JP6990097B2 - Liquid metal sodium recovery method and recovery device - Google Patents

Description

The present invention relates to, for example, a method for recovering liquid metal sodium used in a fast breeder reactor or a test facility thereof, and a device for recovering the liquid metal sodium.

For example, a nuclear power plant having a fast breeder reactor (FBR) uses sodium as a reactor coolant, and the heat generated by the nuclear fission of the fuel in the reactor is taken out by the primary sodium and used to extract it. It is sent to an intermediate heat exchanger to transfer heat to the secondary sodium, which is sent to a steam generator to generate steam, and this steam is sent to a turbine generator to generate electricity.

If liquid metallic sodium leaks from various pipes in such a fast breeder reactor, the leaked liquid metallic sodium chemically reacts with the surrounding air and burns, which may cause a fire in the facility. For example, in the sodium removal treatment equipment for the high-speed core component described in Patent Document 1 below, by introducing an inert gas into the equipment, the chemical reaction between liquid metal sodium and air is reduced and combustion is suppressed. is doing. Then, after the liquid metallic sodium has dropped to a predetermined temperature, the worker recovers the solidified metallic sodium. In addition, when dismantling a fast breeder reactor, it is necessary to clean and recover the metallic sodium remaining in the reactor, various equipment, and piping.

Japanese Unexamined Patent Publication No. 09-178895

In the sodium removal treatment equipment of the fast reactor core component of Patent Document 1 described above, an inert gas is introduced into the equipment to reduce the chemical reaction between the liquid metal sodium and air, and the combustion is suppressed. However, in order to fill the facility with the inert gas, a large-scale inert gas introduction facility is required. Moreover, if the facility is filled with the inert gas, the lack of oxygen makes it impossible for the worker to invade, which makes it difficult to recover the metallic sodium. In addition, in the recovery work of leaked and solidified metallic sodium and the recovery work of residual metallic sodium when dismantling a fast breeder reactor, the worker manually carries out the recovery work of metallic sodium, which is difficult. Not only that, there is a risk of ignition of metallic sodium and explosion of hydrogen generated by reaction with moisture.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a recovery method and a recovery device for liquid metal sodium, which eliminates the need for the introduction of an inert gas and improves work safety.

In the method for recovering liquid metal sodium in order to achieve the above object, the liquid metal sodium is brought into contact with the liquid metal sodium, and the liquid metal sodium is sucked and recovered inside the porous member. It is characterized by that.

Therefore, when the porous member comes into contact with the liquid metal sodium, the liquid metal sodium is sucked into each hole of the porous member by the capillary phenomenon and is recovered inside. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the method for recovering liquid metallic sodium of the present invention, the porous member is characterized by being composed of a material containing at least nickel.

Therefore, by constructing the porous member from a material containing nickel, liquid metal sodium can be appropriately sucked and recovered in the porous member by the capillary phenomenon.

In the method for recovering liquid metallic sodium of the present invention, the porous member is characterized in that the surface of pure nickel, pure iron or stainless steel is nickel-plated.

Therefore, by plating the surface of pure nickel, pure iron, or stainless steel with nickel to form a porous member, liquid metal sodium can be appropriately sucked and recovered by the porosity formed on the surface.

In the method for recovering liquid metallic sodium of the present invention, the porous member is characterized in that an oxide film is provided on the surface of stainless steel.

Therefore, by providing an oxide film on the surface of stainless steel to form a porous member, liquid metal sodium can be appropriately sucked and recovered by the porosity formed on the surface.

The method for recovering liquid metal sodium of the present invention is characterized in that the liquid metal sodium is heated to 150 ° C. or higher and then brought into contact with the porous member.

Therefore, by contacting the porous member after heating the liquid metal sodium to 150 ° C. or higher, the wettability of the liquid metal sodium with respect to the porous member is improved, and the liquid metal sodium can be appropriately sucked and recovered. ..

In the method for recovering liquid metal sodium of the present invention, the porous member is inserted into the equipment and brought into contact with the liquid metal sodium remaining in the equipment to bring the liquid metal sodium inside the porous member. It is characterized by being sucked and collected.

Therefore, by inserting the porous member into the equipment, contacting the porous member with the liquid metal sodium remaining in the equipment, and sucking and recovering the liquid metal sodium, for example, the dismantling work of the equipment can be performed efficiently. It can be carried out safely.

