25 results about "Spent fuel pool" patented technology

The invention provides a corrosion product centrifugal separation device and method for a spent fuel pool, and belongs to the technical field of spent fuel pool purification systems.The corrosion product centrifugal separation device comprises a solid collecting tank and a Venturi tube, a pore plate is installed in a cylindrical section of the upper portion of the solid collecting tank, and the bottom of the solid collecting tank is connected with an inlet pipe; a cyclone impeller is mounted in the inlet pipe, a separation section is arranged at the top of the inlet pipe, a cylindrical guide plate is externally connected to the separation section, the separation section is connected with a connecting pipe, a recovery impeller is mounted in the connecting pipe, the connecting pipe is connected with a Venturi pipe, and the Venturi pipe is connected with an outlet. Based on the obvious density difference of the solid phase and the liquid phase, a rotational flow field can be generated by pool water through the rotational flow impeller, solid-liquid separation is conducted on substances with different specific gravities, corrosion products are efficiently removed through gravity settling, the purpose of purifying the spent fuel pool is achieved, and compatibility with an existing circulating system of the spent fuel pool is high.

The utility model relates to an air pressure adjusting device for verifying a liquid level instrument in a spent fuel pool, which comprises a box body, and an internal pipeline, an air inlet pipeline, an exhaust pipeline and an air supply pipeline are arranged in the box body; the box body is provided with an air source interface capable of being connected with an external air source, an exhaust interface capable of exhausting air outwards and an instrument interface capable of supplying air outwards; one end of the air inlet pipeline is connected with the internal pipeline, and the other end of the air inlet pipeline is connected with the air source interface; one end of the exhaust pipeline is connected with the internal pipeline, and the other end of the exhaust pipeline is connected with the exhaust interface; one end of the air supply pipeline is connected with the internal pipeline, and the other end of the air supply pipeline is connected with the instrument interface; and the high-precision pressure gauge is connected with the internal pipeline and is used for monitoring and displaying an air pressure value in the internal pipeline. The air pressure adjusting device has the remarkable advantages in the aspects of flexible operation and the like, and the requirement for providing stable pressure for the liquid level instrument in the spent fuel pool for verification can be effectively met.

The invention belongs to the technical field of nuclear power plant aging life extension, and particularly relates to a performance supervision sample tree for a neutron absorber of a quadrilateral spent fuel storage grillwork. An upper pipe seat is arranged at the upper end of the quadrangular main body, a lower pipe seat is arranged at the lower end of the quadrangular main body, sample plate shelves are arranged on four sides of the quadrangular main body, 16 groups of sample plates are respectively placed on two groups of opposite sides, eight boron-aluminum plate sample plates are placed on eight groups on one side of each group of opposite sides, and eight groups of boron-aluminum coated sample plates are placed on the other side of each group of opposite sides; meanwhile, water-permeable holes are formed in the lower part of the sample plate shelf. The aging condition of a spent fuel storage grillwork neutron absorber material in a spent fuel pool is monitored, the actual performance of the neutron absorber material is evaluated, and the neutron absorber sample plate is put into a spent fuel storage grillwork and can be taken out regularly for detection.

The invention relates to the field of nuclear power unit overhaul, in particular to a spent fuel pool temperature control system and method during nuclear power unit overhaul, and the system comprises a pressure container which is arranged in a refueling pool, and the refueling pool is connected with a fuel transfer cabin through a spent fuel transfer trolley track. The fuel transfer cabin is connected with the spent fuel pool through a sluice gate; two ends of the normal waste heat discharge pipeline A and the normal waste heat discharge pipeline B are respectively connected with the pressure container; two ends of the spent fuel pool cooling and purifying pipeline A are respectively connected with the spent fuel pool, one end of the spent fuel pool cooling and purifying pipeline B is connected with the refueling pool, and the other end of the spent fuel pool cooling and purifying pipeline B is connected with the spent fuel pool. The system adopts two rows of spent fuel cooling and purifying pipelines and two rows of normal residual heat removal pipelines to cool the spent fuel pool, so that the decay heat exporting capability of the system on the spent fuel assembly of the spent fuel pool is greatly improved, and the temperature of the spent fuel pool during overhaul is reduced.

