JP2001108783A - Spent fuel storage rack and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spent fuel storage rack facilitating its assembling work and, if the lattice-like storage rack is formed of a poor-elongation material, capable of enhancing its reliability without weakening the lattice material. SOLUTION: This spent fuel storage rack is equipped with long division plates 3 each having a plurality of slits bored at fixed intervals and short division plates 2 having projection parts fitted into the slits in the long plates 3. The long plates are put one above another at fixed intervals and the short plates 2 are installed between the long plates to together form a lattice shape with the projection parts fitted into the slits. The long plates and the short plates are joined together by welding at the portions of the projection parts fitted into the slits. A gap g substantially equal to the plate thickness of the short plates is provided between end part walls of each slit in the long plates and side walls of a corresponding projection part of the short plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spent fuel storage rack and a method of manufacturing the same, and more particularly to a spent fuel storage rack having a plurality of long partition plates and a plurality of short partition plates, both of which are assembled in a grid. The present invention relates to a spent fuel storage rack.

[0002]

2. Description of the Related Art Conventionally used fuel storage racks of this type include a stack formed by stacking a plurality of rectangular tubular bodies, and a stack formed by combining a plurality of partition plates in a grid. However, recently, a combination of the latter partition plates having a good space factor in a lattice shape has been often used.

[0003] A fuel storage rack in which a plurality of partition plates are combined in a grid shape usually has a long partition plate having a plurality of slits and a short partition plate having a projection fitted into the slit of the long partition plate. And the short partition plate is arranged on the long partition plate so that the slits and the projections are fitted to each other, and the long partition plate is formed on top of the short partition plate. That is, a lattice-like body is formed by the long partition plate and the short partition plate, and the long partition plate and the short partition plate are formed by welding at a fitting portion between the slit and the projection.

[0004] In this case, the joint portion of the lattice is shaped like a cross joint or a T joint. However, it is difficult to assemble or weld the joint portion. As one of the ideas, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-50189, partition plates are plug welded to each other. That is to say, referring to FIG. 2 for convenience, the long partition plates 3A to 3E and the short partition plates 2A to 2E inserted from below are integrated by plug welding to form a lattice shape. I have.

[0005]

In the spent fuel storage rack formed as described above, there is no particular problem. However, for the purpose of further improving the reliability as in recent years, for example, the partition plate is not provided with the used fuel storage rack. When a stainless steel sheet with boron with low elongation is used, when the projection of the short partition plate is inserted into the slit provided in the long partition plate and butt-welded, welding stress may be generated in the slit portion and the slit portion may be generated. There is a possibility that the long partition plate having the above, that is, the lattice-shaped material may be weakened.

In this configuration, when assembling the long partition plate and the short partition plate, a plurality of projections of the short partition plate must be simultaneously inserted into a plurality of slit holes provided in the long partition plate. If the partition plate is deformed such as warpage or distortion, it becomes very difficult to assemble the partition plate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a grid-like fuel storage rack which is easy to assemble a grid-like body and is made of a material having a small elongation. Even so, it is an object of the present invention to provide a spent fuel storage rack of this kind and a method for manufacturing the same, which can improve reliability without weakening the grid material.

[0008]

That is, the present invention comprises a long partition having a plurality of slits formed at predetermined intervals, and a projection fitted into the slit of the long partition. With a short partition plate, the long partition plates are stacked at a predetermined interval, and the short partition plate between the long partition plates, the slit and the projection are fitted together to form a lattice, In the spent fuel storage rack in which the long partition plate and the short partition plate are welded and joined at a fitting portion of the slit and the projection, an end wall of the slit of the long partition plate and the Between the side wall of the protrusion of the short partition,
A gap (e.g., 5 mm) is provided at a gap substantially equal to the thickness of the short partition plate or at a gap where the slit end wall of the long partition plate is not affected by heat during welding to achieve the intended purpose. It was made.

