fuel cycle system is connected to the fuel solution outlet d and fuel solution inlet c of the reactor core 1 via a primary loop pipe 15. Along the transport direction of the primary loop pipe 15, the primary loop fuel cycle system includes a heat exchanger 2, a solid impurity filtration unit 3 and a gas-liquid separation unit 4 connected in series, and an isotope separation and radioactive waste disposal unit 7 connected in parallel to the primary loop pipe 15.

[0045] The primary loop fuel cycle system also includes a fuel solution cycle unit 9, which is used to provide solution cycle power in the primary loop.

[0046] The heat exchanger 2 is used for heat exchange with the fuel solution; the solid impurity filtration unit 3 is used to remove solid impurities from the fuel solution; the gas-liquid separation unit 4 is used to discharge the gas from the fuel solution; the isotope separation and radioactive waste disposal unit 7 is used to continuously or periodically draw out a portion of the fuel solution from the primary loop pipeline 15 to extract the required radioactive isotopes and separate fission products, and can return the extracted and separated fuel solution to the primary loop pipeline 15.

[0047] In existing technologies, the fuel solution remains static in the container, leading to problems such as unstable core operation and changes in the chemical composition of the solution. Furthermore, adopting an operation mode that involves shutting down the reactor and processing the fuel offline after a period of operation increases operating costs, causes fuel loss during transfer, and increases the risk of radioactive material leakage. Therefore, this invention provides an active circulation solution-type reactor system. This solution allows the fuel solution to flow within a circulation system, enabling a series of online operations such as fuel solution fission, impurity removal, and target isotope extraction in each subsystem along the flow path. This allows the reactor system to operate continuously online, improving both economic efficiency and reactor performance. Specifically, the system includes a primary loop fuel circulation system, which is connected via primary loop pipes 15 to the fuel solution outlet d and fuel solution inlet c of the reactor core 1 to form a circulating fuel solution. The fuel solution circulation unit 9 comprises one or more circulation pumps and valves connected in series in the primary loop to provide circulation power. In actual operation, after the fuel solution inside the reactor core 1 undergoes a fission reaction, producing radioactive isotopes and heat, the fuel solution enters the heat exchanger 2 through the fuel solution outlet d. The heat exchanger 2 discharges the fission heat. After heat exchange, the fuel solution enters the solid impurity filtration unit 3 to remove solid impurities from the fuel solution. Subsequently, it enters the gas-liquid separation unit 4 to separate the gas and liquid in the fuel solution, and the liquid is discharged into the downstream primary loop pipeline 15 for subsequent operations. If the isotope separation and radioactive waste disposal unit 7 can be used to continuously or periodically draw part of the fuel solution from the primary loop to extract usable radioactive isotopes and separate fission products such as rare earth metals, the neutron poison in the fuel solution can be reduced. The isotope separation and radioactive waste disposal unit 7 can be connected to the primary loop via valves, allowing the fuel solution in the primary loop to be exported and processed in a timely manner for the production of radioactive isotopes and the separation of radioactive waste, while returning the remaining fuel solution to the primary loop. After a series of operations, the processed fuel solution can enter the reactor core 1 from the fuel solution inlet c to continue the reaction, forming a circulation channel. It can also perform a series of online operations on the fuel solution, such as impurity removal and target isotope extraction, enabling the reactor system to operate continuously online.

[0048] In the above scheme, the isotope separation and radioactive waste disposal unit 7 includes isotope separation and purification devices, radioactive waste separation, extraction and storage devices, and radioactive waste disposal devices, which can operate independently as needed. The solid impurity filtration system is a device that uses porous materials and bubbling to remove solid impurities from the fuel solution, and it is connected in series in a single loop.

[0049] In this embodiment, to generate water by recombination of hydrogen and oxygen gas, the gas-water separation unit 4 includes a gas-water separation device and a hydrogen-oxygen gas recombination device. The gas-water separation device is used to discharge the gas phase in the fuel solution, and the hydrogen-oxygen gas recombination device is used to recombine the hydrogen and oxygen gas in the gas phase to generate water, which is then transported to the primary loop. In this scheme, the gas-water separation unit 4 has a gas-water separation device and a hydrogen-oxygen gas recombination device for separating the gas generated in the reactor core and the fuel solution, as well as an external exhaust gas treatment device 13. The inlet of this unit is connected to the primary loop. The gas-water mixture of the fuel solution enters through the inlet and has two types of outlets: one is the gas outlet after gas-water separation, which is directly connected to the exhaust gas treatment device 13, through which radioactive gases generated in the reactor core and unrecombined hydrogen and oxygen gas enter the exhaust gas treatment device 13; the other is the liquid outlet, which is connected to the primary loop, through which the remaining fuel solution and the water generated after recombination of hydrogen and oxygen gas re-enter the primary loop.

