JP2007171135A - Cask for spent fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cask for spent fuel capable of enhancing a heat transfer property between a basket and a barrel main body, and capable of enhancing heat removal performance. <P>SOLUTION: This cask is provided with the barrel body 3 for shielding a γ-ray, a neutron shielding body 10 provided in an outer circumferential side of the barrel body 3, and a basket part 4 assembled lattice-likely with a plurality of basket plates 14a-14d, 15a-15d, 16a-16d, 17a-17d insertion-supported by a plurality of grooves 13 formed on an inner circumferential face of the barrel body 3, and for forming a plurality of sections for storing spent fuel assemblies 2, and the plurality of basket plates 14a-14d, 15a-15d, 16a-16d, 17a-17d are layeredly arranged each other along an axial direction of the barrel body 3, by engaging fellow slits 18 formed in a portion crossed mutually with the first basket plate groups 14, 16 aligned in parallel each other toward a lateral direction, and the second basket plate groups 15, 17 aligned in parallel each other toward a vertical direction right-angled to the lateral direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spent fuel cask that transports or stores spent fuel generated mainly from nuclear power plants.

  The fuel used for a certain period at the nuclear power plant is taken out from the core, temporarily stored in a spent fuel pool or the like, and cooled. The fuel cooled for a predetermined period is transported to a reprocessing plant where it is reprocessed, and uranium, plutonium and the like are taken out as reusable resources and reused. Here, spent fuel generated at nuclear power plants has been increasing with the increase in power demand, and even if the reprocessing plant is in operation, it will exceed its processing capacity, so it needs to be stored and managed appropriately. is there. Methods for storing and managing spent fuel inside or outside the nuclear power plant site include dry storage methods such as metal cask storage, vault storage, silo storage, and concrete cask storage, and wet storage methods for water pools. There is. Among these, from the viewpoints of cost reduction and long-term stable storage, dry storage is attracting attention, and metal casks have been put into practical use in Japan.

  In the spent fuel cask, a basket having a plurality of grid-like compartments for storing spent fuel assemblies is arranged inside the trunk body, thereby partitioning the spent fuel assemblies one by one. It comes to store. As an example of this basket, a first basket plate group composed of a plurality of basket plates aligned in parallel to each other in the vertical direction, and a plurality of basket plates aligned in parallel to each other in a lateral direction perpendicular to the vertical direction A second basket plate group made of the above is disclosed in which slits formed at portions intersecting each other are engaged with each other and alternately stacked in a vertical direction (see, for example, Patent Document 1). In this prior art, a pair of partially reinforcing arc-shaped horizontal reinforcing plates are fixed to both ends of the first basket plate group or the second basket plate group in each stage of the laminated structure, and further connected in the vertical direction. The strength is increased by fastening and fixing with bolts.

  Further, as another example of the basket, a basket having a neutron absorption capability and configured by a plurality of square pipes each storing a spent fuel assembly is disclosed (for example, see Patent Document 2). In this prior art, the cavity in the trunk body is processed into a shape that matches the outer shape of the basket, and the basket is inserted so as to be in contact with the inner surface of the trunk body.

JP-A-6-94892 JP 2001-74884 A

  Spent fuel cask has heat removal performance to dissipate decay heat generated from spent fuel to the outside, strength performance that can withstand loads acting during use, and subcriticality to absorb neutrons emitted from spent fuel Performance and shielding performance that shields neutrons and γ rays emitted from spent fuel are required. Of these, improvement of heat removal performance is particularly important in preventing creep breakdown of spent fuel. However, in the above prior art, since the basket is inserted into the trunk body, the outer dimension of the basket needs to be smaller than the inner dimension of the trunk body. A space is created between the surface. Therefore, the heat of the basket is transmitted to the trunk body through the space that is a heat insulating layer, and there is room for improvement in terms of heat conductivity.

  An object of the present invention is to provide a spent fuel cask capable of improving heat transfer performance between a basket and a trunk body and improving heat removal performance.

