Neutron absorption device and use method

Abstract

The invention provides a neutron absorption device and a use method. The neutron absorption device comprises an outer cylinder with a hollow structure; the inner barrel is fixedly connected with the inner side of the outer barrel; the hoisting head is fixedly connected with the first end parts of the outer barrel and the inner barrel, the hoisting head and the outer barrel are coaxially arranged, and the diameter of the section of the hoisting head is larger than that of the section of the outer barrel; the outer sealing bottom is fixedly connected with the second end part of the outer cylinder body; the inner sealing bottom is fixedly connected with the inner side of the outer sealing bottom; the screens are fixedly arranged on the inner sides of the outer barrel body and the outer sealing bottom and the outer sides of the inner barrel body and the inner sealing bottom; the neutron poison support is fixedly connected with the inner sealing bottom and the outer sealing bottom; the neutron poison sleeve is detachably connected with the neutron poison support; wherein the neutron poison sleeve is arranged in or lifted out of the neutron poison support through a lifting appliance. According to the scheme, the utilization rate, safety and repeatability of neutron poison during spent fuel aftertreatment can be improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of spent fuel reprocessing, and particularly to a neutron absorption device and a usage method thereof. Background Art

[0002] In a spent fuel reprocessing facility, it is necessary to shear and dissolve spent fuel assemblies. As a dissolving device for sheared short segments, a dissolver usually uses neutron poisons and geometric measures to ensure critical safety.

[0003] In the prior art, a hanging basket with gadolinium rods in the middle is used to meet critical safety and at the same time achieve selective filtration of insoluble residues. However, after the hanging basket is used, it needs to be replaced regularly and cannot be reused, resulting in low utilization rate of gadolinium rods and increased production costs; moreover, the gadolinium rods in the hanging basket are prone to skew after use, resulting in the risk that the hanging basket cannot be lifted out after use, affecting the continuity and stability of production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a neutron absorption device and a usage method thereof, which can improve the utilization rate, safety, and repeatability of neutron poison absorption and reduce production costs.

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

[0006] A neutron absorption device includes:

[0007] An outer cylinder body with a hollow structure;

[0008] An inner cylinder body fixedly connected to the inner side of the outer cylinder body;

[0009] A lifting head fixedly connected to the first ends of the outer cylinder body and the inner cylinder body, the lifting head is coaxially arranged with the outer cylinder body, and the cross-sectional diameter of the lifting head is larger than the cross-sectional diameter of the outer cylinder body;

[0010] An outer bottom seal fixedly connected to the second end of the outer cylinder body;

[0011] An inner bottom seal fixedly connected to the inner side of the outer bottom seal;

[0012] A screen fixedly arranged on the inner side of the outer cylinder body and the outer bottom seal, and on the outer side of the inner cylinder body and the inner bottom seal;

[0013] A neutron poison support fixedly connected to the inner bottom seal and the outer bottom seal;

[0014] A neutron poison sleeve detachably connected to the neutron poison support;

[0015] Wherein, the neutron poison sleeve is placed into or lifted out of the neutron poison support through a lifting tool.

[0016] Optionally, the inner cylinder body and the outer cylinder body are coaxially arranged.

[0017] Optionally, the neutron poison support is correspondingly arranged with the neutron poison sleeve, and the neutron poison support is made of stainless steel.

[0018] Optionally, a guiding structure is arranged at the top of the neutron poison support.

[0019] Optionally, a shield is arranged outside the neutron poison support, and the shield is correspondingly arranged with the guiding structure.

[0020] Optionally, the neutron absorption device further includes:

[0021] At least three supports fixedly connected to the inner side of the inner cylinder body.

[0022] Optionally, a lifting hole is arranged at the top of the neutron poison sleeve.

[0023] Optionally, the mesh number of the sieve mesh is a preset number.

[0024] Optionally, the lifting head, the outer cylinder body and the inner cylinder body are fixedly connected by welding.

