CN115188512A

CN115188512A - Spent fuel storage grillwork and spent fuel storage container

Info

Publication number: CN115188512A
Application number: CN202210765692.3A
Authority: CN
Inventors: 程呈; 潘跃龙; 唐邵华; 张学岭; 杨锦春; 高景辉; 魏志国; 莫怀森; 唐琼辉; 潘永杰
Original assignee: China General Nuclear Power Corp; China Nuclear Power Engineering Co Ltd; CGN Power Co Ltd; Shenzhen China Guangdong Nuclear Engineering Design Co Ltd
Current assignee: China General Nuclear Power Corp; China Nuclear Power Engineering Co Ltd; CGN Power Co Ltd; Shenzhen China Guangdong Nuclear Engineering Design Co Ltd
Priority date: 2022-07-01
Filing date: 2022-07-01
Publication date: 2022-10-14

Abstract

The invention relates to a spent fuel storage grillwork and a spent fuel storage container. The spent fuel storage grillwork includes: the device comprises a plurality of layered base plates, a plurality of filling plates, a plurality of plug connectors and a sleeve for storing a spent fuel assembly; each layered base plate is provided with a main body part and a positioning part surrounding the periphery of the main body part; each filling plate is provided with an avoiding opening; the layered base plates and the filling plates are alternately stacked along a first direction perpendicular to the layered base plates, wherein the main body parts of the layered base plates correspond to the avoidance openings in the first direction; the plug connector penetrates through the positioning part of each layered base plate and each filling plate along a first direction; the sleeve penetrates through the main body part of each layered base plate along the first direction and passes through the inner side of the avoidance opening of the filling plate. The fuel storage grillwork and the spent fuel storage container are not easy to deform and have high reliability.

Description

Spent fuel storage grillwork and spent fuel storage container

Technical Field

The invention relates to the technical field of spent fuel storage, in particular to a spent fuel storage grillwork and a spent fuel storage container.

Background

The existing spent fuel dry storage container mainly comprises two technical routes of vertical storage and horizontal storage, and both adopt a passive natural ventilation mode to remove decay heat of a spent fuel assembly. In the process operation, in the actual charging and running process, the two storage technologies respectively need to complete spent fuel loading, welding sealing and vacuumizing drying of the fuel plant in a vertical storage state, horizontal transfer between the fuel plant and a storage facility and final spent fuel storage.

In the structural composition of the equipment, two types of storage containers mainly comprise a cylinder body, a bottom plate, a top cover and a fuel hanging basket module. The fuel basket module comprises a fuel basket and a support member, and is a key technical difficulty in designing and manufacturing the whole storage container.

For the fuel basket, each fuel assembly is guaranteed to be loaded with an independent fuel basket unit, and the prior art mainly adopts a mode of assembling and welding plates or assembling and splicing plates. The supporting piece is positioned between the fuel basket and the barrel body and used for supporting and fixing the fuel basket, and mainly adopts a mode of filling the whole body or supporting the ribbed plate.

The defects of the prior art are as follows:

the method is combined with the feedback of manufacturing and operating experiences at home and abroad, and finds that the existing spent fuel dry storage technology has the problems of difficult welding deformation forming of a container grillwork, insufficient heat conduction capability of a matched supporting module and the like, and mainly shows that:

1) The grid welding deformation is large, the shape correction is difficult, and the assembly plugging safety is influenced by the projection of welding spots.

For the framework part, the existing international spent fuel storage tank framework is mainly manufactured by adopting an assembling and welding mode among a plurality of partition plates or square pipes, and the structural design has the outstanding problems of large welding quantity, obvious welding deformation and difficult framework overall shape correction.

Particularly, due to the fact that welding spot protrusions are difficult to thoroughly avoid in the grid welding process, structural deformation caused by residual stress in the welding process is caused, and the spent fuel assemblies are likely to be scratched and damaged in the processes of inserting the spent fuel assemblies into the fuel basket and retrieving the spent fuel assemblies, so that serious radioactive substance leakage events are generated, and the operation safety of a nuclear power plant is affected.

2) The heat transfer efficiency of the framework module is low, and the safety of vertical loading and horizontal transfer thermotechnical work is influenced.

According to the operation process of spent fuel storage, the thermal safety under the working conditions of vertical loading and horizontal transfer are considered simultaneously. Under the working condition of vertical loading, the container is generally required to keep better heat convection capacity, and under the condition of horizontal transportation, equipment is required to have better heat transfer capacity, but due to the structural design limitation of the lattice module, the requirements of high-efficiency heat transfer of decay heat of the spent fuel in vertical and horizontal states cannot be met, so that the safe operation time limit of the spent fuel storage container in vertical loading operation and horizontal transportation is shorter.

Disclosure of Invention

Based on this, there is a need for technology shortcuts for the heat transfer performance of present storage vessels, primarily relying solely on convective and conductive heat transfer. The problems of high-efficiency heat dissipation and fuel safety protection during vertical transfer and horizontal transfer cannot be met, and the spent fuel storage grillwork and the spent fuel storage container which are good in heat conduction performance and high in reliability are provided.

A first aspect of an embodiment of the present application provides a spent fuel storage grid, including: the fuel cell comprises a plurality of layered base plates, a plurality of filling plates, a plurality of plug connectors and a sleeve for storing spent fuel components;

each layered base plate is provided with a main body part and a positioning part arranged around the periphery of the main body part;

each filling plate is provided with an avoiding opening;

the layered base plates and the filling plates are alternately stacked along a first direction perpendicular to the layered base plates, wherein the main body parts of the layered base plates correspond to the avoidance openings in the first direction;

the plug connector penetrates through the positioning part of each layered base plate and each filling plate along a first direction;

the sleeve penetrates through the main body part of each layered base plate along the first direction and passes through the inner side of the avoidance opening of the filling plate.