  (1) In order to achieve the above-mentioned object, the present invention provides a spent fuel cask for storing spent fuel for storage or transportation in a cylinder body for shielding γ rays and an outer peripheral side of the trunk body. The provided neutron shield and a plurality of basket plates inserted and supported in a plurality of grooves formed on the inner peripheral surface of the trunk body are assembled in a lattice shape to form a plurality of compartments for storing the spent fuel. A plurality of basket plates, the first basket plate group aligned parallel to each other in one direction, and the second basket aligned parallel to each other in a direction perpendicular to the one direction. The plate groups are alternately arranged in the axial direction of the trunk body by engaging slits formed at portions intersecting each other.

  In the present invention, the plurality of basket plates are inserted and supported in a plurality of grooves formed on the inner peripheral surface of the trunk body. Thereby, a several basket board and a trunk | drum main body can be made to contact and heat transfer can be improved, and the improvement of heat removal performance can be aimed at.

  (2) In order to achieve the above object, the present invention also provides a spent fuel cask for storing or transporting a spent fuel cask, a gamma ray shielding trunk body, and an outer peripheral side of the trunk body. Inserted into and supported by a plurality of connecting members respectively inserted into a plurality of connecting grooves formed on an inner peripheral surface of the trunk body, and a plurality of grooves formed in the plurality of connecting members. A plurality of basket plates assembled in a lattice shape, and a basket forming a plurality of compartments for storing the spent fuel, and the plurality of basket plates are aligned parallel to each other in one direction. The first basket plate group and the second basket plate group aligned in parallel with each other in the direction perpendicular to the one direction are engaged with each other by slits formed at portions intersecting each other, so that the cylinder is alternately formed. Body axial direction Laminated to place.

  Thereby, a some basket board and a trunk | drum main body can be connected via a connection member, heat conductivity can be improved, and the improvement of heat removal performance can be aimed at.

  (3) In the above (2), preferably, the connecting groove of the trunk body has a portion whose groove width dimension increases in the depth direction, and the connecting member is inserted into the connecting groove. To form.

  (4) In the above (1) or (2), preferably, a bent portion is formed at an end portion of the basket plate, and the groove of the trunk body or the groove of the connecting member is the bent portion of the basket plate. Is formed so as to be inserted.

  (5) In the above (1) or (2), preferably, the basket plate assembly in which the first basket plate group and the second basket plate group are alternately laminated and welded is connected to the trunk body groove or the connection. Insert into the groove of the member.

  (6) In the above (1) or (2), preferably, the barrel main body integrally forms the cylindrical portion and the bottom portion, and then performs cutting to form the groove or the connecting groove.

  (7) In the above (1) or (2), preferably, the body is divided into a cylindrical part and a bottom part, and the cylindrical part is cut to form the groove or the connecting groove. The tube portion and the bottom portion are welded together.

  (8) In the above (1) or (2), preferably, the trunk body is formed by dividing a cylindrical portion and a bottom portion, and the cylindrical portion and the bottom portion are cut to form the groove or the connecting groove, respectively. After the formation, the tube portion and the bottom portion are welded together.

  ADVANTAGE OF THE INVENTION According to this invention, the heat transfer property of a basket and a trunk | drum main body can be improved, and the improvement of heat removal performance can be aimed at.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a partial cross-sectional perspective view showing the overall structure of an embodiment of a spent fuel cask according to the present invention.

  In FIG. 2, a spent fuel cask 1 is used for storing or transporting a spent fuel assembly 2, and a trunk body (inner cylinder) that shields γ rays generated from the spent fuel assembly 2. 3 and a bucket 4 which is provided in the trunk body 3 and forms a plurality of compartments for storing the spent fuel assembly 2. The trunk body 3 is a cylindrical container made of, for example, a rigid alloy, and a primary lid 5 is attached to the opening side (upper side in FIG. 2) by a plurality of bolts (not shown), and the trunk lid 3 is covered with the primary lid 5. The next lid 6 is attached by a plurality of bolts (not shown).

  A plurality of, for example, carbon-rigid support fins 7 are arranged at equal intervals in the circumferential direction on the outer peripheral side of the trunk body 3, and an outer cylinder 8 is provided on the front end side of these support fins 7 (the outer cylinder). 8 is composed of a plurality of curved plates divided in the circumferential direction, and the ends of these curved plates are welded to the front end side of the support fins 7). In addition, a plurality of heat transfer fins 9 made of an alloy having high thermal conductivity, for example, are disposed between the trunk body 3 and the outer cylinder 8, so that the heat transfer between the trunk body 3 and the outer cylinder 8 is enhanced. ing.

