JP2003075581A - Spent fuel storage rack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spent fuel storage rack capable of storing a large quantity of spent fuel and returning the position of spent fuel to an original position. SOLUTION: This spent fuel storage rack to be arranged in a storage pit filled with water is provided with a base set on the bottom surface of the storage pit, a storage part provided on the base to store the spent fuels, and a damper arranged horizontally between the base and the storage part. When a horizontal vibration is generated, the vibration is damped by the damper.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an earthquake-resistant storage rack,
In particular, it relates to a spent fuel storage rack for storing spent fuel taken out of a nuclear reactor.

[0002]

2. Description of the Related Art Generally, a nuclear power plant is provided with a fuel storage pit filled with water, and a so-called spent fuel storage rack for storing so-called spent fuel is provided on the bottom surface of the fuel storage pit. Is installed. After operating a nuclear reactor in a nuclear power plant for a predetermined period, spent fuel is taken out from the nuclear reactor and stored in a storage rack in a storage pit for a predetermined period. Thereby, the spent fuel is cooled and the decay heat of the spent fuel can be removed.

FIG. 8 is a view showing a state in which such a conventional storage rack is installed. Fuel storage pit 10
Zero is filled with water. As can be seen, the fuel storage pit 100 includes a side portion 110 and a bottom surface 120, and a storage rack 20 for storing spent fuel.
0 is installed on the bottom surface 120 of the fuel storage pit 100. After operating a nuclear reactor (not shown) for a predetermined period, the spent fuel 300 is taken out from the nuclear reactor. Then, the spent fuel 300 is stored in the storage rack 200 in the fuel storage pit 100 by using an automatic operation means, for example, an arm (not shown) of a robot. A plurality of gaps are formed in the rack portion of the storage rack 200, and the spent fuel 300 is stored in these gaps.

As described above, in order to remove the decay heat of the spent fuel, the spent fuel 300 is stored in the fuel storage pit 10.
The spent fuel needs to be cooled for a predetermined period while being stored in the storage rack 200 within 0. The bottom 220 of the storage rack 200 is the bottom surface 1 of the fuel storage pit 100.
It is firmly fixed to 20. For example, JP 2001-2
Like the storage rack disclosed in the '8887 publication, the bottom 220 of the storage rack 200 and the bottom 120 of the fuel storage pit 100 are generally connected by using suitable fastening means, such as anchor bolts and nuts. The method of directly fixing the space is adopted.

[0005]

[Patent Document 1] Japanese Unexamined Patent Application Publication No.
When the storage rack itself is directly fixed to the bottom surface of the storage pit as shown in Japanese Patent Laid-Open No. 001-208887, an earthquake causes vibration due to the earthquake, particularly horizontal vibration, to directly occur on the storage rack 200. To be transmitted. Therefore, the storage rack 200 and the spent fuel 300 may collide with each other and may be damaged. Further, even if the fuel storage pit 100, the storage rack 200, and the spent fuel 300 do not collide with each other, the fixing means, for example, the anchor bolt may be damaged and water may leak from the storage pit floor. Since the spent fuel 300 is taken out from the storage rack 200 by the automatic operation means described above, for example, the arm of the robot, Mitsubishi Heavy Industries Technical Report Vol.
Slip seismic isolation type spent fuel storage rack described in “Spent Fuel Storage Rack Seismic Isolation Research” automatically disposes spent fuel 300 by automatic operation means when displacement occurs due to an earthquake. I can't take it out. Therefore, in such a case, it is necessary to manually move the position of the storage rack 200 provided with the spent fuel 300 to the original position. However, such a work causes an additional construction period and the work. Workers who do are exposed to radiation.

Further, as described above, in order to prevent the storage rack 200 or the spent fuel 300 from colliding with the fuel storage pit 100, between the rack portions of the storage rack 200 and between the storage rack 200 and the fuel storage pit 100. It is necessary to properly provide a gap between the and. By providing such a gap, the amount of spent fuel stored in the spent fuel storage pit on the bottom surface 120 is limited.

Therefore, it is an object of the present invention to provide a spent fuel storage rack capable of storing a large amount of spent fuel and returning the spent fuel to its original position.

[0008]

In order to achieve the above-mentioned object, according to the invention as set forth in claim 1, in a spent fuel storage rack arranged in a storage pit filled with water, the storage pit is provided. Base installed on the bottom of
Provided is a spent fuel storage rack comprising: a storage unit provided on the base for storing spent fuel; and a horizontally arranged damper connecting the base and the storage unit. To be done.

That is, according to the invention of claim 1,
Since the horizontal force can be transmitted to the storage unit while being attenuated, the gap between the rack unit of the storage unit and the gap between the storage unit and the storage pit can be reduced, resulting in a large amount. It can store spent fuel.