Further, the liquid metal sodium recovery device of the present invention is characterized in that a porous member for sucking and recovering the liquid metal sodium is arranged below the facility for storing or supplying the liquid metal sodium. Is.

Therefore, when liquid metal sodium leaks from the equipment and the leaked liquid metal sodium falls and comes into contact with the porous member, the liquid metal sodium is sucked into each hole of the porous member by the capillary phenomenon and recovered inside. To. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the liquid metal sodium recovery device of the present invention, the equipment is a pipe, and the porous member is arranged on the floor surface below the pipe.

Therefore, when liquid metal sodium leaks from the connecting part, welded part, or damaged part of the pipe, the leaked and dropped liquid metal sodium comes into contact with the porous member arranged on the floor surface below the pipe, and the liquid metal Since sodium is sucked into the porous member and recovered by the capillary phenomenon, the safety in the recovery work of metallic sodium can be improved.

In the liquid metal sodium recovery device of the present invention, the equipment is a pipe, and the porous member is suspended and supported at a position facing below the pipe.

Therefore, when liquid metal sodium leaks from the connecting part, welded part, or damaged part of the pipe, the leaked and dropped liquid metal sodium comes into contact with the porous member suspended below the pipe, and the liquid metal sodium is released. Since it is sucked into the porous member and recovered by the capillary phenomenon, the safety in the recovery work of metallic sodium can be improved.

Further, the liquid metal sodium recovery device of the present invention is provided with an insertion / discharge device for inserting and discharging a porous member that sucks and recovers the liquid metal sodium inside the equipment in which the liquid metal sodium remains. , Is characterized by that.

Therefore, when the porous member is inserted into the equipment by the insertion / discharge device and the porous member comes into contact with the liquid metal sodium, the liquid metal sodium is sucked into each hole of the porous member by the capillary phenomenon and collected inside. To. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the liquid metal sodium recovery device of the present invention, the equipment is a container, and the insertion / discharge device includes a cord-like body to which the porous member is connected to the tip portion and a drive device for moving the cord-like body. It is characterized by having.

Therefore, the porous member can be inserted into the equipment by moving the cord by the driving device, and the liquid metal sodium recovery work can be smoothly carried out from the outside of the equipment.

According to the liquid metal sodium recovery method and recovery device of the present invention, the introduction of an inert gas becomes unnecessary and the work safety can be improved.

FIG. 1 is a schematic configuration diagram of a nuclear power plant using liquid metal sodium as a reactor coolant. FIG. 2 is a schematic view showing the liquid metal sodium recovery device of the first embodiment. FIG. 3 is a schematic view showing the operation of the liquid metal sodium recovery device. FIG. 4 is a schematic view showing a first modification of the liquid metal sodium recovery device of the first embodiment. FIG. 5 is a schematic view showing a second modification of the liquid metal sodium recovery device of the first embodiment. FIG. 6 is a schematic view showing the liquid metal sodium recovery device of the second embodiment. FIG. 7 is a schematic view showing a recovery operation of liquid metal sodium. FIG. 8 is a schematic view showing a first modification of the liquid metal sodium recovery device of the second embodiment. FIG. 9 is a schematic view showing a second modification of the liquid metal sodium recovery device of the second embodiment.

Hereinafter, preferred embodiments of the liquid metal sodium recovery method and the recovery device according to the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment, and when there are a plurality of embodiments, the present invention also includes a combination of the respective embodiments.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of a nuclear power plant using liquid metal sodium as a reactor coolant.

In the first embodiment, as shown in FIG. 1, the nuclear reactor applied to the nuclear power plant 10 uses a fission chain reaction with fast neutrons to generate energy to generate even more fuel than the fuel used. It is a fast breeder reactor (FBR) that produces. This fast breeder reactor uses liquid metal as a coolant, and here, metallic sodium is used.

The reactor containment vessel 11 contains a fast breeder reactor 12, a primary main cooling system intermediate heat exchanger 13, and a primary main cooling system circulation pump 14, which are protected by a guard vessel. .. Then, the fast breeder furnace 12 and the primary main cooling system intermediate heat exchanger 13 are connected by the primary main cooling system pipe 15a, and the primary main cooling system intermediate heat exchanger 13 and the primary main cooling system circulation pump 14 are connected to the primary main cooling system pipe. It is connected by 15b, and the primary main cooling system circulation pump 14 and the fast breeder furnace 12 are connected by the primary main cooling system pipe 15c.