[0050] In this embodiment, to prevent the risk of hydrogen explosion, several gas-liquid separation units 4 connected in parallel and at least one gas-liquid separation unit 4 connected in series are sequentially arranged along the downstream conveying direction of the solid impurity filtration unit 3. In this scheme, at the outlet of the solid impurity filtration unit 3, several gas-liquid separation units 4 are first connected in parallel, and the liquid outlets of the several parallel gas-liquid separators flow into a primary loop, and then enter the at least one gas-liquid separation unit 4 connected in series. Among them, the multiple gas-liquid separation units 4 connected in parallel can effectively disperse hydrogen and oxygen gases, preventing the risk of hydrogen explosion; secondly, the gas-liquid separation units 4 connected in series can more effectively remove gaseous impurities. In addition, the multi-stage distributed gas-liquid separation units 4 are all arranged downstream of the heat exchanger 2, which can effectively reduce the loss of water in the fuel solution as vapor.

[0051] In this embodiment, to collect and treat the separated waste gas, the primary loop fuel cycle system further includes a waste gas treatment device 13. The gas outlet of each gas-liquid separation unit 4 is connected to the waste gas treatment device 13 via a waste gas conveying pipe 17. Multiple gas-liquid separation units 4 can share a single waste gas treatment device.

[0052] In this embodiment, after the entire reactor system has been operating for a period of time, due to the consumption of fissile nuclides and the accumulation of non-separable fission products, k eff To ensure continuous system operation, the primary loop fuel cycle system further includes a nuclear fuel handling unit 5, which stores fresh fuel solution. Located before the fuel solution inlet c, the nuclear fuel handling unit 5 can deliver the fresh fuel solution to the primary loop pipeline 15 via a first transfer pump 18. In this design, the nuclear fuel handling unit 5 stores unused fresh fuel solution and can deliver the fresh fuel solution from the inlet section of the reactor core 1 in the primary loop to the loading mechanism in the reactor vessel.

[0053] In this embodiment, to control the pressure and volume in the primary loop, the primary loop fuel cycle system further includes a volume control unit 6. The volume control unit 6 is connected to the primary loop pipeline 15 downstream of the fuel solution circulation unit 9. The volume control unit 6 is used to control the liquid phase volume ratio in the primary loop pipeline 15. In this scheme, the volume control unit 6 is used to feed fuel solution from the inlet section of the reactor core 1 in the primary loop into and extract it from the fuel loading mechanism in the reactor vessel. The volume control unit 6 includes a storage tank for storing used fuel solution, and the storage tank contains a pressure control device. The volume control unit 6 can measure and adjust the pressure in the primary loop to ensure that the liquid phase space in the primary loop occupies more than 97%.

[0054] In this embodiment, to ensure volume balance in the primary loop, the solution storage chamber inside the volume control unit 6 is connected to the inlet of the isotope separation and radioactive waste disposal unit 7 via the second transfer pump 19. In this design, the volume control unit 6 can transport an equal amount of spent fuel solution to the isotope separation and radioactive waste disposal unit 7 for processing via the second transfer pump 19, thus ensuring volume balance in the primary loop.

[0055] In this embodiment, to rapidly discharge the molten fuel under accident conditions, the primary loop fuel circulation system also includes a safety tank 8. The safety tank 8 is located directly below the molten fuel inlet c of the reactor core 1 and is connected to the primary loop pipeline 15 via a valve. Opening the valve allows all the molten fuel in the primary loop to flow into the safety tank 8 under gravity. In this design, the tank is located below the reactor core 1. In the event of a severe accident in the reactor system, all fuel in the primary loop can flow into the safety tank 8 under gravity, maintaining a subcritical state. The valve can be used for emergency opening under accident conditions.