According to the invention described in claim 2, in a spent fuel storage rack arranged in a storage pit filled with water, a base installed on the bottom surface of the storage pit and a base provided on the base. A storage unit for storing spent fuel, and a damper that connects the base and the storage unit and is arranged in a horizontal direction, the damper for connecting to the base. A cylindrical casing, which is provided with a base joint and is filled with a fluid, and a piston assembly, which is arranged in the casing, wherein the piston assembly divides the internal space of the casing into two chambers. A piston that is divided and is slidable in the casing, and a piston rod that is provided with a joint portion for the storage portion for joining to the storage portion and that is connected to the piston are provided. Nde and the piston rod extends through an opening formed in the casing,
A spent fuel storage rack is provided in which the piston includes a flow means that allows the fluid to flow between the two chambers when the damper is longitudinally compressed or stretched.

That is, according to the invention of claim 2,
Since the horizontal force can be transmitted to the storage unit while being attenuated, the gap between the rack unit of the storage unit and the gap between the storage unit and the storage pit can be reduced, resulting in a large amount. It can store spent fuel.

According to the third aspect of the invention, the circulating means is a hole provided in the piston. That is, according to the invention described in claim 3, the distribution means can be formed relatively easily.

According to the invention described in claim 4, the circulating means is a notch provided in the outer peripheral portion of the piston. That is, according to the invention of claim 4, the distribution means can be formed more easily.

According to the invention described in claim 5, in the spent fuel storage rack arranged in the storage pit filled with water, the base installed on the bottom surface of the storage pit and the base provided on the base. A storage unit for storing spent fuel, and a damper that connects the base and the storage unit and is arranged in a horizontal direction, the damper for connecting to the base. The casing includes a cylindrical casing provided with a base joint portion, and a piston assembly disposed in the casing, the piston assembly dividing an internal space of the casing into two chambers. A piston slidable therein, and a piston rod provided with a reservoir joint for joining to the reservoir and connected to the piston; Head extends through the opening formed in the casing, the two chambers of the spent fuel storage rack hole communicating with the storage pit is formed in each is provided.

That is, according to the invention described in claim 5,
Since the horizontal forces can be transmitted to the store in a damped state without the need for a separate fluid, the gap between the rack part of the store and the gap between the store and the storage pit. Can be reduced, and as a result, a large amount of spent fuel can be stored.

According to the invention of claim 6, a spring extending in the longitudinal direction is arranged in at least one of the two chambers. That is, according to the invention described in claim 6, it is possible to prevent the storage unit from moving beyond the designed displacement and to restore the position of the storage unit by the spring.

According to the invention described in claim 7, a high-pressure fluid source is further provided, and the high-pressure fluid source is connected to each of the holes via a three-way valve. That is, according to the invention described in claim 7, the position of the storage section can be returned to the original position by remote control using the high-pressure fluid source, so that the period during which the rack becomes unusable is shortened and the worker is exposed to radiation. Can be prevented.

[0018]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following drawings, the same members are designated by the same reference numerals. FIG. 1 is a side view of a spent fuel storage rack according to one embodiment of the present invention. As shown, the spent fuel storage rack 1 of the present invention is installed on the bottom surface 120 of the storage pit. The spent fuel storage rack 1 includes a base or skid 4 installed on the spent fuel storage pit 5 on the bottom surface 120 and a gap (rack portion) for storing spent fuel (not shown).
And a reservoir 2 which is arranged on the skid 4. As can be seen from FIG. 1, a storage portion bracket 7 is provided at the bottom of the storage portion 2, and a skid bracket 8 is provided at the upper portion of the skid 4. The spent fuel storage rack 1 of the present invention further includes a displacement control mechanism or damper 6. As shown in FIG. 3A which is the first embodiment of the spent fuel storage rack 1,
The damper 6 includes a rod side bracket 10 and a casing side bracket 12. In this embodiment, the rod-side bracket 10 of the damper 6 is connected to the storage bracket 7, and the casing-side bracket 12 of the damper 6 is connected to the skid bracket 8 by known methods, for example, screws and bolts. As a matter of course, the rod side bracket 10 may be connected to the skid bracket 8 and the casing side bracket 12 may be connected to the storage part bracket 7.

FIG. 2 is a sectional view taken along the line AA 'in FIG. As shown in FIG. 2, a plurality of dampers 6 are arranged along the outer peripheral portion of the skid 4. These dampers 6
Serves to damp horizontal vibrations, as will be described later. Further, as shown in FIGS. 1 and 2, a plurality of seismic isolation members 3 are arranged on the skid 4 at substantially equal intervals. These seismic isolation members 3 are metal pads having a low coefficient of friction and play a role of preventing the earthquake motion transmitted from the spent fuel storage pit 5 from the skid 4 from being transmitted to the storage unit 2 by sliding horizontally. .

