277 results about "Spent fuel pool" patented technology

The invention relates to a microminiature operation underwater robot of a nuclear power plant, and the robot comprises an underwater robot body and an onshore control system, wherein two propellers are respectively arranged in the horizontal and vertical directions of the robot body, a depth gauge is arranged on the right side of the front part of the robot body, a manipulator is arranged at the bottom in front of the robot body, and a sonar is arranged on the top of the robot body; a control cabin is arranged in the middle rear part of the robot body; an outer cabin is sealed by a transparent glass cover, and is provided with a rearview camera and an auxiliary lighting light-emitting diode (LED) lamp; a front-view camera system is arranged at the front part of the robot body, and comprises a zooming radiation resistant camera tube, a tripod head and a lighting lamp; a video image and control signal is transmitted to the onshore control system through a shield cable; and the control system comprises a movement control rod, a manipulator control button, a keyboard, a main display screen and a speed governing knob. The microminiature operation underwater robot of the nuclear power plant is used for the monitoring and the simple foreign body fishing of a core pool, a spent fuel pool and a component pool of the nuclear power plant.

The invention relates to a method and system for improving reliability of emergency power supplies of a nuclear power plant. At least one path of high-capacity battery energy storage system (fixed energy storage system and/or movable energy storage system) is used to supplement or replace final emergency power supplies of a nuclear power plant. When all existing emergency power supplies of the nuclear power plant fail, the system is started to supply power for equipment in an emergency plant of the nuclear power plant so as to keep discharging waste heat of reactor cores and cooling spent fuel pools of the nuclear power plant, thus ensuring the safety of the nuclear power station. The method and system provided by the invention can be used for resisting against extreme weathers and avoiding common mode failure of the emergency power supplies in the extreme weathers, can strength the reliability of the emergency power supplies of the nuclear power plant and can at least reduce the melting probability of reactor cores by 21.6%, thereby improving the integral nuclear safety level of the nuclear power plant.

An auxiliary system for cooling a spent nuclear fuel pool through a submersible heat exchanger to be located within the pool. In each train or installation, a single loop or series of loops of cooling fluid (e.g., sea water or service water) is circulated. The system is modular, readily and easily installed during an emergency and can be self operating with its own power source. Multiple trains may be used in parallel in order to accomplish the required degree of spent fuel pool cooling required.

The invention discloses an emergency cooling system of a spent fuel pool of a nuclear power station. The emergency cooling system comprises a water intaking pipeline, a water inlet pipeline, a water intaking port, a water inlet port, a circulating cooling pump and a heat exchanger, wherein the water intaking pipeline and the water inflow pipeline are connected with the spent fuel pool, the water intaking port and the water inlet port are respectively mounted on the water intaking pipeline and the water inlet pipeline, an inlet of the circulating cooling pump is connected with the water intaking port, an outlet of the circulating cooling pump is connected with a heat side inlet of the heat exchanger, a heat side outlet of the heat exchanger is connected with the water inlet port, and then a closed cooling loop is formed. The circulating cooling pump and the heat exchanger can be powered by portable power sources. Compared with the prior art, under the working condition surpassing design basis, the emergency cooling system utilizes the circulating cooling system and the heat exchanger independent of a water source and a power source existed in the nuclear power station to conduct waste heat of fuel component in the spent fuel pool via a circulating cooling mode, guarantees immediate conduction of the waste heat of the spent fuel component, so that serious accident is avoided, and safety of the nuclear power station is effectively improved.

The invention provides a module type pressurized water reactor. A reactor module is composed of a reactor body, a cooling agent system, and a safety system, the reactor body, the cooling agent system, and the safety system are all enclosed in a steel safety shell, and the whole reactor module is immersed in a reactor safety water pool, taking the pool water as the final hot trap for heat discharging of accidents. Emergency core cooling and emergency excess heat discharging are achieved by adopting a complete passive way, and the pressure inhibition and long-term heat discharging of the safety shell are achieved through repressing the water in the water pool and the reactor safety water pool; and during the processes of reloading and maintenance of reactor, through arranging a reloading water jacket between the safety shell reloading channel flange and the reactor container flange, direct-moving underwater fuel lifting operation is achieved between the safety shell and the spent fuel pool. A reactor factory can be provided with a plurality of reactor modules, all reactor modules co-use material loading equipment and other nuclear auxiliary systems, and the safety and economy of the reactor are improved through modularized combination arrangement. The module type pressurized water reactor is suitable for being applied to the fields of nuclear electricity generation, gas application, heat application, sea water desalination, and the like.