Therefore, the fast breeder reactor 12, the primary main cooling system intermediate heat exchanger 13, and the primary main cooling system circulation pump 14 form a primary system sodium loop by the primary main cooling system pipes 15a, 15b, 15c, respectively. Therefore, when the nuclear fuel undergoes nuclear splitting in the core of the fast breeder reactor 12 and heat is generated, liquid metal sodium is transferred between the fast breeder reactor 12 and the primary main cooling system intermediate heat exchanger 13 by the primary main cooling system circulation pump 14. The heat generated in the fast breeder reactor 12 is absorbed by the liquid metal sodium and cooled by circulating in.

In the reactor containment vessel 11, a superheater 16 and an evaporator 17 as steam generators are arranged outside, and a secondary main cooling system circulation pump 18 is arranged. Then, the primary main cooling system intermediate heat exchanger 13 and the superheater 16 are connected by the secondary main cooling system pipe 19a, and the superheater 16 and the evaporator 17 are connected by the secondary main cooling system pipe 19b, and are connected to the evaporator 17. The primary main cooling system intermediate heat exchanger 13 is connected by the secondary main cooling system pipe 19c, and the secondary main cooling system circulation pump 18 is provided in the secondary main cooling system pipe 19c.

Therefore, the primary main cooling system intermediate heat exchanger 13, the superheater 16, the evaporator 17, and the secondary main cooling system circulation pump 18 form a secondary system sodium loop by the secondary main cooling system pipes 19a, 19b, 19c, respectively. is doing. Therefore, the liquid metal sodium is circulated by the secondary main cooling system circulation pump 18, and the heat of the primary liquid metal sodium is absorbed by the secondary main cooling system intermediate heat exchanger 13 by the secondary liquid metal sodium. Be cooled.

In this secondary sodium loop, an air cooling pipe 20 for connecting the secondary main cooling system pipe 19a and the secondary main cooling system pipe 19c is provided, and an air cooler 21 is provided in the air cooling pipe 20. Has been done. Therefore, the liquid metallic sodium of the primary system from the primary main cooling system intermediate heat exchanger 13 partially bypasses the superheater 16 and the evaporator 17 and passes through the air cooling pipe 20 to the primary main cooling system intermediate heat exchanger. It is returned to 13.

The tertiary cooling system pipes 22a and 22b are arranged so as to pass through the superheater 16 and the evaporator 17. The downstream end of the tertiary cooling system pipe 22a is connected to the steam turbine 23, and the generator 24 is connected to the steam turbine 23. The steam turbine 23 is provided with a condenser 25, and the condenser 25 is connected to an intake pipe 26 for supplying and discharging cooling water (for example, seawater) and a drain pipe 27, and is connected to the intake pipe 26. A circulating water pump 28 is provided. The condenser 25 is connected to the upstream end of the tertiary cooling system pipe 22b, and the water supply pump 29 is provided in the tertiary cooling system pipe 22b.

Therefore, the superheater 16, the evaporator 17, the steam turbine 23, and the condenser 25 form a tertiary system water loop by the tertiary cooling system pipes 22a and 22b. Therefore, when water is circulated by the water supply pump 29, the heat of the secondary liquid metal sodium is absorbed by the water in the superheater 16 and the evaporator 17 and cooled. That is, the steam generated by heat exchange with the high temperature sodium of the secondary system in the superheater 16 and the evaporator 17 is sent to the steam turbine 23 through the tertiary cooling system pipe 22a, and the steam turbine 23 is generated by this steam. It is driven and power is generated by the generator 24. The used steam that has driven the steam turbine 23 is cooled by the condenser 25 using seawater to become condenser, and is returned to the superheater 16 and the evaporator 17 by the water supply pump 29.

In the nuclear power plant 10 configured in this way, when liquid metallic sodium leaks from various facilities and pipes, the leaked liquid metallic sodium chemically reacts with the surrounding air and burns, causing a fire in the facility. May occur. The first embodiment is a method and apparatus for recovering liquid metallic sodium that safely recovers leaked liquid metallic sodium.

