Underwater collecting and storing device for damaged pipe section of spent fuel assembly

Abstract

The invention provides a spent fuel assembly damaged pipe section underwater collecting and storing device. The spent fuel assembly damaged pipe section underwater collecting and storing device comprises a storage pipe arranged in a storage cavity of a pool storage grillwork; the sealing cover is detachably connected with the upper end opening of the storage pipe through a plurality of connecting bolts; a remote dismounting assembly provided with a plurality of connecting bolts is dismounted; the inflation assembly is arranged on the surface of the sealing cover, and the air outlet end of the inflation assembly communicates with the storage pipe; and the drainage assembly is arranged on the surface of the sealing cover, and the water inlet end of the drainage assembly communicates with the storage pipe. According to the scheme, dismounting of the connecting bolts is achieved through the remote dismounting and mounting assembly, separation of the sealing cover and the storage pipe is achieved, the damaged pipe section of the spent fuel assembly is placed in the storage pipe through fishing equipment, the sealing cover and the storage pipe are connected, and water in the storage pipe is drained through the inflation assembly and the drainage assembly; therefore, after the spent fuel assembly falls off and is disintegrated, fragments such as a shell and a fuel pipe section are cleaned and stored, and radioactive leakage is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of spent fuel assembly processing, and particularly to an underwater storage device for damaged pipe sections of spent fuel assemblies. Background Art

[0002] The main tasks of the spent fuel receiving and storage facility are to receive the spent fuel transport containers transported from nuclear power plants, unload the spent fuel assemblies underwater, and send them to the storage racks in the storage pool for storage. During the unloading process of the spent fuel assemblies, it is necessary to grab the spent fuel assemblies in the spent fuel transport containers through a spent fuel assembly gripper, and transfer the spent fuel assemblies to the storage sleeves of the designated storage racks through a water channel. During this process, there is a risk of the spent fuel assemblies falling. If a spent fuel assembly dropping accident occurs, the spent fuel assembly may collide, be squeezed, or rubbed during the falling process, resulting in the rupture and disintegration of the spent fuel assembly, and causing the fuel pipe sections and cladding fragments of the spent fuel assembly to scatter on the bottom of the pool. If not cleaned and salvaged in time, it will cause continuous release of radionuclides, resulting in a continuous increase in the radioactive levels at the bottom of the pool and in the pool hall.

[0003] Due to the high radioactivity of the partially disintegrated damaged spent fuel assemblies, fuel pipe sections, and cladding fragments of the spent fuel assemblies that have fallen into the storage pool, and the problems of complex underwater environment and narrow space, there is currently no special device for collecting and storing the fragmented nuclear fuel assemblies, outer shells, fuel pipe sections, etc. scattered from the partially damaged and disintegrated spent fuel assemblies at the bottom of the storage pool, and it is impossible to handle the cleaning and storage work of the outer shells, fuel pipe sections, etc. after the spent fuel assembly falls and disintegrates. Summary of the Invention

[0004] The present invention provides an underwater storage device for damaged pipe sections of spent fuel assemblies. By means of a remote disassembly and assembly component, the connection bolts are removed to separate the sealing cover from the storage pipe. The damaged pipe section of the spent fuel assembly is placed in the storage pipe through a salvage device, and the sealing cover and the storage pipe are connected. The water inside the storage pipe is discharged through an inflation component and a drainage component, so as to realize the cleaning and storage work of the outer shells, fuel pipe sections, etc. after the spent fuel assembly falls and disintegrates, and avoid radioactive leakage.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] An underwater storage device for damaged pipe sections of spent fuel assemblies, comprising:

[0007] A storage pipe placed in the storage cavity of the pool storage rack;

[0008] A sealing cover, which is detachably connected to the upper port of the storage pipe through a plurality of connection bolts;

[0009] A remote disassembly and assembly component for disassembling and installing a plurality of connection bolts;

[0010] A detachable inflatable component, which is arranged on the surface of the sealing cover, and the air outlet end of the inflatable component is communicated with the storage pipe;

[0011] A detachable drainage component, which is arranged on the surface of the sealing cover, and the water inlet end of the drainage component is communicated with the storage pipe.