In this case, projections are provided on both sides of the short partition plate to be fitted into the slits of the long partition plate, and the slits of the short partition plate above and below the long partition plate are provided in the slit of the long partition plate. The projections are fitted from both sides. Further, the tip of the projection of the short partition plate is formed at a sharp angle, and the sharp angle is used as a groove at the time of welding.

The present invention further comprises a long partition plate having a plurality of slits formed at predetermined intervals, and a short partition plate having a projection fitted into the slit of the long partition plate. The long partition plates are stacked at a predetermined interval, and the short partition plates are interposed between the long partition plates, the slits and the projections are fitted together, and assembled in a lattice shape, and the long partition plates And a short partition plate is formed by welding at a fitting portion of the slit and the projection, and the slit end wall of the long partition plate located at the uppermost end and the short partition A gap substantially equal to the thickness of the short partition plate is provided between the projecting portion of the partition plate and the side wall.

In this case, a counterbore excavated in the shape of a ship bottom is provided on a slit portion of the long partition plate located at the uppermost end and on an upper surface, and the short counterbore is formed in the counterbore portion. A spent fuel storage rack in which a projection of a partition plate is fillet welded to a long partition plate.

Further, the present invention comprises a long partition plate having a plurality of slits formed at predetermined intervals, and a short partition plate having a projection fitted into the slit of the long partition plate. The long partition plates are stacked at a predetermined interval, and the short partition plates are interposed between the long partition plates, the slits and the projections are fitted together, and assembled in a lattice shape, and the long partition plates And a short partition plate, which is formed so as to be welded and joined at a fitting portion between the slit and the protrusion, wherein the slit end wall of the long partition plate and the short partition Between the side wall of the protruding portion of the plate, there is provided a gap into which the rod-shaped body can be inserted in the thickness of the short partition plate, and the rod-shaped body is inserted from this gap. While modifications, is a projection of the short partition plate that so fitted into the slit of the long partition plate.

That is, in the spent fuel storage rack formed as described above, the thickness of the short partition plate is reduced between the end wall of the slit of the long partition plate and the side wall of the projecting portion of the short partition plate. Since substantially equal gaps are provided, the heat of the weld does not directly affect the slit corners, and even if the fuel storage rack is a grid-like fuel storage rack made of a material with low thermal expansion, The reliability of the storage rack can be improved without weakening the plate, that is, the grid-like material.In assembling, a sharp driver-like tool is inserted from the gap to pry the protruding side of the short partition plate. The slits can be adjusted so that the projections fit in the slits, and thus the grid-like assembling work of the partition plates becomes very easy.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. 1 and 2 show the entire configuration of the spent fuel storage rack in a perspective view (partially cut away) and a side view. 1 is a sheet and 2 (A
...) is a short partition plate, 3 (A ...) is a long partition plate, 11
Is a long partition plate serving as a frame portion, and 15 to 18 are slits provided in the long partition plate. The long partition plate 3 is provided with slits 15 and 17 in advance, and the short partition plate 2 is provided with protrusions 4 and 8.

The assembly of the fuel storage rack having the plate structure is as follows.
The long partition plate 11 is installed horizontally on the sheet 1, and then a plurality of short partition plates 2A are vertically installed on the long partition plate 11 and assembled. In this case, the combination of the long partition plate 11 and the short partition plate 2A
A short partition plate 2A is provided in a slit 17 provided in advance.
The projections 4A and 7A are inserted.

Next, the short partition plate 2
A long partition plate 3A is installed on A, and fillet welding is performed on the slit of the long partition plate and the projection 7A of the short partition plate. Long partition plate 3A and short partition plate 2
In combination with A, the projections 4A and 8A provided on the short partition plate 2A are inserted into the slits 15 and 17 provided on the long partition plate 3A and combined in a lattice shape.
Thereafter, welding is performed with the triangular space defined by the projection 4A and the slit 15 as a groove.