The utility model discloses a nuclear power station spent fuel pool liquidometer pressure verification device, which comprises an installation box and a gas pipeline, the installation box comprises a box body and a box cover which are matched with each other, the box body is provided with a first side plate and a second side plate which are arranged in parallel at an interval, the first end of the gas pipeline is arranged on the first side plate, and the second end of the gas pipeline is arranged on the second side plate. The first end of the gas pipeline is used for being connected with a gas source device, the second end of the gas pipeline is located on the second side plate, and the second end of the gas pipeline is used for being connected with a connector of a measuring barrel in a spent fuel pool of the nuclear power station; the gas pipeline is sequentially provided with a safety exhaust valve, an isolating valve, an adjustable pressure reducing valve and a pressure gauge from the first end to the second end of the gas pipeline. The nuclear power station spent fuel pool liquid level meter pressing verification device is relatively simple in structure, high in use safety, convenient to manufacture and popularize, relatively compact in structure, convenient to transport and store and high in practicability.

This invention belongs to the technical field of nuclear facility safety equipment, and relates to a passive spent fuel pool cooling and replenishment system and waste heat utilization system. The system includes a spent fuel pool, a cooling pool, a spent fuel decay waste heat cooling system, a waste heat utilization system, and a passive replenishment system. The spent fuel pool is filled with coolant to cool the spent fuel assemblies, and the cooling pool is located above the spent fuel pool. The spent fuel decay waste heat cooling system relies on natural circulation to remove the decay waste heat generated by the spent fuel assemblies within the spent fuel pool. The waste heat utilization system is used to convert and utilize the decay waste heat energy of the spent fuel assemblies. The passive replenishment system ensures timely replenishment of the spent fuel pool under both normal and accident conditions. The system proposed in this invention can passively replenish the spent fuel pool under normal and accident conditions during power loss accidents, and solves the problem of low economic efficiency associated with spent fuel pools.

The invention discloses a spent fuel pool underwater additive repairing device and method, and belongs to the field of additive manufacturing. The underwater additive repairing device comprises a radiation shielding device, an underwater laser additive device and a sealing device, wherein the underwater laser additive device and the sealing device are arranged on the inner side and the outer side of the radiation shielding device respectively. The radiation shielding device realizes dynamic sealing and radiation protection through a shielding top cover, a shielding cylinder and a split type shielding bottom cover; the sealing device adopts a pneumatic motion assembly and a vacuum suction technology, and is combined with a semi-ring-shaped sealing belt and a strip-shaped sealing belt, so that the sealing performance of the device in an underwater environment is ensured. The underwater laser additive material device and high-pressure inert gas form a local dry cavity through the drainage cover, and an ideal environment is provided for laser additive material repairing. Through non-contact remote operation, high-precision laser repair and multiple radiation protection measures, the radiation risk of personnel is remarkably reduced, the repair efficiency and quality are improved, the service life of the spent fuel pool is prolonged, and the in-situ maintenance system is suitable for in-situ maintenance of key facilities of the nuclear power station.

The invention discloses a liquid level monitoring instrument and monitoring method for severe accidents of a nuclear power plant, the instrument comprises a mounting plate, the mounting plate is provided with a movable monitoring box, and the monitoring box is provided with a liquid level display screen; a monitoring pipe and a fluid pipe which can communicate with each other penetrate through the bottom of the monitoring box, and a distance measuring generator is arranged at the upper end of the inner wall of the monitoring pipe; the method comprises the following steps: S1, starting liquid conveying and supplying liquid for monitoring; S2, monitoring the displacement of a floating block and calculating the height of the liquid level; S3, discharging the liquid in a monitoring pipe and realizing resetting of the floating block; S4, starting air conveying and cleaning and maintaining the monitoring pipe; the liquid level monitoring system effectively overcomes the defects of traditional nuclear power plant spent fuel pool liquid level monitoring equipment in precision, adaptability, safety and practicability, can stably and accurately complete a liquid level monitoring task in a serious accident scene, and provides powerful guarantee for safe operation of a nuclear power plant.

The application belongs to the technical field of nuclear power, and particularly relates to a boron and water supplement system and method for a spent fuel pool of a nuclear power plant. In view of the problems in the prior art, the application proposes, in the event of an extreme accident of complete loss of in-plant power and borate solution leakage, supplementing the borate solution by using a spare liquid storage space in the existing facilities of the nuclear power plant through gravity flow, which does not require power supply, and supplementing water by combining with external power equipment. The fatal defect that the prior art cannot supplement boron reserves in the extreme accident is effectively solved, and the risk of spent fuel returning to criticality due to the decrease of borate concentration caused by water supplementing alone is avoided. Without the need of large-scale modification of the existing equipment of the nuclear power plant, the modification can be realized only by optimizing the connection mode and operation logic, and the modification cost is low and the implementation period is short.