[0012] Optionally, the inflatable component includes:

[0013] A first male connector, which is connected in the air inlet on the surface of the sealing cover, and the air inlet is communicated with the storage pipe;

[0014] A first female connector that is inserted and matched with the first male connector;

[0015] An air inlet pipe, the air inlet end of which is connected to a gas source, and the air outlet end of which is connected to the first female connector;

[0016] A first remote separation component connected to the first female connector.

[0017] Optionally, the drainage component includes:

[0018] A second male connector, which is connected in the drain hole on the surface of the sealing cover;

[0019] A liquid guide pipe, the first end of which is connected to the drain hole, and the second end of which extends to the inner bottom surface of the storage pipe;

[0020] A second female connector that is inserted and matched with the second male connector;

[0021] A drain pipe, the water inlet end of which is connected to the second female connector;

[0022] A second remote separation component connected to the second female connector.

[0023] Optionally, both the first remote separation component and the second remote separation component include:

[0024] A connecting ring, the inner diameter of which is adapted to the outer diameters of the first female connector and the second female connector;

[0025] First ear plates and second ear plates are respectively formed at both open ends of the connecting ring, and the first ear plates and the second ear plates are connected by fastening bolts and fastening nuts;

[0026] A gantry frame connected to the connecting ring;

[0027] A lifting ring connected to the gantry frame;

[0028] A rope connected to the hanging ring.

[0029] Optionally, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0030] A connection disk formed at the edge of the upper port of the storage pipe, and a plurality of threaded holes are penetrated through the surface of the connection disk. The plurality of threaded holes are evenly distributed in a circumferential manner with the axis of the storage pipe as the reference, and the plurality of threaded holes are adapted to a plurality of connection bolts;

[0031] A plurality of connection through holes are penetrated through the surface of the sealing cover, the plurality of connection through holes correspond to the plurality of threaded holes, and the plurality of connection bolts are located in the plurality of connection through holes.

[0032] Optionally, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0033] An annular groove formed on the surface of the connection disk, and the annular groove is distributed outside the upper port of the storage pipe;

[0034] A sealing ring, the sealing ring is embedded in the annular groove, and a part of the sealing ring protrudes from the upper surface of the connection disk.

[0035] Optionally, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0036] A clamping end connected to the sealing cover.

[0037] Optionally, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0038] A one-way exhaust valve connected to the upper surface of the sealing cover, and the intake end of the one-way exhaust valve is communicated with the storage pipe.

[0039] Optionally, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0040] A reinforcing plate connected to the bottom surface of the storage pipe, and the reinforcing plate abuts against the inner bottom surface of the storage cavity of the pool storage grid.

[0041] Optionally, the remote disassembly and assembly component includes:

[0042] A top threaded rod, and an operation handle is connected to the top end of the top threaded rod;

[0043] Multiple middle threaded rods;

[0044] A bottom threaded rod;

[0045] Connection sleeves are threadedly connected to the outside of the top threaded rod, the multiple middle threaded rods and the bottom threaded rod;

[0046] A screwing block is connected to the bottom end of the bottom threaded rod. An imitation cavity is formed on the bottom surface of the screwing block, and the imitation cavity is adapted to the screwing end of the connecting bolt.

[0047] The above solution of the present invention has at least the following beneficial effects:

[0048] In the above solution of the present invention, the connecting bolt is removed through the remote disassembly and assembly component to separate the sealing cover from the storage pipe. The damaged pipe section of the spent fuel assembly is placed in the storage pipe through the salvage device, and the sealing cover and the storage pipe are connected. The water inside the storage pipe is discharged through the inflation component and the drainage component, so as to realize the cleaning and storage of debris such as the outer shell and the fuel pipe section after the spent fuel assembly drops and disintegrates, and avoid radioactive leakage. Description of the Drawings

[0049] Figure 1 is a schematic structural diagram of an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention;

[0050] Figure 2 is a top view of an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention;

[0051] Figure 3 is a top view of a storage pipe in an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention;

[0052] Figure 4 is a schematic structural diagram of a remote disassembly and assembly component in an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention;

[0053] Figure 5 is a schematic structural diagram of a first remote separation component and a second remote separation component in an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention;

[0054] Figure 6 is a top view of a first remote separation component and a second remote separation component in an underwater storage device for a damaged pipe section of a spent fuel assembly provided by an embodiment of the present invention.