An emergency temporary spent fuel pool cooling system for a nuclear power generating facility that has a permanently installed primary loop within the nuclear containment and a mobile temporary secondary loop. The secondary loop is housed in transport vehicles that can be stored off site and is connectable in heat exchange relationship with the primary loop through quick disconnect couplings that are accessible on the outside of the reactor containment. The transport vehicles also include self-contained power and compressed air sources for powering and controlling the entire emergency cooling system. The system also has a make-up water injection capability for refueling the spent fuel pool and secondary loop.

The invention discloses a spent fuel pool cooling pump for a nuclear power station, which is a cooling pump of a single-stage single-suction cantilever horizontal type, is convenient to maintain and has good shock resistant performance. The spent fuel pool cooling pump comprises a pump body, a pump cover provided with a mechanical sealing chamber, a pump shaft, an impeller, an impeller nut, a shaft sleeve, a bearing body, a cylindrical roller bearing and an diagonally contact ball bearing; a shaft sealing component comprises bearing oil sealing devices and a mechanical sealing device; the pump body is provided with a radial split type double spiral case structure; a suction inlet and a discharge outlet of the pump body are arranged perpendicularly; the pump cover is connected between the front end of the pump body and the rear end of the bearing body; a pre-connecting screw is arranged between the pump cover and the bearing body; the impeller is connected to the back end of the pump shaft through an impeller nut, wherein a steel wire thread sleeve is arranged in an inner cavity of the impeller nut; the cylindrical roller bearing is arranged at a non-drive end of the pump shaft; the diagonally contact ball bearing is arranged at a drive end of the pump shaft in a back to back manner; two sets of bearing oil sealing devices are provided and are both labyrinth sealing devices; and the mechanical sealing device is an assembled type mechanical sealing device.

A system and method of passively monitoring nuclear fuel coolant conditions is disclosed, and includes a passive (non-electrically powered) gamma thermometer(s) located in nuclear fuel coolant area(s) (e.g., in the reactor vessel and/or in the facility spent fuel pool) and in electrical communication with millivolt meter(s) to facilitate passive monitoring of nuclear fuel coolant levels, nuclear fuel coolant temperatures, and/or heat transfer conditions in the nuclear fuel coolant area(s) during a station blackout (SBO) or prolonged station blackout (PSBO) event.

A method of refueling a nuclear reactor that includes the steps of removing the reactor vessel head and upper internals to a storage location and installing a cylindrical tank having open upper and lower ends, on the reactor vessel flange. The cylindrical tank is sealed to the reactor vessel and a penetration on the side of the cylindrical tank is sealed to a refueling canal that is connected to a spent fuel pool. The level of reactor coolant within the reactor vessel is then raised to at least partially fill the cylindrical tank to a level equal to that of the spent fuel pool. The refueling canal is then opened and a refueling machine supported on the reactor vessel is employed to transfer fuel assemblies between the core and the spent fuel pool.

The invention belongs to the field of shape deformation analyzing and ultrasonic ranging of fuel assemblies in a nuclear power plant, in particular to a deformation measurement device and a deformation measurement system for fuel assemblies. The device comprises a fuel assembly, an upper supporting fixing clamp plate, an extending supporting frame, a probe tray carriage, spent fuel pool gate channels and a plurality of probes; the upper supporting fixing clamp plate and the extending supporting frame integrally form a perpendicular supporting frame, the upper supporting fixing clamp plate is fixed on the upper part of one spent fuel pool gate channel, the extending supporting frame is fixed on the inner side of the spent fuel pool gate channel, the probe tray carriage is arranged on the extending supporting frame and can slide vertically along the extending supporting frame, the plurality of probes are fixed on the probe tray carriage, and the fuel assembly is located between the two spend fuel pool gate channels. According to the deformation measurement device, in a high-radiation environment, the self deformation of the fuel assembly can be measured in a mode of noncontact with the assembly by adopting an ultrasonic method.

