JP2014089139A - Nuclear fuel cooling method and nuclear fuel cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nuclear fuel cooling method that can cool a nuclear fuel even when cooling of the nuclear fuel by cooling water held in a plant is disabled.SOLUTION: When a cooling material loss accident takes place, a high pressure core flooder device 8 pours cooling water 36 in a condensate storage tank 15 into a reactor pressure vessel 2 provided with a reactor core having a fuel assembly loaded through cooling water supply pipes 14 and 10. When a water level in the condensate storage tank 15 is lowered to a set water level, an on-off valve 44 is not opened and cooling water 37 of a pressure suppression pool 6 cannot be poured into the reactor pressure vessel 2, sea water to be supplied by a sea water supply pipe 24 is supplied to a reverse osmosis membrane device 46 to generate plain water, and the generated plain water is supplied to the condensate storage tank 15 by a piping 26. The plain water is poured into the reactor pressure vessel 2 through the cooling water supply pipes 14 and 10 as the cooling water 36.

Description

  The present invention relates to a nuclear fuel cooling method and a nuclear fuel cooling device, and more particularly to a nuclear fuel cooling method and a nuclear fuel cooling device suitable for application to a boiling water nuclear power plant.

  In a boiling water nuclear power plant, for example, when a loss of cooling water occurs, an emergency core cooling is performed to cool the core in the reactor pressure vessel, that is, the fuel assembly including the nuclear fuel loaded in the core. Equipment. An example of this emergency core cooling device is described in JP-A-62-2217193. The emergency core cooling device includes a high-pressure core cooling device and a low-pressure core cooling device that supply cooling water of the pressure suppression pool in the reactor containment vessel to the core in the reactor pressure vessel. The high pressure core cooling device and the low pressure core cooling device have a configuration capable of supplying the cooling water in the condensate storage tank to the core instead of the cooling water in the pressure suppression pool.

  In a boiling water nuclear power plant, steam discharged from a turbine is cooled by a condenser and condensed. The water in the condenser generated by the condensation of steam is supplied as feed water into the reactor pressure vessel through the feed water pipe. In the condenser, seawater is supplied into the heat transfer tube, and the steam is condensed by the seawater in the heat transfer tube. A condensate demineralizer filled with ion exchange resin is provided in the water supply pipe.

  As described in Japanese Patent Laid-Open No. Hei 6-170361, this condensate demineralizer is configured to supply seawater when the heat transfer pipe in the condenser is damaged and seawater leaks from the heat transfer pipe. Remove ingredients. For this reason, inflow of the seawater component leaked into the condenser from the heat transfer tube of the condenser into the reactor pressure vessel is prevented.

  Also in a pressurized water nuclear power plant, a countermeasure plan when seawater leaks from a heat transfer tube of a condenser has been proposed (see Japanese Patent Application Laid-Open No. 2009-162514). In this pressurized water nuclear power plant, steam generated by a steam generator is supplied to a turbine through a steam pipe, and steam discharged from the turbine is condensed by a condenser. The water obtained by this condensation is supplied to the steam generator through the water supply pipe as water supply. Part of the feed water supplied from the condenser to the steam generator is supplied to the condensate demineralizer. The above pressurized water nuclear power plant is provided with a makeup water supply facility, and the makeup water supply facility is provided with a pure water device for purifying the raw water and a pure water tank for storing the purified water. The pure water device and the pure water tank are provided in the pipe, and this pipe is connected to the water supply pipe. The steam generator and the condenser are connected with the treated water pipe separately from the water supply pipe. An outflow pipe is connected to the treated water pipe, and a blowdown water circulation line is connected to the outflow pipe and communicated with the pure water apparatus. A reverse osmosis membrane pure water device is used as the pure water device. The raw water as makeup water supplied to the pure water device is filtered water stored in a filtered water tank after filtering seawater.

  In a boiling water nuclear power plant, spent fuel assemblies taken out from the core are stored in a fuel storage pool provided outside the reactor containment vessel, and are cooled by cooling water in the fuel storage pool. The cooling water in the fuel storage pool is heated by decay heat generated by a large number of spent fuel assemblies stored in the fuel storage pool, and the temperature rises. The cooling water in the fuel storage pool whose temperature has risen is cooled by the cooling device and supplied again to the fuel storage pool. A part of the cooling water in the fuel storage pool is heated by the decay heat and evaporates. Since the cooling water in the fuel storage pool is reduced by this evaporation, an amount of cooling water corresponding to the evaporation amount of the cooling water is supplied from the condensate storage tank or the pressure suppression pool into the fuel storage pool.

  The fuel storage pool is provided with a cooling water cooling device that cools the cooling water in the fuel storage pool, and a nuclear fuel cooling device that has a cooling water replenishing device that supplies cooling water in an amount corresponding to the evaporation amount. The above-described emergency core cooling device is also a kind of nuclear fuel cooling device, and cools the nuclear fuel (fuel assembly) loaded on the core in the reactor pressure vessel.

JP 62-217193 A JP-A-6-170361 JP 2009-162514 A

  The inventors have examined the events that occur in these nuclear fuel coolers to improve the reliability of the nuclear fuel coolers, specifically, the emergency core coolers, and the nuclear fuel coolers installed in the fuel storage pool. did.

  In the emergency core cooling device, as described above, the cooling water in the pressure suppression pool and the cooling water in the condensate storage tank are supplied to the core in the reactor pressure vessel. However, each cooling water in the pressure suppression pool and the condensate storage tank is finite. For this reason, when an emergency core cooling device is used to supply both cooling waters to the core in the event of an emergency, an event occurs in which the amount of cooling water supplied to the core is insufficient, and for some reason, If the cooling water cannot be supplied to the core and the cooling water that can be supplied to the core is only the cooling water in the condensate storage tank, the nuclear fuel in the core may not be sufficiently cooled.

  As described above, it is desired to enable cooling of the core even when the cooling water stored in the boiling water nuclear power plant is insufficient and the core cannot be cooled.

  In addition, even in the nuclear fuel cooling device provided in the fuel storage pool, when both cooling waters were supplied to the fuel storage pool using the nuclear fuel cooling device, an event that the supply amount of the cooling water to the fuel storage pool was insufficient occurred. If the cooling water in the pressure suppression pool cannot be supplied to the fuel storage pool for any reason and the cooling water that can be supplied to the fuel storage pool is only the cooling water in the condensate storage tank, the fuel storage pool There is a possibility that the nuclear fuel (spent fuel assembly) inside cannot be sufficiently cooled.

  An object of the present invention is to provide a nuclear fuel cooling method and a nuclear fuel cooling apparatus capable of cooling nuclear fuel even when the nuclear fuel cannot be cooled by cooling water held in the nuclear power plant.