[0055] The description of the reference numerals is as follows:

[0056] 1. Storage tube; 11. Connection plate; 12. Threaded hole; 13. Annular groove; 14. Sealing ring; 15. Reinforcing plate; 2. Sealing cover; 21. Clamping end; 22. Air inlet; 23. Drain hole; 24. Connection through hole; 31. First male connector; 41. Second male connector; 42. Liquid guide tube; 5. Connection bolt; 6. One-way exhaust valve; 71. Top threaded rod; 72. Bottom threaded rod; 73. Connection sleeve; 74. Operating handle; 75. Screwing block; 76. Profiled cavity; 81. Connection ring; 82. Gantry; 83. Suspension ring; 84. First ear plate; 85. Second ear plate; 86. Fastening bolt; 87. Fastening nut; 9. Pool storage grid. Detailed implementation mode

[0057] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0058] As Figures 1 to 6 shown, an underwater storage device for a damaged pipe section of a spent fuel assembly according to an embodiment of the present invention includes:

[0059] A storage tube 1 placed in the storage cavity of a pool storage grid 9;

[0060] A sealing cover 2, and the sealing cover 2 is detachably connected to the upper port of the storage tube 1 through a plurality of connection bolts 5;

[0061] A remote disassembly and assembly component for disassembling and installing a plurality of connection bolts 5;

[0062] A detachable inflation component, the inflation component is arranged on the surface of the sealing cover 2, and the air outlet end of the inflation component is communicated with the storage tube 1;

[0063] A detachable drainage component, the drainage component is arranged on the surface of the sealing cover 2, and the water inlet end of the drainage component is communicated with the storage tube 1.

[0064] In this embodiment, under normal conditions, the storage tube 1 is placed in the storage cavity of the pool storage grid 9, and the sealing cover 2 is connected to the upper port of the storage tube 1 to seal the storage tube 1;

[0065] When there are debris such as the outer shells and fuel pipe segments of locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies scattered at the bottom of the storage pool, remove multiple connecting bolts 5 through the remote disassembly and assembly component, release the connection between the sealing cover 2 and the upper port of the storage pipe 1, clamp and remove the sealing cover 2 with the salvage equipment, install the inflation component and the drainage component, clamp and salvage the debris such as the outer shells and fuel pipe segments of the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies with the salvage equipment and place them in the storage pipe 1. After all the debris such as the outer shells and fuel pipe segments of the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies are stored in the storage pipe 1, place the sealing cover 2 at the upper port of the storage pipe 1 with the salvage equipment, and screw multiple connecting bolts 5 through the remote disassembly and assembly component to realize the connection between the sealing cover 2 and the upper port of the storage pipe 1 and seal the storage pipe 1. Inflate the inside of the storage pipe 1 through the inflation component, and under the action of air pressure, drain the water in the storage pipe 1 through the drainage component. After the water in the storage pipe 1 is drained, disassemble the inflation component and the drainage component to complete the collection and storage of the debris such as the outer shells and fuel pipe segments of the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies, and avoid radioactive leakage;

[0066] In this embodiment, the outer shape of the storage pipe 1 is adapted to the shape of the storage cavity of the pool storage grid 9 to ensure the stability of the storage pipe 1 in the storage cavity of the pool storage grid 9 and ensure the stable safety of the storage pipe 1. Specifically, the length of the storage pipe 1 is 222 mm, the width is 222 mm, the height is 4400 mm, and the wall thickness is 3 mm;

[0067] The salvage equipment in this embodiment includes a spent fuel assembly dropping and salvage device and an underwater foreign object salvage tool, and both the spent fuel assembly dropping and salvage device and the underwater foreign object salvage tool are existing tools;

[0068] The upper end component of the spent fuel assembly dropping and salvage device is connected to the special hoisting position of the crane. The lower end component of the spent fuel assembly dropping and salvage device is fixed to the connecting rod with bolts upward. The component is composed of various devices such as an underwater camera, two waterproof servo motors, an angle adjustment gear, a pitch adjustment gear, a positioning plate, a grabbing plate, and a safety pin, so that the lower end component can complete various actions such as rotation, upward tilt, downward droop, fixation, grabbing, and locking control, so as to complete the clamping and removal of the sealing cover 2, as well as the clamping and storage of the spent fuel assembly in the storage pipe 1;

[0069] The main structure of the underwater foreign object salvage tool consists of a wire winding mechanism, a connecting rod, and a grabbing head component; the shape, type, and depth of the foreign objects dropped in the pool can be observed through an underwater observation mirror. After determining the length, material of the connecting component of the underwater foreign object salvage device, and the type of the grabbing claws, connect the connecting rods one by one, connect and fasten the grabbing head component through the quick connector of the connecting steel wire rope, and complete the clamping of the scattered outer shell fragments and fuel pipe segments one by one through the two independent wire winding mechanisms on the control operation handle and place them in the storage pipe 1.