The utility model relates to a reactor core fuel assembly transfer device of a nuclear reactor and a transfer track thereof, the transfer device comprises a transfer track, the transfer track comprises a KX side transfer track, a KX side straight track and a KX side turnover track, the KX side straight track is located in a spent fuel pool of a fuel plant; the KX side overturning track is arranged above the KX side straight track so as to realize overturning of the loader; the RX side transfer track comprises an RX side straight track and an RX side turnover track, and the RX side straight track is located in a refueling pool of a reactor building; the RX side overturning track is arranged above the RX side straight track so as to realize overturning of the loader; the transfer channel is installed in a containment wall between the fuel plant and the reactor plant in a penetrating mode, an inner rail is installed in the transfer channel, and the two ends of the inner rail are arranged corresponding to the KX side straight rail and the RX side straight rail respectively; and the rail transfer mechanism is mounted at the bottom of the RX side straight rail corresponding to the RX side turnover rail, and is matched with the transfer trolley to realize high-low switching of the inlet position of the RX side turnover rail.

A method of handling spent nuclear fuel assemblies immerses the spent nuclear fuel assemblies in water in a relatively short time period when compared to traditional methods. A spent nuclear fuel assembly is removed from a nuclear reactor core, inserted into a sodium removal machine having a receiver, a cleaning vessel, and an elevator. A cleaning fluid is applied to the cleaning vessel and fuel assembly, and the fuel assembly is flushed with water while in the cleaning vessel. The cleaning vessel is at least partially submerged in the spent fuel pool during cleaning to provide passive heat removal. The cleaning vessel is lowered by an elevator into the spent fuel pool. The fuel assembly may then be loaded into a rack and / or a cask for long-term storage.

Leakage detection systems and methods of monitoring leakage using probes of fiber optic and / or Time Domain Reflectometry (TDR) cables that provide at least one of an electric and electromagnetic signal upon coming in contact with a liquid from the pool. An interrogator may be multiplexed with several of the cables and generate interrogation signals whose reflection determines an exact position along the cable of leakage contact. The cables may be run under a floor and / or wall of a spent fuel pool or other liquid volume in a nuclear power plant. Leakage even of deionized water near room temperature may be detectable. The cables may be a single serpentine cable or several straight cables wrapping around the volume. The cables may be small, such as 10 millimeters or less in diameter. Cables may be run behind liners at any pitch or interval, potentially between supporting structures and the liner.

The application provides a personnel intervenable time calculation method, system and medium under a spent pool accident scenario, and relates to the field of nuclear power. The personnel intervenable time calculation method comprises the following steps: obtaining refueling data of a nuclear power plant, and calculating total decay heat power of the spent pool before an accident according to the refueling data; obtaining spent pool data of the spent fuel pool and the number of newly added spent fuel assemblies corresponding to each accident time within the total duration of the accident; calculating a boiling time through time step iteration according to the number of newly added spent fuel assemblies, the spent pool data and the total decay heat power of the spent pool before the accident; and calculating a water supply starting time, a water supply ending time and a total required water supply amount through time step iteration according to the boiling time, the number of newly added spent fuel assemblies, the spent pool data and the total decay heat power of the spent pool before the accident.

The invention discloses a dirt self-separation ultrasonic cleaning and descaling device for a pressurized water reactor fuel assembly. The dirt self-separation ultrasonic cleaning and descaling device comprises a spent fuel pool, an assembly cleaning mechanism, a dirt collecting tank, a dirt depositing tank, a first water circulating pipeline, a first filter assembly, a first circulating pump, a second water circulating pipeline, a second filter assembly and a second circulating pump. The dirt collecting tank is arranged on the bottom side of the assembly cleaning mechanism. The dirt deposition tank is arranged below the dirt collection tank; one end of the first water circulating pipeline is connected to the top of the dirt collecting tank, and the other end is communicated with the spent fuel pool; the first filter assembly and the first circulating pump are arranged on the first water circulating pipeline; one end of the second water circulating pipeline is connected to the dirt collecting tank, and the other end is communicated with the first water circulating pipeline; and the second filter assembly and the second circulating pump are arranged on the second water circulating pipeline. The problem that after ultrasonic descaling is carried out on the fuel assembly, deposited scales are discharged into a spent fuel pool, and the radioactive level is increased can be solved.