  A feature of the present invention that achieves the above-described object is that the cooling water in the cooling water source tank is injected into a structure of a nuclear power plant filled with cooling water and nuclear fuel is disposed in the cooling water, When the water level in the tank drops to the set water level, seawater is supplied to the desalination unit to generate fresh water from the seawater, the generated fresh water is supplied to the cooling water source tank, and the fresh water in the cooling water source tank is cooled to the cooling water. It is to be injected into the structure.

  Since fresh water generated from seawater by a desalination device is injected into a nuclear power plant structure where nuclear fuel is placed inside, even when cooling of nuclear fuel by cooling water held in the nuclear power plant becomes impossible The nuclear fuel in the structure can be cooled using the fresh water generated by the desalination apparatus.

  The above-described structure is, for example, a reactor pressure vessel or a fuel storage pool.

  According to the present invention, nuclear fuel can be cooled even when the nuclear fuel cannot be cooled by the cooling water held in the nuclear power plant.

It is a block diagram of the emergency core cooling device which is a nuclear fuel cooling device used for the nuclear fuel cooling method of Example 1 which is one suitable Example of this invention. It is a block diagram of the emergency core cooling device which is a nuclear fuel cooling device used for the nuclear fuel cooling method of Example 2, which is another preferred embodiment of the present invention. It is a block diagram of the emergency core cooling device which is a nuclear fuel cooling device used for the nuclear fuel cooling method of Example 3 which is another suitable Example of this invention. It is a block diagram of the nuclear fuel cooling device provided in a fuel storage pool which is a nuclear fuel cooling device used for the nuclear fuel cooling method of Example 4 which is another suitable Example of this invention. It is a block diagram of the nuclear fuel cooling device provided in a fuel storage pool which is a nuclear fuel cooling device used for the nuclear fuel cooling method of Example 5 which is another suitable Example of this invention.

  Examples of the present invention will be described below.

  A nuclear fuel cooling method according to embodiment 1, which is a preferred embodiment of the present invention, will be described with reference to FIG. The nuclear fuel cooling method of this embodiment is applied to a boiling water nuclear plant.

  As shown in FIG. 1, the boiling water nuclear power plant to which the nuclear fuel cooling method of the present embodiment is applied has a reactor pressure vessel 2 and a reactor containment vessel 3 surrounding the reactor pressure vessel 2. The reactor containment vessel 3 is installed in the reactor building 23. A dry well 4 and a pressure suppression chamber 5 which are separated from each other are formed in the reactor containment vessel 3. A pressure suppression pool 6 filled with cooling water 37 is formed in the pressure suppression chamber 5.

  The reactor pressure vessel 2 is disposed in the dry well 4. A core (not shown) loaded with a plurality of fuel assemblies (not shown) containing nuclear fuel is disposed in the reactor pressure vessel 2.

  An emergency core cooling device 1 that is a nuclear fuel cooling device used in the nuclear fuel cooling method of the present embodiment will be described with reference to FIG. The emergency core cooling device 1 includes a reactor isolation cooling device 16, a high pressure core water injection device 8, a low pressure core water injection device (not shown), and a reverse osmosis membrane device 46 which is a desalination device. The reactor isolation cooling device 16 includes cooling water supply pipes 18 and 21 and a pump 17 provided in the cooling water supply pipe 18. One end of the cooling water supply pipe 18 is connected to a strainer 19 disposed in the cooling water 37 in the pressure suppression pool 6. The other end of the cooling water supply pipe 18 is connected to the reactor pressure vessel 2. An on-off valve 20 is provided in the cooling water supply pipe 18 upstream of the pump 17. One end of the cooling water supply pipe 21 is connected to a condensate storage tank (cooling water source tank) 15, and the other end of the cooling water supply pipe 21 is connected to the cooling water supply pipe 18 between the on-off valve 20 and the pump 17. An on-off valve 22 is provided in the cooling water supply pipe 21. The pump 17 is provided with a driving turbine, and a steam supply pipe connected to the reactor pressure vessel 2 is connected to a steam supply port of the turbine. The steam discharge pipe connected to the steam discharge port of the turbine reaches the cooling water 37 of the pressure suppression pool 6.

  The high-pressure core water injection device 8 includes cooling water supply pipes 10 and 14, a pump 9 provided in the cooling water supply pipe 10, and a pump 12 provided in the cooling water supply pipe 14. One end of the cooling water supply pipe 10 is connected to the strainer 11 disposed in the cooling water 37 in the pressure suppression pool 6. The other end of the cooling water supply pipe 10 is connected to the reactor pressure vessel 2. An on-off valve 44 is provided in the cooling water supply pipe 10 upstream of the pump 9. One end of the cooling water supply pipe 14 is connected to the condensate storage tank 15, and the other end of the cooling water supply pipe 14 is connected to the cooling water supply pipe 10 downstream of the pump 9. An on-off valve 13 is provided in the cooling water supply pipe 14 downstream of the pump 12.

  The reverse osmosis membrane device 46 includes a reverse osmosis membrane 47 and a high-pressure pump 48 as in Example 2 described later (see FIG. 2). The detailed configuration of the reverse osmosis membrane device 46 will be described with reference to FIG. The reverse osmosis membrane 47 is installed in the container 52, and the container 52 is separated into a treated water (seawater) region and a permeated water region. The reverse osmosis membrane 47 is attached to a porous support member (not shown) through which permeated water passes so as to withstand reverse osmosis pressure. The high-pressure pump 48 is disposed upstream of the container 52 and is provided in the seawater supply pipe 24. The seawater supply pipe 24 extends to the sea. The seawater supply pipe 24 is connected to the container 52 downstream of the high-pressure pump 48 and communicates with the treated water region in the container 52. A pipe 26 that guides the permeated water that has passed through the reverse osmosis membrane 47 is connected to the container 52, communicates with the permeated water region in the container 52, and is further connected to the condensate storage tank 15. A discharge pipe 51 provided with an on-off valve 53 is connected to a container 52 and communicates with a treated water region in the container 52.

  A water level gauge 21 is provided in the condensate storage tank 15. A cable 28 connected to the external power source 27 (or emergency diesel generator) is connected to the high-pressure pump 48 via the circuit breaker 29. In addition, a power generation facility (not shown) mounted on the power supply vehicle 30 is connected to the high-pressure pump 48 by the cable 45.

  Although not shown in the figure, in the low pressure core water injection device, similarly to the high pressure core water injection device 8, cooling with one end connected to another strainer arranged in the cooling water 37 in the pressure suppression pool 6 and provided with a pump. The other end of the water supply pipe is connected to the reactor pressure vessel 2, the other end is connected to the condensate storage tank, and the other end of the other cooling water supply pipe provided with a pump and on-off valve is connected to the other strainer. Connected to the connected cooling water supply pipe.