The invention relates to a spent fuel circulating cooling system, which comprises a spent fuel water storage pool (3), an intermediate heat exchange pool (1) connected with the spent fuel water storage pool (3) and a final heat trap (2) containing cold water body. The intermediate heat exchange pool (1) and the final heat trap (2) are isolated by a final heat trap isolation gate (5) between the two. The spent fuel pool closed cycle cooling system provided by the invention maintains the technical advantage of a spent fuel wet storage method, significantly decreases the system cost and spent fuel storage cost through the simplified design, and is especially suitable for a spent fuel intermediate storage facility.

An apparatus for cooling a spent fuel pool having a heat exchanger includes a cooling water pool positioned above the spent fuel pool; a floating device configured to be elevated according to a water level of a cooling water in the spent fuel pool; and an emergency cooling water supply pipe configured to form a path through which the cooling water of the cooling water pool is moved to the spent fuel pool and configured to include a floating valve that opens or closes a flow passage of the cooling water in connection with the elevation of the floating device.

Various embodiments of a decay heat conversion to electricity system and related methods are disclosed. According to one exemplary embodiment, a decay heat conversion to electricity system may include a spent fuel rack configured to pressurize spent fuel bundles to obtain superheated vapor to drive a turbine-driven pump and fast alternator all submerged with the spent fuel rack and positioned at the bottom of the spent fuel pool for conversion of electricity distributed outside of the spent fuel pool via cables without impairing spent fuel pool operations.

The invention discloses a supplementary cooling device for a spent fuel pool of a nuclear power plant. The device comprises a first loop which is positioned in a nuclear island plant building, and a second loop which is positioned outside the nuclear island plant building, wherein water in the spent fuel pool can circularly flow in the first loop; the heat is conveyed to the second loop through the first loop by utilizing an intermediate heat exchanger; heat of the fluid in the second loop is dissipated through a cooling tower. Compared with the prior art, the device has the advantages that adouble-loop cold chain is designed to limit the spent fuel pool into the nuclear island plant building, so that radioactive substances can be prevented from leaking from the nuclear island plant building by accident, and as a result, the safety and the reliability of the device are improved, and the cooling capacity of the spent fuel pool can be obviously improved; meanwhile, a double-die power supplying manner is adopted, and an independent hot trap is additionally arranged, so that the emergency treatment capacity of the spent fuel pool to whole-plant power-off accident and hot trap losing accident can be improved.

Refueling of a nuclear reactor (40) includes removing a fuel assembly (10). The removal method includes lowering a lifting tool (80) of a crane (44) onto a top of the fuel assembly. The lowered lifting tool including a plurality of downwardly extending elements (82) that surround and vertically overlap a portion (74) of a control rod assembly (70) extending above the top of the fuel assembly. The downwardly extending elements are locked with corresponding mating features (26) at the top of the fuel assembly to connect the lifting tool with the fuel assembly. The connected fuel assembly is moved into a spent fuel pool (42) using the crane, and the lifting tool is disconnected from the top of the fuel assembly by unlocking the downwardly extending elements from the corresponding mating features at the top of the fuel assembly.

The invention discloses a water level control and waste heat discharge device of a passive spent fuel storage pool, which belongs to the technical field of nuclear power plant safety equipment. The device of the present invention includes two loops of float filling and draining and natural circulation cooling. The water level of the spent fuel pool is controlled by the float, and at the same time, the cooling function of the water in the spent fuel storage pool can be completed by passive natural circulation. The two loops complement each other. Together, they guarantee the water level control and cooling process of the spent fuel pool. There are many passive modes such as natural circulation, gravity action and pressure action in the device, which are convenient to implement, simple to control, high in reliability, safe and stable.

The present invention relates to passive cooling systems and methods for cooling a spent fuel pool in a nuclear power plant in the absence of onsite and offsite power, e.g., in a station blackout event. The systems include a gap formed along the periphery of the spent fuel pool, a heat sink, one or more thermal conductive members, a water supply system for delivering water to at least partially fill the gap and conduct heat generated from the spent fuel pool through the gap to at least one thermal conductive member for transporting heat to the heat sink, and a thermal switch mechanism for activating and deactivating the water supply system.

In particular, the passive spent fuel pool cooling systems and methods of the invention are useful when the active spent fuel pool cooling system is unavailable or inoperable.

A method of inspecting or utilizing tools in the underwater environment of a nuclear reactor vessel, a spent fuel pool or equipment pit includes floating a platform for transporting inspection devices and/or tools over an underwater target site and deploying the devices or tools to the underwater target site. The platform may be coupled to a boom whose opposite end is carried by a cart movable about a floor area surrounding the pool. Alternatively, the platform may be independently movable along the water surface by thrusters.

