JP2013156028A - Fuel holder, method of using fuel holder, and method of transporting fuel assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel holder, a method of using the fuel holder, and a method of transporting a fuel assembly housed in the fuel holder capable of: housing a plurality of kinds of fuel assemblies together even if any of the fuel assemblies are formed according to different specifications; and preventing the fuel assemblies from moving in an axial direction and colliding against a top cover even when strong accelerating force affects in the axial direction of the fuel holder during transportation of the fuel holder housing the fuel assemblies.SOLUTION: Provided are: a fuel holder comprising a fixed plate having a contact surface in contact with a level difference surface, of a fuel assembly, whose position in an axial direction is displaceably formed; a method of using the fuel holder; and a method of transporting the fuel assembly.

Description

  The present invention relates to a fuel holder, a method of using the fuel holder, and a method of transporting the fuel assembly. More specifically, the present invention has a fixing plate that prevents the fuel assembly from moving in the axial direction. A fuel holder that can be shared with a fuel assembly formed according to any standard by forming the position of the contact surface in the axial direction so as to be displaceable, a method of using the fuel holder, and fuel The present invention relates to a method for transporting aggregates.

  The fuel assembly used in the boiling water reactor is accommodated in a fuel holder, and this fuel holder is further loaded in a transport container and transported to a demand place. In the fuel assembly, a large number of fuel rods are bundled at both end portions by an upper tie plate and a lower tie plate, and an intermediate portion thereof is bundled by a support lattice, and the interval between the fuel rods is maintained. The fuel holder has a long internal space, and the fuel assembly is accommodated in the internal space. Further, a gap is provided between the axial end portion of the fuel assembly and the inner wall surface of the top portion of the fuel holder in the axial direction.

  Conventionally, when a fuel assembly is accommodated in a fuel holder and transported to a demand place, the fuel assembly moves in the fuel holder by restraining the fuel assembly from the side of the elongated fuel holder. I was trying not to. However, in the conventional method of restraining the fuel assembly from the side surface direction of the fuel holder, for example, when a large acceleration force is applied to the fuel assembly such as when a trailer loaded with the fuel holder suddenly stops, Since there is a gap between the tip of the fuel assembly and the top of the fuel holder, the fuel assembly may move in the axial direction of the fuel holder and collide with the inner wall surface of the top of the fuel holder.

As means for solving such a problem, Patent Document 1 states that “at least one of the fastening plates for fastening the lower tie plate has a stepped plate shape with a dimension that does not contact the finger spring provided on the lower tie plate. with boiling according the stepped plate clamping plate to claim 1, characterized in that the axial displacement of the fuel assembly by arranging the stepped portion of the lower tie plate comprising the step of restraining by said lower tie plate portion "Transportation method of water reactor fuel body" (Claim 4 of Patent Document 1) is described.

  By the way, there are a plurality of types of standards for the fuel assemblies currently developed depending on the type of the boiling water reactor. For example, the external dimensions of the fuel assemblies differ by several mm for each standard. Therefore, various dimensions of the fuel holder are determined in accordance with a fuel assembly of a specific standard.

  For example, the fastening plate for fastening the lower tie plate described in Patent Document 1 can be loaded with an arbitrary fastening force from the side direction of the lower tie plate. Even if there is a difference in the external dimensions, the fuel assembly can be fixed from the lateral direction by displacing the fastening plate in the lateral direction. Therefore, regarding the dimension in the side surface direction of the lower tie plate in the fuel assembly, it is not necessary to change the dimension of the fuel holder in accordance with the outer dimension for each standard of the fuel assembly. On the other hand, the stepped plate-like clamping plate for preventing the fuel assembly from moving in the axial direction is a lower tie plate in accordance with the outer dimensions of the fuel assembly formed according to a specific standard. The stepped plate-like clamping plate is positioned in the axial direction so as to be in contact with the step portion. Therefore, if a fuel assembly of another standard is accommodated in a fuel holder formed in accordance with the outer dimensions of a fuel assembly formed in accordance with a certain standard, the position of the step portion of the lower tie plate is shifted. It becomes impossible to bring the plate-shaped clamping plate into contact with the stepped portion.

  As described above, since the position of the step portion is displaced for each fuel assembly standard, a fuel holder for housing a fuel assembly formed in accordance with a certain standard is strictly matched to the outer dimension of the fuel assembly. Designed to. Therefore, there is no idea that a fuel assembly according to another standard is accommodated in the fuel holder, and in reality, a fuel holder having various dimensions is manufactured so as to be adapted only to the fuel assembly for each standard of the fuel assembly. There is a need.

  Further, when a fuel assembly according to a certain standard is accommodated in a fuel holder suitable for the fuel assembly, a fuel holder accommodating a fuel assembly according to another standard is not used and is in an idle state. The idle fuel holder causes problems such as requiring a storage place.

Japanese Patent No. 3142493

  An object of the present invention is to be compatible with the fact that a fuel assembly formed according to a certain standard and a fuel assembly formed according to another standard can accommodate these plural types of fuel assemblies together. Even when a large acceleration force acts in the axial direction of the fuel holder when transporting the fuel holder containing the fuel assembly, the fuel assembly moves in the axial direction and collides with the top. It is to provide a fuel holder capable of preventing the fuel, a method of using the fuel holder, and a method of transporting the fuel assembly accommodated in the fuel holder. The fuel holder will be further described. The object of the present invention is to provide a fuel holder that can accommodate any fuel assembly of different standards and can be used for any fuel assembly. To provide.