As shown in FIG. 2, the projections 4 are also provided on the short partitions 2B to 2E in the same manner as the short partition 2A.
B to 4E and 8B to 8E are provided, and the long partition plates 3B to 3D have slits 1 similarly to the long partition plate 3A.
5 and 17 are provided and are similarly assembled. That is, the protruding portions 4B- of the short partition plates 2B-2E.
4E is inserted into the slits 15 and 17 of the long partition plates 3B to 3D and combined in a grid. Thereafter, the projections 4B to 4E and the wall of the slit 15 are welded.

FIG. 3 is an enlarged detail view of this joint, that is, the frame A of FIG. 2, in which the projection 4C of the short partition plate 2C is inserted and set in the slit 15 of the long partition plate 3c. The state is shown. FIG. 4 is a plan view (along CC of FIG. 3), and FIG.
It is -D sectional drawing.

As described above, the projections 4C of the short partition plate are fitted into the slits 15, and what is important here is that the slit 15 of the long partition plate has the longitudinal direction of the short partition plate 2C. Larger than the length of the projection 4C,
That is, it is formed larger than the size necessary for inserting the projection. That is, as shown in FIG. 1B which shows the same portion in a perspective view, the length of the slit 15 is formed to have a length with a gap g on both sides of the length L of the protrusion. is there.

With such a relationship between the slit and the projection, a large gap, that is, an adjustment slit 16 is formed at both ends of the projection 4C when fitted. That is, the projection 4C (4A) of the short partition plate 2C (2A)
When it is difficult to insert into the slit 15 of the long partition plate 3C (3A), as shown in FIG. Adjust the deformation,
The protruding part is inserted.

FIG. 6 shows a state in which the projection 4C of the short partition 2C is inserted into the slit 15 of the long partition 3C and assembled. The tip of the projection 4C is sharply pointed and has a shape that can be easily inserted into the slit. Also,
FIG. 7 shows a short partition 2D in which a groove formed by the sharpness of the projection 4C of the short partition 2C and the slit 15 is welded 5 to form a short partition 2D.
Has been set. Thus, the protrusion 4
The pointed tip of C is easy to insert and has a grooved butt groove between itself and the slit 15 and is suitable for welding. A short partition is further disposed on the long partition 3C. FIG.
D shows a state where the long partition plate 3C and the fillet weld 6 are formed.

The short partition has another projection, and FIG. 9 shows the relationship between the projection and the long partition 3C. That is, this drawing is a detailed view of the B-frame portion in FIG. 2, and the projection 8C of the first short partition plate 2C is inserted into the slit 17 of the long partition plate 3C from below and positioned. This is a state where the projection 7D of the second short partition plate 2D is inserted from above and assembled. FIG. 10 is a plan view thereof.

In this case as well, there are gap slits 18 (air gaps) on both sides of the projection 8C, and when it is difficult to insert the projection 8D into the slit 17, a minus screwdriver having a sharper tip than the slit 18 is inserted. Short partition plate 2C
The protrusion 8C is formed on the slit 17 by prying
Can be easily inserted. FIG. 11 shows the slit 17
In this state, the projection 8C is inserted from below and the projection 7D is inserted from above.

Slit 1 provided on long partition plate 3C
7, the projection 8C of the short partition plate 2C is inserted from below,
The projection 7D of the short partition plate 2D is inserted from above and positioned accurately.

FIG. 12 is a detailed view of a T-shaped joint portion of the frame portion, that is, a portion C of FIG. The projection 9 of the short partition 2N is inserted from below into a slit 19 provided in the long partition 12 at the upper end. FIG. 13 is a plan view of FIG. Adjustment slits (voids) at both ends of the projection 9
In this case, similarly to the above, when the protrusion 9 cannot be inserted into the slit 19, a sharp tool with a dry-shaped tip is inserted through the adjustment slit 20 to pry and move the short partition plate 2N. The protrusion 9 can be easily inserted into the slit 19.