The invention discloses a passive water replenishment and heat export system for a spent fuel pool. The system comprises a cooling pool, a loop heat pipe system, and a spray system, wherein the cooling pool is arranged above the spent fuel pool; one end of the loop heat pipe system is arranged in the spent fuel pool, and the other end of the loop heat pipe system is arranged in the cooling pool; a condensing medium is arranged in the loop heat pipe system; the spray system is arranged between the spent fuel pool and the cooling pool, is communicated with the cooling pool, and comprises water orifices and spray start valves used for the connection or disconnection of the cooling pool and the water orifices. The system has the advantages that through the loop heat pipe system, heat in the spent fuel pool can be transmitted into the cooling pool through the condensing medium, so that heat dissipation of spent fuels is facilitated; meanwhile, through the spray system, a cooling agent in the cooling pool can be sprayed into the spent fuel pool for passive water replenishment when spent fuel assemblies are exposed due to an excessively low liquid level of the spent fuel pool, so that the safety of the spent fuel assemblies is guaranteed.

A system and method for measuring and monitoring axial flux to determine subcriticality in a spent fuel pool of a nuclear power plant. In certain embodiments of this invention, one or more neutron detectors are operable to generate signals resulting from neutron interactions in the spent fuel pool, a counting device counts the signals which are generated by the one or more neutron detectors, a connecting means electrically connects the one or more neutron detectors to the counting device, a signal analyzer is used to determine reactivity of the fuel assemblies in the spent fuel pool based on the counted signals, a power supply provides power for the neutron detectors, the counting device and the system analyzer, and a software code containing an axial flux curve index is used to correlate the counted signals to determine the subcriticality of the spent fuel pool.

The invention relates to the technology of spent fuel storage design of a nuclear power plant, and specifically relates to a novel thermal hydraulic coupling calculating method for a spent fuel pool and a storage grid. The method is able to perform actual simulation and coupling calculation for a flowing field and a temperature field of the whole spent fuel pool and the storage grid, so as to obtain the distribution of cooing agent temperature fields of the whole spent fuel pool and the storage grid as well as the distribution of temperature of a spent fuel assembly. With the adoption of the calculation method, the safety of the spent fuel storage can be accurately evaluated, so that the economy of the spent fuel storage of the nuclear power plant can be increased, and the safety of the spent fuel storage in the operation period of the nuclear power plant can be ensured.

The invention provides a spent fuel tank passive after-heat removing system based on water cooling heat pipes. The spent fuel tank passive after-heat removing system based on the water cooling heat pipes comprises a heat pipe evaporation section, a heat pipe condensation section, a heat pipe descending section, a water dropping liquid distributor, a safety shell top water tower, a spent fuel tank, a spent fuel component and a baffle, wherein the baffle is arranged in the spent fuel tank, and the bottom of the baffle is provided with a baffle hole; the spent fuel component is arranged in the spent fuel tank and is positioned on the inner side of the baffle; the heat pipe evaporation section is arranged between the baffle and the spent fuel tank, and the outlet part of the heat pipe evaporation section extends out of the spent fuel tank; the heat pipe condensation pipe is arranged at the upper part outside the spent fuel tank, and the inlet of the heat pipe condensation section is connected with the outlet of the heat pipe evaporation section; the heat pipe descending section is arranged at the outer side of the spent fuel tank, and the inlet of the heat pipe descending section is connected with the outlet of the heat pipe condensation pipe; the outlet of the heat pipe descending section is connected with the inlet of the heat pipe evaporation section; the water dropping liquid distributor is arranged above the heat pipe condensation section, and is connected with the safety shell top water tower. The spent fuel tank passive after-heat removing system based on the water cooling heat pipes has the advantages of high reliability, safety hazard eradication and simple structure.

The invention belongs to the technical field of circulating cooling of nuclear power plants and in particular relates to a passive water supplementation spraying system of a spent fuel pool. A spraying pipeline is suspended above the spent fuel pool; sprayers are arranged on the spraying pipeline; an outlet is formed in the bottom of a water supplementation tank which is connected with the spraying pipeline through a pipeline; a fixed net rack is arranged in the spent fuel pool; a hollow rod is arranged in the net bracket; a pipe plug is arranged at the outlet in the bottom of the water supplementation tank; a bearing line bypasses pulleys; two ends of the bearing line are respectively connected with the hollow rod and the pipe plug. The system can be used in most existing wet type storage spent fuel pools in the nuclear power plants and can run under the condition of severe accidents without pushing of power; by the adoption of a passive security technology, the system of the nuclear power plant can automatically recover to a security state, so that the security of the nuclear power plant can be greatly improved.