The method for recovering liquid metal sodium according to the first embodiment is to bring the porous member into contact with the liquid metal sodium, and to suck and recover the liquid metal sodium inside the porous member.

In the method for recovering liquid metal sodium according to the first embodiment, the porous member is composed of a material containing at least nickel. Specifically, for example, the porous member is configured by nickel-plating the surface of pure nickel, pure iron, or stainless steel. Alternatively, the porous member is configured by providing an oxide film on the surface of stainless steel.

Hereinafter, the porous member will be described in detail. As the porous member, many types can be considered as described below.
1. 1. The surface of pure nickel, pure iron, or stainless steel is nickel-plated to form a porous member.
2. 2. A porous member is formed by heating stainless steel to 300 ° C. or higher in air to form an oxide film on the surface.
3. 3. A porous member is formed by laminating metal meshes.
4. Porous members are made of sintered metal. In this case, the material of the sintered metal is pure nickel, pure iron, or stainless steel with nickel plating on the surface, or stainless steel heated to 300 ° C. or higher in the air to form an oxide film on the surface. Is preferable.
The porosity of the porous member is preferably 20 to 50%.

Since the melting point of sodium is 98 ° C., when recovering this sodium, it is heated to 150 ° C. or higher and recovered as liquid metal sodium. At this time, it is preferable to select a porous material having good wettability, and it is preferable to bring the porous material into contact with liquid metal sodium heated to 250 ° C. or higher. This wettability can be defined by the contact angle, and the angle between the liquid surface and the solid surface (of the liquid) at the position where the free surface of the static liquid (liquid metallic sodium) is in contact with the solid wall (porous member). The internal angle) is preferably 60 degrees or less.

Further, the liquid metal sodium recovery device of the first embodiment is configured by arranging a porous member for sucking and recovering the liquid metal sodium below the equipment for storing or supplying the liquid metal sodium. FIG. 2 is a schematic view showing the liquid metal sodium recovery device of the first embodiment, and FIG. 3 is a schematic view showing the operation of the liquid metal sodium recovery device.

As shown in FIG. 2, the pipe 30 as equipment is configured by connecting the first pipe 31 and the second pipe 32. The first pipe 31 and the second pipe 32 are configured by forming flange portions 31b and 32b at the axial ends of the pipe bodies 31a and 32a, respectively. The pipe 30 is configured such that the flange portion 31b of the first pipe 31 and the flange portion 32b of the second pipe 32 are butted against each other and connected by a plurality of bolts 33 and nuts 34.

As shown in FIG. 1, the pipe 30 is, for example, primary main cooling system pipes 15a, 15b, 15c, secondary main cooling system pipes 19a, 19b, 19c and the like. As shown in FIG. 2, in the building in which the pipe 30 is arranged, a stainless steel liner 36 is laid on the concrete structure 35 to form a floor surface. The above-mentioned porous member 37 is arranged on the liner (floor surface) 36 below the pipe 30.

In the pipe 30, the porous member 37 is generally arranged below the connecting portion and the bent portion because leakage of liquid metal sodium from the connecting portion and the bent portion due to bolts and welded portions is considered. Therefore, the porous member 37 has a plate shape having a predetermined thickness, and is arranged so as to face the lower side of each flange portion 31b, 32b to which the first pipe 31 and the second pipe 32 are connected.

Therefore, as shown in FIG. 3, when the liquid metal sodium Na-1 leaks from between the flange portions 31b and 32b to which the first pipe 31 and the second pipe 32 are connected, the leaked liquid metal sodium Na-1 is released. , Drops onto the porous member 37. Then, the liquid metal sodium Na-1 comes into contact with the surface of the porous member 37, is sucked into the porous member 37 by the capillary phenomenon, and is recovered. At this time, the liquid metal sodium Na-2 is maintained inside the porous member 37, and the liquid metal sodium product Na-3 is produced around the liquid metal sodium Na-2. Here, the case where the entire porous member 37 is a porous layer has been described, but when the porous layer exists only on the surface of the porous member 37, liquid metallic sodium is inside the porous layer. Na-2 is maintained, and the surface of the liquid metallic sodium Na-2 is burned to generate a liquid metallic sodium product Na-3 composed of sodium oxide or the like around it. Since this product Na-3 is formed so as to enclose the liquid metal sodium Na-2 in the porous member 37, the inflow of air into the liquid metal sodium Na-2 is blocked and combustion is prevented. ..