In one embodiment, the positioning part of each layered base plate is provided with base plate inserting through holes, and each filling plate is provided with filling plate inserting through holes corresponding to the base plate inserting through holes one to one;

each plug connector is plugged in the corresponding base plate plugging through hole and the corresponding filling plate plugging through hole so as to penetrate through the positioning part of each layered base plate and each filling plate.

In one embodiment, each pad insertion through hole is disposed around the center of the body portion.

In one embodiment, the main body part of each layered base plate is provided with a positioning through hole, and the positioning through holes on the layered base plates are arranged at corresponding positions in the first direction;

each sleeve is inserted into the corresponding positioning through hole of each layered base plate so as to penetrate through the main body part of each layered base plate.

In one embodiment, the main body portion of the layered backing plate includes a plurality of grid cells, and the grid holes in each grid cell form positioning through holes.

In one embodiment, the filling plate comprises a plurality of filling blocks, the filling plate insertion through holes are formed in the filling blocks, and the plurality of filling blocks jointly enclose the avoiding opening.

In one embodiment, the outer contour of the projection of the main body portion on the filling plate coincides with the edge of the escape opening.

In one embodiment, the plug connector is constructed as a tubular element so as to form a ventilation cavity with two ends communicated inside the plug connector;

the end part of the plug connector close to the first side is provided with a flanging structure, and the end part of the plug connector close to the second side penetrates through and is supported on the filling block.

In one embodiment, the plug connector comprises a main plug connector and an auxiliary plug connector;

the plurality of grid cells include a first grid cell and a second grid cell arranged around an outer side of the first grid cell, the first grid cell being arranged in an array such that an area occupied by the first grid cell is configured as a square area;

the auxiliary plug connector is located on the side of the end portion of a diagonal line of the square area, the main plug connector is located on the circumferential outer side of the second grid unit, and the setting position of the main plug connector corresponds to the side length of the square area.

In one embodiment, the outer edge of the positioning part is configured in a ring shape;

the number of the main connectors corresponding to one side length of the square area is gradually reduced from the center of the one side length of the square area to two sides.

In one embodiment, the filling blocks comprise main filling blocks and auxiliary filling blocks, the main filling blocks are used for the main plug connectors to penetrate through, and the auxiliary filling blocks are used for the auxiliary plug connectors to penetrate through.

In one embodiment, the filling plate closest to the second side is provided with a ventilation slot therein which opens towards the main body, the ventilation slot communicating with the end opening of the sleeve near the second side and the ventilation slot communicating with the end opening of the plug-in connector near the second side.

In one embodiment, the main body part comprises a plurality of criss-cross grid bars, and the grid bars jointly define grid units; the spent fuel storage grid further comprises a plurality of neutron absorbers, and the neutron absorbers are connected to the grid bars, so that the plurality of neutron absorbers are located between the sleeves.

In one embodiment, the end of the sleeve close to the second side is provided with a ventilation gap so that the sleeve is communicated with the ventilation groove of the filling plate; and/or

And in the neutron absorber closest to the second side, an opening corresponding to the ventilation notch is formed in the end part close to the second side, and the position of the opening corresponds to the ventilation notch of the sleeve.

A second aspect of the embodiment of the present application provides a spent fuel storage container, which includes a shell having an accommodating cavity therein and the spent fuel storage grid frame described above;

the spent fuel storage grillwork is positioned in the holding cavity, and the cavity wall of the holding cavity is matched with the outer contour of the spent fuel storage grillwork so as to position the spent fuel storage grillwork.

Drawings

Fig. 1a is a schematic structural diagram of a spent fuel storage container according to an embodiment of the present application;

fig. 1b is a top view of a spent fuel storage container according to an embodiment of the present application;

fig. 1c is a bottom view of a spent fuel storage container according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a spent fuel storage lattice provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram illustrating a structure of a spent fuel storage lattice frame in which a layered backing plate and a plug connector are matched with each other according to an embodiment of the present application;

fig. 4 is a schematic structural diagram illustrating a matching structure of a filler plate and a plug connector in a spent fuel storage lattice according to an embodiment of the present application;

fig. 5 is a top view of a filler plate in a spent fuel storage grid according to an embodiment of the present application;

fig. 6 is a schematic structural diagram of a first layered backing plate in a spent fuel storage lattice provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a second layered backing plate in the spent fuel storage grid according to the embodiment of the present application;

fig. 8 is a schematic structural view of an insert member in a spent fuel storage grid according to an embodiment of the present application;

FIG. 9 is a schematic view of the structure of the main packing block in the first packing plate;

FIG. 10 is a schematic view of the structure of the auxiliary filling block in the first filling board;

fig. 11 is a schematic structural diagram of a second infill panel in the spent fuel storage grid according to an embodiment of the present application;

FIG. 12 is a schematic view of the main packing block in the second packing plate;

FIG. 13 is a schematic view of the structure of the auxiliary filling block in the second filling board;

fig. 14 is a front view of a spent fuel storage lattice provided in an embodiment of the present application;

fig. 15 is a schematic structural diagram of a neutron absorber in a spent fuel storage grid according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of a first neutron absorber in a spent fuel storage lattice according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of a second neutron absorber in the spent fuel storage grid according to the present embodiment;

FIG. 18 is a schematic structural view of a spent fuel storage grid according to an embodiment of the present application with neutron absorbers mounted on the layered separators;

figure 19 is a schematic diagram of the path of gas flow in a spent fuel storage lattice provided in an embodiment of the present application;

figure 20 is a schematic view of the path of gas flow in a spent fuel storage lattice provided in an embodiment of the present application;

fig. 21 is a schematic structural view of a spent fuel storage grid provided in an embodiment of the present application in a horizontal state.