  Assume that a coolant loss accident has occurred. In the cooling water loss accident, piping connected to the reactor pressure vessel 2, for example, the main steam piping breaks in the reactor containment vessel 3, and the high-temperature and high-pressure cooling water in the reactor pressure vessel 2 becomes the main steam piping. High temperature steam is injected from the breakage point into the dry well 4. For this reason, there is a risk that the level of the cooling water in the reactor pressure vessel 2 is lowered and the cooling of the fuel assembly loaded in the reactor core is hindered. In order to avoid such a state, the cooling water is supplied into the reactor pressure vessel 2 by the operation of the emergency core cooling device 1 to cool the fuel assembly in the core. When the pressure in the reactor pressure vessel 2 is higher than the predetermined pressure, cooling water is supplied into the reactor pressure vessel 2 by the high pressure core water injection device 8 and the reactor isolation cooling device 16, and the pressure in the reactor pressure vessel 2 is increased. Is higher than a predetermined pressure, cooling water is supplied into the reactor pressure vessel 2 by the low-pressure core water injection device. At this time, the cooling water 36 in the condensate storage tank 15 and the cooling water 37 in the pressure suppression pool 6 are used as the cooling water injected into the reactor pressure vessel 2.

  When the high-pressure core water injection device 8 and the reactor isolation cooling device 16 are normal, when a coolant loss accident occurs, the on-off valves 13 and 22 are opened and the pumps 12 and 17 are driven, and the high-pressure core water injection device 8 And the reactor isolation cooling device 16 operates. The pump 17 is driven by the steam in the reactor pressure vessel 2 being guided to a turbine for driving the pump 17. In the high pressure core water injection device 8, the cooling water 36 in the condensate storage tank 15 is injected into the reactor pressure vessel 2 through the cooling water supply pipe 14 and the cooling water supply pipe 10. In the reactor isolation cooling device 16, the cooling water 36 in the condensate storage tank 15 is injected into the reactor pressure vessel 2 through the cooling water supply pipe 21 and the cooling water supply pipe 18. The fuel assembly in the core is cooled by injecting the cooling water 36 into the reactor pressure vessel 2. When the water level of the cooling water 36 in the condensate storage tank 15 measured by the water level gauge 21 drops to the lower limit set water level (hereinafter referred to as the lower limit set water level), the high pressure core water injection device 8 and the reactor isolation cooling device When 16 is normal, the on-off valves 44 and 20 are opened, the pump 9 is driven, and the cooling water 37 in the pressure suppression pool 6 is supplied into the reactor pressure vessel 2 through the cooling water supply pipes 10 and 18. At this time, the pump 12 is stopped and the on-off valves 13 and 22 are closed.

  However, when the source of cooling water supplied to the reactor pressure vessel 2 is switched from the condensate storage tank 15 to the pressure suppression pool 6, for example, it is assumed that the on-off valves 44 and 20 are not opened for some reason. In this case, the cooling water 37 in the pressure suppression pool 5 cannot be supplied to the reactor pressure vessel 2, and eventually it becomes difficult to cool the fuel assembly in the core. The respective opening degrees of the on-off valves 44 and 20 are detected, and it can be known whether the on-off valves 44 and 20 are in an open state or in a closed state based on the detected opening degrees.

  When the water level of the cooling water 36 in the condensate storage tank 15 is lowered to the lower limit set water level, the on-off valves 44 and 20 are not opened, and the atoms of the cooling water 37 by the high pressure core water injection device 8 and the reactor isolation cooling device 16 are not opened. In the present embodiment, when the supply to the furnace pressure vessel 2 is impossible, the high pressure pump 48 of the reverse osmosis membrane device 46 is driven. The seawater led through the seawater supply pipe 24 and pressurized by the high-pressure pump 48 is supplied to the region to be processed in the container 52 of the reverse osmosis membrane device 46. The seawater flows from the sea into the seawater supply pipe 24 by driving the high-pressure pump 48. The water contained in the seawater that has reached the region to be treated passes through the reverse osmosis membrane 47. The opening degree of the on-off valve 53 provided in the discharge pipe 51 is adjusted so that the pressure of the seawater that is the water to be treated in the treated water region becomes a predetermined reverse osmosis pressure. The permeated water that has passed through the reverse osmosis membrane 47 does not contain components contained in seawater and is fresh water, and reaches the permeated water region in the container 52. The permeate, which is fresh water, is supplied to the condensate storage tank 15 through the pipe 26. The water level in the condensate storage tank 15 rises by the supplied permeate. Seawater that has flowed into the treated water region in the container 52 is concentrated in the contained seawater component, discharged to the discharge pipe 51, and returned to the sea.

  The high pressure pump 48 is driven as follows. The water level in the condensate storage tank 15 measured by the water level gauge 21 is input to the control device 25. The control device 25 closes the circuit breaker 29 when the measured value of the water level input from the water level gauge 21 falls to the lower limit set water level and the on-off valves 20 and 44 do not open. Electric power is supplied from the external power source 27 to the high-pressure pump 48 through the cable 28, and the high-pressure pump 48 is driven. At this time, power is supplied from the external power source 27 to the pump 12 and the on-off valves 13 and 22. If the on-off valves 20 and 44 are normal, they are operated by electric power supplied from an external power source including the pump 9. When the external power supply 27 is lost, they, including the high pressure pump 48, are operated with power supplied from the diesel generator being driven. In addition, when the in-house power supply and the external power supply are lost and the diesel generator is not driven, the control device 25 is connected to the power supply car 30 when the water level drops to the lower limit set water level without opening the on-off valves 20 and 44. Drives the installed generator. Electric power generated by the generator is supplied to the high-pressure pump 48 through the cable 45, and the high-pressure pump 48 is driven to supply seawater into the reverse osmosis membrane 47. When the generator mounted on the power supply vehicle 30 is driven, the pump 12 and the on-off valves 13 and 22 are operated with electric power supplied from another power supply vehicle.

  When the water level in the condensate storage tank 15 rises to the upper limit set water level higher than the lower limit set water level due to the supply of permeated water, the control device 25 opens the circuit breaker 29 and stops the supply of power to the high pressure pump 48. . Thereby, the supply of seawater into the reverse osmosis membrane 47 is stopped. When the water level in the condensate storage tank 15 drops again to the lower limit set water level, the circuit breaker 29 is closed and the high pressure pump 48 is driven, and the permeated water that has passed through the reverse osmosis membrane 47 is supplied to the condensate storage tank 15. Is done. When the water level in the condensate storage tank 15 drops to the lower limit set water level, the circuit breaker 29 is closed until the water level reaches the upper limit set water level, and the drive of the high-pressure pump 48 is continued and transmitted through the pipe 26. Water is supplied to the condensate storage tank 15.