Means for solving the problems are as follows:
(1) orthogonal to each other, forming an accommodation space capable of accommodating a fuel assembly having a lower tie plate for a boiling water reactor fuel body having a stepped surface formed on a side surface of a substantially square cylindrical grid A containment shell having four side walls;
A fixing plate provided on an inner wall surface of the side wall to prevent the fuel assembly from moving in the axial direction thereof,
The fixing plate has a contact surface that contacts the step surface, and is formed so that the position of the contact surface in the axial direction can be displaced.

As a preferred embodiment of the above (1),
(2) The fixed plate has a guide portion that protrudes from a surface that contacts the inner wall surface of the fixed plate, and is formed so that the position in the axial direction can be fixed by a fixing means.
The fuel holder according to (1), wherein the side wall includes a guide hole having a size capable of interpolating the guide portion and moving the guide portion in the axial direction.
(3) The fixed plate is a rotating plate that rotates about a rotation axis orthogonal to the inner wall surface,
The rotary shaft is in the housing space, when accommodating the fuel assembly formed in accordance with certain standards, said axis direction from the stepped surface L ₁ in the fuel assembly formed in accordance with a certain standard to said rotation axis When the fuel assembly formed according to another standard is accommodated in the accommodation space with the distance t ₁ , the rotational axis extends from the step surface L ₂ in the fuel assembly formed according to another standard. Is provided at a position where the distance in the axial direction is t ₂ ,
The rotating plate is distance t ₁ from the rotary shaft, and a first contact surface which is formed to be contact with the stepped surface L _1, the distance from the rotary shaft be t ₂ and a fuel holder according to (1), characterized in that a second abutment surface formed contactable to said step surface L _2,
(4) The fuel holder according to (3), wherein the fixing plate is formed so that the position in the axial direction can be fixed by a fixing means.

Means for solving the other problems are as follows:
(5) A method of using a fuel holder, wherein the fuel assembly is housed in the fuel holder according to any one of (1) to (4).

Means for solving the still another problem is as follows.
(6) A method for transporting a fuel assembly, wherein the fuel assembly is accommodated in the fuel holder according to any one of (1) to (4) and transported.

  A fuel holder according to the present invention includes a fixed plate having a contact surface that contacts a step surface formed on a side surface of a grid in a lower tie plate for a boiling water reactor fuel body, and the fixed plate is a fuel assembly. Is prevented from moving in the axial direction, and the position of the abutting surface in the axial direction is formed to be displaceable. Therefore, the fuel holder according to the present invention can be used as a common holder that can accommodate all the various fuel assemblies formed according to different standards, and also transports the fuel holder that houses the fuel assemblies. In doing so, even if a large acceleration force acts in the axial direction of the fuel holder, the fuel assembly can be prevented from moving in the axial direction and colliding with the top.

  The method of using the fuel holder according to the present invention accommodates and transports the fuel assembly in the fuel holder having the fixed plate. Therefore, even if the fuel assembly is formed according to any standard, these plural types of fuels are used. When transporting a fuel holder containing a fuel assembly, the fuel assembly moves in the axial direction even when a large acceleration force acts in the axial direction of the fuel holder. Colliding with the top can be prevented. Therefore, it is not necessary to manufacture a fuel holder for each fuel assembly having a different standard. Further, when the fuel assembly is accommodated in the fuel holder, there is no complicated work of selecting the fuel holder according to the fuel assembly having different standards. In addition, since one type of fuel holder can be used for any fuel assembly formed in accordance with any standard, the inspection method and management method of the fuel holder are uniform, and maintenance is not complicated. .

  In the method for transporting fuel assemblies according to the present invention, the fuel assemblies are accommodated in the fuel holder having the fixed plate and transported. The fuel assembly can be accommodated together, and when the fuel holder containing the fuel assembly is transported, even if a large acceleration force acts in the axial direction of the fuel holder, the fuel assembly moves in the axial direction. Collision with the top can be prevented. Therefore, it is not necessary to manufacture a fuel holder for each fuel assembly having a different standard. Further, when the fuel assembly is accommodated in the fuel holder, there is no complicated work of selecting the fuel holder according to the fuel assembly having different standards.

  Further, for example, ten fuel holders A that can accommodate only fuel assemblies manufactured according to a standard X as in the prior art are prepared, and only fuel assemblies Y manufactured according to another standard can be stored. When 10 fuel holders B are prepared, there is no problem when the fuel assembly X10 is transported to the demand place P and the fuel assembly Y10 is transported to the demand place R. When it is necessary to deliver 10 bodies to the demand areas P and R, if the 10 fuel assemblies X are accommodated in the fuel holder A and delivered to one demand area P, the other demand area R Since there is a shortage of the fuel holder A that accommodates the fuel assembly X to be delivered to the vehicle, the delivery of the fuel assembly X to one demand point P is completed and the loading place (including the fuel factory) of the fuel assembly A is completed. ) Until fuel holder A returns The fuel assembly X to be delivered to the other demand centers R was forced to wait. However, the fuel assembly transportation method according to the present invention can accommodate a fuel assembly manufactured according to any of the X and Y standards in the fuel holder. Since the fuel holder can be shared, all the fuel assemblies X to be delivered can be loaded at the loading place regardless of the standard. As a result, the fuel holder that accommodates the fuel assembly X to be delivered to the demand area P is sufficient, but the fuel holder that accommodates the fuel assembly X to be delivered to the demand area R is not short. It is possible to reduce the waiting time while waiting for the shipment of the fuel assembly X at the loading place.