[0056] In this embodiment, to increase capacity, there are multiple safety tanks 8, each connected to the primary loop pipe 15; the total volume of the multiple safety tanks 8 is at least 1.5 times the total volume of all fuel solutions in the primary loop. There are at least three safety tanks 8, and each safety tank 8 remains in a subcritical state when filled with new fuel solution.

[0057] In this embodiment, for the collection and treatment of radioactive waste, the primary loop fuel cycle system further includes a fission product disposal device 14, and the fission product outlet of the isotope separation and radioactive waste disposal unit 7 is connected to the fission product disposal device 14.

[0058] Example 2: Based on Example 1, Example 2 provides a specific structure for a two-loop cooling circulation system.

[0059] In this embodiment, to realize the cooling circulation loop, a secondary cooling circulation system is also included. The secondary cooling circulation system includes a final heat sink 12 and a secondary circulation pump 11. The cooling medium outlet of the final heat sink 12 is connected to the cooling medium inlet of the heat exchanger 2 through a secondary pipe 16 and the secondary circulation pump 11 to deliver a low-temperature cooling medium. The cooling medium outlet of the heat exchanger 2 is connected to the cooling medium inlet of the final heat sink 12 to deliver a high-temperature cooling medium after heat exchange.

[0060] The dual-loop cooling circulation system can use a closed-loop circulation loop with liquid cooling medium or an open-loop circulation loop with gaseous cooling medium.

[0061] When a closed-loop circulation system using liquid cooling medium is adopted, the secondary loop cooling circulation system further includes a heat exchange medium storage tank 10, which is used to replenish cooling water into the secondary loop pipeline 16 through the fourth delivery pump 21.

[0062] The heat exchanger 2 is a multi-tube convection radiator.

[0063] In this scheme, the secondary loop cooling circulation system includes a nuclear heat transfer unit, which includes a primary loop heat exchange section, a secondary loop, a heat exchanger 2, and a circulation pump that drives the flow of the heat exchange medium. The primary loop heat exchange section consists of multiple branch pipes connected in series in the primary loop main pipeline. The heat exchanger can be a container that encloses the aforementioned branch pipes, with sufficient space inside the container for the cooling medium to pass through. The heat exchanger 2 is connected in series in the secondary loop. The secondary loop adopts a closed-loop circulation loop with liquid coolant or an open-loop circulation pipeline with gaseous cooling medium. The cooling medium is made to flow through the heat exchanger 2 by a power device (such as a circulation pump) to realize the exchange of heat between the primary and secondary loops. If the secondary loop adopts a closed-loop circulation loop with liquid coolant, it also includes a heat exchange medium storage tank 10 for storing the heat exchange medium.

[0064] In actual operation, the secondary loop cooling circulation system operates at atmospheric pressure. If water is used as the cooling medium, the low-temperature cooling water flows through the heat exchanger 2 driven by the secondary loop circulation pump 11. The fission heat generated by the reactor core heats the cooling water. The high-temperature cooling water passes through the final heat sink 12, and its temperature decreases before returning to the heat exchanger 2 via the secondary loop pipe 16, thus completing the cycle. The lost cooling water is replenished by the heat exchange medium storage tank 10.

[0065] Example 3: Based on Example 1 or Example 2, Example 3 further provides a specific structure of reactor core 1, such as... Figure 2 As shown.

[0066] In this embodiment, the reactor core 1 includes a main reactor vessel, which includes a core conduit and an outer wall. An annular space is formed between the core conduit and the outer wall and filled with a neutron reflector layer b. The fuel solution inlet c is located at the bottom of the core conduit, and several fuel solution outlets d are circumferentially opened at the top of the core conduit, all of which are connected to the primary loop. In this scheme, the reactor core 1 includes a main reactor vessel for controlling nuclear fuel fission and generating isotopes and fission heat, and a reactor control system for controlling the reactivity of the core. The main reactor vessel includes an outer wall and a core conduit spaced apart, wherein a sealed annular space is formed between the outer wall and the core conduit space, in which water is injected or filled with materials such as graphite, beryllium metal, and beryllium oxide as the neutron reflector layer b. The interior of the core conduit is the active zone of the core, and the bottom of the core conduit space has an opening connected to the primary loop. The top of the core conduit space is sealed, and multiple openings at the top of the core conduit space are connected to the primary loop. Secondly, reactor core 1 also has a reactivity control system for regulating the fission of nuclear fuel, which is located in the core active zone, including a drive mechanism for driving the movement of control rods f, control rods f and their channels distributed in the core active zone.