The reference numbers indicate:

100. a spent fuel storage framework; 10. layering a base plate; 101. a first layered backing plate; 102. a second layered backing plate; 11. a main body part; 1101. positioning the through hole; 110. grid bars; 111. a grid unit; 1111. a first grid cell; 1112. a second grid cell; 12. a positioning part; 120. a sub-positioning portion; 121. the base plate is inserted into the through hole; 1211. the base plate is mainly inserted into the through hole; 1212. the base plate is inserted with the through hole in an auxiliary manner;

20. a infill panel; 21. a first infill panel; 211. the filling plate is inserted into the through hole; 212. filling the main inserting through holes of the plate; 213. the filling plate assists in inserting the through hole; 22. a second infill panel; 23. filling blocks; 231. 231', 231", main stuffing block; 232. 232', 232 ″ and auxiliary filling blocks; 24. a ventilation slot; 25. a main ventilation slot; 26. an auxiliary ventilation slot;

30. a plug-in unit; 301. a flanging structure; 31. a main plug connector; 32. an auxiliary plug connector;

40. lifting lugs; 41. a notch; 42. the side length of the square area; 43. a bevel structure; 44. avoiding the opening; 45. an opening; 46. a spent fuel assembly;

50. a sleeve; 51. a ventilation gap;

60. a neutron absorber; 61. a first neutron absorber; 611. a first plug-in joint; 62. a second neutron absorber; 621. a second plug-in joint;

200. a spent fuel storage vessel; 210. a housing; 2101. a barrel; 2102. a top cover; 2121. an inner cover plate; 2122. an outer cover plate; 2103. a base plate; 220. and a drainage assembly.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

The spent fuel storage framework and the spent fuel storage container according to the embodiment of the present application will be described with reference to the drawings.

Fig. 1a is a schematic structural diagram of a spent fuel storage container according to an embodiment of the present application, fig. 1b is a top view of the spent fuel storage container according to the embodiment of the present application, and fig. 1c is a bottom view of the spent fuel storage container according to the embodiment of the present application. Fig. 1b and 1c are schematic structural views of the spent fuel storage container 200 with the top cover 2102 and the bottom plate 2103 removed.

Referring to fig. 1a, 1b and 1c, an embodiment of the present application provides a spent fuel storage container 200, which includes a shell 210 having a receiving cavity therein and a spent fuel storage lattice 100; the spent fuel storage grid 100 is located in the accommodating cavity, and the cavity wall of the accommodating cavity is matched with the outer contour of the spent fuel storage grid 100 so as to position the spent fuel storage grid 100.

The spent fuel storage grid 100 is located in the accommodating cavity, and the cavity wall of the accommodating cavity matches with the outer contour of the spent fuel storage grid 100, which means that the top of the accommodating cavity abuts against the top of the spent fuel storage grid 100, the bottom of the accommodating cavity abuts against the bottom of the spent fuel storage grid 100, and the side cavity wall of the accommodating cavity contacts with the side contour of the spent fuel storage grid 100, so that the spent fuel storage grid 100 can be supported in the accommodating cavity. It should be noted that, the top, the bottom, the side walls of the accommodating cavity and the spent fuel storage grid 100 are all in contact with each other, which means that in the use state, in the non-use state, a certain thermal expansion gap is required between the top and the side walls of the accommodating cavity and the spent fuel storage grid 100.

In a specific implementation, the housing 210 may include a barrel 2101, and a top cover 2102 and a bottom plate 2103 respectively disposed at the top end (upper side of the drawing shown in fig. 1) and the bottom end (lower side of the drawing shown in fig. 1) of the barrel 2101, wherein the barrel 2101, the top cover 2102 and the bottom plate 2103 together define a receiving cavity and form a sealed containment boundary of the entire spent fuel storage container 200.

The top cover 2102 abuts against the top of the spent fuel storage grid 100, the bottom plate 2103 abuts against the bottom of the spent fuel storage grid 100, and the barrel 2101 contacts with the side profile of the spent fuel storage grid 100, so that the spent fuel storage grid 100 can be supported on the shell 210.

Among other things, the top cover 2102 can include an inner cover plate 2121 and an outer cover plate 2122 that are stacked on top of each other to provide a dual redundant seal for the spent fuel storage container 200. An aeration hole and a drain hole unit (not shown) are provided on the inner cover plate 2121, and a drain assembly 220, which will be described later, is connected to the drain hole unit provided on the inner cover plate 2121, and is used to perform operations such as aeration and drainage, vacuum pumping, and dry helium gas filling on the inside of the spent fuel storage container 200 when the spent fuel storage container 200 is in the vertical loading operation.

With continued reference to fig. 1a, the spent fuel storage container 200 is not limited to include the above-described barrel 2101 and the spent fuel storage lattice 100, but may further include a drain assembly 220, etc., wherein the drain assembly 220 may be connected to a drain hole unit provided on the inner cover 2121 to perform a drain operation, etc., on the interior of the spent fuel storage tank.

Fig. 2 is a schematic structural diagram of a spent fuel storage grid provided in an embodiment of the present application, fig. 3 is a schematic structural diagram of mutual matching between a layered backing plate and a connector in the spent fuel storage grid provided in the embodiment of the present application, and fig. 4 is a schematic structural diagram of mutual matching between a filling plate and a connector in the spent fuel storage grid provided in the embodiment of the present application.