FIG. 1 is a partial cross-sectional schematic view of a fuel holder and a fuel assembly, showing one embodiment of a fuel holder according to the present invention. FIG. 2 is a partial cross-sectional schematic view of the main part showing the fuel assembly in an enlarged manner near the lower tie plate in the fuel holder. FIG. 3A is a schematic diagram of a main part when the fixing plate of the fuel holder shown in FIG. 1 is viewed from the inside of the fuel holder. FIG. 3B is a schematic view of the main part when the fixing plate of the fuel holder shown in FIG. 1 is viewed from the outside of the fuel holder. FIG. 4 shows another embodiment of the fuel holder according to the present invention, and is an enlarged partial cross-sectional schematic view of the main part showing the vicinity of the lower tie plate in the fuel holder and the fuel assembly. Fig.5 (a) is a principal part schematic diagram when the fixing plate of the fuel holder shown in FIG. 4 is seen from the inside of a fuel holder. FIG.5 (b) is a principal part schematic diagram when the fixing plate of the fuel holder shown in FIG. 4 is seen from the outer side of a fuel holder. FIG. 6A is a partial schematic cross-sectional view of an essential part showing an enlarged view of the vicinity of the lower tie plate in the fuel holder and the fuel assembly shown in FIG. FIG. 6B is a partial schematic cross-sectional view of the main part showing a state after the fixing plate is rotated 180 ° in the fuel holder shown in FIG. FIG. 7 is a schematic cross-sectional view of the main part when the fixing plate of the fuel holder shown in FIG. 6 is viewed from the inside of the fuel holder. FIG. 8 shows still another embodiment of the fuel holder according to the present invention, and is a schematic view of a main part when a fixing plate of the fuel holder is viewed from the inside of the fuel holder.

Hereinafter, a fuel holder according to the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional schematic view of a fuel holder and a fuel assembly, showing one embodiment of a fuel holder according to the present invention. FIG. 2 is a partial schematic cross-sectional view of an essential part showing the vicinity of a lower tie plate in the fuel holder and the fuel assembly shown in FIG.

  As shown in FIGS. 1 and 2, the fuel holder 1 includes a bottom portion 2, a housing shell 3 that rises from an edge of the bottom portion 2 and extends in the direction of the axis O, and a bottom portion 2 of the housing shell 3. The top 4 is provided on the opposite side, and the fuel assembly 10 can be housed in an internal space surrounded by the housing shell 3, the bottom 2, and the top 4. A fixing plate 5 that prevents the fuel assembly 1 housed in the fuel holder 1 from moving in the direction of the axis O is provided in the housing shell 3. The fuel holder 1 is an embodiment of the fuel holder according to the present invention.

  A fuel assembly 10 accommodated in the fuel holder 1 is a fuel assembly used in a boiling water nuclear reactor. A plurality of fuel rods 11 and a water pipe (not shown) are an upper tie plate 6 and a support lattice. 7 and a lower tie plate 8.

  The lower tie plate 8 includes a substantially square cylindrical grid 9 that bundles fuel rods 11, a hollow inverted pyramid-shaped inverted pyramid 13 that decreases in width from an end of the grid 9 toward the cylindrical portion 15, and a cylindrical portion 15. And a nosepiece 16 coupled to the. In the lower tie plate 8, when the fuel assembly 10 is installed in the boiling water reactor, a liquid, for example, cooling water is introduced from below, and the cooling water is introduced through the cylindrical portion 15 and the inverted pyramid portion 13. Thus, the fuel rod 11 is designed to be cooled.

  The grid 9 is formed in a substantially cylindrical shape and includes protrusions 17 on four side surfaces 14 facing the housing shell 3 of the fuel holder 1. The protrusion 17 has a step surface 12 that rises vertically from the side surface 14 and faces the upper tie plate 6. The fuel assembly 10 has the protrusions 17 on the four side surfaces 14, but the protrusions may be formed on the two opposite side surfaces or the three side surfaces. Further, in this fuel assembly 10, a step surface 12 is formed at the boundary between the grid 9 and the inverted pyramid portion 13, but the position of the step surface 12 is not particularly limited, and is near the center of the grid 9 in the axis O direction. A stepped surface may be formed on the surface.

The fuel rod 11 is configured by enclosing a plurality of cylindrical fuel pellets in a long metal cladding tube. The fuel pellets are, for example, plutonium oxide (PuO ₂ ) and uranium oxide (UO ₂ ). It is formed by the MOX fuel which mixed.