  The permeated fresh water that has passed through the reverse osmosis membrane 47 and supplied into the condensate storage tank 15 passes through the cooling supply pipes 14 and 10 of the high-pressure core water injection device 8 as cooling water 36, and the reactor isolation cooling device 16. Are supplied to the reactor pressure vessel 2 through the cooling water supply pipes 21 and 18. For example, even if an event occurs in which the cooling water 37 of the pressure suppression pool 6 cannot be supplied into the reactor pressure vessel 2 by the high pressure core water injection device 8 and the reactor isolation cooling device 16 due to a malfunction of the on-off valves 44 and 20. The fresh water generated by the desalination of seawater by the reverse osmosis membrane device 46 is supplied to the condensate storage tank 15, and the fuel assembly loaded into the reactor core in the reactor pressure vessel 2 by the cooling water 36 that is fresh water. Cooling can be continued.

  When the pressure in the reactor pressure vessel 2 drops to the set pressure, the low-pressure core water injection device described above is operated, and when the low-pressure core water injection device is normal, the cooling water in the pressure suppression pool 6 is supplied to the reactor pressure vessel. 2 is supplied. Similar to the high-pressure core cooling device 8, the low-pressure core cooling device is also provided in the cooling water supply pipe connecting the strainer disposed in the cooling water 37 in the pressure suppression pool 6 and the reactor pressure vessel 2. When the on-off valve is not opened, the cooling water 37 cannot be supplied to the reactor pressure vessel 2 by the low-pressure core cooling device. In this case, the fresh water generated by the reverse osmosis membrane device 46 and stored in the condensate storage tank 15 is used as the cooling water 36, as in the case of the high pressure core water injection device 8 and the reactor isolation cooling device 16. It can be supplied to the reactor pressure vessel 2 using a cooling water supply pipe of a low-pressure core cooling device connected to the condensate storage tank 15. As described above, in this embodiment, even when an event in which the cooling water 37 in the pressure suppression pool 6 cannot be supplied to the reactor pressure vessel 2 by the low-pressure core cooling device occurs, The fresh water generated by the desalination can be supplied to the reactor pressure vessel 2 as the cooling water 36.

  In this embodiment, the pressure suppression pool 6 and the fuel storage pool 7 are connected to each other by a cooling water supply pipe (not shown) provided with a pump (not shown). In order to replenish the amount of cooling water 38 evaporated by heating due to decay heat generated in a spent fuel assembly (not shown) stored in the fuel storage pool 7, the cooling water 38 in the fuel storage pool The cooling water 37 in the pressure suppression pool 6 is supplied to the fuel storage pool 7 through the cooling water supply pipe.

  Furthermore, a cooling water cooling device 55 for cooling the spent fuel assembly stored in the fuel storage pool 7 is provided in the fuel storage pool 7. The cooling water cooling device 55 includes a cooling device 56 and a pump 57. The cooling device 56 and the pump 57 are installed in a cooling water pipe 58 having one end connected to the upper end of the fuel storage pool 7 and the other end connected to the bottom of the fuel storage pool 7. The cooling water 38 that has risen in the spent fuel assembly within the fuel storage pool 7 and has risen in temperature due to decay heat generated in the spent fuel assembly is driven above the spent fuel assembly by driving the pump 57. It flows into the cooling water pipe 58. The cooling water 38 is cooled by the cooling device 56 and the temperature is lowered, and is supplied to the bottom of the fuel storage pool 7. The spent fuel assembly in the fuel storage pool 7 is cooled by the cooling water 38 which is cooled by the cooling device 56 and the temperature thereof is lowered.

  When cooling water is supplied to the reactor pressure vessel 2 by the low-pressure core cooling device, some factor (for example, a minute through crack is generated in the pipe connected to the reactor pressure vessel 2 and the reactor is removed from the through crack. The period during which cooling water is supplied into the reactor pressure vessel 2 becomes longer due to leakage of the cooling water in the pressure vessel 2, and the cooling water 36 in the condensate storage tank 15 and the cooling water 37 in the pressure suppression pool 6 are Even if the capacity that can be supplied to the reactor pressure vessel 2 is fully used and cooling water can be supplied to the reactor pressure vessel 2 from the condensate storage tank 15 and the pressure suppression pool 6, reverse osmosis is possible. In the present embodiment in which fresh water generated by desalination of seawater in the membrane device 46 is supplied to the condensate storage tank 15, the fresh water can be supplied to the reactor pressure vessel 2 as cooling water 37. In this case, the on-off valve provided in the cooling water supply pipe connecting the pressure suppression pool and the reactor pressure vessel of the low-pressure core cooling device is normally opened.

  According to the present embodiment, when an event (for example, a coolant loss accident) in which the high-temperature and high-pressure cooling water in the reactor pressure vessel 2 is discharged as high-temperature steam to the dry well 4 occurs, the reverse osmosis membrane Since the fresh water generated by the desalination of seawater in the device 46 can be supplied into the condensate storage tank 15, there is an event that the cooling water 37 in the pressure suppression pool 6 cannot be supplied to the reactor pressure vessel 2. Even if it occurs, the fresh water can be supplied as cooling water to the reactor pressure vessel, and the fuel assembly in the core can be cooled.

Further, in this embodiment, since fresh water generated by desalination of seawater is supplied into the reactor pressure vessel 2, seawater components (for example, Cl ⁻ ) are prevented from being supplied into the reactor pressure vessel 2. it can. For this reason, the boiling water nuclear power plant in which the coolant loss accident has occurred can be reused after repair.

  Since the control device 25 controls the driving and stopping of the high-pressure pump 48 based on the water level in the condensate storage tank 15 measured by the water level gauge 21, the burden on the operator can be reduced. Without using the control device 25, the operator may control the driving and stopping of the high-pressure pump 48 by turning on and off the circuit breaker 29 based on the measured value of the water level gauge 21.

  The boiling water nuclear power plant is provided with a residual heat removal device. This residual heat removal device has a function of removing decay heat generated in the core when the reactor is shut down. The cooling water in the reactor pressure vessel 2 is guided to the cooling device for cooling, and the cooled cooling water is removed. It is returned to the reactor pressure vessel 2. Cooling water connected to a condensate storage tank 15 and a cooling water supply pipe having one end immersed in the cooling water 37 of the pressure suppression pool 6 in a pipe connected to the inlet of the cooling device of the residual heat removal device Connect the supply pipe. With such a configuration, fresh water that has been desalinated by the reverse osmosis membrane device 46 and supplied to the condensate storage tank 15 can be supplied to the reactor pressure vessel 2 as cooling water 37 through the cooling device of the residual heat removal device. it can. An apparatus configured by connecting the condensate storage tank 15 connected to the reverse osmosis membrane apparatus 46 to such a residual heat removal apparatus can also function as a low-pressure core cooling apparatus, and at the time of a loss of coolant accident The fuel assembly in the core can be cooled.