  The space surrounded by the heat transfer fins 9 and the like is filled with a neutron shield (specifically, a resin containing a large amount of boron having a high neutron absorption capacity) 10, and the interior of the primary lid 5 and the trunk body 3. The bottom (not shown) is also filled with the neutron shield 10. Thereby, neutrons generated from the spent fuel assembly 3 are shielded.

  The bottom side (lower side in FIG. 2) and the lid side (upper side in FIG. 2) of the spent fuel cask 1 are provided with flanges 11A and 11B for mounting shock absorbers, respectively, A buffer (not shown) is attached to the upper side of the lid side flange 11B. Thereby, for example, the impact load at the time of dropping should be relieved. In addition, a plurality of trunnions 12 are provided on the outside of the spent fuel cask 1 for hanging a hanging tool during crane transportation or the like.

  FIG. 1 is an exploded perspective view showing a structure of a basket 4 which is a main part of the present invention, and FIG. 3 is a radial cross-sectional view showing a quarter structure of a spent fuel cask 1.

  1 and 3, a plurality of grooves 13 extending in the axial direction (vertical direction in FIG. 1) are formed on the inner peripheral surface of the trunk body 3, and the basket 4 is formed in the plurality of grooves 13. A plurality of basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d that are inserted and supported and are assembled in a lattice shape to form a plurality of sections by mutual gaps. In addition, the some basket plate 14a-14d, 15a-15d, 16a-16d, 17a-17d uses the alloy etc. which added the boron to the material excellent in intensity | strength and heat conductivity, for example.

  The plurality of basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d are, for example, a first-stage basket plate group 14 aligned in parallel with each other from the lower side to the upper side, for example, in the horizontal direction. Second basket plate group 15 aligned parallel to each other in the vertical direction perpendicular to the direction, third vertical basket plate group 16 aligned parallel to each other in the horizontal direction, and perpendicular to the horizontal direction The basket plate groups 14 to 17 intersecting at right angles are alternately stacked in the axial direction of the trunk body 3, such as a fourth-stage basket plate group 17 aligned parallel to each other in the vertical direction.

  The axial dimensions H of the basket plates 15a to 15d and 16a to 16d constituting the middle basket plate group 15 and 16 are the same, and 14a to 14d constituting the lowermost basket plate group 14 and the uppermost basket plate group. The axial dimension of 17a-17d which comprises 17 is (1/2) H of the half. The adjacent basket plate groups (for example, 14 and 15, 15 and 16, 16 and 17) have slits 18 formed at the intersecting portions, and the slits 18 are engaged with each other in the axial direction alternately. Are stacked.

  The slits 18 are provided at a pitch corresponding to one section for storing the spent fuel assembly 2. The depth dimension d of the slit 18 is, for example, (1) so that the sum of the depth dimensions d of the slits 18 that are engaged with each other is about half of the axial dimension H of the basket plates 15a to 15d and 16a to 16d. / 4) H. Accordingly, when the basket plate groups 14 to 17 are stacked, the upper side of the first-stage basket plate group 14 and the lower side of the third-stage basket plate group 16 or the upper side of the second-stage basket plate group 15 The lower sides of the fourth stage basket plate group 17 are in contact with each other.

  The trunk body 3 is formed with a plurality of grooves 13 by, for example, integrally forming a cylindrical portion and a bottom portion and cutting with a cutting tool inserted from the opening side (see FIG. 4). The groove 13 of the trunk body 3 is formed in the horizontal direction or the vertical direction corresponding to both ends of the plurality of basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d, and the basket plates 14a to 14d. , 15a to 15d, 16a to 16d, and 17a to 17d, the width w substantially corresponds to the thickness dimension t. Further, the groove 13 of the trunk body 3 is formed with an axial length that does not reach the bottom surface, and a stopper portion 19 is formed. Thereby, the cutting work of the trunk | drum main body 3 is reduced. The basket plates 14a to 14d constituting the first-stage basket plate group 14 and the basket plates 15a to 15d constituting the second-stage basket plate group 15 are fitted with stoppers 19 at both ends of the lower edge portion. A notch 20 is formed for each. Thus, the first-stage basket plate group 14 and the second-stage basket plate group 15 can be inserted to the vicinity of the bottom surface of the trunk body 3.