  As the standard of the fuel assembly 10, an appropriate standard can be adopted according to the type and size of the boiling water reactor, for example, 8 × 8 fuel, 9 × 9 fuel S lattice, C lattice , N lattice, and D lattice. The fuel assembly used in the boiling water reactor may differ in external dimensions of the fuel assembly by several millimeters, for example, depending on the standard. In particular, the shapes of the grid 9 and the inverted pyramid 13 in the lower tie plate differ depending on the standard of the fuel assembly. Therefore, the position of the step surface 12 formed on the side surface of the grid 9 in the direction of the axis O may vary by about several millimeters depending on the standard of the fuel assembly.

  The bottom 2 of the fuel holder 1 is formed in a substantially square shape, and the housing shell 3 rising from the edge and extending in the direction of the axis O has four side walls 18 orthogonal to each other. The opening is closed by the top 4. The bottom portion 2 is provided with a cylindrical shock absorber 20. When the fuel assembly 10 is accommodated, the nose piece 16 is inserted into the shock absorber 20, and the upper portion of the shock absorber 20. The cylindrical portion 15 is brought into contact with the end edge. The bottom portion 2, the housing shell 3, and the top portion 4 are usually a housing space of a size that can accommodate the largest fuel assembly of fuel assemblies formed in different standards. Designed.

  The bottom 2 and the top 4 are preferably each fixed to the side wall 18. In addition, it does not specifically limit as a fixing means, Well-known means, such as adhesion | attachment, welding, engagement, fitting, or screwing, or means easily conceivable by those who have normal knowledge in the technical field of this invention are adopted. can do.

  The fixing plate 5 is provided on each of the inner wall surfaces 19 of the four side walls 18 and is formed so as to contact the step surface 12 formed on the lower tie plate 8. The fixed plate 5 includes a presser plate that can move in the side surface direction of the grid 9 and a receiving plate that cannot move in the side surface direction of the grid 9. The holding plate is provided at least on the two side walls 18 and may be provided on three or four side walls. In many cases, the presser plate is provided on two adjacent side walls, and the presser plate and the receiving plate are opposed to each other. When the fuel assembly 10 is accommodated in the fuel holder 1, the presser plate is moved in the side surface direction of the grid 9, whereby the presser plate and the receiving plate are brought into contact with the side surface of the grid 9, so that the fuel assembly 10 is pressed. Restrained from the side by the plate and the backing plate. Further, the fixed plate 5 abuts against the stepped surface 12 to prevent the fuel assembly 10 from moving in the direction of the upper tie plate 6 of the axis O.

  The fixing plate 5 of this embodiment will be described in more detail. 3A is a schematic view of the main part when the fixing plate shown in FIG. 1 is viewed from the inside of the fuel holder, and FIG. 3B is a view of the fixing plate shown in FIG. 1 viewed from the outside of the fuel holder. FIG. As shown in FIGS. 2 and 3, the fixing plate 5 includes a rectangular plate-like first plate 21 and a guide portion that protrudes from the first surface 22 of the first plate 21 that contacts the inner wall surface 19 of the fuel holder 1. 23 and a second plate 25 provided on the second surface 24 opposite to the first surface 22 and having a width smaller than that of the first plate 21. The surface of the second plate 25 opposite to the surface on which the first plate 21 is provided is formed as a pressing surface 26 that presses the grid 9 from the side surface direction so as to contact the side surface 14 of the grid 9. Of the four surfaces extending from the edge of the pressing surface 26 toward the first plate 21, the surface in the direction of the bottom 2 of the axis O is in contact with the step surface 12 of the projection 17 as the contact surface 27. Be placed. The guide portion 23 is inserted into a guide hole 31 provided in the side wall 18 and is fixed at a predetermined position by a fixing means 32.

  As shown in FIG. 3B, the guide hole 31 is a hole that penetrates the side wall 18, and the planar shape of the guide hole is not particularly limited as long as the guide portion can be slid inside. The length of the guide hole 31 in the direction perpendicular to the axis O is substantially equal to the length of the guide part 23 in the direction perpendicular to the axis O, and the guide part 23 is fitted in the guide hole 31. The length of the guide hole 31 in the direction of the axis O is larger than the length of the guide portion 23 in the direction of the axis O, so that the guide portion 23 can be slid in the direction of the axis O in a state where the guide portion 23 is fitted in the guide hole 31. Has been. The guide hole 31 displaces the position in the direction of the axis O of the fixed plate 5 so that the contact surface 27 of the fixed plate 5 is a step of the fuel assembly, regardless of which standard is accommodated. The length in the direction of the axis O is set so as to contact the surface. When the guide portion 23 is positioned at a predetermined position in the guide hole 31, the guide portion 23 is fixed by the fixing means 32 so as not to move in the axis O direction.

  The members constituting the fuel holder 1 such as the bottom 2, the side wall 3, the top 4, the buffer 20, and the fixing plate 5 are temperature conditions from when the fuel assembly 10 is accommodated to when the fuel assembly 10 is conveyed. The material is not particularly limited as long as it satisfies the required mechanical strength, and for example, stainless steel, boron-containing stainless steel, heat-resistant nickel-base alloy, and the like can be employed.