[0070] As Figure 1 shown, in an alternative embodiment of the present invention, the inflation assembly includes:

[0071] A first male connector 31, the first male connector 31 is connected to the air inlet 22 on the surface of the sealing cover 2, and the air inlet 22 is communicated with the storage pipe 1;

[0072] A first female connector that is inserted and mated with the first male connector;

[0073] An air inlet pipe, the air inlet end of the air inlet pipe is connected to a gas source, and the air outlet end of the air inlet pipe is connected to the first female connector;

[0074] A first remote separation assembly connected to the first female connector.

[0075] In this embodiment, the first male connector 31 and the first female connector are respectively the male connector and the female connector of a quick connector. The first male connector 31 is in a sealed state under normal conditions. After the first female connector is inserted and connected to the first male connector 31, the first female connector and the first male connector 31 are communicated;

[0076] The first male connector 31 is connected in the air inlet 22; after the sealing cover 2 is clamped and taken out of the water tank by a fishing device, the first female connector is inserted and connected to the first male connector 31 to realize the connection between the air inlet pipe and the first male connector 31; the first remote separation assembly is connected to the first female connector;

[0077] After all the fragments such as the outer shell and fuel pipe section of the partially damaged and disassembled nuclear fuel assembly and spent fuel assembly are stored in the storage pipe 1, the sealing cover 2 is placed at the upper port of the storage pipe 1 by a fishing device, and a plurality of connecting bolts 5 are screwed by a remote disassembly and assembly component to realize the connection between the sealing cover 2 and the upper port of the storage pipe 1 and seal the storage pipe 1;

[0078] Gas is injected into the storage pipe 1 through the gas source, the air inlet pipe, the first female connector and the first male connector 31. Under the action of air pressure, the water in the storage pipe 1 is discharged through the drainage assembly; after the water in the storage pipe 1 is discharged, the first female connector is pulled by the first remote separation assembly to realize the separation between the first female connector and the first male connector 31, and the first male connector 31 is in a sealed state.

[0079] As Figure 1 shown, in an alternative embodiment of the present invention, the drainage assembly includes:

[0080] A second male connector 41, the second male connector 41 is connected to the drain hole 23 on the surface of the sealing cover 2;

[0081] A liquid guide pipe 42, the first end of the liquid guide pipe 42 is connected to the drain hole 23, and the second end of the liquid guide pipe 42 extends to the inner bottom surface of the storage pipe 1;

[0082] A second female connector that is inserted and mated with the second male connector 41;

[0083] A drain pipe, the water inlet end of the drain pipe is connected to the second female connector;

[0084] A second remote separation assembly connected to the second female connector.

[0085] In this embodiment, the second male connector 41 and the second female connector are respectively the male connector and the female connector of a quick connector. The second male connector 41 is in a sealed state under normal conditions. After the second female connector is inserted and connected to the second male connector 41, the second female connector and the second male connector 41 are in communication;

[0086] The second male connector 41 is connected in the drain hole 23, and the liquid guide pipe 42 is connected in the drain hole 23; after the sealing cover 2 is clamped and taken out of the pool by a fishing device, the second female connector is inserted and connected to the second male connector 41 to realize the communication between the drain pipe and the second male connector 41; the second remote separation assembly is connected to the second female connector;

[0087] After all the debris such as the outer shell and fuel pipe sections scattered from the partially damaged and disassembled nuclear fuel assembly and spent fuel assembly are stored in the storage pipe 1, the sealing cover 2 is placed at the upper port of the storage pipe 1 by a fishing device, and a plurality of connecting bolts 5 are screwed by a remote disassembly and assembly assembly to realize the connection between the sealing cover 2 and the upper port of the storage pipe 1 and the sealing of the storage pipe 1;

[0088] Air is injected into the storage pipe 1 through the air injection assembly. Under the action of air pressure, the water in the storage pipe 1 is discharged through the liquid guide pipe 42, the second male connector 41, the second female connector and the drain pipe; after the water in the storage pipe 1 is discharged, the second female connector is pulled by the second remote separation assembly to realize the separation of the second female connector from the second male connector 41, and the second male connector 41 is in a sealed state.