The specific structure of the spent fuel storage grid 100 will be described with reference to the drawings, and it should be noted that, for convenience of description, a vertical direction in the drawing of fig. 1, that is, a direction perpendicular to the layered base plates 10, is defined as a first direction G of the spent fuel storage grid and the spent fuel storage containers, the first direction includes a first side F and a second side S which are oppositely arranged, and corresponds to fig. 1, an upper side of the drawing of fig. 1 is the first side F, and a lower side of the drawing of fig. 1 is the second side S.

Referring to fig. 2, 3, and 4, the spent fuel storage lattice 100 according to the embodiment of the present application includes: a plurality of layered backing plates 10, a plurality of infill plates 20, a plurality of plug members 30, and a sleeve 50 for storing spent fuel assemblies 46; each layered cushion plate 10 is provided with a main body part 11 and a positioning part 12 surrounding the main body part 11; each filling plate 20 is provided with an avoidance opening 44;

the layered mats 10 and the packing plates 20 are alternately stacked in a first direction G perpendicular to the layered mats 10, wherein the main body 11 of the layered mats 10 corresponds to the position of the escape opening 44 in the first direction G.

The plug-in unit 30 penetrates the positioning part 12 of each layered backing plate 10 and each filling plate 20 along the first direction G; the grommet 50 penetrates the main body portion 11 of each layered mat 10 in the first direction G and passes inside the escape opening 44 of the filler plate 20.

In the above-described aspect, the positioning of the respective layered mats 10 and the filling plates 20 in the first direction G is achieved by the layered mats 10 and the filling plates 20 being alternately laminated together in the first direction G, and the layered mat 10 or the filling plate 20 located at the lowermost layer is used to be supported at the bottom of the spent fuel storage container 200. And the plug connector 30 penetrates through each filling plate 20 along the first direction G and penetrates through the positioning part 12 of each layered backing plate 10, so that each layered backing plate 10 and each filling plate 20 are positioned in the direction perpendicular to the first direction G. Further, the sleeve 50 penetrates the main body 11 of each layered mat 10 in the first direction G to store the spent fuel, so that each component in the spent fuel storage grid 100 is positioned by splicing. Because the need of welding connection is avoided as in the prior art, the deformation caused by welding can be avoided, the residual stress of welding can not occur, the whole storage grid frame is not easy to deform, and the reliability is higher.

In other words, the spent fuel storage grillwork 100 of the present application is spliced in layers, and the spent fuel storage grillwork 100 matched with the spent fuel storage container 200 capable of efficiently transferring heat under vertical and horizontal working conditions is realized.

The number of the layered backing plate 10 and the filling plate 20 is plural, and the plural number means two or more. Also, the layered backing plate 10 and the infill plate 20 need to be alternately stacked in the first direction G. In fig. 1, the number of the layered cushion plate 10 and the number of the filling plate 20 are 13 for example, and the layered cushion plate 10 and the filling plate 20 are sequentially and alternately arranged from the first side F to the second side S for explanation, and similar to this, the description is omitted here for the case where the number is other.

Fig. 5 is a top view of a filler plate in a spent fuel storage grid according to an embodiment of the present application.

Referring to fig. 2 and 3, each layered cushion plate 10 has a main body 11 and a positioning portion 12, and the positioning portion 12 surrounds the main body 11, but the positioning portion 12 may be a continuous ring structure or a discontinuous structure. The plug 30 penetrates the positioning portion 12 of each layered pad 10 and each infill panel 20 in the first direction G, so that the layered pads 10 and the infill panels 20 can be connected in series to the plug 30.

The filler plate 20 may be provided with an escape opening 44, and the position of the escape opening 44 corresponds to the main body portion 11 of the layered mat 10, which means that when the layered mat 10 is projected onto the filler plate 20, the projection of the main body portion 11 and the escape opening 44 have an overlapping portion.

When the sleeve 50 is inserted, the filling plate 20 may surround the circumferential outer side of the sleeve 50, that is, when the sleeve 50 penetrates the main body portion 11 of each layered mat 10 in the first direction G, the sleeve 50 may pass through the inside of the escape opening 44 of the filling plate 20.

Fig. 6 is a schematic structural diagram of a first layered backing plate in the spent fuel storage grid according to the embodiment of the present application;

fig. 7 is a schematic structural diagram of a second layered backing plate in the spent fuel storage grid according to the embodiment of the present application.

Referring to fig. 3, 5 and 6, the positioning portion 12 of each layered cushion plate 10 is provided with cushion plate insertion through holes 121, and each filling plate 20 is provided with filling plate insertion through holes 211 corresponding to the cushion plate insertion through holes 121 one to one. The one-to-one correspondence may refer to positions of the pad insertion through holes 121 and the filling plate insertion through holes 211 corresponding to each other, and may be, for example, a center of each of the pad insertion through holes 121 and the filling plate insertion through holes 211 aligned in the first direction G.

And each shim plate insertion hole 121 may be provided around the center of the body portion 11 to better support each layered shim plate 10.

Each of the plug-in units 30 is inserted into the corresponding pad insertion through-hole 121 and filling plate insertion through-hole 211 to penetrate the positioning part 12 of each layered pad 10 and each filling plate 20. The plug 30 may be a bar extending along the first direction G, and in particular may be configured as a tube, such as a vent tube. So as to form a ventilation cavity with two through ends in the plug-in unit 30; the end part of the plug-in unit 30 close to the first side is provided with a flanging structure, and the end part of the plug-in unit 30 close to the second side penetrates through and is supported on the filling block 23.

With reference to fig. 2 and 3, for example, the main body 11 of each layered cushion plate 10 is provided with positioning through holes 1101, and the positioning through holes 1101 on each layered cushion plate 10 are arranged at positions corresponding to each other in the first direction G;

each sleeve 50 is inserted into a corresponding positioning through hole 1101 of each layered backing plate 10 to penetrate through the main body portion 11 of each layered backing plate 10.