  The position of the fixing plate 5 of this embodiment can be displaced as follows. First, the guide portion 23 is slid in the direction of the axis O so that the abutment surface 27 of the fixing plate 5 and the stepped surface 12 of the projection portion 17 abut on the dimensions of the fuel assembly 10 for each standard. After the guide portion 23 is slid to a predetermined position, the guide portion 23 is fixed by the fixing means 32 so that the guide portion 23 does not move in the direction of the axis O. Next, the fuel assembly 10 is accommodated in the fuel holder 1. In many cases, the fuel assembly 10 is accommodated with the fuel holder 1 placed vertically. In this case, the fuel assembly 10 is accommodated in the fuel holder 1 with the lower tie plate 8 of the fuel assembly 10 facing down. Next, the holding plate that is movable in the side surface direction of the grid 9 is moved in the fixed plate 5, and the holding plate and the receiving plate are adjusted so as to contact the side surface of the grid 9.

  As described above, according to the fuel holder according to the present invention, the guide 23 is slid in the direction of the axis O to accommodate the contact surface 27 even when the fuel assembly formed according to any standard is accommodated. Since the step surface 12 can be brought into contact with each other, it can be used as a common holder that can accommodate various fuel assemblies formed in accordance with different standards, and the fuel holder can be used in the direction of the axis O. When a large acceleration force is generated, the fuel assembly 10 can be prevented from moving inside the fuel holder 1, and there is no need to manufacture a fuel holder for each fuel assembly having a different standard.

  The guide portion 23 and the guide hole 31 of this embodiment are formed so that the guide portion 23 can slide in the guide hole 31. As another example of this embodiment, the guide portion 23 is a screw. Yes, the guide hole 31 is a screw hole, and the screw hole is formed at a plurality of locations on the side wall, so that the screw is screwed into a predetermined screw hole according to the standard of the fuel assembly, so that the push plate May be fixed at a predetermined position.

  Further, in the fixing plate 5 of this embodiment, the first plate 21 and the second plate 25 form a stepped plate. However, as long as the fixing plate 5 has the contact surface 27 that contacts the step surface 12, the fixing plate 5 The shape is not particularly limited, and may be formed in a rectangular plate shape by a single plate.

  In the above description, the method of housing the fuel assembly 10 in the fuel holder 1 after fixing the fixing plate 5 at a position suitable for each standard of the fuel assembly 10 has been described. After being accommodated in the holder 1, the fixing plate 5 may be slid and fixed at a suitable position.

  Next, an example of a method for using the fuel holder 1 and a method for transporting the fuel assembly 10 will be described.

  It is assumed that a fuel assembly formed according to a certain standard is accommodated in this fuel holder.

First, the guide portion 23 is slid in the direction of the axis O so that the abutment surface 27 of the fixing plate 5 and the stepped surface 12 of the projection portion 17 abut on the dimensions of the fuel assembly 10 for each standard. After the guide portion 23 is slid to a predetermined position, the guide portion 23 is fixed by the fixing means 32 so that the guide portion 23 does not move in the direction of the axis O.
Next, the fuel holder 1 is placed vertically so that its axial direction is the vertical direction, the side wall 18 is opened, and the fuel assembly 10 is disposed in the accommodation space of the fuel holder 1. At this time, the nosepiece 16 is inserted into the buffer body 20 so that the cylindrical portion 15 contacts the upper edge of the buffer body 20. Further, the fuel assembly 10 is arranged so that the holding plate 33 and the receiving plate 34 and the side surface of the upper tie plate 6 are in contact with the side surface 14 of the fixing plate 5 and the lower tie plate 8.

  After the fuel assembly 10 is arranged in the fuel holder 1, the four side walls 18 are fixed in a state of being orthogonal to each other. The side walls 18 before the fuel assemblies 10 are arranged may or may not be fixed to each other. That is, the side wall 18 before the fuel assembly 10 is disposed is, for example, a mode in which the side walls 18 are separated from each other, a mode in which two side walls 18 between the side walls 18 that are adjacent to each other are fixed, 3 Either the side wall 18 is fixed and only one side wall 18 is separated, or the four side walls 18 are fixed so as to be orthogonal to each other. Further, the side wall 18 may be integrally formed from an end edge fixed to the bottom portion 2 to an end edge fixed to the top portion 4, and is formed by a plurality of side walls, and after the fuel assembly 10 is disposed. The side walls may be fixed by known means such as welding or engagement.

  The bottom 2 before placing the fuel assembly 10 may be fixed to all four side walls 18 or may not be fixed to all four side walls 18 or may be fixed to some side walls 18. Good. After the fuel assembly 10 is disposed, the bottom 2 and all the side walls 18 are fixed by a known means such as welding or engagement. The top 4 is also fixed in the same manner as the bottom 2.

  Next, the holding plate that is movable in the side surface direction of the grid 9 is displaced in the fixed plate 5, and the holding plate and the receiving plate are adjusted so as to contact the side surface of the grid 9.

  The fuel holder 1 in which the fuel assembly 10 is accommodated is further loaded in a transport container, and is transported to a demand place such as a nuclear power plant and other nuclear fuel facilities by a transportation means such as a trailer or a ship. The number of fuel holders 1 loaded in one transport container differs depending on the type of transport container, and examples thereof include 4, 9, 12 and the like. The fuel holder 1 of the present invention is transported by a conventionally known transport container. Is done.