FIG. 3A is a longitudinal sectional view of a damper used in the spent fuel storage rack according to the first embodiment of the present invention. The damper 6 is mainly composed of a casing 13 filled with a fluid, for example, a viscous fluid, a piston 14 slidable in the casing 13, and a piston rod 11 connected to the piston 14. Further, the casing side bracket 12 is provided at the tip of the casing 13, and the rod side bracket 10 is provided at the base end of the piston rod 11, that is, the end opposite to the end where the piston 14 is provided. Has been. Further, an opening 33 is formed in the casing 13, and the piston rod 11 extends through the opening 33 while maintaining a sealed state. As can be seen from FIG. 3A, the internal space of the casing 13 is divided into two chambers 30 and 31 by the piston 14.

FIG. 3B is an end view of the piston included in the damper used in the spent fuel storage rack according to the first embodiment of the present invention. FIG. 3C is a partial view of the piston included in the damper used in the spent fuel storage rack according to the first embodiment of the present invention. Figure 3 (b)
Further, as shown in FIG. 3C, in the present embodiment, the piston 14 is formed with a through hole 15 extending in the direction of the piston rod 11. This allows the two chambers 30 and 31 in the casing 13 to communicate with each other when the piston 14 and the piston rod 11 are assembled.

When the damper 6 of this embodiment is assembled to the spent fuel storage rack 1 and a horizontal force acts on the damper 6 due to an earthquake, for example, the damper 6 receives the horizontal force and compresses. Stretch. When the damper 6 is compressed, the piston 14 moves toward the casing-side bracket 12
While moving in the direction toward, a part of the fluid in the chamber 30 moves from the chamber 30 to the chamber 31 through the through hole 15 of the piston 14. Further, when the damper 6 is extended (not shown), the piston 14 moves in a direction opposite to the direction toward the casing side bracket 12, while a part of the fluid in the chamber 31 passes from the chamber 31 through the through hole 15. Move to room 30. As a result, the force acting in the horizontal direction is transmitted from the skid 4 installed on the bottom surface of the storage pit to the storage unit 2 via the damper 6 in a damped state. As described above, in the present invention, since the horizontal force can be transmitted to the storage unit 2 in a attenuated state, the spent fuel, the storage unit 2 and the side portion 110 of the fuel storage pit 100 collide with each other. Can be hindered. Therefore, in the present invention, it is possible to reduce the gaps between the rack portions of the storage portion and between the storage portion and the side portions of the storage pits, so that the spent fuel can be stored in the storage portion in the storage pit 5. The capacity of spent fuel can be increased.

FIG. 3 (d) is an end view of the piston included in the damper used in the spent fuel storage rack according to another embodiment of the present invention, and FIG. 3 (e) is another embodiment of the present invention. FIG. 6 is a partial view of a piston included in a damper used in a spent fuel storage rack based on a configuration. In the present embodiment, instead of the through hole 15, a notch 16 extending in the direction of the piston rod 11 is formed on the outer peripheral portion of the piston 14. Similar to the above-described embodiment, when the damper 6 is assembled, the notch 16 allows the fluid in the casing 13 to flow between the two chambers 30 and 31.
Therefore, also in the case of this embodiment, the storage part 2 and the side part 11
It is possible to prevent the 0s from colliding with each other and increase the capacity of the spent fuel that can be stored in the storage portion of the spent fuel storage pit 5. Of course, instead of forming the notch 16, the piston 14 may be formed to have a diameter smaller than the inner diameter of the casing 13 to allow fluid to flow between the piston 14 and the inner wall of the casing 13. It is within the scope of the invention to form possible annular holes. By adopting such an embodiment, the two chambers of the casing can be more easily circulated than the above-described embodiments.

4 (a) and 4 (b) are longitudinal sectional views of a damper used in a spent fuel storage rack according to the second embodiment of the present invention. In this embodiment, holes 17 and 18 are formed in the two chambers 30 and 31 near both ends of the casing 13. Since these holes 17 and 18 communicate with the water in the storage pit 100, the two chambers in the casing 13 are filled with the water in the storage pit 100 in this embodiment.
Therefore, in the embodiment, since the water in the storage pit 100 can be used, it is not necessary to separately prepare the fluid for the casing. Further, when oil or the like is used as the casing fluid, the leaked oil may contaminate the water in the storage pit 100. In this case, however, it is possible to prevent the pit water from being contaminated due to such leakage. .