The number of the positioning through holes 1101 can be set according to actual needs, and the number of the positioning through holes 1101 is described as 32, that is, the number of the sleeves 50 inserted into the positioning through holes 1101 is 32. And the storage capacity can be adjusted to other quantities in combination with the hoisting weight limit requirements of the nuclear power plant, such as: 12, 15, 24, 37, etc.

The casing 50 can be inserted by the spent fuel assembly 46, and is illustrated by taking a square tube suitable for international pressurized water reactor spent fuel AFA2G and AFA3G assemblies as an example. In practical applications, other regular polygonal square tubes, such as a regular hexagonal square tube used with the VVER regular hexagonal spent fuel assembly 46, may be adopted according to the structural shape of the spent fuel assembly 46. The positioning through-hole 1101 may be formed as a square hole corresponding to the structure of the sleeve 50.

Referring to fig. 3 and 6, as one possible embodiment, the main body 11 of the layered mat 10 may include a plurality of grid cells 111, and the grid holes in each grid cell 111 may form positioning through holes 1101.

In addition, in order to prevent the filler plate 20 from interfering with the insertion of the bushing 50, the outer contour of the projection of the main body portion 11 on the filler plate 20 may be overlapped with the edge of the escape opening 44.

As described above, the first direction G defines a first side F and a second side S which are oppositely arranged, where the first side F is the top side of the spent fuel storage grid 100, and the second side S is the bottom side of the spent fuel storage grid 100 as an example, as shown in fig. 3, the layered mat 10 closest to the first side F among the layered mat 10 is a first layered mat 101, and all the layered mats 10 except the first layered mat 101 among the layered mats 10 are second layered mats 102.

In the embodiment of the present application, referring to fig. 1b, 4 and 6, in order to facilitate the hoisting of the spent fuel storage lattice 100, a lifting lug 40 is generally disposed at the top of the spent fuel storage lattice, for example, the lifting lug 40 may be disposed on the filler plate 20. Correspondingly, a notch 41 is formed in the first layered backing plate 101 at a position corresponding to the lifting lug 40, so that the lifting lug 40 on the filling plate 20 can extend out conveniently. The number of the notches 41 corresponds to the number of the lifting lugs 40, and may be four, for example. And the second layered backing plate 102 is arranged at the lower side of the lifting lug 40, so that the notch 41 is not needed. In other words, the first layered shim plate 101 and the second layered shim plate 102 differ only in the gap 41. When stacked, the first layered mat 101, the filler sheet 20, the second layered mat 102, and the filler sheet 20, \ 8230 \ 8230;, are stacked from the first side F to the second side S.

Fig. 8 is a schematic structural view of an insert member in a spent fuel storage grid according to an embodiment of the present application.

In addition, referring to fig. 3, 6 and 8, the end of the plug 30 close to the first side F is provided with a flanging structure 301, and the flanging structure 301 is overlapped with the edge of the pad insertion through hole 121 of the first layered pad 101. This prevents the layered mat 10 from being removed from the insert 30.

Further, referring to fig. 3 and 7, the plug 30 may include a main plug 31 and an auxiliary plug 32;

the plurality of grid cells 111 may include a first grid cell 1111 (a grid cell within a region framed by a one-dot chain line) and a second grid cell 1112 disposed to surround the first grid cell 1111, the first grid cell 1111 being arranged in an array such that the region occupied by the first grid cell 1111 is configured as a square region M; the auxiliary plug 32 is located on the side of the end of the diagonal line D of the square region, the main plug 31 is located on the outer side in the circumferential direction of the second grid unit 1112, and the installation position of the main plug 31 corresponds to the side length of the square region M.

Since the plug-in units 30 are positioned in one-to-one correspondence with the pad insertion through holes 121, the pad insertion through holes 121 may define a pad main insertion through hole 1211 and a pad auxiliary insertion through hole 1212. The main insertion through hole 1211 of the pad is adapted for inserting the main insertion part 31, and the auxiliary insertion through hole 1212 of the pad is adapted for inserting the auxiliary insertion part 32.

Here, the auxiliary connector 32 is located on the side of the end of the diagonal line D of the square area M, and the main connector 31 is located at a position corresponding to the side length of the square area M. In a specific implementation, the main insertion through hole 1211 of the pad plate may be located at a side of the square region M, and the auxiliary insertion through hole 1212 of the pad plate may be located at a side of an end of the diagonal line D.

With further modification of the above embodiment, referring to fig. 6 and 7, in order to correspond to the inner wall of the cylinder of the spent fuel storage container 200, the outer edge of the positioning portion 12 is configured to be annular, so that four sub-positioning portions 120 are defined between the square outer edge of the main body portion 11 and the annular outer edge of the positioning portion 12, that is, each side length of the square region M corresponds to one sub-positioning portion 120, and the inner edge of the sub-positioning portion 120 is a flat surface and the outer edge is an arc surface. The four sub-positioning portions 120 are all configured to have a large width at the middle portion and small width at the two end portions, and accordingly, the number of the pad main insertion through holes 1211 disposed on the sub-positioning portions 120 may gradually decrease from the center of one side of the square region M to the two sides. In other words, the number of the plurality of main connectors 31 corresponding to one side of the square region M, for example, the side 42 of the square region, gradually decreases from the center of the side 42 of the square region to both sides.

In the present embodiment, the cross section of the plug 30 may be formed in an elongated shape, and it should be noted that the main plug 31 near the center of the side 42 of the square region has a longitudinal direction P along the column direction L of the first grid unit 1111, and the main plug 31 far from the center of the side 42 has a longitudinal direction R parallel to the row direction H of the first grid unit 1111.