  According to the method of using and transporting the fuel holder 1, even if the position of the step surface 12 of the lower tie plate 8 in the direction of the axis O changes according to the fuel assembly standard, the position of the fixed plate 5 in the direction of the axis O is displaced. Since the abutment surface 27 of the fixed plate 5 can be brought into contact with the step surface 12 in the lower tie plate 8, the fuel assemblies formed according to any standard can be used for these plural types of fuel assemblies. And when the fuel assembly is subjected to a large acceleration force, the fuel assembly can be prevented from moving in the direction of the top 4 (see FIG. 1). There is no need to manufacture a fuel holder for each different fuel assembly. Further, there is no complicated operation of selecting a fuel holder for each fuel assembly having different standards. In addition, since one type of fuel holder can be used for any fuel assembly formed in accordance with any standard, the inspection method and management method of the fuel holder are uniform, and maintenance is not complicated. .

  In addition, according to this method of transporting the fuel assemblies 10, for example, ten fuel holders A that can only accommodate fuel assemblies manufactured according to a standard X as in the prior art are prepared and manufactured according to another standard. When ten fuel holders B that can accommodate only the fuel assembly Y are prepared, the fuel assembly X10 body is transported to the demand place P and the fuel assembly Y10 body is transported to the demand place R. However, if 10 fuel assemblies X need to be delivered to each of the two demand areas P and R, 10 fuel assemblies X are accommodated in the fuel holder A at one of the demand areas P. When the fuel is delivered, the fuel holder A that houses the fuel assembly X to be delivered to the other demand area R is insufficient, so that the delivery of the fuel assembly X to the one demand area P is completed and the fuel is consumed. Loading place of assembly X (fuel factory To include) to the fuel holder A come back, we had to wait for the fuel assemblies X to be delivered to the other of the demand area R. However, the fuel assembly transportation method according to the present invention can accommodate a fuel assembly manufactured according to any of the X and Y standards in the fuel holder. Since the fuel holder can be shared, all the fuel assemblies X to be delivered can be loaded at the loading place regardless of the standard. As a result, the fuel holder that accommodates the fuel assembly X to be delivered to the demand area P is sufficient, but the fuel holder that accommodates the fuel assembly X to be delivered to the demand area R is not short. It is possible to reduce the waiting time while waiting for the shipment of the fuel assembly X at the loading place.

Next, a second embodiment of the fixing plate in the fuel holder 1 will be described with reference to the drawings. FIG. 4 shows another embodiment of the fuel holder according to the present invention, and is an enlarged partial cross-sectional schematic view of the main part showing the vicinity of the fuel assembly and the lower tie plate of the fuel holder. FIG. 5A is a schematic view of the main part when the fixing plate shown in FIG. 4 is viewed from the inside of the fuel holder, and FIG. 5B is a view of the fixing plate shown in FIG. FIG.

  The fixing plate 205 of the second embodiment shown in FIGS. 4 and 5 and the fixing plate 5 of the first embodiment shown in FIG. 3 are arranged so as to contact the step surfaces of the fuel assemblies having different standards. It is the same in that the position of the tangential surface in the direction of the axis O is formed to be displaceable.

  As shown in FIGS. 4 and 5, the fixed plate 205 of the second embodiment includes a first rotating plate 221 having a disk shape and a first abutting against the inner wall surface 219 of the fuel holder 201 in the first rotating plate 221. A rectangular rotary plate-like second rotating plate 225 provided on the second surface 224 opposite to the surface 222, and a rotating rod capable of rotating the first rotating plate 221 and the second rotating plate 225 together. 223 and fixing means 232 for fixing the fixing plate 205 so as not to rotate.

The surface of the second rotating plate 225 opposite to the surface on which the first rotating plate 221 is provided is formed to be in contact with the side surface 214 of the grid 209 as a pressing surface 226 that presses the grid 209 from the side surface direction. Yes. Of the four surfaces extending from the edge of the second rotating plate 225 toward the first rotating plate 221, the surface toward the bottom portion 202 of the axis O serves as the first contact surface 227 and is formed in accordance with a certain standard. It is designed to abut against the stepped surface L ₁ of the case that houses the assembly. The surface facing the top portion 204 (not shown) opposite to the first contact surface 227 is rotated as a second contact surface 228 around a rotation axis X along the rotation rod 223 described later. It is designed to abut against the stepped surface L ₂ when accommodating the fuel assembly formed in accordance with other standards.

  The fixing means 232 is provided so as to be orthogonal to the inner wall surface 219, and is aligned with the rotating rod 223 in the axial direction of the second rotating plate 225 having a rectangular plate shape as viewed from the inside of the fuel holder 201. It is provided on both sides centered on.