The position where the porous member 37 is arranged is not limited to the above-mentioned position. FIG. 4 is a schematic view showing a first modification of the liquid metal sodium recovery device of the first embodiment, and FIG. 5 is a schematic view showing a second modification of the liquid metal sodium recovery device of the first embodiment. be.

In the first modification, as shown in FIG. 4, the first pipe 31 and the second pipe 32 constituting the pipe 30 are connected at the axial end by a welded portion 41, and the heat insulating material 42 is wound around the outer surface thereof. And covered. The porous member 43 is formed by being wound around the outer surface of the heat insulating material 42 on the outside of the first pipe 31 and the second pipe 32. Therefore, when the liquid metal sodium leaks from the welded portion 41 to which the first pipe 31 and the second pipe 32 are connected, the leaked liquid metal sodium comes into contact with the inner surface of the porous member 43 through the heat insulating material 42, and due to the capillary phenomenon. It is sucked into the porous member 43 and recovered.

In the second modification, as shown in FIG. 5, the first pipe 31 and the second pipe 32 constituting the pipe 30 are covered with a heat insulating material 42 wound around the outer surface thereof. In the first pipe 31 and the second pipe 32, a support plate 44 having a curved shape (or a planar shape) is hung from the building or the pipe 30 below the connecting portion, and the curved shape (or a curved shape) is placed on the support plate 44. Alternatively, the porous member 45 forming a planar shape) is fixed. Therefore, when the liquid metal sodium leaks from the connecting portion between the first pipe 31 and the second pipe 32, the leaked liquid metal sodium comes into contact with the inner surface of the porous member 45 through the heat insulating material 42, and the porous member 45 due to the capillary phenomenon. It is sucked inside and collected.

As described above, in the method for recovering liquid metal sodium of the first embodiment, by contacting the liquid metal sodium with the porous members 37, 43, 45, the liquid metal is inside the porous members 37, 43, 45. Aspirate and recover sodium.

Therefore, when the porous members 37, 43, 45 come into contact with the liquid metal sodium, the liquid metal sodium is sucked into the pores of the porous members 37, 43, 45 by the capillary phenomenon and is recovered inside. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the method for recovering liquid metal sodium of the first embodiment, the porous members 37, 43, 45 are made of a material containing at least nickel. Therefore, by constructing the porous members 37, 43, 45 from the material containing nickel, the liquid metal sodium can be appropriately sucked and recovered in the porous members 37, 43, 45 by the capillary phenomenon.

In the method for recovering liquid metal sodium of the first embodiment, the porous members 37, 43, 45 are formed by nickel-plating the surface of pure nickel, pure iron, or stainless steel. Therefore, by plating the surface of pure nickel, pure iron, or stainless steel with nickel to form a porous member, liquid metal sodium can be appropriately sucked and recovered by the porosity formed on the surface.

In the method for recovering liquid metal sodium of the first embodiment, the porous members 37, 43, 45 are configured by providing an oxide film on the surface of stainless steel. Therefore, by providing an oxide film on the surface of stainless steel to form a porous member, liquid metal sodium can be appropriately sucked and recovered by the porosity formed on the surface.

Further, in the liquid metal sodium recovery device of the first embodiment, the porous members 37, 43, 45 for sucking and recovering the liquid metal sodium are arranged below the equipment for storing or supplying the liquid metal sodium. do.

Therefore, when the liquid metal sodium leaks from the pipe 30, and the leaked liquid metal sodium falls and comes into contact with the porous members 37, 43, 45, the liquid metal sodium leaks from the porous members 37, 43, 45 due to the capillary phenomenon. It is sucked into each hole and collected inside. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the liquid metal sodium recovery device of the present embodiment, the porous member 37 is arranged on the floor surface below the pipe. Therefore, when liquid metal sodium leaks from the connecting portion, the welded portion, or the damaged portion of the pipe 30, the leaked and dropped liquid metal sodium comes into contact with the porous member 37 arranged on the floor surface below the pipe 30. Since the liquid metallic sodium is sucked into the porous member 37 by the capillary phenomenon and recovered, the safety in the recovery work of the metallic sodium can be improved.