  For example, when assembling the basket 4, the basket plate group 14 is inserted into the groove 13 of the trunk body 3, and then the basket plate group 15 is inserted into the groove 13 of the trunk body 3. A plate group 15 is arranged. Thereafter, the basket plate group 16 is inserted into the groove 13 of the trunk body 3, and the basket plate group 16 is disposed on the upper stage of the basket plate group 15. Further, the basket plate group 17 is inserted into the groove 13 of the trunk body 3, and the basket plate group 17 is arranged on the upper stage of the basket plate group 16.

  In the present embodiment configured as described above, the plurality of basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d are inserted and supported in the grooves 13 formed on the inner peripheral surface of the trunk body 3. The Thereby, several basket plates 14a-14d, 15a-15d, 16a-16d, 17a-17d, and the trunk | drum main body 3 can be contacted, and heat conductivity can be improved. That is, the heat generated in the spent fuel assembly 2 is efficiently transferred and dissipated as indicated by an arrow A in FIG. 5 in the manner of the basket 4 → the trunk body 3 → the heat transfer fins 9 and the like → the outer cylinder 8. (The heat of the trunk body 3 is also transmitted to the primary lid 5 and the secondary lid 6 to dissipate heat). Therefore, the heat removal performance can be improved. Moreover, since the outermost edge part of the basket 4 is supported by the trunk | drum main body 3, the structural soundness of the basket 4 can be ensured.

  In the above embodiment, an example of a structure in which both end portions of the basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d are inserted into the grooves 3a and 3b of the trunk body is illustrated and described. Not limited to. That is, for example, the ends of the basket plates 14a to 14d, 15a to 15d, 16a to 16d, and 17a to 17d (one side end or both side ends) are bent, and the groove of the trunk body 3 is inserted so that the bent portions are inserted. May be formed. Such a modification will be described below.

  FIG. 6A is a perspective view illustrating a structure of a first modification of the basket plate, and FIG. 6B is a cross-sectional view illustrating a structure of the first modification of the basket plate.

  6A and 6B is formed with a bent portion 22a bent in one direction, for example, at a right angle. And the groove | channel 13A of the trunk | drum main body 3 is formed in a cross-sectional L shape, and the bending part 22a of 21 A of basket boards is inserted.

  FIG. 7A is a perspective view illustrating the structure of a second modification of the basket plate, and FIG. 7B is a cross-sectional view illustrating the structure of the second modification of the basket plate.

  The ends of the basket plate 21B shown in FIGS. 7A and 7B are formed with bent portions 22b that are divided into two in the axial direction and bent at right angles in alternate directions. And the groove | channel 13B of the trunk | drum board 3 is formed in cross-sectional T shape, and the bending part 22b of the basket board 21B is inserted.

  FIG. 8A is a perspective view illustrating a structure of a third modification of the basket plate, and FIG. 8B is a cross-sectional view illustrating a structure of the third modification of the basket plate.

  The end portions of the basket plate 21 </ b> C shown in FIGS. 8A and 8B are divided into three in the axial direction, and bent portions 22 c that are bent at right angles in alternate directions are formed. And the groove | channel 13B of the trunk | drum main body 3 is formed in a cross-sectional T shape, and the bending part 22c of the basket board 21C is inserted.

  Also in the above modification, the same effect as the above-described embodiment can be obtained. Moreover, in the modification mentioned above, the contact area of basket board 21A (or 21B, 21C) and the trunk | drum main body 3 can be increased. Thereby, the heat conductivity of the basket 4 and the trunk | drum main body 3 can further be improved, and the improvement of heat removal performance can be aimed at.