  A nuclear fuel cooling method according to embodiment 2, which is another preferred embodiment of the present invention, will be described with reference to FIG. The nuclear fuel cooling method of this embodiment is applied to a boiling water nuclear plant.

  An emergency core cooling device 1A, which is a nuclear fuel cooling device used in the nuclear fuel cooling method of the present embodiment, will be described with reference to FIG. The emergency core cooling device 1 </ b> A has a configuration in which an on-off valve 34 is provided to the emergency core cooling device 1 used in the first embodiment and a bypass pipe 33 that bypasses the condensate storage tank 15 is added. The upstream end of the bypass pipe 33 is connected to the pipe 26, and the downstream end of the bypass pipe 33 is connected to the cooling water supply pipe 14. An on-off valve 32 is provided in the pipe 26 downstream of the connection point between the pipe 26 and the bypass pipe 33. An on-off valve 31 is provided in the seawater supply pipe 24 upstream of the high-pressure pump 48. The pipe 26 on the downstream side of the on-off valve 32, the high-pressure pump 48, and the seawater supply pipe 24 between the on-off valve 31 are connected by a pipe 36 provided with an on-off valve 37. One end of the pipe 49 provided with the on-off valve 50 is connected to the seawater supply pipe 24 between the high-pressure pump 48 and the container 52, and the other end of the pipe 49 is piped upstream from the connection point between the pipe 26 and the bypass pipe 33. 26. A check valve 35 is provided in the cooling water supply pipe 14 upstream of the connection point between the bypass pipe 33 and the cooling water supply pipe 14. Other configurations of the emergency core cooling device 1A are the same as those of the emergency core cooling device 1.

  The detailed configuration of the reverse osmosis membrane device 46 is described in the first embodiment with reference to FIG. The reverse osmosis membrane device 46 shown in FIG. 2 is also used in the above-described first embodiment and later-described third to fifth embodiments.

  If a coolant loss accident occurs, the cooling water 37 in the condensate storage tank 15 is transferred to the reactor pressure vessel 2 using the high pressure core water injection device 8 and the reactor isolation cooling device 16 as in the first embodiment. Supply in. In addition, when the cooling water 36 in the condensate storage tank 15 measured by the water level gauge 21 falls to the lower limit set water level, the cooling in the pressure suppression pool 6 is performed by the high pressure core water injection device 8 and the reactor isolation cooling device 16. When an event in which water 37 cannot be injected into the reactor pressure vessel 2 occurs, as in the first embodiment, the control device 25 for inputting the water level measured by the water level gauge 21 closes the circuit breaker 29 and closes the high-pressure pump. 48 is driven. The on-off valves 31 and 32 are open, and the on-off valves 34, 37, and 50 are closed. Seawater guided by the seawater supply pipe 24 is supplied to the treated water region in the container 52, and water contained in the seawater becomes permeated water that permeates the reverse osmosis membrane 47 from the permeated water region in the container 52 to the pipe 26. Discharged. This permeate flows into the condensate storage tank 15, is pressurized by the pump 12, and is injected into the reactor pressure vessel 2 through the cooling water supply pipes 14 and 10. The permeate in the condensate storage tank 15 is further injected into the reactor pressure vessel 2 through the cooling water supply pipes 21 and 18 by driving the pump 17. The concentrated water having a high salinity concentration in the treated water region in the container 52 is discharged to the discharge pipe 51.

  At this time, if a failure occurs in the pump 12 and the pump 12 is not driven, the on-off valves 31 and 32 are closed and the on-off valves 34, 37, and 50 are opened. When the pump 12 fails and the cooling water 36 cannot be boosted, the pressure measured by the pressure gauge 54 provided in the cooling water supply pipe 14 decreases, so the pressure measured by the pressure gauge 54 By monitoring this, it is possible to know that a malfunction has occurred in the pump 12. Since the high-pressure pump 48 is driven, the water (cooling water 36) in the condensate storage tank 15 is led to the high-pressure pump 48 through the pipes 26 and 36 to be pressurized, and the pipes 49 and 26 and the bypass pipe 33 are used. Through the cooling water supply pipe 14. Further, part of the water whose pressure has been increased by the high-pressure pump 48 flows into the treated water region in the container 52. Since the on-off valve 53 is closed, the water that has flowed into the treated water region passes through the reverse osmosis membrane 47 to become permeated water, is discharged from the permeated water region in the container 52 to the pipe 26, and The water is mixed with the water supplied from the pipe 49 to the pipe 26 and flows into the cooling water supply pipe 14. This water flowing into the cooling water supply pipe 14 is supplied as cooling water to the reactor pressure vessel 2 through the cooling water supply pipes 14 and 10.

  When the water level in the condensate storage tank 15 falls to the lower limit set water level, the control device 25 that inputs the measured value of the water level meter 21 temporarily stops the high-pressure pump 48, opens the on-off valves 31 and 32, and opens the on-off valve 34. , 37 and 50 are closed. Thereafter, the high-pressure pump 48 is driven by the control device 25, and the seawater supplied through the seawater supply pipe 24 is pressurized by the high-pressure pump 48 and supplied to the treated water region in the container 52. Water contained in seawater in the treated water region passes through the reverse osmosis membrane 27 to become fresh water, and is further supplied from the permeated water region in the container 52 to the condensate storage tank 15 through the pipe 26. The permeate is stored in the condensate storage tank 15 and the water level in the condensate storage tank 15 rises. When this water level reaches the upper limit set water level, the operation of the control device 25 stops the drive of the high-pressure pump 48, the on-off valves 31 and 32 are closed, and the on-off valves 34, 37 and 50 are opened. Thereafter, when the high-pressure pump 48 is driven, the permeated water in the condensate storage tank 15 is supplied as cooling water through the pipes 26, 36, 49 and 26 and the bypass pipe 33 as described above. It flows into the tube 14. This permeated water is supplied to the reactor pressure vessel 2 through the cooling water supply pipes 14 and 10.

  The aforementioned opening / closing operation of the opening / closing valves 31, 32, 34, 37 and 50 is performed by the control device 25, although not shown in FIG.

  In this embodiment, after the water in the condensate storage tank 15 is supplied into the reactor pressure vessel 2 by the high pressure pump 48 and the water level in the condensate storage tank 15 is lowered to the lower limit set water level, the reverse osmosis membrane device While the fresh water generated at 46 is supplied to the condensate storage tank 15, the injection of cooling water from the condensate storage tank 15 to the reactor pressure vessel 2 is stopped. However, since this cooling water injection stop period is short, even if the cooling water is not supplied to the reactor pressure vessel 2, the water level in the reactor pressure vessel 2 exists above the core, The fuel assembly is sufficiently cooled. When the water level in the condensate storage tank 15 reaches the upper limit set water level due to the supply of the fresh water, the cooling water can be injected into the reactor pressure vessel 2 from the condensate storage tank 5 again.

