Buffer device for spent fuel transport container and spent fuel transport container

Abstract

The embodiment of the present application provides a buffer device for a spent fuel transport container and a spent fuel transport container. The buffer device includes: a base body made of wood and an outer coating for covering the surface of the base body. The base body includes: a central column, which has a first end face perpendicular to the axial direction and a second end face opposite to the first end face; a central ring body, which is arranged on the radial outer side of the central column, and has a third end face perpendicular to the axial direction and a fourth end face opposite to the third end face, the third end face is located on the same side as the first end face and the third end face is arranged flush with the first end face; the fourth end face is located on the same side as the second end face and the second end face protrudes outward from the fourth end face; a first end ring body, which is connected to the third end face, and the inner diameter of the first end ring body is larger than the inner diameter of the central column. The central column, the central ring body and the first end ring body jointly define a receiving groove for accommodating one end of the container body of the spent fuel transport container.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear waste transportation, and in particular to a buffer device of a spent fuel transportation container and a spent fuel transportation container. Background Art

[0002] Spent fuel transport containers are containers used to transport spent fuel assemblies. In order to ensure the integrity of spent fuel transport containers during normal transportation and in the event of an accident, spent fuel transport containers should pass a 9m drop test.

[0003] In order to enable the spent fuel transport container to pass the 9m drop test, buffer devices (also called buffers or shock absorbers) are usually provided at both ends of the spent fuel transport container. The buffer device is usually made of stainless steel wrapped in wood. The structural design of the existing buffer device is usually suitable for small spent fuel transport containers. For large spent fuel transport containers, the structural design of the existing buffer device is difficult to meet the requirements of the 9m drop test. Summary of the invention

[0004] In view of the above technical problems, the embodiments of the present application provide a buffer device for a spent fuel transport container and a spent fuel transport container.

[0005] In a first aspect, an embodiment of the present application provides a buffer device for a spent fuel transport container, comprising: a base body made of wood and an outer coating layer for coating a surface of the base body,

[0006] Wherein, the matrix comprises:

[0007] A central cylinder having a first end surface perpendicular to the axial direction and a second end surface opposite to the first end surface;

[0008] a central ring body, arranged on the radially outer side of the central cylinder, having a third end face perpendicular to the axial direction and a fourth end face opposite to the third end face, wherein the third end face is located on the same side as the first end face of the central cylinder and the third end face is arranged flush with the first end face of the central cylinder; the fourth end face is located on the same side as the second end face of the central cylinder and the second end face of the central cylinder protrudes outwardly from the fourth end face;

[0009] The first end ring body is connected to the third end face of the central ring body, and the inner diameter of the first end ring body is greater than the inner diameter of the central cylinder.

[0010] The central column, the central ring and the first end ring together define a receiving groove for receiving an end portion of one side of the container body of the spent fuel transport container.

[0011] In a second aspect, an embodiment of the present application provides a spent fuel transport container, comprising:

[0012] A container body for containing the spent fuel assembly; and

[0013] One or two buffer devices as described in the first aspect of the present application, each of which is arranged at one end of the container body.

[0014] In the buffer device of the embodiment of the present application, since the second end face of the central column is arranged to protrude outwardly from the fourth end face of the central ring body, when the spent fuel transport container falls at an angle, the central ring body / the first end ring body and the protruding portion of the central column can jointly play a buffering role, thereby improving the buffering effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0016] Figure 1 is a top view of a buffer device according to an embodiment of the present invention;

[0017] Figure 2 yes Figure 1 A cross-sectional view of the buffer device shown along the AA direction;

[0018] Figure 3 yes Figure 2 A partial enlarged view of area B is shown;

[0019] Figure 4 is a schematic diagram of a buffer device according to another embodiment of the present invention after the outer covering layer is omitted;

[0020] Figure 5 yes Figure 4 A bottom view of the buffer device shown;

[0021] Figure 6 is a cross-sectional view of a buffer device according to another embodiment of the present invention, wherein the direction of the cross-sectional line in the figure represents the grain direction of the paulownia wood; and

[0022] Figure 7 is a partial cross-sectional view of a spent fuel transport container according to an embodiment of the present invention.

[0023] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiment is one embodiment of the present invention, not all embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this application should have the common meanings understood by persons having ordinary skills in the field to which the invention belongs.