FIGS. 14 and 15 are sectional views of FIG.
4 shows an assembled state, and FIG. 15 shows a welding completed state. In FIG. 14, the protrusion 9 has a sharp tip and the slit 1
9 is easy to insert. On the other hand, since the long partition plate 12 at the upper end is a groove 21 excavated to the bottom of the ship, the upper end of the protrusion 9 is located in the bottom of the long partition plate 12 and has a space for the storage rack. Fillet welding can be performed without increasing the size.

In this configuration, the long partition plate 12 is excavated and fillet welded, so that welding can be performed without increasing the size of the fuel rack. Since the joining of the protrusion 9 of the short partition plate 2N and the slit 19 of the long partition plate 12 is performed by fillet welding 22, the binding force is weak, so that the welding stress can be suppressed low. Cracks do not occur even in materials that do not stretch.

FIGS. 16 and 17 show this conventional joint portion. With this structure, there is no escape area for welding stress and the welding stress is increased, and as a result, there is no elongation like stainless steel containing boron. In the case of materials, cracks occur when the amount of welding increases.

As described above, in the spent fuel storage rack formed according to the present invention, the space between the end wall of the slit of the long partition plate 3 and the side wall of the projecting portion of the short partition plate 2 is provided. In addition, since the gap 16 (18, 20) is provided, the heat of the welded portion does not directly affect the slit corner portion, and even if the grid-shaped fuel storage rack is formed of a material having low thermal expansion. Even in this case, the reliability of the storage rack can be improved without the partition plate becoming weak.

Further, since this gap, that is, an adjusting slit is provided and, for example, a driver can be inserted and the short partition plate can be squeezed and moved, setting is easy even if the short partition plate is deformed. In addition, the long partition plate has a positioning slit, and the projections of the upper and lower short plates are inserted into the positioning slit for positioning, thereby improving dimensional accuracy.

In the uppermost long partition plate, the vicinity of the slit is formed in a ship bottom shape and is joined by fillet welding, so that welding can be performed without taking up a space larger than the surface of the long partition plate. That is, the projection of the short partition plate can be lower than the outer surface of the long partition plate. In addition, even if the welding amount increases due to the fillet welding, the welding stress is not so high unlike the butt welding in which the welding stress does not escape, and the occurrence of cracks can be prevented without being affected by the heat during welding.

[0032]

As described above, according to the present invention, the assembling work is easy, and even if the fuel storage rack is a grid-like fuel storage rack made of a material having a small elongation, the grid-like material can be used. It is possible to obtain a spent fuel storage rack of this type that can improve reliability without being weakened.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view and an enlarged view of a main part showing an embodiment of a fuel storage rack of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is a view taken in the direction of arrows CC in FIG. 3;

FIG. 5 is a diagram illustrating a situation in which a flathead screwdriver is operated before setting a first short plate.

FIG. 6 is a diagram showing the situation after setting the first short plate.

7 is a cross-sectional view along line BB in FIG. 3 (in a state where welding of the slit of the long partition plate and the projection of the first short partition plate has been completed and the second short partition plate has been set). .

FIG. 8 is a diagram showing a state where welding of the second short partition plate is completed.

FIG. 9 is an enlarged view of a portion B in FIG. 2;

FIG. 10 is a view as seen in the direction of arrows EE in FIG. 9;

FIG. 11 is a sectional view taken along line FF of FIG. 10;

FIG. 12 is an enlarged view of a portion C in FIG. 2;

FIG. 13 is a view taken along the line GG in FIG. 12;

14 is a sectional view (state after assembly) taken along line HH of FIG. 12;

FIG. 15 is a cross-sectional view (a state after welding) along the line HH in FIG. 12;

FIG. 16 is a view showing a state after assembly of a conventional fuel storage rack.

FIG. 17 is a view showing a state after welding of a conventional fuel storage rack.