  By increasing the radix of the reverse osmosis membrane device 46, the amount of fresh water produced by the reverse osmosis membrane device 46 can be increased. By taking such measures, it is possible to shorten the time for raising the water level in the condensate storage tank 15 from the lower limit set water level to the upper limit set water level, and to supply cooling water from the condensate storage tank 15 to the reactor pressure vessel 2. It is possible to reduce the time during which the injection becomes impossible. For this reason, the temperature rise of the cooling water in the reactor pressure vessel 2 can be suppressed, and the cooling efficiency of the fuel assembly in the core is improved.

  Another bypass pipe 33 having a bypass valve 34 is connected to the pipe 26 and a cooling water supply pipe connected to the condensate storage tank 15 of the low-pressure core cooling device. In this way, by connecting the other bypass pipe 33 connected to the pipe 26 to the cooling water supply pipe connected to the condensate storage tank 15 of the low-pressure core cooling apparatus, the pressure suppression pool by the low-pressure core cooling apparatus. Even if an event occurs in which the cooling water 37 in the reactor 6 cannot be supplied to the reactor pressure vessel 2 and a failure occurs in the pump provided in the cooling water supply pipe of the low-pressure core cooling device, the above-described high pressure In the same way as when the pump 12 malfunctions in the core water injection device 8, fresh water generated by desalination of seawater by the reverse osmosis membrane device 46 is supplied as cooling water to the reactor pressure vessel 2 by the low pressure core cooling device. can do.

  In the present embodiment, each effect produced in the first embodiment can be obtained. Furthermore, the present embodiment provides a reverse osmosis membrane even when a malfunction occurs in the pump that supplies the cooling water in the condensate storage tank 15 to the reactor pressure vessel 2 of the high pressure core water injection device 8 or the low pressure core water injection device. Permeated water (fresh water) generated by the reverse osmosis membrane device 46 using the high-pressure pump 48 of the device 46 can be supplied to the reactor pressure vessel 2 as cooling water, and the fuel assembly in the core is cooled. Can do.

  In this embodiment, when a malfunction occurs in the pump 12 and the cooling water 36 (permeated water) in the condensate storage tank 15 is poured into the reactor pressure vessel 2 using the high-pressure water pump 48, the pressure is increased by the high-pressure pump 48. A part of the cooling water 36 is supplied to the treated water region in the container 52, but most of the cooling water 36 pressurized by the high-pressure pump 48 passes through the pipe 49, thereby preventing the reverse osmosis membrane 47 from being damaged. can do.

  A nuclear fuel cooling method according to embodiment 3, which is another preferred embodiment of the present invention, will be described with reference to FIG. The nuclear fuel cooling method of this embodiment is applied to a boiling water nuclear plant.

  An emergency core cooling apparatus 1B, which is a nuclear fuel cooling apparatus used in the nuclear fuel cooling method of this embodiment, will be described with reference to FIG. The emergency core cooling apparatus 1B has a configuration in which a demineralizer 39 and a bypass pipe 40 provided with an on-off valve 41 are added to the emergency core cooling apparatus 1 used in the first embodiment. The desalinator 39 is provided in the pipe 26, and both ends of a bypass pipe 40 that bypasses the desalinator 39 are connected to the pipe 26. Other configurations of the emergency core cooling device 1B are the same as those of the emergency core cooling device 1 used in the first embodiment.

  Also in the present embodiment, as in the first embodiment, when a coolant loss accident occurs, the reactor pressure of the cooling water 36 in the condensate storage tank 15 by the high pressure core water injection device 8 and the reactor isolation cooling device 16 is reduced. Water is poured into the container 2. Further, when the cooling water 36 in the condensate storage tank 15 measured by the water level gauge 21 is lowered to the lower limit set water level, the cooling in the pressure suppression pool 6 is performed by the high pressure core water injection device 8 and the reactor isolation cooling device 16. When an event in which water 37 cannot be injected into the reactor pressure vessel 2 occurs, fresh water generated by desalination of seawater by the reverse osmosis membrane device 46 is used as cooling water in the same way as in the first embodiment. Water can be injected into the reactor pressure vessel 2 by the core water injection device 8 and the reactor isolation cooling device 16. Even when the low-pressure core water injection device is driven, when an event in which the cooling water 37 in the pressure suppression pool 6 cannot be injected into the reactor pressure vessel 2 occurs, the reverse osmosis membrane device 46 generates the event. Fresh water can be injected into the reactor pressure vessel 2 as cooling water by a low pressure core water injection device.

  At the start and end of operation of the reverse osmosis membrane device 46, the performance of the reverse osmosis membrane 47 deteriorates, so the quality of the permeated water generated by the reverse osmosis membrane device 46 deteriorates. That is, the conductivity value of the permeated water that passes through the reverse osmosis membrane 47 increases. Therefore, in this embodiment, the on-off valve 41 is closed at the start and end of the operation of the reverse osmosis membrane device 46, and the permeated water, which is fresh water generated by the reverse osmosis membrane device 46, is allowed to pass through the demineralizer 39. To the condensate storage tank 15. Since the permeated water is supplied to the demineralizer 39, the permeated water is purified and the conductivity of the permeated water is reduced. Therefore, even when the reverse osmosis membrane device 46 starts operation and at the end of operation, the permeated water having low conductivity is used as cooling water by the high pressure core water injection device 8 and the reactor isolation cooling device 16 or the low pressure core water injection device. Water can be poured into the pressure vessel 2.

  At the start of operation of the reverse osmosis membrane device 46 and at the time of operation of the reverse osmosis membrane device 46 other than the end of operation, the on-off valve 41 is opened, and the permeated water of fresh water generated by the reverse osmosis membrane device 46 is passed through the bypass pipe 40. To the condensate storage tank 15. At this time, since the conductivity of the permeated water is low, even when the reverse osmosis membrane device 46 is operated at the start of operation and other than the end of the operation, the permeated water having a low conductivity is poured into the reactor pressure vessel 2 as cooling water. be able to.

  In the present embodiment, each effect produced in the first embodiment can be obtained. In the present embodiment, since the desalination apparatus 39 is provided in the pipe, the permeated water having low conductivity can be poured into the reactor pressure vessel 2 as cooling water. Further, since the bypass pipe 40 provided with the on-off valve 41 is provided, the reverse osmosis membrane device 46 having low conductivity of the permeated water permeates the desalinator 39 at the time of operation other than the start of operation and the end of operation. The supply amount of water is reduced, and deterioration of the desalting performance of the ion exchange resin filled in the desalting apparatus 39 can be suppressed. Even if the bypass pipe 40 provided with the on-off valve 41 is not connected to the pipe 26, the permeated water having low conductivity can be poured into the reactor pressure vessel 2 as cooling water.