[0026] In the description of the embodiments of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] See also Figure 1 and Figure 2 The buffer device of the spent fuel transport container of the embodiment of the present invention comprises: a base body made of wood and an outer coating layer for covering the surface of the base body. The outer coating layer is usually made of stainless steel material.

[0028] The base body may include a central column 10 , a central ring 20 and a first end ring 30 .

[0029] The central cylinder 10 has a first end surface perpendicular to the axial direction and a second end surface opposite to the first end surface.

[0030] The central ring body 20 is arranged radially outside the central cylinder 10, and has a third end face perpendicular to the axial direction and a fourth end face opposite to the third end face. The third end face is located on the same side as the first end face of the central cylinder 10, and the third end face is arranged flush with the first end face of the central cylinder 10. The fourth end face is located on the same side as the second end face of the central cylinder 10, and the second end face of the central cylinder 10 protrudes outward from the fourth end face.

[0031] The first end ring body 30 is connected to the third end face of the center ring body 20, and the inner diameter of the first end ring body 30 is larger than the inner diameter of the center column 10. The center column 10, the center ring body 20 and the first end ring body 30 together define a receiving groove 101 for receiving the end of one side of the container body of the spent fuel transport container.

[0032] The side end surface of the buffer device in the related art away from the container body is usually a plane, so when the spent fuel transport container falls at an angle, only the side surface of the buffer device can provide buffering. However, the buffer device of the embodiment of the present application protrudes the second end surface of the central column 10 outward from the fourth end surface of the central ring body 20, so that when the spent fuel transport container falls at an angle, the protruding part of the central ring body 20 / the first end ring body 30 and the central column 10 can jointly play a buffering role, thereby improving the buffering effect.

[0033] It is easy to understand that since the first end face of the central column 10, the third end face of the central ring body 20 and the radial inner surface of the first end ring body 30 are also covered by the coating layer, the receiving groove 101 is essentially formed by the outer coating layer covering the first end face of the central column 10, the third end face of the central ring body 20 and the radial inner surface of the first end ring body 30.

[0034] In some embodiments, the coating layer includes a first plate 93 and a first inner ring plate 91. The first plate 93 is coated on the third end surface of the center ring body 20 and the first end surface of the center column 10 on the radial inner side of the first end ring body 30. The first inner ring plate 91 is coated on the radial inner surface of the first end ring body 30 and protrudes outward from the first end ring body 30. The first plate 93 and the first inner ring plate 91 together form the groove wall of the receiving groove 101.

[0035] Since the first plate 93 and the first inner ring plate 91 play the role of installing and fixing the container body, the thickness of the first plate 93 and the first inner ring plate 91 can be greater than the thickness of the coating layer on other surfaces.

[0036] In some embodiments, a plurality of mounting holes 23 are provided inside the central ring body 20, which penetrate the central ring body 20 axially and communicate with the receiving groove 101, and are used to fix the end of the container body by fasteners passing through the mounting holes 23. The outer coating also includes a sleeve covering the inner wall of the mounting hole 23, so that the outer coating encloses all the base material. In the embodiment of the present application, the end of the container body is fixed by fasteners passing through the mounting holes 23 of the central ring body 20, so that the connection between the container body and the buffer device is more stable.

[0037] In some embodiments, the fastener is a bolt, that is, the buffer device is fixed to the container body by bolts. The mounting hole 23 is used for the rod of the bolt to pass through and be threadedly connected with the container body. The inner diameter of the hole section where the mounting hole 23 connects with the receiving groove 101 is larger than the inner diameter of the remaining hole sections. In this way, the diameter of the mounting hole 23 near the container body is larger, which can be used to absorb the deformation of the bolts during the falling process of the spent fuel transport container and prevent the bolts from being sheared and broken.

[0038] In some embodiments, the substrate may be made of paulownia wood. In some embodiments, the density of paulownia wood may be 0.25±0.05 g / cm 3 .

[0039] In some embodiments, see Figure 6 The central column 10 is made of paulownia wood with the same grain (or longitudinal grain). Since the central column 10 is located in the middle and plays a buffering role, compared with paulownia wood with other textures, the use of paulownia wood with the same grain can improve the vertical buffering and energy absorption capacity of the central column 10.

[0040] It is easy to understand that the longitudinal grain means that the extension direction of the three-dimensional texture of the wood is perpendicular to the thickness direction; the transverse grain means that the extension direction of the texture is parallel to the thickness direction; and the diagonal grain means that there is an angle between the extension direction of the texture and the thickness direction.