In the liquid metal sodium recovery device of the present embodiment, the porous member 45 is suspended and supported at a position facing below the pipe 30. Therefore, when liquid metal sodium leaks from the connecting portion, the welded portion, or the damaged portion of the pipe 30, the leaked and dropped liquid metal sodium comes into contact with the porous member 45 suspended below the pipe 30 and becomes liquid. Since the metallic sodium is sucked into the porous member 45 by the capillary phenomenon and recovered, the safety in the recovery operation of the metallic sodium can be improved.

In the first embodiment described above, the pipe 30 is applied as the equipment, but the equipment is not limited to the pipe 30, and the equipment is not limited to the pipe 30, for example, the superheater 16, the evaporator 17, and the secondary main cooling system circulation pump 18. And so on.

[Second Embodiment]
FIG. 6 is a schematic view showing the liquid metal sodium recovery device of the second embodiment. The members having the same functions as those of the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 6, in the superheater 16, the lower body 51 has a cylindrical shape with an upper portion open and a lower portion closed, and a sodium outlet 52 is provided at a lower end portion. The upper body 53 has a cylindrical shape with the lower part open and the upper part closed, and is provided with a sodium inlet 54 on the side portion. Further, the upper body 53 is provided with a steam inlet 55 and a steam outlet 56 at the upper part. The upper body 53 is fixed so as to close the opening of the lower body 51.

The upper support plate 57 and the lower support plate 58 are fixed to the lower body 51. The lower body 51 is adjacent to the inner wall surface and is provided with a plurality of descending pipes 59 along the vertical direction and arranged in the circumferential direction. Further, the lower body 51 is provided with a plurality of heat transfer tubes 60 adjacent to the inside of each descending tube 59 along the vertical direction and arranged in the circumferential direction. Each descending tube 59 and each heat transfer tube 60 are supported by an upper support plate 57 and a lower support plate 58. The upper end of each descending pipe 59 is connected to the steam inlet 55, the lower end is connected to the lower end of each heat transfer tube 60 by the connecting pipe 61, and the upper end of each heat transfer tube 60 is connected to the steam outlet 56. It is connected.

Therefore, the secondary liquid metal sodium is introduced into the superheater 16 from the sodium inlet 54 of the upper body 53, moves downward inside, and is discharged to the outside from the sodium outlet 52 of the lower body 51. On the other hand, the steam of the tertiary system is introduced into the superheater 16 from the steam inlet 55 of the upper body 53 and moves downward through the inside of each descending pipe 59, and at this time, with the steam of the tertiary system in each descending pipe 59. It exchanges heat with an external secondary liquid metal sodium. That is, the steam of the tertiary system takes heat from the liquid metal sodium of the secondary system and is heated, flows to each heat transfer tube 60 through the connecting pipe 61, moves upward through the inside of each heat transfer tube 60, and is the upper part. It is discharged to the outside from the steam outlet 56 of the body 53.

In the superheater 16 configured in this way, the liquid metal sodium inside is discharged to the outside at the time of dismantling, but a part of the liquid metal sodium remains inside. The second embodiment is a method and apparatus for recovering liquid metal sodium that safely recovers the liquid metal sodium remaining in the superheater 16.

The method for recovering liquid metal sodium according to the second embodiment is to bring the porous member into contact with the liquid metal sodium, and to suck and recover the liquid metal sodium inside the porous member. The porous member is configured in the same manner as in the first embodiment described above.

In the method of recovering the liquid metal sodium of the second embodiment, the porous member is inserted into the superheater 16 as equipment or a container and brought into contact with the liquid metal sodium remaining in the superheater 16 to obtain the porous member. Liquid metal sodium is sucked inside and recovered. At this time, the liquid metal sodium remaining in the superheater 16 is preheated to 150 ° C. or higher, and then the porous member is brought into contact with the superheater 16.

Further, the liquid metal sodium recovery device of the second embodiment is an insertion / discharge device that inserts and discharges a porous member that sucks and recovers the liquid metal sodium into the inside of the superheater 16 in which the liquid metal sodium remains. Has 70.