  The configuration used in the second embodiment, that is, the bypass pipe 33 provided with the on-off valve 34, the pipe 36 provided with the on-off valve 37, the pipe 49 provided with the on-off valve 50, and the on-off valves 31 and 32 are applied to this embodiment. can do. In this case, the connection point between the bypass pipe 33 and the pipe 26 and the connection point between the pipe 49 and the pipe 26 are arranged downstream of the demineralizer 39. By using such a configuration, in the present embodiment, similarly to the second embodiment, the high-pressure pump 48 is used to supply the cooling water (for example, the permeated water of the reverse osmosis membrane 47) in the condensate storage tank 15 to the reactor. The pressure vessel 2 can be supplied.

  A nuclear fuel cooling method according to embodiment 4, which is another preferred embodiment of the present invention, will be described with reference to FIG. The nuclear fuel cooling method of the present embodiment is applied to cooling spent fuel assemblies stored in a fuel storage pool of a boiling water nuclear plant.

  A nuclear fuel cooling device 1C used in the nuclear fuel cooling method of the present embodiment will be described with reference to FIG. The nuclear fuel cooling device 1 </ b> C includes a cooling water cooling device 55, a cooling water supply device 59, and a reverse osmosis membrane device 46. The cooling water cooling device 55 has the same configuration as that of the first embodiment.

  The cooling water supply device 59 includes cooling water supply pipes 43 and 14A, a pump 42 provided in the cooling water supply pipe 43, and a pump 12A provided in the cooling water supply pipe 14A. One end of the cooling water supply pipe 43 is connected to a strainer 19 </ b> A disposed in the cooling water 37 in the pressure suppression pool 6. The other end of the cooling water supply pipe 43 is connected to the reactor pressure vessel 2. An on-off valve 44 is provided in the cooling water supply pipe 43 upstream of the pump 42. One end of the cooling water supply pipe 14 A is connected to the condensate storage tank 15, and the other end of the cooling water supply pipe 14 A is connected to the cooling water supply pipe 43 downstream of the pump 42. An on-off valve 13A is provided in the cooling water supply pipe 14 downstream of the pump 12A.

  Similar to the second embodiment, the reverse osmosis membrane device 46 includes a high-pressure pump 48 and a container 52 in which a reverse osmosis membrane 47 is installed.

  A plurality of spent fuel assemblies including nuclear fuel taken out from the core of the reactor pressure vessel 2 are stored and stored in a fuel storage rack (not shown) installed in the cooling water in the fuel storage pool 7. Is done. These spent fuel assemblies are cooled by cooling water 38 in the fuel storage pool 7. The cooling water 38 is heated by the decay heat of the nuclear fuel in the spent fuel assembly, and the temperature rises. The cooling water 38 in the fuel storage pool 7 whose temperature has risen is led to the cooling device 56 of the cooling water cooling device 55 to be cooled, and is supplied into the fuel storage pool 7 from the bottom.

  A part of the cooling water in the fuel storage pool 7 is heated by the decay heat and evaporates. Due to this evaporation, the cooling water 38 in the fuel storage pool 7 decreases, so that an amount of cooling water corresponding to the evaporation amount of the cooling water is supplied to the fuel storage pool 7. This cooling water supply is performed using the cooling water supply device 59.

  The replenishment of the cooling water to the fuel storage pool 7 using the cooling water replenishing device 59 will be specifically described. When the water level in the fuel storage pool 7 measured by a water level meter (not shown) installed in the fuel storage pool 7 is measured and the measured water level drops to the first lower limit set water level, the on-off valve 13A It opens and the pump 12A is driven. By driving the pump 12A, the cooling water 36 in the condensate storage tank 15 is supplied to the fuel storage pool 7 through the cooling water supply pipes 14A and 43. At this time, the on-off valve 44 is closed and the pump 42 is also stopped. When the level of the cooling water 38 in the fuel storage pool 7 rises to the first upper limit set water level due to the supply of the cooling water 36, the driving of the pump 42 is stopped and the supply of the cooling water 36 to the fuel storage pool 7 is stopped. The The supply of the cooling water to the fuel storage pool 7 by the cooling water supply device is performed not only during the operation of the boiling water nuclear plant but also during the operation of the boiling water nuclear plant. The water level of the cooling water 38 in the fuel storage pool 7 is maintained so as not to hinder the cooling of the spent fuel assembly stored in the fuel storage pool 7.

  When the water level of the cooling water 36 in the condensate storage pool 15 is lowered to the second lower limit set water level, the drive of the pump 12A is stopped, the on-off valve 13A is closed, and the on-off valve 44 is opened to turn off the pump 42. Driven. The cooling water 37 in the pressure suppression pool 6 is supplied to the fuel storage pool 7 through the cooling water supply pipe 43 by driving the pump 42. However, when the water level in the condensate storage pool 15 drops to the second lower limit set water level, the on-off valve 44 does not open, and the supply of the cooling water 37 of the pressure suppression pool 6 to the fuel storage pool 7 is impossible. In this case, the on-off valve 13A is opened and the pump 12A is kept in operation, and the high-pressure pump 48 is driven and the seawater supplied through the seawater supply pipe 24 as in the first embodiment. Is supplied to the treated water region in the container 52 of the reverse osmosis membrane device 46. The permeated water, which is fresh water that passes through the reverse osmosis membrane 47 and becomes fresh water, is contained in the seawater is discharged from the permeated water region in the container 52 and supplied to the condensate storage tank 15 through the pipe 26. . This permeated water is boosted by the pump 12A as cooling water 36 and supplied to the fuel storage pool 7 through the cooling water supply pipes 14A and 43. As a result, the fresh water generated by the reverse osmosis membrane device 46 is used for cooling the spent fuel assembly in the fuel storage pool 7.

  The high pressure pump 48 is driven by the electric power supplied from the external power source 27 while the operation of the boiling water nuclear plant is stopped, such as when the fuel assembly is replaced. During operation of the boiling water nuclear power plant, the high-pressure pump 48 is driven by electric power supplied from an internal power source. When power cannot be supplied from the external power supply 27, the internal power supply, and the emergency diesel generator to the high-pressure pump 48, power is supplied from the power supply vehicle 30 to the high-pressure pump 48.

  According to the present embodiment, since fresh water generated by desalination of seawater in the reverse osmosis membrane device 46 can be supplied into the condensate storage tank 15, the cooling water 37 in the pressure suppression pool 6 is supplied to the reactor pressure. Even if an event that cannot be supplied to the container 2 occurs, the fresh water can be supplied to the fuel storage pool 7 as cooling water, and the spent fuel assembly stored in the fuel storage pool 7 is cooled. be able to.

In this embodiment, since fresh water generated by seawater desalination is supplied into the fuel storage pool 72, seawater components (for example, Cl ⁻ ) can be prevented from being supplied into the fuel storage pool 7. For this reason, the risk of corrosion due to seawater components of the lining material forming the inner surface of the fuel storage pool 7 and the cladding of the fuel rods contained in the spent fuel assembly stored in the fuel storage pool is eliminated. can do.