[0041] In some embodiments, the buffer device further includes: a central cover plate 50, which is disposed on the second end surface of the central column 10, and the central cover plate 50 is made of horizontal-grained paulownia wood.

[0042] The center cover plate 50 is relatively thin, and may be, for example, about 2 cm to 5 cm thick.

[0043] In the embodiment of the present application, a thin layer of transverse-grained paulownia wood is added to the end of the central column 10 away from the container body. Since the transverse-grained paulownia wood is soft, it can play a primary buffering role when the spent fuel transport container falls at an angle to prevent the first plate 93 from deforming.

[0044] In some embodiments, the central ring body 20 is composed of an inner ring body 21 located radially inwardly and an outer ring body 22 located outwardly, and the first end ring body 30 is connected to the outer ring body 22. The cross-sectional shapes and sizes of the first end ring body 30 and the outer ring body 22 are substantially the same. Specifically, the inner diameter of the outer ring body 22 may be slightly smaller than the inner diameter of the first end ring body 30, and the outer diameter of the outer ring body 22 is equal to the outer diameter of the first end ring body 30.

[0045] The outer ring body 22 can be made of paulownia wood with longitudinal grains. The outer ring body 22 mainly plays a buffering role when the container body falls horizontally. The use of paulownia wood with longitudinal grains can improve its buffering capacity.

[0046] The inner ring body 21 can also be made of paulownia wood with horizontal grains. The inner ring body 21 at the center of the buffer device uses paulownia wood with horizontal grains as the basis of the buffer device. The first end ring body 30 can also be made of paulownia wood with horizontal grains.

[0047] The embodiment of the present application adopts softer transverse-grained paulownia wood in the parts near the container body (such as the first end ring body 30 and the inner ring body 21), which can maintain the instantaneous buffering performance of the buffer device, reduce the buffering force, achieve the effect of maintaining the balance of the buffer device, and prevent the bolts from shearing and breaking.

[0048] In some embodiments, the axial thickness of the first end ring body 30 is smaller than the axial thickness of the center ring body 20 ; the axial thickness of the first end ring body 30 is greater than half of the axial thickness of the center ring body 20 , thereby further improving the buffering effect.

[0049] In some embodiments, the buffer device further includes: a second end ring body 40 connected to the fourth end face of the center ring body 20, and the inner diameter of the second end ring body 40 is the same as the inner diameter of the first end ring body 30. The second end face of the center column 10 protrudes outward from the second end ring body 40. In the embodiment of the present application, the second end ring body 40 is provided to buffer the container body when an angle drop occurs.

[0050] In some embodiments, the second end ring body 40 is made of twill paulownia wood, so that the second end ring body 40 can better buffer the container body when the spent fuel transport container falls at an angle.

[0051] In some embodiments, the diagonal grain of the diagonal paulownia wood may be 25° to 75°, that is, the angle between the extension direction of the grain and the thickness direction is 25° to 75°. Within this angle range, the cushioning effect on the container body can be further improved. In a further embodiment, the diagonal grain of the diagonal paulownia wood may be 70° to 75°.

[0052] It is easy to understand that the 9m drop test of the transport container needs to consider different drop postures, such as horizontal, vertical, large angles over the center of gravity, small angles and other different postures. Different postures have different requirements for buffering performance. In the embodiment of the present application, the buffer device is configured to include a central column 10, a central cover plate 50, a central ring body 20, a first end ring body 30 and a second end ring body 40, and paulownia wood with different textures is selected to form the central column 10, the central cover plate 50, the central ring body 20, the first end ring body 30 and the second end ring body 40, so that the buffer device of the embodiment of the present application can balance the buffering performance of the transport container under various drop postures. The buffer device can fully play its role under different drop postures of the transport container. In addition, the buffer device of the embodiment of the present application has a compact structure under limited space, has the advantages of less material and good effect, and does not cause redundant waste of materials. At the same time, each layer of material has its specific function, taking into account the functions of energy absorption and protection of bolts.

[0053] It is easy to understand that paulownia wood blocks of different grains (i.e. textures) can be glued together with paulownia wood boards of the same grain.

[0054] The second end ring body 40 , the first end ring body 30 , and the center ring body 20 have the same outer diameter.

[0055] In some embodiments, the axial thickness of the second end ring body 40 is less than the axial thickness of the first end ring body 30. The axial thickness of the second end ring body 40 may be equal to or less than half of the axial thickness of the center ring body 20, thereby further improving the buffering effect.