The insertion / discharge device 70 has a drive device 71 and a wire (cord-like body) 72. Although not shown, the drive device 71 has a rotatable reel and a motor for rotating the reel, and the base end portion of the wire 72 is wound around the drive device 71. Further, the wire 72 is supported by a plurality of pulleys 74, and a porous member 73 is connected to the tip end portion thereof. Further, the liquid metal sodium recovery device has a heating device 75 arranged around the superheater 16.

Therefore, when the superheater 16 is disassembled, the liquid metal sodium inside is discharged to the outside, but a part of the liquid metal sodium remains inside. At this time, the upper body 53 is removed from the lower body 51, and the lower body 51 is heated by the heating device 75. Then, the wire 72 is unwound from the drive device 71 by the insertion / discharge device 70, and the porous member 73 connected to the tip of the wire 72 is inserted into the lower body 51.

FIG. 7 is a schematic view showing a recovery operation of liquid metal sodium. As shown in FIG. 7, by feeding out the wire 72, the porous member 73 is lowered in the lower body 51 and brought into contact with the liquid metal sodium. At this time, it is preferable to attach the camera to the tip of the wire 72 and operate the insertion / ejection device 70 while the operator visually recognizes the inside of the lower body 51 from the outside by the monitor of the camera. At this time, the liquid metal sodium Na-4 remains, for example, at the corner where the inner surface of the lower body 51 and the upper surface of the upper support plate 57 intersect, and when the surface of the porous member 73 comes into contact, due to the capillary phenomenon. It is sucked into the porous member 73 and recovered. At this time, the liquid metal sodium Na-2 is maintained inside the porous member 73.

The structure of the porous member 73 is not limited to the above-mentioned structure. FIG. 8 is a schematic view showing a first modification of the liquid metal sodium recovery device of the second embodiment, and FIG. 9 is a schematic view showing a second modification of the liquid metal sodium recovery device of the second embodiment. be.

In the first modification, as shown in FIG. 8, a rod-shaped heater (heating device) 81 is connected to the tip of the wire 72, and the porous member 82 is fixed around the tip of the heater 81. Therefore, by feeding out the wire 72, the heater 81 and the porous member 82 are lowered in the lower body 51 and brought into contact with the solid metallic sodium. At this time, the porous member 82 is heated by the heater 81 and maintained at a high temperature state, and the solid metallic sodium remaining at the corner where the inner surface of the lower body 51 and the upper surface of the upper support plate 57 intersect is porous. When the quality member 82 comes into contact with the material member 82, it melts into liquid metal sodium Na-4, which is sucked into the porous member 82 by a capillary phenomenon and recovered. At this time, the liquid metal sodium Na-2 is maintained inside the porous member 82.

In the second modification, as shown in FIG. 9, a rod-shaped heater 81 is connected to the tip of the wire 72, and a tubular guide 83 is fixed around the heater 81. The porous member 84 has a band shape, is arranged around the tip of the heater 81, and is movably supported along the longitudinal direction by the guide 83. Although not shown, a device for moving the porous member 84 is provided. Therefore, by feeding out the wire 72, the heater 81, the guide 83, and the porous member 84 are lowered in the lower body 51 and brought into contact with the solid metallic sodium. At this time, the porous member 84 is heated by the heater 81 and maintained at a high temperature state, and the solid metallic sodium remaining in the lower body 51 is melted by the contact with the porous member 84 and is liquid metal sodium Na. It becomes -4, and it is sucked into the porous member 84 and recovered by the capillary phenomenon. At this time, by moving the porous member 84 along the heater 81, the contact position of the porous member 84 with respect to the liquid metal sodium Na-4 is updated, and a large amount of the liquid metal sodium Na-4 can be recovered.

As described above, in the method for recovering the liquid metal sodium of the second embodiment, the porous members 73, 82, 84 are inserted into the superheater 16 and brought into contact with the liquid metal sodium remaining in the superheater 16. Then, the liquid metal sodium is sucked into the inside of the porous members 73, 82, 84 and recovered.

Therefore, the porous members 73, 82, 84 are inserted into the superheater 16, and the porous members 73, 82, 84 are brought into contact with the liquid metal sodium remaining in the superheater 16 to suck and recover the liquid metal sodium. By doing so, for example, the dismantling work of the superheater 16 can be carried out efficiently and safely.