[0089] Such as Figure 5 and Figure 6 shown, in an alternative embodiment of the present invention, both the first remote separation assembly and the second remote separation assembly include:

[0090] A connecting ring 81, the inner diameter of the connecting ring 81 is adapted to the outer diameters of the first female connector and the second female connector;

[0091] First ear plates 84 and second ear plates 85 are respectively formed at both open ends of the connecting ring 81, and the first ear plates 84 and the second ear plates 85 are connected by fastening bolts 86 and fastening nuts 87;

[0092] A gantry 82 connected to the connecting ring 81;

[0093] A lifting ring 83 connected to the gantry 82;

[0094] The rope connected to the lifting ring 83.

[0095] In this embodiment, the first female joint or the second female joint is passed through the connecting ring 81, the air inlet pipe or the drain pipe is passed out of the gantry 82, the fastening bolt 86 is passed through the first ear plate 84 and the second ear plate 85, and the fastening nut 87 is screwed onto the end of the fastening bolt 86 to clamp and fix the connecting ring 81 outside the first female joint or the second female joint; the rope is connected to the lifting ring 83;

[0096] After the water in the storage pipe 1 is drained, the lifting ring 83 is pulled by the rope, and the connecting ring 81 is pulled by the gantry 82, so that the connecting ring 81 drives the first female joint to separate from the first male joint 31, or the second female joint to separate from the second male joint 41;

[0097] In this embodiment, the lifting ring 83 is located in the middle of the gantry 82. By pulling the connecting ring 81 through the lifting ring 83 and the gantry 82, the connecting ring 81 can be evenly stressed, so that the first female joint or the second female joint is evenly stressed, which is convenient for separating the first female joint from the first male joint 31, or the second female joint from the second male joint 41.

[0098] Such as Figure 1 and Figure 2 shown, in an alternative embodiment of the present invention, the underwater storage device for the damaged pipe section of the spent fuel assembly further includes:

[0099] A connecting disk 11 formed on the edge of the upper port of the storage pipe 1, and a plurality of threaded holes 12 are penetrated on the surface of the connecting disk 11. The plurality of threaded holes 12 are evenly distributed circumferentially with the axis of the storage pipe 1 as the reference, and the plurality of threaded holes 12 are adapted to the plurality of connecting bolts 5;

[0100] A plurality of connecting through holes 24 are penetrated on the surface of the sealing cover 2. The plurality of connecting through holes 24 correspond to the plurality of threaded holes 12, and the plurality of connecting bolts 5 are located in the plurality of connecting through holes 24.

[0101] In this embodiment, the connection between the sealing cover 2 and the connecting disk 11 is realized through the plurality of connecting bolts 5, which can ensure the stability of the connection between the sealing cover 2 and the upper port of the storage pipe 1;

[0102] The number of the connecting through holes 24 is an even number, and any one of the connecting through holes 24 has a connecting through hole 24 symmetrically distributed with it with the axis of the storage pipe 1 as the reference. Through this setting, the connection force between the sealing cover 2 and the connecting disk 11 can be symmetric and uniform, further ensuring the stability of the connection between the sealing cover 2 and the upper port of the storage pipe 1;

[0103] In this embodiment, the depth of the connecting through-hole 24 is greater than half of the length of the threaded section of the connecting bolt 5. With this setting, when the connecting bolt 5 is disassembled, after the connecting bolt 5 is completely disengaged from the threaded hole 12, the connecting thread can be stably located inside the connecting through-hole 24. When the sealing cover 2 is clamped and moved by the fishing equipment, the connecting bolt 5 can be prevented from disengaging from the connecting through-hole 24.

[0104] In an alternative embodiment of the present invention, the underwater storage device for damaged pipe sections of spent fuel assemblies further includes:

[0105] An annular groove 13 formed on the surface of the connecting plate 11, and the annular groove 13 is distributed outside the upper port of the storage pipe 1.