The cross section of the auxiliary plug 32 is also elongated, and the longitudinal direction of the cross section of the auxiliary plug 32 may be along the row direction H and the column direction L of the arrangement of the first grid cells 1111.

It should be noted that, one sub-positioning portion 120 is taken as an example for description, and the arrangement manner of the pad insertion through hole 121 on the other sub-positioning portions 120 is similar to that, and is not described again here.

In the embodiment of the present application, referring to fig. 5, each filling plate 20 may include a plurality of filling blocks 23, the filling plate insertion through holes 211 are formed in the filling blocks 23, and the plurality of filling blocks 23 jointly enclose the avoiding opening 44.

Illustratively, the plurality of fillers 23 are assembled together in an annular configuration, and the inner side surfaces of the fillers 23 collectively define the escape opening 44. Here, a 360 ° full circumferential coating of the entire region of the sleeve 50 can be achieved by using the filling blocks 23. It should be noted that a certain thermal expansion gap needs to be reserved between each component of the layered backing plate 10, the filling block 23 and the like.

The filler block 23 may include a main filler block 231 and an auxiliary filler block 232, wherein the main filler block 231 is penetrated by the main plug 31, and the auxiliary filler block 232 is penetrated by the auxiliary plug 32. The main filling blocks 231 and the auxiliary filling blocks 232 may be spaced and alternately arranged in the circumferential direction of the main body portion 11.

In addition, the material of the filling block 23 may be a metal material or a composite material having a low density and good heat conductivity.

As described above, the outer contour of the projection of the main body portion 11 on the filling plate 20 coincides with the edge of the escape opening 44, the outer contour of the projection of the layered shim plate 10 on the filling plate 20 coincides with the outer contour of the filling plate 20, and specifically, the positioning portion 12 of the second layered shim plate 102 described later coincides with the filling plate 20.

In addition, the filling plate insertion through hole 211 formed in the filling block 23 may include a filling plate main insertion through hole 212 and a filling plate auxiliary insertion through hole 213, and in the first direction G, the filling plate main insertion through hole 212 coincides with the base plate main insertion through hole 1211, and the filling plate auxiliary insertion through hole 213 coincides with the base plate auxiliary insertion through hole 1212. Coincidence here includes both size and contour shape and placement position.

Fig. 9 is a schematic structural view of a main filling block in a first filling plate, fig. 10 is a schematic structural view of an auxiliary filling block in the first filling plate, and fig. 11 is a schematic structural view of a second filling plate in a spent fuel storage grid according to an embodiment of the present application.

Referring to fig. 10, 11, 12, similar to the layered pallet 10, the infill panel 20 also includes a first infill panel 21 and a second infill panel 22, wherein the first infill panel 21 is the infill panel 20 adjacent the first side F and the infill panel 20 is the second infill panel 22 except for the first infill panel 21. The first filling plate 21 and the second filling plate 22 are different in that, in order to avoid the lifting lug 40, a surface of the auxiliary filling block 232' in the first filling plate 21, which is close to the first side F, is provided with a slope structure 43. While the surface of the auxiliary filling block 232 "in the second filling plate 22 close to the first side F is not provided with a slope structure.

Further, with continued reference to fig. 11, the filling plate 20 closest to the second side S is provided with a ventilation groove 24 that opens toward the body portion 11, the ventilation groove 24 communicates with the opening of the end portion of the grommet 50 near the second side S, and the ventilation groove 24 communicates with the opening of the end portion of the plug 30 near the second side S.

Fig. 12 is a schematic structural view of a main filling block in the second filling plate, and fig. 13 is a schematic structural view of an auxiliary filling block in the second filling plate.

In concrete implementation, referring to fig. 12 and 13, as mentioned above, the second filling plate 22 is provided with the ventilating slots 24, the main filling block 231 ″ is provided with the main ventilating slots 25 with trapezoidal cross sections corresponding to the main filling block 231 ″, and the main ventilating slots 25 are further communicated with the filling plate main insertion through holes 212,

the auxiliary filling block 232' of the second filling plate 22 is provided with an auxiliary ventilation groove 26 having a trapezoidal cross section, and the auxiliary ventilation groove 26 is further communicated with the filling plate auxiliary insertion through hole 213.

In other examples, the cross section of the main ventilation slot 25 on the main filling block 231 ″ is isosceles trapezoid, and the two left and right waists extend to both sides of the sleeve 50 covered by the main ventilation slot, so as to ensure that the air at the second side end of each sleeve 50 can enter the main ventilation slot 25.

Here, the depth of the main ventilation groove 25 is the same as that of a ventilation notch 51 of the later-described sleeve 50 to reduce flow resistance, and to promote smooth entry of air inside the sleeve 50 into the main ventilation groove 25.

Fig. 14 is a front view of a spent fuel storage lattice according to an embodiment of the present application.

Referring to fig. 14, the depth design requirement for the ventilation slot 24 has the following features: considering the relatively large airflow resistance between the second side end of the spent fuel assembly 46 and the bottom plate 2103 of the spent fuel storage container 200, the depth of the ventilation slot 24 is required to be greater than or equal to the distance d1 between the bottom of the spent fuel assembly 46 and the bottom plate to sufficiently strengthen the horizontal direction flow of the bottom of each fuel storage unit.

Figure 15 is a schematic structural diagram of a neutron absorber in a spent fuel storage lattice according to an embodiment of the present application,

figure 16 is a schematic structural view of a first neutron absorber in a spent fuel storage lattice according to an embodiment of the present application,

fig. 17 is a schematic structural view of a second neutron absorber in the spent fuel storage grid according to the embodiment of the present application, and fig. 18 is a schematic structural view of the spent fuel storage grid according to the embodiment of the present application, in which the neutron absorber is mounted on a layered separator.