  In the above-described embodiment, the basket 4 has been described by taking an example of a structure in which the four-stage basket plate groups 14 to 17 are stacked. However, the present invention is not limited to this. A stacked structure may be used. In the above-described embodiment, the case where the basket plate groups 14, 15, 16, and 17 are sequentially inserted into the grooves 13 of the trunk body 3 has been described as an example of the assembly procedure of the basket 4. . That is, for example, when the 12-stage basket plate groups 23A to 23L are stacked and arranged, as shown in FIG. 9, the 4-stage basket plate groups are previously stacked and welded together (however, the spent fuel assembly 2 For example, three basket plate division assemblies 25A, 25B, and 25C are respectively assembled, and these basket plate division assemblies 25A, 25B, and 25C are sequentially inserted into the grooves 13 of the trunk body 3. May be. Further, as shown in FIG. 10, a basket plate total assembly 26 in which 12 stages of basket plate groups 23 </ b> A to 23 </ b> L are stacked in advance and welded together is assembled, and this basket plate total assembly 26 is assembled in the groove 13 of the trunk body 3. It may be inserted. Thus, the assembly time can be reduced by inserting the basket plate divided assemblies 25A, 25B, 25C or the basket plate total assembly 26 into the groove 13 of the trunk body 3 after assembling in advance.

Further, in the above-described embodiment, the case where the body 3 is integrally formed with the cylindrical portion and the bottom portion and cut to form the plurality of grooves 13 has been described as an example. And the bottom may be divided and formed. Such a modification will be described below.
For example, as shown in FIG. 11, a cylindrical portion 27A having an axial dimension corresponding to the axial length of the groove 13 and a bottom portion 29A having a counterbore portion 28a are separately formed, and the inner peripheral surface of the cylindrical portion 27A is cut. Then, the plurality of grooves 13 may be formed, and then the cylindrical portion 27A and the bottom portion 29A may be joined by welding means or the like. Alternatively, for example, as shown in FIG. 12, a cylindrical part 27B having an axial dimension slightly longer than the axial length of the groove 13 and a bottom part 29B having a counterbore part 28b are separately formed, and the inner peripheral surface of the cylindrical part 27B is cut. The plurality of grooves 13 may be formed by processing, and then the cylindrical portion 27B and the bottom portion 29B may be joined by welding means or the like. Alternatively, for example, as shown in FIG. 13, a cylindrical portion 27C having an axial dimension shorter than the axial length of the groove 13 and a bottom portion 29C having a counterbore portion 28c are separately formed, and the inner peripheral surfaces of the cylindrical portion 27C and the bottom portion 29C. Then, the plurality of grooves 13 may be formed by cutting, and then the cylindrical portion 27C and the bottom portion 29C may be joined by welding means or the like while aligning the positions of the grooves 13 with each other. Thus, the workability | operativity of cutting can be improved by carrying out the division | segmentation shaping | molding of the trunk | drum main body 3, and cutting.

  Another embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment in which a plurality of connecting members are respectively inserted into a plurality of connecting grooves formed on the inner peripheral surface of the trunk body, and a plurality of basket plates are respectively inserted into the plurality of grooves formed in these connecting members. is there.

  FIG. 14 is a radial partial cross-sectional view illustrating the structure of the spent fuel cask according to the present embodiment. Note that description of parts equivalent to those of the above-described embodiment is omitted as appropriate.

  In the present embodiment, a plurality of connecting grooves 31 extending in the axial direction (a direction perpendicular to the paper surface in FIG. 14) are formed on the inner peripheral surface of the trunk body 30. The connecting members 32 are respectively fitted and fixed with bolts 33. A groove 35 for inserting and supporting the end portion of the basket plate 34 is formed on the inner peripheral side (lower right side in FIG. 14) of the connecting member 32. Although not shown, a plurality of basket plates 34 are inserted and supported in the grooves 35 of the plurality of connecting members 32 and assembled in a lattice shape to constitute a basket. In addition, the groove 35 of the connecting member 32 is formed in the vertical direction or the horizontal direction corresponding to both end portions of the plurality of basket plates 34.