  As in the first embodiment, since the control device 25 controls the driving and stopping of the high-pressure pump 48 based on the water level in the condensate storage tank 15 measured by the water level gauge 21, the burden on the operator can be reduced. it can.

  Also in this embodiment, as in the second embodiment, the bypass pipe 33 provided with the on-off valve 34, the pipe 36 provided with the on-off valve 37, the pipe 49 provided with the on-off valve 50, and the on-off valves 31 and 32 are applied. be able to.

  A nuclear fuel cooling method according to embodiment 5, which is another preferred embodiment of the present invention, will be described with reference to FIG. The nuclear fuel cooling method of the present embodiment is applied to cooling spent fuel assemblies stored in a fuel storage pool of a boiling water nuclear plant.

  A nuclear fuel cooling device 1D used in the nuclear fuel cooling method of the present embodiment will be described with reference to FIG. The nuclear fuel cooling device 1D has a configuration in which a demineralizer 39 and a bypass pipe 40 provided with an on-off valve 41 are added to the nuclear fuel cooling device 1C used in the fourth embodiment, as in the third embodiment. Other configurations of the nuclear fuel cooling device 1D are the same as those of the nuclear fuel cooling device 1C.

  The method of cooling the spent fuel assembly in the fuel storage pool 7 using the nuclear fuel cooling device 1C in the present embodiment is the same as that of the spent fuel assembly in the fuel storage pool 7 using the nuclear fuel cooling device 1C in the fourth embodiment. It is performed in the same manner as the cooling method.

  However, in this embodiment, the on-off valve 41 is closed at the start and end of the operation of the reverse osmosis membrane device 46, and the permeated water, which is fresh water generated by the reverse osmosis membrane device 46, is allowed to pass through the desalination device 39. Supply to the condensate storage tank 15. In addition, when the reverse osmosis membrane device 46 is started and when the reverse osmosis membrane device 46 is in operation other than the end of the operation, the on-off valve 41 is opened to bypass the fresh water permeate generated by the reverse osmosis membrane device 46. It is led to the condensate storage tank 15 through the pipe 40.

  For this reason, in this embodiment, permeated water having low conductivity can be supplied to the fuel storage pool 7 as cooling water. In the present embodiment, each effect produced in the fourth embodiment can be obtained.

  Also in the present embodiment, as in the third embodiment, the bypass pipe 33 provided with the on-off valve 34, the pipe 36 provided with the on-off valve 37, the pipe 49 provided with the on-off valve 50, and the on-off valves 31 and 32 are applied. be able to.

  DESCRIPTION OF SYMBOLS 1,1A, 1B ... Emergency core cooling device (nuclear fuel cooling device), 1C, 1D ... Nuclear fuel cooling device, 2 ... Reactor pressure vessel, 3 ... Reactor containment vessel, 4 ... Dry well, 5 ... Pressure suppression chamber, 6 ... Pressure suppression pool, 7 ... Fuel storage pool, 8 ... High pressure core water injection device, 9, 12, 12A, 17, 42 ... Pump, 10, 14, 14A, 16, 21, 43 ... Cooling water supply pipe, 15 ... Condensate storage tank, 21 ... water level gauge, 24 ... seawater supply pipe, 25 ... control device, 26, 36, 49 ... piping, 33, 40 ... bypass piping, 39 ... desalination device, 46 ... reverse osmosis membrane device, 47 ... reverse osmosis membrane, 48 ... high pressure pump, 52 ... container, 55 ... cooling water cooling device, 59 ... cooling water supply device.

Claims (9)

  When cooling water in the cooling water source tank is injected into a structure of a nuclear power plant filled with cooling water and nuclear fuel is disposed in the cooling water, and the water level in the cooling water source tank drops to a set water level , Supplying seawater to a desalination apparatus to generate fresh water from the seawater, supplying the generated fresh water to the cooling water source tank, and using the fresh water in the cooling water source tank as the cooling water in the structure A nuclear fuel cooling method, characterized by being injected.   The nuclear fuel cooling method according to claim 1, wherein the fresh water in the cooling water source tank is injected into a reactor pressure vessel or a fuel storage pool which is the structure.   When a reverse osmosis membrane device is used as the desalination device, the water level in the cooling water source tank drops to a set water level, and a failure occurs in the pump that supplies the cooling water in the cooling water source tank into the structure The fresh water is generated from the seawater by supplying the seawater to the reverse osmosis membrane of the reverse osmosis membrane device using a high-pressure pump provided in the reverse osmosis membrane device, and the fresh water is supplied to the cooling water source tank The nuclear fuel cooling method according to claim 1, wherein the fresh water is injected from the cooling water source tank into the structure using the high-pressure pump.   The nuclear fuel cooling method according to claim 1 or 2, wherein the fresh water generated by the desalination apparatus is purified by a desalting apparatus, and the purified fresh water is supplied to the cooling water source tank.   A cooling water source tank filled with cooling water, and a cooling water injection pipe connected to the structure of the nuclear power plant connected to the cooling water source tank and filled with cooling water and nuclear fuel is disposed in the cooling water And a pump provided in the cooling water injection pipe for boosting the cooling water in the cooling water source tank, and a seawater desalination device for desalinating seawater and supplying the generated fresh water to the cooling water source tank. A nuclear fuel cooling device characterized by that.   The water level measuring device provided in the cooling water source tank and the water level information measured by the water level measuring device are input, and when the measured water level falls to the lower limit set water level, the desalination device is driven. The nuclear fuel cooling device according to claim 5, wherein a control device for generating the fresh water is provided.   The nuclear fuel cooling device according to claim 5 or 6, wherein the cooling water supply pipe is connected to a reactor pressure vessel or a fuel storage pool which is the structure.   The desalination apparatus is a reverse osmosis membrane apparatus having a reverse osmosis membrane that desalinates the seawater, and a high-pressure pump that supplies the reverse osmosis membrane. A first on-off valve is provided and the reverse osmosis membrane is generated. A first pipe and a second on-off valve for guiding the fresh water to the cooling water source tank are provided to bypass the cooling water source tank, and are connected to the first pipe upstream of the first on-off valve. A second pipe connected to the injection pipe, connected to the cooling water source tank and the inlet of the high-pressure pump, connected to a third pipe provided with a third on-off valve, and a discharge port of the high-pressure pump; 7. The fourth pipe according to claim 5, wherein a fourth pipe connected to the first pipe upstream of a connection point between the first pipe and the second pipe and provided with a fourth on-off valve is provided. Nuclear fuel cooling system.   The nuclear fuel cooling device according to claim 5 or 6, further comprising a desalination device that passes when the fresh water generated by the desalination device is supplied to the cooling water source tank.

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