In the embodiment of the present application, as mentioned above, the main body 11 includes a plurality of grid cells 111, and in a specific implementation, referring to fig. 6, the main body 11 may include a plurality of criss-cross grid bars 110, and the grid bars 110 together define the grid cells 111.

Referring to fig. 15, 16, 17, and 18, the spent fuel storage lattice 100 further includes a plurality of neutron absorbers 60, and the neutron absorbers 60 are connected to the grid bars 110 such that the plurality of neutron absorbers 60 are positioned between the sleeves 50. Wherein the neutron-absorber 60 is used to achieve critically safe control of the spent fuel assembly 46.

The neutron absorber 60 may be a structural-functional integrated neutron absorber material, or may be a stainless steel substrate, and then a stainless steel protective layer is welded to one side or both sides of the substrate to cover the neutron absorber plate therein. Meanwhile, in order to increase the heat conduction and heat exchange capacity, metal materials with good heat conduction performance, such as aluminum plates and the like, can be additionally arranged in the neutron absorber.

Specifically, the neutron absorber 60 may include a plurality of first neutron absorbers 61 and a plurality of second neutron absorbers 62, the plurality of first neutron absorbers 61 may be arranged in parallel with each other, the plurality of second neutron absorbers 62 may be arranged in parallel with each other, and the first neutron absorbers 61 and the second neutron absorbers 62 may be inserted into each other at the first side F and the second side S to form the neutron absorber 60. Referring to fig. 16 and 17, a first inserting joint 611 is formed at an end portion of the first neutron absorber 61 close to the second side, a second inserting joint 621 is formed at an end portion of the second neutron absorber 62 close to the first side F, and the first inserting joint 611 and the second inserting joint 621 are arranged oppositely and are inserted into each other.

Fig. 19 is a schematic diagram illustrating a path of gas flow in the spent fuel storage grid provided in the embodiment of the present application, fig. 20 is a schematic diagram illustrating a path of gas flow in the spent fuel storage grid provided in the embodiment of the present application, and fig. 21 is a schematic structural diagram illustrating the spent fuel storage grid provided in the embodiment of the present application in a horizontal state.

Referring to fig. 19 and 20, for example, the end of the sleeve 50 near the second side S is provided with a ventilation notch 51 to communicate the sleeve 50 with the ventilation groove 24 of the filling plate 20.

Further, in the neutron absorber 60 closest to the second side S, an opening 45 corresponding to the ventilation notch 51 is opened at an end portion close to the second side S, and the position of the opening 45 corresponds to the ventilation notch 51 of the sleeve 50.

Thus, the gas in the sleeve 50 can flow into the ventilation slot 24 of the filling board 20 through the ventilation gap 51, and the ventilation slot 24 is communicated with the plug 30, so that a gas circulation channel can be formed, as shown by black arrows in fig. 19 and 20.

In the embodiment of the present application, the spent fuel storage container 200 is a vertical storage container, and can simultaneously take into account the thermal safety under the working conditions of vertical loading and horizontal transportation. Under the vertical loading condition, the spent fuel storage container 200 can keep better convection heat transfer capability, and can meet the high-efficiency heat transfer requirement of spent fuel decay heat under the horizontal transfer condition.

Specifically, according to the operation scheme of the spent fuel dry storage process, the spent fuel storage container 200 generally has two operation conditions in a vertical state. The first is a short-term operation condition, that is, the spent fuel storage container 200 is kept in a vertical state for short-term drainage/vacuum drying and helium filling. And secondly, after the vertical loading of the spent fuel assemblies 46 is completed for horizontal transfer, the spent fuel storage container 200 is turned over for vertical long-term storage.

In response to the above two operating conditions, the decay heat of the spent fuel assembly 46 is mainly transferred by air convection because the spent fuel assembly 46 is kept in the vertical storage state. The gas convection path will be described in detail below with reference to fig. 19 and 20 as follows:

the gas in each sleeve 50 flows out of the sleeve 50 from the vent gap 51 at the bottom of the sleeve 50 and into the vent slot 24 of the fill plate 20 toward the first side F;

the air is accumulated in the cavity of the ventilation slot 24 and then enters the plug connector 30 communicated with the ventilation slot 24;

the gas continues to flow up to the first side F end of the insert 30 and out of the insert 30, into the cavity between the first layered gasket 101 and the top cap 2102, and into the first side F end of the sleeve 50. The circulation is performed in such a way to form a gas circulation channel in the spent fuel storage container 200. So that the gas filled inside the spent fuel storage container 200 realizes the internal continuous circulation convection in the vertical storage state.

Referring to fig. 19, a schematic diagram (1/4 section) of a vertical heat transfer path of the spent fuel storage container 200 is shown. According to the operation scheme of the spent fuel dry storage process, the heat transfer path of the spent fuel storage container 200 in the vertical state is suitable for two operation conditions. One is a short term operation condition, i.e., maintaining the storage vessel 200 in a vertical position for short term drainage/vacuum drying and helium gas filling. And secondly, after the vertical loading of the spent fuel assemblies is completed for horizontal transfer, the storage container 200 is turned over for vertical long-term storage.