[0067] As a redundancy scheme, the fuel solution in this scheme is a uranyl nitrate solution with a U-235 enrichment of 20%; the reactor power is 500kW; the reactor control system consists of 7 bundles of silver-indium-chromium control rods f with a diameter of 2.5cm and a drive mechanism; the reflector layer b is 20cm thick beryllium oxide; the outer wall and the core shroud are made of stainless steel.

[0068] Secondly, the isotope separation and radioactive waste disposal unit 7 preferably uses a continuous online processing method to process the fuel solution, with a branch flow rate of approximately 1% of the primary loop flow rate. The final heat sink 12 is a small cooling tower.

[0069] How this solution works:

[0070] The active circulation solution reactor system provided by this invention includes a primary loop fuel circulation system and a secondary loop cooling circulation system.

[0071] In the primary loop fuel cycle system, the fuel solution undergoes a fission reaction in the reactor core 1, generating radioactive isotopes and heat. The fission heat is discharged via heat exchanger 2, and solid impurities are removed from the fuel solution via solid impurity filtration unit 3. After passing through a three-stage gas-liquid separation unit 4, the gas and liquid in the fuel solution are separated, and the hydrogen and oxygen gases in the gas recombine into water, which flows back into the primary loop. The remaining gas is discharged into the waste gas treatment device 13 via waste gas delivery pipe 17 for treatment. The fuel solution that has completed the above treatment process flows back to the reactor core 1 under the impetus of the fuel solution circulation unit 9, and the above process is repeated. In the primary loop, the volume control unit 6 measures and adjusts the pressure in the primary loop to ensure that the liquid phase space occupies more than 97% of the primary loop. According to production needs, the isotope separation and radioactive waste disposal unit 7 continuously or periodically draws a portion of the fuel solution from the primary loop to extract usable radioactive isotopes and separates fission products such as rare earth metals, which are then sent to the fission product disposal device 14 to reduce neutron poisoning in the fuel solution. After the entire reactor system has been operating for a period of time, due to the consumption of fissile nuclides and the accumulation of non-separable fission products, k eff As the temperature gradually decreases, to ensure continuous system operation, the nuclear fuel handling unit 5 transports the stored new fuel solution to the primary loop via the first transfer pump 18. Simultaneously, to maintain volume balance in the primary loop, an equal amount of used fuel solution is transported to the isotope separation and radioactive waste disposal unit 7 via the second transfer pump 19. In the event of a severe accident in the reactor system, all fuel in the primary loop flows into the three safety containers 8 under gravity, maintaining a subcritical state.

[0072] The secondary loop cooling circulation system operates at atmospheric pressure, using water as the cooling medium. Low-temperature cooling water, driven by the secondary loop circulation pump 11, flows through the heat exchanger 2. The fission heat generated in the reactor core heats the cooling water. The high-temperature cooling water passes through the final heat sink 12, where its temperature decreases, and returns to the heat exchanger 2 via the secondary loop pipe 16, repeating the cycle. Lost cooling water is replenished by the heat exchange medium storage tank 10.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An active circulation solution-type reactor system, characterized in that, include: The primary loop fuel cycle system is connected to the fuel solution outlet (d) and fuel solution inlet (c) of the reactor core (1) via a primary loop pipe (15); along the transport direction of the primary loop pipe (15), the primary loop fuel cycle system includes a heat exchanger (2), a solid impurity filtration unit (3) and a gas-liquid separation unit (4) connected in series, and an isotope separation and radioactive waste disposal unit (7) connected in parallel to the primary loop pipe (15). The primary loop fuel cycle system also includes a fuel solution cycle unit (9), which is used to provide solution cycle power in the primary loop; The heat exchanger (2) is used to exchange heat with the fuel solution; the solid impurity filtration unit (3) is used to remove solid impurities from the fuel solution; the gas-water separation unit (4) is used to discharge the gas from the fuel solution; the isotope separation and radioactive waste disposal unit (7) is used to continuously or periodically draw out a portion of the fuel solution from the primary loop pipeline (15) to extract the required radioactive isotopes and separate fission products, and can return the extracted and separated fuel solution to the primary loop pipeline (15).