The rotating rod 223 is provided at the center of the first rotating plate 221 so as to be orthogonal to the inner wall surface 219, and is inserted through a hole 231 provided in the side wall 218, as shown in FIGS. . The fixed plate 205 can be rotated about the rotation axis X along the rotary rod 223. The rectangular plate-shaped second rotating plate 225 is formed on the second surface 224 of the disk-shaped first rotating plate 221, and the center of the first rotating plate 221 and the center of the second rotating plate 225, that is, 2 in the second rotating plate 225. The intersections of the two diagonal lines do not coincide with each other and are shifted. Therefore, the center of the rectangular plate-shaped second rotating plate 225 does not coincide with the rotation axis X. For example, as shown in FIGS. 4 and 5A, the second rotating plate 225 is closer to the bottom 202 side than the first rotating plate 221, and the rotation axis X is from the center of the second rotating plate 225. It has shifted | deviated to the top part 204 (not shown) side. Therefore, not the same as the distance _{t 1} from the rotation axis X to the first abutment surface 227 and the distance _{t 2} from the rotation axis X to the second abutment surface _228, which is t 1> _{t 2.}

Rotating rod 223 having an axis of rotation X, when containing the fuel assembly formed in accordance with a certain standard, the distance in the axial O direction from the stepped surface L ₁ of the fuel assembly to the rotational axis X is t ₁ and, when containing the fuel assembly formed in accordance with other standards, a distance of the axis O direction to the rotation axis X is provided at a position which is t ₂ from the stepped surface L2 of the fuel assembly.

The position of the contact surface on the fixing plate 205 of the second embodiment can be displaced as follows. When a fuel assembly formed in accordance with a certain standard is accommodated, for example, as shown in FIGS. 4 and 5A and 5B, the first contact surface 227 has an axis O toward the bottom portion 202. The fixed plate 205 is arranged so as to be orthogonal. Rotation axis X is arranged at a distance t ₁ from the stepped surface L _1, the distance between the rotation axis X and the first abutment surface 227 is t _1, the stepped surface L and the first abutment surface 227 ₁ abuts. At this time, it is preferable to fix the fixing plate 205 by the fixing means 232 so that the fixing plate 205 does not rotate about the rotation axis X.

When a fuel assembly formed in accordance with another standard is accommodated, the fixing means 232 is removed, the fixing plate 205 is made rotatable, and then the fixing plate 205 is rotated about the rotation axis X by 180 °. FIGS. 6B and 7 show a state after the fixing plate 205 shown in FIGS. 4 and 5 is rotated by 180 °. FIG. 6A is a partial schematic cross-sectional view of the main part, showing the vicinity of the lower tie plate of the fuel assembly and the fuel holder shown in FIG. As shown in FIGS. 6B and 7, the fixing plate 205 is disposed such that the second contact surface 228 is orthogonal to the axis O toward the bottom portion 202. When another fuel assembly 310 formed according to the standard is received in the receiving space of the fuel holder 201, with respect to the position of the axis O direction of the step surface L ₁ in the fuel assembly 201 shown in FIG. 6 (a) as shown in FIG. 6 (b), the direction of the axis O of the position of the step surface L ₂ is, for example, displaced several mm on top direction. Rotation axis X is arranged at a distance t ₂ from the stepped surface L _2, the distance between the rotation axis X and the second contact surface 228 is t _2, stepped surface L and the second abutment surface 228 ₂ abuts.

  As described above, according to the fuel holder 201 of this embodiment, the position of the contact surface in the direction of the axis O can be displaced by rotating the fixing plate 205. It can be shared by one type of fuel holder 201, and when the fuel holder 201 is subjected to a large acceleration force in the direction of the axis O, the fuel assembly 210 is prevented from moving inside the fuel holder 201. Can do.

  The fixed plate 205 of this embodiment forms a stepped plate by the first rotating plate 221 and the second rotating plate 225. However, as long as it has a contact surface that contacts the step surface, the fixed plate 205 The shape of is not particularly limited, and may be formed of only the second rotary plate 225, for example.

  Further, the fixing means 232 of this embodiment is provided on both sides of the rotating rod 223. However, as long as the fixing plate 205 does not rotate after the fuel assembly 210 is accommodated in the fuel holder 201, the number and means are not particularly limited. There may be only one fixing means, and in some cases, there is no need to install the fixing means.

The fuel holder 201 of this embodiment can accommodate two different types of fuel holders, but can also be designed to accommodate three or more different types of fuel holders. That is, since the fixed plate 205 of the second embodiment has the first contact surface 227 and the second contact surface 228 on two opposite surfaces, respectively, by rotating the fixed plate 205 by 180 °, One of the surfaces is designed to abut against the step surfaces L ₁ and L ₂ of the fuel assembly 210. For example, as shown in FIG. The contact surfaces 327, 328, 329, and 330 may be designed.

The fuel holder 301 of the third embodiment shown in FIG. 8 has the same configuration as the fixing plate 205 of the second embodiment, except that it has four contact surfaces 327, 328, 329, 330. .
Rotation axis X ₂ of the fixed plate 305 do not coincide with the center or two diagonals of the intersection of the second rotation plate 325 of the rectangular plate of the second rotary plate 325, from the center of the rectangular plate of the second rotating plate 325 8 are shifted in the horizontal direction and the vertical direction in FIG. For example, the distance from the rotation axis X ₂ to the first contact surface 327 is t ₁ , the distance from the rotation axis X 2 to the second contact surface 328 is t ₂ , and the distance from the rotation axis X 3 to the third contact surface 329. T ₃ , and the distance from the rotation axis X ₄ to the fourth contact surface 330 is t ₂ , t ₁ , t ₂ , t ₃ , and t ₄ are not equal, and t ₃ > t ₄ > t ₁ > and it has a t _2.