[0056] In some embodiments, the coating layer further includes: a second plate 94, which covers the fourth end surface of the center ring body 20 radially inside the second end ring body 40. The thickness of the first plate 93, the second plate 94 and the first inner ring plate 91 is greater than the thickness of other parts of the outer coating layer.

[0057] In some embodiments, see Figure 4 and Figure 5 The center ring body 20 is formed by splicing a plurality of center arc segments 25, the first end ring body 30 is formed by splicing a plurality of first arc segments 31, and the second end ring body 40 is formed by splicing a plurality of second arc segments 41. A center arc segment 25, a first arc segment 31 and a second arc segment 41 are bonded to form a sector body of an integral structure. Two adjacent sectors are connected by a rib plate 99.

[0058] The rib plate 99 is welded to at least a portion of the outer covering layer. For example, the rib plate 99 and a portion of the outer covering layer may be welded by a fillet weld.

[0059] See also Figure 1 and Figure 2 The coating layer includes: a second inner ring plate 92, which is coated on the radial inner surface of the second end ring body 40, and at least one through hole is opened on the second inner ring plate 92.

[0060] See also Figure 3 The buffer device further includes: at least one fuse ring 81 and at least one T-shaped fuse plug 82. Each fuse ring 81 extends from a through hole of the second inner ring plate 92 toward the central column 10. Each T-shaped fuse plug 82 is inserted into the fuse ring 81. The T-shaped fuse plug is made of a material with a melting point lower than a preset temperature. The preset temperature may be, for example, 500°C.

[0061] By providing the fuse ring 81 and the T-shaped fuse plug 82, when the spent fuel transport container is in normal use, the T-shaped fuse plug 82 can play the role of sealing the coating layer; when the spent fuel transport container is burned by fire, the T-shaped fuse plug 82 is melted by heat, and the inside of the coating layer is connected to the outside through the fuse ring 81, so that the gas inside the coating layer can be discharged, thereby improving the safety and stability of the buffer device.

[0062] In some embodiments, the fuse ring 81 is made of stainless steel, and the T-shaped fuse plug 82 is made of tin-bismuth alloy. The melting point of tin-bismuth alloy is relatively low, and it can be melted at 150-200°C.

[0063] In some embodiments, the second inner ring plate 92 is not welded to the rib plate 99. This arrangement forms a connected cavity inside the coating layer, and when the T-shaped fuse plug 82 is heated and melted, the pressure inside the coating layer increases, and the gas can be exhausted from the fuse ring 81.

[0064] In some embodiments, the number of through holes may be multiple, and multiple fuse rings 81 and multiple T-shaped fuse plugs 82 are provided accordingly, so that when the spent fuel transport container is caught in fire, the gas inside the coating layer can be quickly discharged to the outside.

[0065] exist Figure 1 In the illustrated embodiment, the number of through holes is two, which are respectively arranged on the second inner ring plate 92 opposite to each other.

[0066] The through hole may be provided in the middle of the second inner ring plate 92 in the height direction to increase the exhaust rate.

[0067] The buffer device of the embodiment of the present application was applied to the large spent fuel transport container of China National Nuclear Corporation. Tests showed that the spent fuel transport container could meet the 9m drop test requirements in different drop postures, such as horizontal, vertical, large angle over the center of gravity, and small angle.

[0068] In some embodiments, main parameters of the paulownia wood used for the buffer device are shown in Table 1.

[0069] Table 1 Main parameters of Paulownia wood used for buffer device

[0070]

[0071] The present application also provides a spent fuel transport container. Figure 7 The spent fuel transport container includes: a container body 200 and one or two buffer devices. The container body 200 is used to contain the spent fuel assembly. The buffer device is a buffer device according to any embodiment of the present application. Each buffer device is arranged at one end of the container body 200.

[0072] When the spent fuel transport container of the embodiment of the present application falls at an angle, the buffer device can provide a good buffering effect on the container body 200 .