[Explanation of symbols]

1 ... sheet, 2 ... short partition plate, 3 ... long partition plate,
4, 7, 8 ... projection part, 11 ... long partition board which becomes a frame part,
15-18 ... Slits.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroo Koide 3-1-1, Sachimachi, Hitachi-City, Ibaraki Pref. Nuclear Power Division, Hitachi, Ltd. 1-1 Nuclear Power Division, Hitachi, Ltd. (72) Inventor Hidetoshi Kanai 3-1-1 Sayukicho, Hitachi, Hitachi, Ibaraki Prefecture Nuclear Power Division, Hitachi, Ltd. (72) Inventor ▲ Toshiyori Taka ▼ 3-1-1, Sachimachi, Hitachi City, Ibaraki Prefecture Within the Nuclear Power Division of Hitachi, Ltd.

Claims (7)

[Claims] 1. A long partition plate having a plurality of slits formed at predetermined intervals and a short partition plate having a projection fitted into the slit of the long partition plate. The long partition plates are stacked at a predetermined interval, and the short partition plate is assembled between the long partition plates in a lattice shape by fitting the slits and the projections, and the long partition plate and the short partition are assembled. In a spent fuel storage rack in which a plate and a slit are formed by welding at a fitting portion between the slit and the protrusion, an end wall of the slit of the long partition plate and a side wall of a protrusion of the short partition plate. Wherein a gap substantially equal to the thickness of the short partition plate is provided between the fuel storage racks. 2. A long partition plate having a plurality of slits perforated at predetermined intervals, and a short partition plate having a projection fitted into the slit of the long partition plate, The long partition plates are stacked at a predetermined interval, and the short partition plate is assembled between the long partition plates in a lattice shape by fitting the slits and the projections, and the long partition plate and the short partition are assembled. In a spent fuel storage rack in which a plate and a slit are formed by welding at a fitting portion between the slit and the protrusion, an end wall of the slit of the long partition plate and a side wall of a protrusion of the short partition plate. Wherein the slit end wall of the long partition plate is provided with a gap which is not affected by the heat during welding. 3. A short parting plate is provided on both sides thereof with projections to be fitted into slits of the long partitioning plate, and slits of the long partitioning plate above and below the long partitioning plate are provided in the slits of the long partitioning plate. 3. The spent fuel storage rack according to claim 1, wherein the protrusions are fitted from above and below. 4. The used end according to claim 1, wherein the projection end surface of the short partition plate is formed with a sharp angle, and the sharp angle portion is used for a groove at the time of welding. Fuel storage rack. 5. A long partition plate having a plurality of slits perforated at a predetermined interval, and a short partition plate having a projection fitted into the slit of the long partition plate. The long partition plates are stacked at a predetermined interval, and the short partition plate is assembled between the long partition plates in a lattice shape by fitting the slits and the projections, and the long partition plate and the short partition are assembled. A spent fuel storage rack formed by welding a plate with a fitting portion between the slit and the projection, wherein the slit end wall of the long partition located at the uppermost end and the short partition A spent fuel storage rack, wherein a gap is provided between a side wall of the projecting portion and a thickness of the short partition plate or more. 6. A counterbore excavated in a ship bottom shape is provided on the upper surface of the slit portion of the long partition plate located at the uppermost end, and the short partition plate is formed in the counterbore portion. 6. The spent fuel storage rack according to claim 5, wherein the projecting portion is fillet-welded to the long partition plate. 7. A long partition having a plurality of slits perforated at predetermined intervals, and a short partition having a projection fitted into the slit of the long partition. The long partition plates are stacked at a predetermined interval, and the short partition plate is assembled between the long partition plates in a lattice shape by fitting the slits and the projections, and the long partition plate and the short partition are assembled. In a method for manufacturing a spent fuel storage rack, wherein a plate and a slit are formed by welding at a fitting portion between the slit and the protrusion, the slit end wall of the long partition plate and the projecting portion of the short partition plate are formed. Between the side walls, a gap in which the rod-shaped body can be inserted is provided in the thickness of the short partition, and the rod is inserted from the gap, while correcting the deformation and distortion of the short partition with the rod. Manufacturing method of spent fuel storage rack, characterized in that the projection of the elongated partition plate was set to fitted into the slit of the long partition plate.