  In the present embodiment configured as described above, the plurality of basket plates 34 and the trunk body 30 can be coupled via the coupling member 32 to enhance heat transfer. Thereby, the heat removal performance can be improved as in the above embodiment. Moreover, all the connection grooves 31 of the trunk | drum main body 30 can be made into the same shape, and can improve the workability | operativity in the cutting work. Further, the connecting member 32 is easier to handle than the trunk body 30, and the working operation of the groove 35 is also easy.

  In addition, in the said other embodiment, although demonstrated taking the example of the structure which fixed the connection member 32 with the volt | bolt 33, you may fix with the welding 36, for example, as shown in FIG. In this case, the same effect as described above can be obtained.

  The connecting member 32 can be changed to various shapes without departing from the technical idea of the present invention. Such modifications will be described with reference to FIGS.

  In the modification shown in FIG. 16, the connecting groove 31A of the trunk body 30 is formed so that the groove width dimension gradually increases in the depth direction (upper right direction in the figure). The connecting member 32A is inserted into the connecting groove 37A of the trunk body 30 and inserted into and supported by the end of the basket plate 34 on the inner side (lower left side in the figure) of the inserting portion 37a. It is comprised with the support part 38 in which the groove | channel 35 of this was formed.

  In the modification shown in FIG. 17, the connecting groove 31 </ b> B of the trunk body 30 is formed with a step so that the groove width dimension increases rapidly in the depth direction. The connecting member 32B is formed with an insertion portion 37b that is inserted into the connection groove 31B of the trunk body 30, and a groove 35 that protrudes on the inner side of the insertion portion 37b to insert and support the end portion of the basket plate 34. And a supporting portion 38.

  In the modification shown in FIG. 18, the connection groove 31 </ b> C of the trunk body 30 is formed in a pentagonal cross section, for example, so that the groove width dimension expands in the depth direction and then decreases. The connecting member 32 </ b> C is formed with an insertion portion 37 c that is inserted into the connection groove 31 </ b> C of the trunk body 30, and a groove 35 that protrudes inside the insertion portion 37 c and inserts and supports the end portion of the basket plate 34. And a supporting portion 38.

  Also in the modified examples shown in FIGS. 16 to 18, the same effects as in the above embodiment can be obtained. Further, since the connecting members 32A, 32B, and 32C can be easily attached without using the bolt 33, the weld 36, or the like, workability can be improved.

  Note that the connecting member 31 (or 31A, 31B, 31C) may be made to have a common component by allowing the orientation of the groove 35 to be changed in the vertical direction or the horizontal direction by reversing the arrangement left and right. Further, for example, as shown in FIG. 19, parts may be made common by forming longitudinal and lateral grooves 35 in the connecting member 31A (or 31, 31B, 31C).

  Further, for example, the end portion of the basket plate 34 is bent, and the groove of the connecting member 31 (or 31A, 31B, 31C) is formed in an L-shaped or T-shaped cross section so that the bent portion of the basket plate 34 is inserted. May be. Also in this case, the same effect as the above embodiment can be obtained.

It is a disassembled perspective view showing the structure of the basket which comprises one Embodiment of the cask for spent fuel of this invention. It is a partial cross section perspective view showing the whole structure of one embodiment of the spent fuel cask of the present invention. It is radial direction sectional drawing showing the 1/4 structure of one Embodiment of the cask for spent fuel of this invention. It is an axial sectional view showing the structure of the trunk body which constitutes one embodiment of the cask for spent fuel of the present invention. It is radial direction sectional drawing for demonstrating the heat flow in one Embodiment of the cask for spent fuel of this invention. . It is the perspective view and sectional drawing showing the structure of the 1st modification of a basket board. It is the perspective view and sectional drawing showing the structure of the 2nd modification of a basket board. It is the perspective view and sectional drawing showing the structure of the 3rd modification of a basket board. It is a perspective view showing the basket division | segmentation assembly at the time of a basket assembly. It is a perspective view showing the basket total assembly at the time of a basket assembly. It is an axial direction sectional view showing the structure of the 1st modification of a trunk body. It is an axial direction sectional view showing the structure of the 2nd modification of a trunk body. It is an axial direction sectional view showing the structure of the 3rd modification of a trunk body. It is a radial direction fragmentary sectional view showing the structure of other embodiment of the cask for spent fuel of this invention. It is sectional drawing showing the structure of the 1st modification of a connection member. It is sectional drawing showing the structure of the 2nd modification of a connection member. It is sectional drawing showing the structure of the 3rd modification of a connection member. It is sectional drawing showing the structure of the 4th modification of a connection member. It is sectional drawing showing the structure of the 5th modification of a connection member.