[0025] An embodiment of the present invention further provides a method for using a neutron absorption device, which is applied to the neutron absorption device as described above. The method includes:

[0026] Lifting the neutron absorption device to the dissolver in the hot cell by a lifting tool;

[0027] Transferring the lifting tool to directly above the neutron absorption device, opening the claws of the lifting tool and fixedly connecting them to the top of the neutron poison sleeve;

[0028] Lifting the neutron poison sleeve by the lifting tool to separate the neutron poison sleeve from the neutron poison support;

[0029] Dumping the residue filtered inside the outer cylinder body;

[0030] Checking the states of the outer cylinder body and the sieve mesh, and replacing with a new cylinder body if there is damage;

[0031] Lifting the neutron poison sleeve by the lifting tool and reassembling it into the neutron poison support.

[0032] The above technical solutions of the present invention have at least the following technical effects:

[0033] The above neutron absorption device of the present invention is provided with an outer cylinder body having a hollow structure; an inner cylinder body fixedly connected to the inner side of the outer cylinder body; a lifting head fixedly connected to the first ends of the outer cylinder body and the inner cylinder body, the lifting head being coaxially arranged with the outer cylinder body, and the cross-sectional diameter of the lifting head being greater than the cross-sectional diameter of the outer cylinder body; an outer bottom seal fixedly connected to the second end of the outer cylinder body; an inner bottom seal fixedly connected to the inner side of the outer bottom seal; a screen fixedly arranged on the inner side of the outer cylinder body and the outer bottom seal, and on the outer side of the inner cylinder body and the inner bottom seal; a neutron poison support fixedly connected to the inner bottom seal and the outer bottom seal; a neutron poison sleeve detachably connected to the neutron poison support; wherein, the neutron poison sleeve is placed into or lifted out of the neutron poison support through a lifting tool. It can improve the utilization rate, safety and repeatability of neutron poisons during spent fuel reprocessing, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of the neutron absorption device of the present invention;

[0035] Figure 2 is a schematic diagram of the neutron poison of the neutron absorption device of the present invention.

[0036] DESCRIPTION OF THE REFERENCE NUMERALS:

[0037] 1 - neutron poison sleeve; 2 - lifting head; 3 - outer cylinder body; 4 - inner cylinder body; 5 - screen; 6 - outer bottom seal; 7 - neutron poison support; 8 - inner bottom seal; 9 - support; 10 - guiding structure; 11 - shield. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Hereinafter, the exemplary embodiments of the present invention will be described in more detail with reference to the 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 communicated to those skilled in the art.

[0039] As Figure 1 shown, an embodiment of the present invention provides a neutron absorption device, including:

[0040] An outer cylinder body 3 having a hollow structure;

[0041] An inner cylinder body 4 fixedly connected to the inner side of the outer cylinder body 3;

[0042] A lifting head 2 fixedly connected to the first ends of the outer cylinder body 3 and the inner cylinder body 4, the lifting head 2 being coaxially arranged with the outer cylinder body 3, and the cross-sectional diameter of the lifting head 2 being greater than the cross-sectional diameter of the outer cylinder body 3;

[0043] An outer bottom seal 6 fixedly connected to the second end portion of the outer cylindrical body 3;

[0044] An inner bottom seal 8 fixedly connected to the inner side of the outer bottom seal 6;

[0045] A sieve 5 fixedly arranged on the inner sides of the outer cylindrical body 3 and the outer bottom seal 6, and on the outer sides of the inner cylindrical body 4 and the inner bottom seal 8;

[0046] A neutron poison support 7 fixedly connected to the inner bottom seal 8 and the outer bottom seal 6;

[0047] A neutron poison sleeve 1 detachably connected to the neutron poison support 7;

[0048] Wherein, the neutron poison sleeve 1 is placed into or lifted out of the neutron poison support 7 through a lifting tool.