2. The active circulation solution-type reactor system according to claim 1, characterized in that, The gas-water separation unit (4) includes a gas-water separation device and a hydrogen-oxygen gas recombination device. The gas-water separation device is used to discharge the gas phase in the fuel solution, and the hydrogen-oxygen gas recombination device is used to recombine the hydrogen and oxygen in the gas phase to generate water and transport it to the primary loop.

3. The active circulation solution-type reactor system according to claim 2, characterized in that, Along the downstream conveying direction of the solid impurity filtration unit (3), a plurality of gas-water separation units (4) connected in parallel and at least one gas-water separation unit (4) connected in series are arranged sequentially.

4. The active circulation solution-type reactor system according to claim 3, characterized in that, The primary fuel cycle system also includes an exhaust gas treatment device (13), and the gas outlet of each gas-water separation unit (4) is connected to the exhaust gas treatment device (13) through an exhaust gas conveying pipe (17).

5. The active circulation solution-type reactor system according to claim 1, characterized in that, The primary loop fuel cycle system also includes a nuclear fuel operation unit (5), which stores a new fuel solution. The nuclear fuel operation unit (5) is located before the fuel solution inlet (c) and can deliver the new fuel solution to the primary loop pipeline (15) via a first delivery pump (18).

6. The active circulation solution-type reactor system according to claim 1, characterized in that, The primary loop fuel circulation system also includes a volume control unit (6), which is connected to the primary loop pipeline (15) downstream of the fuel solution circulation unit (9). The volume control unit (6) is used to control the liquid phase volume ratio in the primary loop pipeline (15).

7. The active circulation solution-type reactor system according to claim 6, characterized in that, The solution storage chamber inside the volume control unit (6) is connected to the inlet of the isotope separation and radioactive waste disposal unit (7) via the second delivery pump (19).

8. The active circulation solution-type reactor system according to claim 1, characterized in that, The primary loop fuel cycle system also includes a safety tank (8), which is located directly below the fuel solution inlet (c) of the reactor core (1) and is connected to the primary loop pipeline (15) via a valve; opening the valve allows all the fuel solution in the primary loop to flow into the safety tank (8) under the action of gravity.

9. The active circulation solution-type reactor system according to claim 8, characterized in that, There are several safety tanks (8), and each of the several safety tanks (8) is connected to the primary loop pipeline (15); the total volume of the several safety tanks (8) is more than 1.5 times the volume of all fuel solutions in the primary loop.

10. The active circulation solution-type reactor system according to claim 1, characterized in that, The primary loop fuel cycle system also includes a fission product disposal device (14), and the fission product outlet of the isotope separation and radioactive waste disposal unit (7) is connected to the fission product disposal device (14).

11. An active circulation solution-type reactor system according to any one of claims 1 to 10, characterized in that, It also includes a secondary cooling circulation system, which includes a final heat sink (12) and a secondary circulation pump (11). The cooling medium outlet of the final heat sink (12) is connected to the cooling medium inlet of the heat exchanger (2) via a secondary pipe (16) and the secondary circulation pump (11) to deliver a low-temperature cooling medium. The cooling medium outlet of the heat exchanger (2) is connected to the cooling medium inlet of the final heat sink (12) to deliver a high-temperature cooling medium after heat exchange.

12. The active circulation solution-type reactor system according to claim 11, characterized in that, The dual-loop cooling circulation system can use a closed-loop circulation loop with liquid cooling medium or an open-loop circulation loop with gaseous cooling medium. When a closed-loop circulation system using liquid cooling medium is used, the secondary loop cooling circulation system also includes a heat exchange medium storage tank (10), which is used to replenish cooling water into the secondary loop pipeline (16) via a fourth transfer pump (21).

13. An active circulation solution-type reactor system according to any one of claims 1 to 10, characterized in that, The heat exchanger (2) is a multi-pipe convection radiator.

14. An active circulation solution-type reactor system according to any one of claims 1 to 10, characterized in that, The reactor core (1) includes a reactor main container, which includes a core conduit and an outer wall. An annular space is formed between the core conduit and the outer wall and is filled with a neutron reflector. The fuel solution inlet (c) is located at the bottom of the core conduit, and several fuel solution outlets (d) are circumferentially located on the upper part of the core conduit. All of the fuel solution outlets (d) are connected to the primary loop.

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