Provided is a long-cycle high-burnup fuel management method, which comprises the following steps: S1. determining the number of fuel assemblies to be unloaded, wherein the fuel assemblies to be unloaded include a group of fuel assemblies located at the center of the core; S2. loading fuel assemblies, wherein the fuel assemblies include a group of old fuel assemblies that can be reused in the spent fuel pool and the remaining groups of brand-new fuel assemblies; S3. replacing the fuel assemblies located at the center of the core with the old fuel assemblies and loading brand-new fuel assemblies, so that the loaded fuel assemblies and the fuel assemblies that are not unloaded are in a chessboard distribution, the loaded new fuel assemblies are the same enrichment fuel assemblies or different enrichment fuel assemblies, and the enrichment of the new fuel assemblies is greater than 5%; and S4. repeating steps S1 to S3 at an interval of a 24-month refueling cycle. The above method significantly increases the cycle length on the basis of using fuel with a nuclear fuel enrichment of more than 5.0%, and achieves the long-cycle refueling target.

The invention belongs to the technical field of nuclear power station spent pool liquid level detection, and particularly relates to a high-reliability compensation type cable liquid level meter which comprises an on-site measurement assembly and an on-site instrument box, and the on-site measurement assembly is connected with the on-site instrument box through a coaxial cable. The field measurement assembly is used for measuring the liquid level of the spent fuel pool in real time, generating a high-frequency electromagnetic wave analog signal and transmitting the high-frequency electromagnetic wave analog signal to the on-site instrument box; and the in-situ instrument box is used for receiving the high-frequency electromagnetic wave analog signal, converting the analog signal into a digital signal, processing the digital signal to obtain liquid level information of the spent fuel pool, and outputting the liquid level information of the spent fuel pool to the main control room. The liquid level of the spent pool in the nuclear power station can be accurately monitored.

The invention discloses a natural circulation and power generation circulation combined spent fuel pool cooling system, which comprises a spent fuel pool, a natural circulation cooling system and a power generation circulation system, and is characterized in that the natural circulation cooling system is partially arranged in the spent fuel pool; the other part of the natural circulation cooling system is arranged outside the spent fuel pool; the power generation circulating system is arranged on the other part; under the condition that no external input exists when an accident happens, under the cooperation of the natural circulation cooling system and the power generation circulation system, it is guaranteed that high-temperature heat can be discharged in time after the accident happens to the spent fuel pool, and a long enough time window is provided for later accident treatment.

This invention discloses a refueling system and method for a small nuclear power reactor. The system, located within the reactor building, includes a reactor pool, a spent fuel pool, and a fuel transfer channel. The spent fuel pool comprises a spent fuel storage area and other storage areas separated by walls lower than the spent fuel pool itself. The fuel transfer channel is a passage enclosed by walls and extends from the bottom of the spent fuel pool to the reactor pool. During refueling, the water in the reactor pool and spent fuel pool is at the refueling level, which is higher than the walls. The reactor pool is connected to the spent fuel pool via the fuel transfer channel, and the spent fuel storage area is connected to the other storage areas. After refueling, the water in the reactor pool and fuel transfer channel is drained, and the spent fuel pool is drained to the storage level, which is lower than the walls. The reactor pool and spent fuel pool, as well as the spent fuel storage area and other storage areas, are now isolated. This invention improves the reliability of the refueling system.

The invention provides a method and a system for calculating personnel intervention time in a spent pool accident scene, and a medium, and relates to the field of nuclear power. The personnel intervention time calculation method comprises the following steps: acquiring refueling data of a nuclear power plant, and calculating the total decay heat power of a spent pool before an accident according to the refueling data; acquiring spent fuel pool data of the spent fuel pool and the number of newly added spent fuel assemblies corresponding to each accident moment in the total accident occurrence duration; according to the number of the newly added spent fuel assemblies, the spent pool data and the spent pool total decay heat power before the accident, the boiling moment is obtained through time step iterative calculation; according to the boiling moment, the number of the newly added spent fuel assemblies, the spent pool data and the spent pool total decay heat power before the accident, the water supplementing starting moment, the water supplementing ending moment and the total required water supplementing amount are obtained through time step iterative calculation.

A method of handling spent nuclear fuel assemblies immerses the spent nuclear fuel assemblies in water in a relatively short time period when compared to traditional methods. A spent nuclear fuel assembly is removed from a nuclear reactor core, inserted into a sodium removal machine having a receiver, a cleaning vessel, and an elevator. A cleaning fluid is applied to the cleaning vessel and fuel assembly, and the fuel assembly is flushed with water while in the cleaning vessel. The cleaning vessel is at least partially submerged in the spent fuel pool during cleaning to provide passive heat removal. The cleaning vessel is lowered by an elevator into the spent fuel pool. The fuel assembly may then be loaded into a rack and / or a cask for long-term storage.