[0049] In this embodiment, as Figure 1As shown, the outer side of the neutron absorption device is an outer cylinder body 3. The outer wall of the outer cylinder body 3 is provided with a hollow structure, having a relatively large passing space. The outer cylinder body 3 can provide a cylindrical support structure to form the main outline of the neutron absorption device. At the top of the outer cylinder body 3 and the inner cylinder body 4, a lifting head 2 is provided. The lifting head 2 is fixedly arranged around the first end of the outer cylinder body 3 and the inner cylinder body 4. The lifting head 2 protrudes from the outer cylinder body 3 to a certain extent, so that when a lifting tool hoists the neutron absorption device, the neutron absorption device can be firmly clamped through the lifting head 2. An outer bottom seal 6 is provided at the second end of the outer cylinder body 3. The outer bottom seal 6 is also a hollow structure. The outer cylinder body 3 and the outer bottom seal 6 are connected by welding. The outer bottom seal 6 and the outer cylinder body 3 are connected to form an integral structure. A screen 5 is provided on the side of the outer cylinder body 3 and the outer bottom seal 6 facing the inside of the cylinder body. The screen 5 is evenly distributed on the outer cylinder body 3 and the outer bottom seal 6. A screen 5 is provided in the gap between the outer cylinder body 3 and the inner cylinder body 4. The screen 5 fills the hollow part between the outer cylinder body 3 and the inner cylinder body 4 and is used to filter solid impurities in the spent fuel waste liquid. An inner bottom seal 8 is closely arranged inside the outer bottom seal 6. A screen 5 is provided in the gap between the outer bottom seal 6 and the inner bottom seal 8. The screen 5 fills the hollow part between the outer bottom seal 6 and the inner bottom seal 8 and is used to filter solid impurities in the spent fuel waste liquid. The inner cylinder body 4 and the inner bottom seal 8 are fixed together by welding, which can make the overall structure of the neutron absorption device more firm and make the fixation of the screen 5 more stable. The neutron poison sleeve 1 can be placed in the neutron poison support 7 or can be hoisted out of the neutron poison support 7 by a lifting tool. Neutron poison materials are placed inside the neutron poison sleeve 1. The neutron poison materials absorb thermal neutrons through substances with large neutron absorption cross-sections such as boron, cadmium, gadolinium, etc., thereby inhibiting the nuclear fission chain reaction. It is mainly used in the spent fuel reprocessing process. Preferably, the neutron poison material adopts an aluminum-based boron carbide material. Aluminum-based boron carbide is an aluminum-based composite material formed by adding boron carbide particles to an aluminum or aluminum alloy matrix. It has the advantages of high boron content, low density, high thermal conductivity, high absorption cross-section, wide absorption energy spectrum, etc. It can absorb a large amount of neutrons without forming any radioactive isotopes, and the waste is easy to process, making it suitable as a neutron poison material.

[0050] With the assistance of a crane and a manipulator, the neutron absorption device of the solution of the present invention realizes the disassembly and reuse of the whole and local parts of the neutron poison. While ensuring critical safety, it realizes the selective filtration of insoluble residues, improves the low utilization rate of the neutron poison material, reduces the production cost, and ensures that the neutron poison sleeve 1 does not tilt relative to the outer cylinder body 3.

[0051] As Figure 1 shown, in an optional embodiment of the present invention, the inner cylinder body 4 and the outer cylinder body 3 are coaxially arranged.

[0052] In this embodiment, as Figure 1As shown, an inner cylinder 4 is closely arranged inside the outer cylinder 3. The lifting head 2, the outer cylinder 3, and the inner cylinder 4 are fixed together by welding. The axes of the outer cylinder 3 and the inner cylinder 4 are symmetrically arranged on the same straight line.

[0053] As Figure 1 shown, in an alternative embodiment of the present invention, the neutron poison support (7) is correspondingly arranged with the neutron poison sleeve (1), and the neutron poison support (7) is made of stainless steel.

[0054] In this embodiment, as Figure 1 shown, at the central positions of the outer bottom seal 6 and the inner bottom seal 8, a neutron poison support 7 is fixedly arranged. The neutron poison support 7 is a hollow structure, located in the accommodation space of the outer cylinder 3, and is correspondingly arranged with the neutron poison sleeve 1. The inner diameter of the neutron poison support 7 is slightly larger than the outer diameter of the neutron poison sleeve 1, and is used to fix the neutron poison sleeve 1 so that the neutron poison sleeve 1 can be firmly placed in the accommodation space of the outer cylinder 3; the inner ring surface of the neutron poison support 7 and the inner bottom seal 8 are connected by welding, and the neutron poison support 7 and the outer bottom seal 6 are connected by welding at the stepped surface where the neutron poison support 7 contacts the outer surface of the outer bottom seal 6, making the connection of the neutron poison support 7 more firm; the stainless steel material has the characteristics of corrosion resistance, high strength, not easy to deform, high temperature resistance, long service life, environmental protection and beauty, etc.