The invention provides a nuclear power plant design and operation support method and system. The method includes the following steps that: the reactor core of a reactor is designed; three-dimensionalreactor core power distribution information is obtained according to design parameters; a reactor core model is built, the state of the reactor core is monitored and predicted in real time, and the reactor core model is amended according to stages; the calculation model of a spent fuel pool is constructed, so that the critical safety analysis calculation of the spent fuel pool can be performed, and nuclide tracking calculation is performed for an old fuel assembly; a spent fuel transportation container calculation model and a spent fuel storage container calculation model are constructed, so that the critical safety analysis calculation of a spent fuel transportation container and a spent fuel storage container can be performed; a reactor core source item model is built, the analysis and calculation of a primary loop source term and a secondary loop source term are performed, so that source item information can be obtained; and the calculation model of a reactor main shield is built, and ray measurement information in the reactor is calculated according to the calculation model. With the method and system of the invention adopted, design precision and operation reliability can be improved, and therefore, the safety and economy of a nuclear power plant can be improved.

The invention relates to a boron-untrusted controlling method for criticality safety of a spent fuel pool framework. Isolation regions are arranged around the spent fuel pool framework so as to prevent increase of reactivity caused by falling-off of a fuel assembly, and storage space of spent fuel assemblies is increased to reduce reactivity of a whole system. With such a technical scheme provided by the invention, under normal and credible accident working conditions, a spent fuel storage pool can realize high density storage in virtue of addition of solid neutron poison and combustion of trusted spent fuel assemblies while guaranteeing criticality safety, without trusting of soluble boron in water at the same time.

The invention discloses a floating passive cooling device of a spent fuel pool in a nuclear power plant. The passive cooling device at least comprises a heat exchange tube assembly. The heat exchange tube assembly comprises a plurality of heat exchange tubes and a grillwork, wherein the heat exchange tubes are filled with a certain quantity of cooling working media, and certain negative pressure is kept inside each heat exchange tube; the heat exchange tubes are evenly arranged on the grillwork in an equidistant mode, and the grillwork can generate a certain amount of buoyancy in liquid of the spent fuel pool so that the heat exchange tube assembly can float on the liquid level of the spent fuel pool. The portion, placed under the liquid level of the spent fuel pool, of each heat exchange tube is a heat absorption end, and the portion, placed over the liquid level of the spent fuel pool, of each heat exchange tube is a heat release end. The cooling working media are low boiling point working media. The invention further discloses a floating passive cooling system of the spent fuel pool in the nuclear power plant. By implementing the floating passive cooling device and system of the spent fuel pool in the nuclear power plant, operating can be conducted in a completely passive mode, so that safety is improved; the heat radiating area is further increased, and the heat removal capacity is greatly improved; the heat transfer working media can be recycled, and the device and system are environmentally friendly and stable.

The invention discloses a damping device of a spent fuel pool liquid level and temperature monitoring device. The damping device of the spent fuel pool liquid level and temperature monitoring device comprises a mounting pipe used for enabling the spent fuel pool liquid level and temperature monitoring device to be mounted and further comprises an outer tube arranged on the outer side of the mounting tube in a sleeve mode and a damping device body arranged between the mounting tube and the outer tube. According to the technical scheme and the damping device of the spent fuel pool liquid level and temperature monitoring device, the outer tube is arranged on the outer side of the mounting tube provided with the spent fuel pool liquid level and temperature monitoring device in the sleeved mode, the damping device body is arranged between the mounting tube and the outer tube, therefore, when earthquakes occur or a spent fuel pool encounters large impact force, the force received by the outer tube will be transmitted to the damping device body, the damping device body absorbs the force transmitted by the outer tube, the vibration directly acting on the spent fuel pool liquid level and temperature monitoring device is reduced, a certain protection effect is performed on the spent fuel pool liquid level and temperature monitoring device, and thus the earthquake resistant performance of the spent fuel pool liquid level and temperature monitoring device is improved to a certain extent.