[0106] A sealing ring 14, the sealing ring 14 is embedded in the annular groove 13, and a part of the sealing ring 14 protrudes from the upper surface of the connecting plate 11.

[0107] In this embodiment, by providing the sealing ring 14, after the connection between the sealing cover 2 and the connecting plate 11 is completed, the sealing ring 14 is fully in contact with the sealing cover 2, ensuring the connection sealing performance between the sealing cover 2 and the connecting plate 11, thereby ensuring the sealing performance of the storage pipe 1 and the storage safety of the fragments such as the outer shell and fuel pipe sections of the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies.

[0108] Such as Figure 1 and Figure 2 shown, in an alternative embodiment of the present invention, the underwater storage device for damaged pipe sections of spent fuel assemblies further includes:

[0109] A clamping end 21 connected to the sealing cover 2.

[0110] In this embodiment, the clamping end 21 is adapted to the clamping end of the fishing equipment, so that the clamping end of the fishing equipment clamps the clamping end 21, thereby realizing the clamping and removal of the sealing cover 2 and placing the sealing cover 2 at the upper end port of the storage pipe 1.

[0111] Such as Figure 2 shown, in an alternative embodiment of the present invention, the underwater storage device for damaged pipe sections of spent fuel assemblies further includes:

[0112] A one-way exhaust valve 6 connected to the upper surface of the sealing cover 2, and the air inlet end of the one-way exhaust valve 6 is communicated with the storage pipe 1.

[0113] In this embodiment, when storing the debris such as the housing and fuel pipe segments of the nuclear fuel assembly and spent fuel assembly that are partially damaged and disassembled through the storage pipe 1, the temperature inside the storage pipe 1 will rise, causing the internal pressure of the storage pipe 1 to increase. By setting the one-way exhaust valve 6, the release of the internal pressure of the storage pipe 1 can be achieved, ensuring the safety of the storage pipe 1, thereby ensuring the safety of storing the debris such as the housing and fuel pipe segments of the nuclear fuel assembly and spent fuel assembly that are partially damaged and disassembled, and avoiding radioactive leakage.

[0114] As Figure 1 shown, in an alternative embodiment of the present invention, the underwater storage device for damaged pipe segments of spent fuel assemblies further includes:

[0115] A reinforcing plate 15 connected to the bottom surface of the storage pipe 1, and the reinforcing plate 15 abuts against the bottom surface of the storage cavity of the pool storage grid 9.

[0116] In this embodiment, by providing the reinforcing plate 15 at the bottom surface of the storage pipe 1 and the reinforcing plate 15 abutting against the bottom surface of the storage cavity of the pool storage grid 9, the overall strength of the storage pipe 1 can be increased. At the same time, when the storage pipe 1 is placed in the storage cavity of the pool storage grid, it can effectively support the storage pipe 1, ensuring the safety and stability of the storage pipe 1 in the storage cavity of the pool storage grid, avoiding deformation and damage of the storage pipe 1, ensuring the safety of storing the debris such as the housing and fuel pipe segments of the nuclear fuel assembly and spent fuel assembly that are partially damaged and disassembled, and avoiding radioactive leakage.

[0117] As Figure 4 shown, in an alternative embodiment of the present invention, the remote disassembly and assembly component includes:

[0118] A top threaded rod 71, and an operation handle 74 is connected to the top end of the top threaded rod 71;

[0119] Multiple middle threaded rods;

[0120] A bottom threaded rod 72;

[0121] Connecting sleeves 73 are threadedly connected to the outside of the top threaded rod 71, multiple middle threaded rods, and the bottom threaded rod 72;

[0122] A screwing block 75, the screwing block 75 is connected to the bottom end of the bottom threaded rod 72, and a profiling cavity 76 is formed on the bottom surface of the screwing block 75, and the profiling cavity 76 is adapted to the screwing end of the connecting bolt 5.