[0055] As Figure 1 shown, in an alternative embodiment of the present invention, a guiding structure 10 is arranged at the top of the neutron poison support 7.

[0056] In this embodiment, as Figure 1 shown, a guiding structure 10 is arranged at the top of the neutron poison support 7. The guiding structure 10 is in an upward inclined state and opens outward. When the neutron poison sleeve 1 is placed into the neutron poison support 7, it provides a direction guide for the neutron poison sleeve 1, facilitating the neutron poison sleeve 1 to more easily align with the entrance of the neutron poison support 7 and be smoothly placed on the neutron poison support 7.

[0057] As Figure 1 shown, in an alternative embodiment of the present invention, a shield 11 is arranged outside the neutron poison support 7, and the shield 11 is correspondingly arranged with the guiding structure 10.

[0058] In this embodiment, as Figure 1 shown, outside the neutron poison support 7, at a position corresponding to the guiding structure 10, a shield 11 is arranged. The shield 11 is in a downward inclined state and opens outward. When the neutron poison sleeve 1 is placed at the bottom of the neutron poison support 7, the shield 11 and the guiding structure 10 just close together to form a relatively sealed space, thus preventing impurities in the filtering medium from entering the assembly seam between the neutron poison sleeve 1 and the neutron poison support 7.

[0059] As Figure 1 shown, in an alternative embodiment of the present invention, the neutron absorption device further includes:

[0060] At least three supports 9 fixedly connected to the inner side of the inner cylinder 4.

[0061] In this embodiment, as Figure 1 shown, at least three uniformly distributed supports 9 are fixedly connected to the inner side of the inner cylinder 4. The supports 9 extend to the side wall position of the neutron poison support 7, which is used to ensure the coaxiality between the neutron poison sleeve 1 and the outer cylinder 3 and make the placement of the neutron poison sleeve 1 more stable.

[0062] As Figure 2 shown, in an alternative embodiment of the present invention, a lifting hole is provided at the top of the neutron poison sleeve 1.

[0063] In this embodiment, as Figure 2 shown, a lifting hole is provided at the top of the neutron poison sleeve 1. The size of the lifting hole is matched with the lifting tool used, which is convenient for using the lifting tool to hoist the neutron poison sleeve 1.

[0064] In an alternative embodiment of the present invention, the mesh number of the sieve 5 is a preset number.

[0065] In this embodiment, the mesh number of the sieve 5 is selected according to the filtration requirements. If larger solid impurities need to be screened, the mesh number can be set smaller; if smaller solid impurities need to be screened, the mesh number can be set larger; it needs to be determined according to the situation of solid impurities in the treated waste liquid.

[0066] In an alternative embodiment of the present invention, the lifting head 2, the outer cylinder 3, and the inner cylinder 4 are fixedly connected by welding.

[0067] In this embodiment, the lifting head 2, the outer cylinder 3, and the inner cylinder 4 are fixedly connected by welding. The welding fixing method has high connection quality, strong applicability, and high structural strength, which can make the overall structure of the neutron absorption device more firm.

[0068] The embodiment of the present invention further provides a method for using a neutron absorption device, which is applied to the neutron absorption device as described above. The method includes:

[0069] Hoist the neutron absorption device into the hot cell through a lifting tool;

[0070] Transfer the lifting tool to directly above the neutron absorption device, open the claws of the lifting tool and fixedly connect them to the top of the neutron poison sleeve 1;

[0071] Lift the neutron poison sleeve 1 by means of the sling, so that the neutron poison sleeve 1 is separated from the neutron poison support 7;

[0072] Dump the residue filtered inside the inner cylinder 4;

[0073] Check the states of the outer cylinder 3 and the screen 5, and replace with a new cylinder if there is any damage;

[0074] Lift the neutron poison sleeve 1 by means of the sling and reassemble it into the neutron poison support 7.