[0073] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0074] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A buffer device for a spent fuel transport container, characterized in that: include: A substrate made of wood and an outer covering layer for covering the surface of the substrate, Wherein, the matrix comprises: A central cylinder having a first end surface perpendicular to the axial direction and a second end surface opposite to the first end surface; a central ring body, arranged on the radially outer side of the central cylinder, having a third end face perpendicular to the axial direction and a fourth end face opposite to the third end face, wherein the third end face is located on the same side as the first end face of the central cylinder and the third end face is arranged flush with the first end face of the central cylinder; the fourth end face is located on the same side as the second end face of the central cylinder and the second end face of the central cylinder protrudes outwardly from the fourth end face; The first end ring body is connected to the third end face of the central ring body, and the inner diameter of the first end ring body is greater than the inner diameter of the central cylinder. The central column, the central ring and the first end ring together define a receiving groove for receiving an end portion of one side of the container body of the spent fuel transport container.

2. The buffer device according to claim 1, characterized in that: The center ring body is provided with a plurality of mounting holes which penetrate the center ring body in the axial direction and communicate with the receiving groove, and are used to fix the end of the container body by fasteners passing through the mounting holes; The outer covering layer includes a sleeve covering the inner wall of the mounting hole.

3. The buffer device according to claim 2, characterized in that: The fastener is a bolt, and the mounting hole is used for the rod of the bolt to pass through so as to be threadedly connected with the container body. Wherein, the inner diameter of the hole section where the mounting hole is connected to the receiving groove is larger than the inner diameters of the remaining hole sections.

4. The buffer device according to claim 1, characterized in that: The central column is made of paulownia wood with the same grain.

5. The buffer device according to claim 4, characterized in that: Also includes: The central cover plate is arranged on the second end surface of the central column, and the central cover plate is made of paulownia wood with horizontal grains.

6. The buffer device according to claim 1, characterized in that: The first end ring body is made of horizontal-grained paulownia wood.

7. The buffer device according to claim 1, characterized in that: The central ring body is composed of an inner ring body located radially inward and an outer ring body located radially outward, and the first end ring body is connected to the outer ring body; Wherein, the inner ring body is made of paulownia wood with transverse grains, and the outer ring body is made of paulownia wood with parallel grains.

8. The buffer device according to claim 1, characterized in that: Also includes: A second end ring body connected to the fourth end face of the central ring body, wherein the inner diameter of the second end ring body is the same as the inner diameter of the first end ring body; The second end surface of the central column protrudes outwardly from the second end ring body.

9. The buffer device according to claim 8, characterized in that: The second end ring is made of twill-grained paulownia wood.

10. The buffer device according to claim 8, characterized in that: The second end ring body, the first end ring body and the center ring body have the same outer diameter.

11. The buffer device according to claim 10, characterized in that: The central ring body is formed by splicing a plurality of central arc segments, the first end ring body is formed by splicing a plurality of first arc segments, and the second end ring body is formed by splicing a plurality of second arc segments; Wherein, one of the central arc segments, one of the first arc segments and one of the second arc segments are bonded to form a sector-shaped body of an integrated structure; Two adjacent fan-shaped bodies are connected by rib plates.

12. The buffer device according to claim 11, characterized in that: The rib plate is welded to at least a portion of the outer covering layer.

13. The buffer device according to claim 12, characterized in that: The coating layer comprises: a second inner ring plate, which is coated on the radial inner surface of the second end ring body, and the second inner ring plate is provided with at least one through hole; Wherein, the buffer device further comprises: at least one fuse ring, each of the fuse rings extending from one of the through holes toward the central column, and At least one T-shaped fuse plug, each of which is inserted into the fuse ring, and the T-shaped fuse plug is made of a material with a melting point lower than a preset temperature.

14. The buffer device according to claim 13, characterized in that: The fuse ring is made of stainless steel; The T-shaped fuse plug is made of tin-bismuth alloy.

15. The buffer device according to claim 13, characterized in that: The second inner ring plate and the rib plate are not welded.

16. The buffer device according to claim 8, characterized in that: The coating layer comprises: A first plate, covering the third end surface of the central ring body and the first end surface of the central column at the radial inner side of the first end ring body; and a first inner ring plate, covering the radial inner surface of the first end ring body and protruding outward from the first end ring body, The first plate and the first inner ring plate together form a groove wall of the receiving groove.

17. The buffer device according to claim 16, characterized in that: The coating layer also includes: a second plate, covering the fourth end surface of the central ring body at the radial inner side of the second end ring body; The thickness of the first plate, the second plate and the first inner ring plate is greater than the thickness of other parts of the outer cover.

18. A spent fuel transport container, characterized in that: include: The container body is used to contain the spent fuel assembly; and One or two buffer devices according to any one of claims 1 to 17, each of which is arranged at one end of the container body.

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