The rotation rod 323 having an axis of rotation X2, when accommodating the fuel assembly formed in accordance with a certain standard, the distance in the axial O direction from the stepped surface L ₁ of the fuel assembly to the rotational axis X ₂ is t _1, and, when containing the fuel assembly formed in accordance with other standards, a distance of the axis O direction from the stepped surface L ₂ of the fuel assembly to the rotational axis X ₂ is t _2, and , when further containing a fuel assembly formed in accordance with the fuel assembly formed in accordance with other standards, a distance of the axis O direction from the stepped surface L ₃ of the fuel assembly to the rotational axis X ₂ is at t ₃ There, and, if further also houses a fuel assembly formed in accordance with the fuel assembly formed in accordance with another standard, the distance in the axial O direction from the stepped surface L ₄ of the fuel assembly to the rotary shaft X ₃ provided at a position but is t ₄ It has been.

When accommodating a fuel assembly formed according to a certain standard, for example, the first abutting surface 327 is arranged so as to be orthogonal to the axis O toward the bottom portion 302. At this time, the first contact surface 327 of the stepped surface L ₁ and the fixing plate 305 of the fuel assembly abuts. Then, when accommodating a fuel assembly formed in accordance with other standards, for example, as a third abutment surface 329 is perpendicular to the axis O towards the bottom 302, about the rotation axis X ₂ The fixing plate 305 is rotated 90 degrees and arranged. At this time, the stepped surface L ₃ of the fuel assembly and the third abutment surface 329 of the fixed plate 305 abuts. Similarly, when the fixed plate 305 is rotated by 90 °, the position of the contact surface of the fixed plate 305 in the direction of the axis O can be displaced to four different positions in total.

1,201,301 Fuel holder 2,202,302 Bottom 3,203 Housing shell 4,204,304 Top 5,205,305 Fixing plate (presser plate or receiving plate)
6 Upper tie plate 7 Support grid 8, 208, 308 Lower tie plate 9, 209, 309 Grid 10, 210, 310 Fuel assembly 11, 211, 311 Fuel rod 12, 212, 312 Stepped surface 13, 213, 313 Inverted pyramid Part 14, 214, 314 Side surface 15, 215, 315 Cylindrical part 16, 216, 316 Nosepiece 17, 217, 317 Protrusion part 18, 218, 318 Side wall 19, 219, 319 Inner wall surface 20 Buffer 21 First plate 22, 222 First surface 23 Guide portion 24, 224 Second surface 25 Second plate 26, 226 Holding surface 27 Abutting surface 31 Guide hole 32, 232 Fixing means 33 Holding plate 34 Receiving plate 221, 321 First rotating plate 223 323 Rotating rods 225 and 325 Second rotating plates 227 and 327 First contact surfaces 228 and 328 Second contact surfaces 329 Third contact Surface 330 fourth hole abutment surface 231

Claims (6)

Four orthogonally crossing each other forming an accommodation space capable of accommodating a fuel assembly having a lower tie plate for a boiling water reactor fuel body having a stepped surface formed on a side surface of a substantially square cylindrical grid. A housing shell having a side wall;
A fixing plate provided on an inner wall surface of the side wall to prevent the fuel assembly from moving in the axial direction thereof,
The fuel holder according to claim 1, wherein the fixing plate has a contact surface that contacts the step surface, and the position of the contact surface in the axial direction is displaceable. The fixing plate has a guide portion that protrudes from a surface that contacts the inner wall surface of the fixing plate, and is formed so that the position in the axial direction can be fixed by a fixing means.
2. The fuel holder according to claim 1, wherein the side wall includes a guide hole having a size capable of interpolating the guide portion and moving the guide portion in the axial direction. The fixed plate is a rotating plate that rotates around a rotation axis orthogonal to the inner wall surface,
The rotary shaft is in the housing space, when accommodating the fuel assembly formed in accordance with certain standards, said axis direction from the stepped surface L ₁ in the fuel assembly formed in accordance with a certain standard to said rotation axis When the fuel assembly formed according to another standard is accommodated in the accommodation space with the distance t ₁ , the rotational axis extends from the step surface L ₂ in the fuel assembly formed according to another standard. Is provided at a position where the distance in the axial direction is t ₂ ,
The rotating plate is distance t ₁ from the rotary shaft, and a first contact surface which is formed to be contact with the stepped surface L _1, the distance from the rotary shaft be t ₂ The fuel holder according to claim 1, further comprising a second contact surface formed so as to be able to contact the stepped surface L ₂ .   The fuel holder according to claim 3, wherein the fixing plate is formed so that a position in the axial direction can be fixed by a fixing means.   A method of using a fuel holder, wherein the fuel assembly is accommodated in the fuel holder according to any one of claims 1 to 4.   A method for transporting a fuel assembly, wherein the fuel assembly is accommodated in the fuel holder according to any one of claims 1 to 4 and transported.

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