The invention discloses a spent fuel pool waste heat power generation self-cooling safety system. The spent fuel pool waste heat power generation self-cooling safety system comprises a spent fuel pool, a water pump assembly and a power generation system. The spent fuel pool is filled with hot water; the water inlet end and the water outlet end of the water pump assembly are respectively communicated with the spent fuel pool; the power generation system comprises a power generation assembly and a heat exchange assembly. The power generation assembly communicates with the water pump assembly, the heat exchange assembly communicates with the power generation assembly, and the heat exchange assembly is matched with part of the power generation assembly in a heat exchange mode. Under the condition of emergency power failure, the spent pool waste heat power generation self-cooling safety system fully cools hot water in the spent fuel pool, so that the temperature of the hot water in the spent fuel pool is kept below a stable and safe temperature, the power generation efficiency is higher, the power utilization requirements of a power generation system and a water pump assembly are met, and long-term operation after an accident is guaranteed; and a long enough time window is provided for later accident treatment.

The invention belongs to the technical field of fast reactor spent fuel pool purification devices, and particularly relates to an efficient low-emission solid-liquid separator for fast reactor spent fuel pool corrosion products. The separator comprises an inlet component, an impeller, a solid-liquid separation component, an injection pipe and a solid storage and discharge component. A solid-liquid mixture flows in through the inlet component, the impeller forms a rotational flow field, and solid particles move towards the wall face through centrifugal force. The solid-liquid separation component is provided with a radial nozzle and an inclined nozzle, solid particles and part of liquid are discharged into an inverted-cone-shaped separation groove of the solid storage and discharge component, and the liquid flows into the injection pipe. Solid particles are settled in the separation groove by means of gravity, the injection pipe forms high-speed jet flow through the gradually-shrunk injection opening, low pressure is generated to suck separated liquid in the backflow pipe in an entrainment mode, and the separated liquid is discharged from the outlet component after being mixed in the mixing cavity. According to the invention, efficient separation of corrosion products and pool water recovery are realized, radioactive wastewater discharge is reduced, and replacement frequency and operation cost are reduced.

The invention provides a spiral tube type spent fuel pool corrosion product purification device and method, and belongs to the technical field of solid-liquid two-phase cyclone separation, the spiral tube type spent fuel pool corrosion product purification device comprises a spiral tube and a solid collection tank, an inlet is formed in the bottom of the spiral tube, the spiral tube comprises a separation section, the separation section is located in the solid collection tank, and the separation section is located in the solid collection tank. A plurality of separation holes are formed in the outer side of the separation section, the top of the spiral pipe is connected with the connecting pipe, the connecting pipe is connected with the Venturi pipe, the Venturi pipe comprises a contraction section, a throat and an expansion section which are sequentially connected, backflow holes are formed in the throat, the wall face of the backflow holes is evenly distributed in the circumferential direction, and the top of the expansion section is connected with the outlet. When a mixture flows along the spiral flow channel, the centrifugal force enables heavy-phase corrosion product solids with larger density to move towards the outer side and light-phase pool water to gather towards the inner side to form stable solid-liquid layering, and a matched opening structure is designed on the outer side of the spiral pipe, so that the corrosion products are separated, and the purpose of purifying the water quality of the spent fuel pool is achieved.

The application relates to a spent fuel pool cooling system of a passive separated heat pipe, belonging to the technical field of spent fuel pool design of nuclear power plants. The system comprises a heat end heat exchanger and a cold end condenser. The heat end heat exchanger is arranged on the two side wall surface areas of the spent fuel pool in the spent fuel plant house according to a set form. The cold end condenser is arranged in an air cooling tower outside the spent fuel plant house. The heat end heat exchanger and the cold end condenser are correspondingly connected through an ascending pipeline and a descending pipeline, and the external environment is used as a final heat sink, so that passive cooling of the spent fuel pool area is realized. The system provided by the application can enhance two-phase heat exchange by using a low-pressure heat pipe, and improve the safety performance and economy of the spent pool cooling system.

The invention belongs to the technical field of heavy water reactor spent fuel pools, aims to solve the problem of water quality of spent pools, and discloses an underwater dust suction device and method for a heavy water reactor nuclear power plant spent fuel pool. The device comprises a driving motor, a driving screw rod, a dirt suction head, a water inlet pipe, a bottom plate, a filter, a pump front pipe, a water outlet pipe and a water suction pump; the filter is connected with the dirt suction head through a water inlet pipe, the dirt suction head is connected with the long push rod, the filter is connected with the water suction pump through a pump front pipe, and the water suction pump is connected with a water outlet pipe; according to the method, underwater dust collection of the spent fuel pool is implemented by using the device. Particles suspended in the middle of the pool can be absorbed, the manual cleaning difficulty is reduced, and dust particles in the pool can be absorbed and concentrated, so that the water quality is improved, and the critical safety is ensured.