In the method for recovering liquid metal sodium according to the second embodiment, the liquid metal sodium is heated to 150 ° C. or higher, and then the porous members 73, 82, 84 are brought into contact with each other. Therefore, the wettability of the liquid metal sodium with respect to the porous members 73, 82, 84 is improved, and the liquid metal sodium can be appropriately sucked and recovered.

Further, in the liquid metal sodium recovery device of the second embodiment, the porous members 73, 82, 84 that suck and recover the liquid metal sodium into the inside of the superheater 16 in which the liquid metal sodium remains are sucked and recovered. Is provided with an insertion / discharge device 70 for inserting and discharging.

Therefore, when the porous members 73, 82, 84 are inserted into the superheater 16 by the insertion / discharge device 70 and the porous members 73, 82, 84 come into contact with the liquid metal sodium, the liquid metal sodium becomes porous due to the capillary phenomenon. It is sucked into each hole of the member 73, 82, 84 and collected inside. Therefore, the introduction of the inert gas becomes unnecessary, and the worker does not have to directly recover the metallic sodium, so that the safety of the work can be improved.

In the liquid metal sodium recovery device of the second embodiment, the insertion / discharge device 70 is provided with a wire 72 to which the porous members 73, 82, 84 are connected to the tip portion, and a drive device 71 for moving the wire 72. There is. Therefore, the porous members 73, 82, 84 can be inserted into the superheater 16 by moving the wire 72 by the drive device 71, and the liquid metal sodium recovery work can be smoothly carried out from the outside of the equipment. Can be done.

In the second embodiment described above, the superheater 16 is applied as the equipment or container, but the equipment or container is not limited to the superheater 16, and for example, the evaporator 17 and the secondary main cooling system circulation. It may be a pump 18 or the like.

10 Nuclear power plant 11 Reactor containment vessel 12 Fast breeder reactor 13 Primary main cooling system intermediate heat exchanger 14 Primary main cooling system circulation pump 15a, 15b, 15c Primary main cooling system piping 16 Superheater (equipment, container)
17 Evaporator 18 Secondary main cooling system circulation pump 19a, 19b, 19c Secondary main cooling system piping 20 Air cooling piping 21 Air cooler 22a, 22b Tertiary cooling system piping 23 Steam turbine 24 Generator 25 Condenser 30 piping ( Facility)
31 1st pipe 32 2nd pipe 37,43,45,73,82,84 Porous member 41 Welded part 42 Insulation material 44 Support plate 70 Insertion / discharge device 71 Drive device 72 Wire (cord)
75 Heating device 81 Heater (heating device)
83 Guide

Claims (7)

By bringing the porous member into contact with the liquid metal sodium, the liquid metal sodium is sucked and recovered inside the porous member.
The porous member is made of a material containing at least nickel.
The porous member is formed by plating the surface of pure nickel or stainless steel with nickel.
A method for recovering liquid metal sodium. By bringing the porous member into contact with the liquid metal sodium, the liquid metal sodium is sucked and recovered inside the porous member.
The porous member is made of a material containing at least nickel.
The porous member is configured by providing an oxide film on the surface of stainless steel.
A method for recovering liquid metal sodium. By bringing the porous member into contact with the liquid metal sodium, the liquid metal sodium is sucked and recovered inside the porous member.
By inserting the porous member into the facility and bringing it into contact with the liquid metal sodium remaining in the facility, the liquid metal sodium is sucked and recovered inside the porous member.
A method for recovering liquid metal sodium. The method for recovering liquid metal sodium according to any one of claims 1 to 3 , wherein the porous member is brought into contact with the liquid metal sodium after being heated to 150 ° C. or higher. A porous member for sucking and recovering the liquid metal sodium is arranged below the equipment for storing or supplying the liquid metal sodium .
The equipment is a pipe, and the porous member is suspended and supported at a position facing below the pipe.
A liquid metal sodium recovery device characterized by that. An insertion / discharge device for inserting and discharging a porous member that sucks and recovers the liquid metal sodium is provided inside the equipment in which the liquid metal sodium remains.
A liquid metal sodium recovery device characterized by that. The equipment is a container, and the insertion / discharge device is characterized by having a cord-like body to which the porous member is connected to a tip portion and a drive device for moving the cord - like body. The liquid metal sodium recovery device described.

Images