Corresponding to the above two operating conditions, since the spent fuel storage assembly is kept in the vertical storage state, the lower pipe seat of the spent fuel assembly is located on the storage container bottom plate 2103, and a necessary gap is reserved between the spent fuel assembly and the square pipe (i.e., the sleeve 50), under the operating condition, decay heat of the spent fuel assembly is mainly transferred by air convection. In order to enhance the air convection heat transfer effect, the inert gas filled in the storage container 200 of the present invention realizes continuous convection heat transfer through the square tube and the plug-in ventilation tube 30 (i.e. the plug-in member 30) penetrating the filling block 23, and the gas convection path is described in detail as follows:

1) The air in each square tube flows out from the ventilation groove on the side wall of the bottom of the square tube;

2) Then flows upward into a stepped vent cavity in the bottom fill block 23, see fig. 20 for details;

3) The gas is accumulated in the step ventilation cavity and then enters the plugging ventilation pipe pore canal penetrating through the bottom filling block 23, which is shown in detail in figure 20;

4) The gas continuously flows upwards to the inserted ventilation pipe of the filling block positioned in the middle part;

5) The gas continues to flow upwards to the inserted ventilation pipe of the filling block positioned at the top;

6) The gas flows out of the filling block positioned at the top and enters the cavity between the top cover 2102 and the square pipe;

7) Then the gas flows downwards along the top of each square pipe of the spent fuel storage assembly to the cavity inside each square pipe.

8) And (4) repeating the step 1), wherein the gas filled in the spent fuel storage container realizes internal continuous circulation convection in a vertical storage state.

Specifically, as shown in fig. 21, a schematic diagram of a heat transfer path in a horizontal state of the spent fuel storage container 200 is shown. The heat transfer path in the horizontal state of the spent fuel storage vessel 200 is suitable for two operating conditions according to the operation scheme of the spent fuel dry storage process. The first is a short-term operation condition, that is, a short-term horizontal transfer is performed after the spent fuel storage container 200 is loaded. And secondly, the spent fuel assemblies are stored in a long-term horizontal state after being horizontally transported.

Corresponding to the two operating conditions, because the spent fuel assembly keeps a horizontal storage state, the side surface of the spent fuel assembly is directly attached to one surface of the square tube of the spent fuel storage container 200, and under the operating condition, decay heat of the spent fuel assembly is mainly transferred by heat conduction. In order to enhance the heat conduction effect, the invention mainly depends on the square tube, the special-shaped filling block and the cylinder body for heat conduction, and the heat conduction path is explained in detail as follows:

1) The spent fuel assembly directly transfers decay heat of the spent fuel assembly to the square pipe through wall surface contact;

2) The square tube transfers heat to the special-shaped filling block 23 which coats the 360-degree circumferential direction of the square tube through heat conduction;

3) The special-shaped filling block 23 transfers the decay heat of the spent fuel assembly to the cylinder 2101 of the spent fuel storage container 200;

4) The external air cools and dissipates heat from the barrel 2101 of the spent fuel storage container 200, so that decay heat of the spent fuel assembly is continuously conducted out.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. A spent fuel storage grid, comprising: the device comprises a plurality of layered base plates, a plurality of filling plates, a plurality of plug connectors and a sleeve for storing a spent fuel assembly;

each filling plate is provided with an avoiding opening;

the layered base plate and the filling plate are alternately stacked along a first direction perpendicular to the layered base plate, wherein the main body part of the layered base plate corresponds to the position of the avoidance opening in the first direction;

the plug connector penetrates through the positioning part of each layered cushion plate and each filling plate along the first direction;

2. The spent fuel storage lattice frame of claim 1, wherein the positioning portion of each of the layered backing plates is provided with a backing plate insertion through hole, and each of the packing plates is provided with a packing plate insertion through hole corresponding to the backing plate insertion through hole one to one;

3. The spent fuel storage lattice frame of claim 2, wherein the main body of each of the layered backing plates is provided with positioning through holes, and the positioning through holes of each of the layered backing plates are arranged at positions corresponding to each other in the first direction;

each sleeve is inserted into the corresponding positioning through hole of each layered cushion plate so as to penetrate through the main body part of each layered cushion plate.

4. The spent fuel storage lattice according to claim 3, wherein the main body portion of the layered mat comprises a plurality of grid cells, the grid holes in each of the grid cells forming the positioning through holes.

5. The spent fuel storage grid according to claim 4, wherein the filling plate comprises a plurality of filling blocks, the filling plate insertion through holes are formed in the filling blocks, and the plurality of filling blocks jointly enclose the avoidance opening.

6. The spent fuel storage lattice according to claim 4 or 5, wherein the socket connector is configured as a tubular member to form a ventilation cavity inside the socket connector through both ends;

7. The spent fuel storage lattice of claim 6, wherein the plug includes a primary plug and a secondary plug;

the plurality of grid units comprise first grid units and second grid units arranged at the outer sides of the first grid units in a surrounding mode, and the first grid units are arranged in an array mode so that the area occupied by the first grid units is configured to be a square area;

8. The spent fuel storage lattice according to claim 7, wherein the filler blocks include a main filler block through which the main plug member passes and an auxiliary filler block through which the auxiliary plug member passes.

9. The spent fuel storage lattice according to claim 8, wherein the filler panel closest to the second side has a ventilation slot therein that opens toward the body portion, the ventilation slot communicating with an end opening of the sleeve proximate to the second side and the ventilation slot communicating with an end opening of the plug proximate to the second side.

10. The spent fuel storage lattice according to claim 9, wherein the main body portion includes a plurality of criss-cross grid bars, the plurality of grid bars collectively defining the grid cells; the spent fuel storage grid further comprises a plurality of neutron absorbers, and the neutron absorbers are connected to the grid bars, so that the plurality of neutron absorbers are located between the sleeves.

11. The spent fuel storage lattice according to claim 10, wherein an end of the sleeve adjacent to the second side is provided with a ventilation gap to communicate the sleeve with the ventilation slot of the filler panel; and/or

12. A spent fuel storage container, comprising a shell having a receiving cavity therein and the spent fuel storage lattice according to any one of claims 1 to 11;

the spent fuel storage grillwork is located in the accommodating cavity, and the cavity wall of the accommodating cavity is matched with the outer contour of the spent fuel storage grillwork so as to position the spent fuel storage grillwork.