[0075] In this embodiment, the usage method of the neutron absorption device is as follows:

[0076] Lift the neutron absorption device into the hot cell by means of a sling;

[0077] Use the numerically controlled crane hook in the hot cell to hang the sling and transfer the sling directly above the neutron absorption device;

[0078] Use the master-slave manipulator in the hot cell to hold the sling and open its claws, and connect them to the small holes at the top of the neutron poison sleeve 1;

[0079] Lift vertically to separate the neutron poison sleeve 1 from the neutron poison support 7;

[0080] Dump the residue filtered inside the cylinder;

[0081] Clean the cylinder and check whether the screen 5 is damaged;

[0082] Check the neutron poison sleeve 1 to confirm whether the neutron poison sleeve 1 is damaged;

[0083] If neither the screen 5 nor the neutron poison sleeve 1 is damaged, reassemble the old neutron poison sleeve 1 and the old neutron poison support 7 for reuse;

[0084] If the neutron poison sleeve 1 is damaged, replace the damaged neutron poison sleeve 1 and then reassemble for reuse. If the screen 5 is damaged, replace the part other than the neutron poison sleeve 1.

[0085] The solution of the present invention provides a detachable and reusable neutron absorption device, which can realize the disassembly and reuse of the whole and local parts of the neutron poison device with the assistance of a crane and a manipulator, and realize the selective filtration of insoluble residues while ensuring critical safety. It improves the utilization rate of neutron poison materials, reduces the production cost, and ensures that the neutron poison sleeve will not be skewed relative to the outer cylinder.

[0086] 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 modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A neutron absorption device, characterized in that, Comprising: An outer cylinder body (3) having a hollow structure; An inner cylinder body (4) fixedly connected to the inner side of the outer cylinder body (3); A lifting head (2) fixedly connected to the first ends of the outer cylinder body (3) and the inner cylinder body (4), the lifting head (2) being coaxially arranged with the outer cylinder body (3), and the cross-sectional diameter of the lifting head (2) being greater than the cross-sectional diameter of the outer cylinder body (3); An outer bottom seal (6) fixedly connected to the second end of the outer cylinder body (3); An inner bottom seal (8) fixedly connected to the inner side of the outer bottom seal (6); A screen (5) fixedly arranged on the inner sides of the outer cylinder body (3) and the outer bottom seal (6), and on the outer sides of the inner cylinder body (4) and the inner bottom seal (8); A neutron poison support (7) fixedly connected to the inner bottom seal (8) and the outer bottom seal (6); A neutron poison sleeve (1) detachably connected to the neutron poison support (7); Wherein, the neutron poison sleeve (1) is placed into or lifted out of the neutron poison support (7) through a lifting tool.

2. The neutron absorption device according to claim 1, characterized in that The inner cylinder body (4) is coaxially arranged with the outer cylinder body (3).

3. The neutron absorption device according to claim 2, characterized in that, The neutron poison support (7) is correspondingly arranged with the neutron poison sleeve (1), and the neutron poison support (7) is made of stainless steel.

4. The neutron absorption device according to claim 3, characterized in that, A guiding structure (10) is arranged at the top of the neutron poison support (7).

5. The neutron absorption device according to claim 4, wherein A shield (11) is arranged on the outer side of the neutron poison support (7), and the shield (11) is correspondingly arranged with the guiding structure (10).

6. The neutron absorption device according to claim 1, characterized in that Further comprising: At least three supports (9) fixedly connected to the inner side of the inner cylinder body (4).

7. The neutron absorption device according to claim 1, wherein A lifting hole is arranged at the top of the neutron poison sleeve (1).

8. The neutron absorption device according to claim 1, characterized in that, The mesh number of the screen (5) is a preset number.

9. The neutron absorption device according to claim 2, characterized in that, The lifting head (2), the outer cylinder body (3), and the inner cylinder body (4) are fixedly connected by welding.

10. A method for using a neutron absorption device, characterized in that, Applied to the neutron absorption device according to any one of claims 1 to 9, the method comprises: Lifting the neutron absorption device into the hot cell through a lifting tool; Transferring the lifting tool directly above the neutron absorption device, opening the claws of the lifting tool and fixedly connecting them to the top of the neutron poison sleeve (1); Lifting the neutron poison sleeve (1) through the lifting tool to separate the neutron poison sleeve (1) from the neutron poison support (7); Dumping the residue filtered inside the outer cylinder body (3); Checking the states of the outer cylinder body (3) and the screen (5), and replacing with a new cylinder body if there is damage; Lifting the neutron poison sleeve (1) through the lifting tool and reassembling it into the neutron poison support (7).

Images