Explanation of symbols

1 Spent fuel cask 2 Spent fuel assembly (spent fuel)
3 trunk body 4 basket 10 neutron absorber 13 groove 13A, 13B, 13C groove 14 basket plate group (first basket plate group)
14a to 14d Basket plate 15 Basket plate group (second basket plate group)
15a to 15d Basket plate 16 Basket plate group (first basket plate group)
16a to 16d Basket plate 17 Basket plate group (second basket plate group)
17a to 17d Basket plate 18 Slit 21A, 21B, 21C Basket plate 22a, 22b, 22c Bending portion 25A, 25B, 25C Basket plate split assembly (basket plate assembly)
26 basket plate total assembly (basket plate assembly)
27A, 27B, 27C Cylinder portion 29A, 29B, 29C Bottom 30 Body body 31 Connection groove 31A, 31B, 31C Connection groove 32 Connection member 32A, 32B, 32C Connection member 34 Basket plate 35 Groove

Claims (8)

In a spent fuel cask that stores spent fuel for storage or transport,
a body for gamma ray shielding;
A neutron shield provided on the outer peripheral side of the trunk body;
A plurality of basket plates inserted and supported in a plurality of grooves formed on the inner peripheral surface of the trunk body are assembled in a lattice shape, and a basket that forms a plurality of compartments for storing the spent fuel, and
The plurality of basket plates include a first basket plate group aligned in parallel to one direction and a second basket plate group aligned in parallel to each other in a direction perpendicular to the one direction. A spent fuel cask characterized in that slits formed at intersecting portions are engaged with each other and alternately stacked in the axial direction of the trunk body. In a spent fuel cask that stores spent fuel for storage or transport,
a body for gamma ray shielding;
A neutron shield provided on the outer peripheral side of the trunk body;
A plurality of connecting members respectively inserted into a plurality of connecting grooves formed on the inner peripheral surface of the trunk body;
A plurality of basket plates inserted and supported in a plurality of grooves respectively formed in the plurality of connecting members are assembled in a lattice shape, and a basket forming a plurality of compartments for storing the spent fuel,
The plurality of basket plates include a first basket plate group aligned in parallel to one direction and a second basket plate group aligned in parallel to each other in a direction perpendicular to the one direction. A spent fuel cask characterized in that slits formed at intersecting portions are engaged with each other and alternately stacked in the axial direction of the trunk body.   3. The spent fuel cask according to claim 2, wherein the connecting groove of the trunk body has a portion whose groove width dimension increases in the depth direction, and the connecting member is inserted into the connecting groove. A spent fuel cask characterized by being formed into   3. The spent fuel cask according to claim 1, wherein a bent portion is formed at an end portion of the basket plate, and the bent portion of the basket plate is inserted into the groove of the trunk body or the groove of the connecting member. A spent fuel cask characterized by being fitted.   3. The spent fuel cask according to claim 1, wherein the basket plate assembly in which the first basket plate group and the second basket plate group are alternately laminated and welded is connected to the groove of the trunk body or the connecting member. A spent fuel cask characterized by being inserted into a groove.   3. The spent fuel cask according to claim 1, wherein the trunk body is formed by integrally forming a cylindrical portion and a bottom portion and then cutting to form the groove or the connecting groove. For cask.   3. The spent fuel cask according to claim 1, wherein the cylinder main body is formed by dividing and forming the cylinder part and the bottom part, and the cylinder part is cut to form the groove or the connecting groove, and then the cylinder body is formed. A spent fuel cask characterized by joining a bottom part and a bottom part.   3. The spent fuel cask according to claim 1, wherein the trunk main body is formed by separately forming a cylindrical portion and a bottom portion, and cutting the cylindrical portion and the bottom portion to form the groove or the connecting groove, respectively. A spent fuel cask characterized by joining the cylindrical portion and the bottom portion.

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