[0123] In this embodiment, the connection sleeve 73 can be used to achieve the docking connection between the top threaded rod 71 and the middle threaded rod, the docking connection between two middle threaded rods, and the docking connection between the middle threaded rod and the bottom threaded rod 72; in specific use, by adjusting the number of middle threaded rods, the length adjustment of the remote disassembly and assembly component can be achieved to meet different usage requirements;

[0124] When disassembling and installing multiple connecting bolts 5, an operator holds the operating handle 74, aligns the profiling cavity 76 with the screwing end of the connecting bolt 5, and inserts the screwing end of the connecting bolt 5 into the profiling cavity 76. The operator rotates the top threaded rod 71 through the operating handle 74, causing the screwing block 75 to drive the connecting bolt 5 to rotate, thus achieving the disassembly or installation of the connecting bolt 5, enabling the operator to remotely operate to complete the disassembly and installation of the connecting bolt 5 and ensuring the safety of the operator.

[0125] Underwater storage method for damaged pipe sections of spent fuel assemblies:

[0126] Under normal conditions, the storage pipe 1 is placed in the storage cavity of the pool storage grid 9, and the sealing cover 2 is connected to the upper port of the storage pipe 1 to seal the storage pipe 1;

[0127] When there are debris such as the outer shells and fuel pipe sections scattered from the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies at the bottom of the storage pool, according to the position of the storage pipe 1, select an appropriate number of middle threaded rods. Through the connecting sleeve 73, the docking connection between the top threaded rod 71 and the middle threaded rod can be achieved, the docking connection between two middle threaded rods can be realized, and the docking connection between the middle threaded rod and the bottom threaded rod 72 can be achieved to complete the assembly of the remote disassembly and assembly component; The operator holds the operation handle 74, aligns the profiling cavity 76 with the screwing end of the connecting bolt 5, and makes the screwing end of the connecting bolt 5 enter the inside of the profiling cavity 76. The operator rotates the top threaded rod 71 through the operation handle 74, and the screwing block 75 drives the connecting bolt 5 to rotate to achieve the disassembly of the connecting bolt 5; Clamp and remove the sealing cover 2 through the salvage equipment; Pass the first female joint through the connecting ring 81 of the first remote separation component, and screw the fastening nut 87 of the first remote separation component, and cooperate with the fastening bolt 86 to achieve the connection between the connecting ring 81 of the first remote separation component and the first female joint, and make the first female joint and the first male joint 31 inserted and connected to complete the installation of the inflation component; Pass the second female joint through the connecting ring 81 of the second remote separation component, and screw the fastening nut 87 of the second remote separation component, and cooperate with the fastening bolt 86 to achieve the connection between the connecting ring 81 of the second remote separation component and the second female joint, and make the second female joint and the second male joint 41 inserted and connected to complete the installation of the drainage component; Clamp and salvage the debris such as the outer shells and fuel pipe sections scattered from the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies through the salvage equipment and place them in the storage pipe 1. After all the debris such as the outer shells and fuel pipe sections scattered from the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies are stored in the storage pipe 1, place the sealing cover 2 at the upper port of the storage pipe 1 through the salvage equipment. The operator rotates the top threaded rod 71 through the operation handle 74, and the screwing block 75 drives the connecting bolt 5 to rotate to achieve the installation of the connecting bolt 5, thereby realizing the connection between the sealing cover 2 and the upper port of the storage pipe 1 and realizing the sealing of the storage pipe 1; Inject gas into the storage pipe 1 through the gas source, the inlet pipe, the first female joint and the first male joint 31, and under the action of air pressure, the water in the storage pipe 1 is discharged through the liquid guide pipe 42, the second male joint 41, the second female joint and the drain pipe; After the water in the storage pipe 1 is discharged, pull the ropes of the first remote separation component and the second remote separation component respectively. Pull the lifting ring 83 through the rope, and pull the connecting ring 81 through the gantry 82, so that the connecting ring 81 drives the first female joint to separate from the first male joint 31, or the second female joint to separate from the second male joint 41, to complete the collection and storage of the debris such as the outer shells and fuel pipe sections scattered from the locally damaged and disassembled nuclear fuel assemblies and spent fuel assemblies, and avoid radioactive leakage;

[0128] Through the above process, it is possible to realize the cleaning and storage of debris such as outer shells and fuel pipe sections after the drop and disassembly accident of spent fuel assemblies, avoid radioactive leakage, and all operations can be completed remotely, which can ensure the safety of operators.

[0129] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An underwater storage device for a damaged pipe section of a spent fuel assembly, characterized in that, Comprising: A storage tube (1) placed in the storage cavity of a pool storage rack (9); A sealing cover (2), which is detachably connected to the upper port of the storage tube (1) by a plurality of connecting bolts (5); A remote disassembly and installation assembly for disassembling and installing a plurality of connecting bolts (5); A detachable inflation assembly, which is arranged on the surface of the sealing cover (2), and the air outlet end of the inflation assembly is communicated with the storage tube (1); A detachable drainage assembly, which is arranged on the surface of the sealing cover (2), and the water inlet end of the drainage assembly is communicated with the storage tube (1).

2. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 1, wherein The inflation assembly includes: A first male connector (31), which is connected in the air inlet (22) on the surface of the sealing cover (2), and the air inlet (22) is communicated with the storage tube (1); A first female connector that is inserted and matched with the first male connector (31); An air inlet pipe, the air inlet end of which is connected to a gas source, and the air outlet end of which is connected to the first female connector; A first remote separation assembly connected to the first female connector.

3. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 2, characterized in that, The drainage assembly includes: A second male connector (41), which is connected in the drain hole (23) on the surface of the sealing cover (2); A liquid guide pipe (42), the first end of which is connected to the drain hole (23), and the second end of which extends to the inner bottom surface of the storage tube (1); A second female connector that is inserted and matched with the second male connector (41); A drain pipe, the water inlet end of which is connected to the second female connector; A second remote separation assembly connected to the second female connector.

4. The underwater storage device for the damaged pipe section of the spent fuel assembly according to claim 3, wherein, Both the first remote separation assembly and the second remote separation assembly include: A connecting ring (81), the inner diameter of which is adapted to the outer diameters of the first female connector and the second female connector; First ear plates (84) and second ear plates (85) are respectively formed at both ends of the opening of the connecting ring (81), and the first ear plates (84) and the second ear plates (85) are connected by a fastening bolt (86) and a fastening nut (87); A gantry (82) connected to the connecting ring (81); A lifting ring (83) connected to the gantry (82); A rope connected to the lifting ring (83).

5. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 1, wherein It further includes: A connecting disk (11) formed on the edge of the upper port of the storage tube (1), and a plurality of threaded holes (12) are formed through the surface of the connecting disk (11). The plurality of threaded holes (12) are evenly distributed in a circumferential manner with the axis of the storage tube (1) as the reference, and the plurality of threaded holes (12) are adapted to the plurality of connecting bolts (5); A plurality of connecting through holes (24) are formed through the surface of the sealing cover (2). The plurality of connecting through holes (24) correspond to the plurality of threaded holes (12), and the plurality of connecting bolts (5) are located in the plurality of connecting through holes (24).

6. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 5, characterized in that, It further includes: An annular groove (13) formed on the surface of the connecting disk (11), and the annular groove (13) is distributed outside the upper port of the storage tube (1). A sealing ring (14), the sealing ring (14) is embedded in the annular groove (13), and a part of the sealing ring (14) protrudes from the upper surface of the connection disc (11).

7. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 1, characterized in that, Further comprising: A clamping end (21) connected to the sealing cover (2).

8. The underwater storage device for the damaged pipe section of the spent fuel assembly according to claim 1, characterized in that, Further comprising: A one-way exhaust valve (6) connected to the upper surface of the sealing cover (2), and an air inlet end of the one-way exhaust valve (6) is communicated with the storage pipe (1).

9. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 1, characterized in that, Further comprising: A reinforcing plate (15) connected to the bottom surface of the storage pipe (1), and the reinforcing plate (15) abuts against the inner bottom surface of the storage cavity of the water tank storage grid (9).

10. The underwater storage device for damaged pipe sections of spent fuel assemblies according to claim 1, wherein The remote disassembly and assembly component comprises: A top threaded rod (71), and an operation handle (74) is connected to the top end of the top threaded rod (71); Multiple middle threaded rods; A bottom threaded rod (72); Connection sleeves (73) are threadedly connected to the outer sides of the top threaded rod (71), the multiple middle threaded rods, and the bottom threaded rod (72); A screwing block (75), the screwing block (75) is connected to the bottom end of the bottom threaded rod (72), a profiling cavity (76) is formed on the bottom surface of the screwing block (75), and the profiling cavity (76) is adapted to the screwing end of the connection bolt (5).

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