When the damper 6 of this embodiment is assembled to the spent fuel storage rack 1, when a horizontal force is generated in the damper 6 due to an earthquake, for example, the damper 6 receives the horizontal force to be compressed. Stretch. When the damper 6 is compressed, the piston 14 moves toward the casing-side bracket 12
Some of the fluid in the chamber 30 flows out of the chamber 30 into the storage pit 100 through the holes 18 and some of the fluid in the storage pit 100 while moving in the direction toward the storage pit 1.
00 through the hole 17 to the chamber 31. further,
When the damper 6 is extended as shown in FIG. 4B, the piston 14 moves in a direction opposite to the direction toward the casing-side bracket 12, while a part of the fluid in the chamber 31 partially moves into the chamber 31.
Through the hole 17 into the storage pit 100, and a part of the fluid in the storage pit 100 is stored in the storage pit 100.
Through hole 18 to chamber 30. This allows
The force acting in the horizontal direction is transmitted from the skid 4 installed on the bottom surface of the storage pit to the storage unit 2 via the damper 6 in a damped state. Therefore, as in the above-described embodiment, the horizontal force can be attenuated and transmitted to the storage unit 2, so that the spent fuel, the storage unit 2, and the side portion 110 of the storage pit 100 can be prevented from colliding with each other. Can hinder. Therefore, in the present invention, the gaps between the rack parts of the storage part and between the storage part and the side part of the storage pit can be reduced, so that it can be used without the need for a separate casing fluid. It is possible to increase the capacity of the spent fuel that can be stored in the storage portion of the spent fuel storage pit 5.

FIGS. 5 (a) and 5 (b) are longitudinal sectional views of a damper used in the spent fuel storage rack according to the third embodiment of the present invention. In the present embodiment, the spring 1 extending in the longitudinal direction inside the chamber 30 of the casing 13.
9 are installed. As can be seen from FIGS. 5A and 5B, the ends of the springs 19 are connected to the surface of the piston 14 forming the chamber 30 and the inner surface of the chamber 30 adjacent to the casing-side bracket 12, respectively. .

When the damper 6 of this embodiment is assembled to the spent fuel storage rack 1 and a horizontal force is generated in the damper 6 due to an earthquake, for example, the damper 6 receives the horizontal force and is compressed. Stretch. When the damper 6 is compressed, the piston 14 moves toward the casing-side bracket 12
Some of the fluid in the chamber 30 flows out of the chamber 30 into the storage pit 100 through the holes 18 and some of the fluid in the storage pit 100 while moving in the direction toward the storage pit 1.
00 through the hole 17 to the chamber 31. further,
When the damper 6 is extended as shown in FIG. 5B, the piston 14 moves in a direction opposite to the direction toward the casing-side bracket 12, while part of the fluid in the chamber 31
Through the hole 17 into the storage pit 100, and a part of the fluid in the storage pit 100 is stored in the storage pit 100.
Through hole 18 to chamber 30. This allows
The force acting in the horizontal direction is transmitted from the skid 4 installed on the bottom surface of the storage pit to the storage unit 2 via the damper 6 in a attenuated state. Therefore, as in the above-described embodiment, the horizontal force can be attenuated and transmitted to the storage unit 2, thus preventing the spent fuel, the storage unit 2 and the side portion 110 of the storage pit 100 from colliding with each other. be able to. Therefore, in the present invention, it is possible to reduce the gaps between the rack portions of the storage portion and between the storage portion and the side portions of the storage pits, so that the spent fuel can be stored in the storage portion in the storage pit 5. The capacity of spent fuel can be increased. Further, since the spring 19 is arranged in this embodiment, the damper 6 extends only up to a predetermined distance as shown in FIG. 5B. Therefore, in this embodiment, it is possible to prevent the storage unit 2 from moving beyond the designed displacement and restore the position of the storage unit by the spring.

FIG. 6 is a longitudinal sectional view of a damper used in a spent fuel storage rack according to the fourth embodiment of the present invention. In the present embodiment, a high-pressure fluid source 23 capable of supplying a high-pressure fluid, for example, water is provided, and pipes 22 and 24 extending from the high-pressure fluid source 23 are provided with chambers 31, 18 through holes 17 and 18, respectively. 30 are respectively connected. As can be seen from FIG. 6, the three-way valves 20, 21 are provided between the pipe 22 and the hole 17 and between the pipe 24 and the hole 18.
Are provided respectively. In the initial state, these three-way valves 20 and 21 are set so that the chambers 31 and 30 of the casing 13 and the storage pit 100 are in communication.

When the damper 6 of this embodiment is assembled to the spent fuel storage rack 1, when a horizontal force acts on the damper 6 due to an earthquake, for example, the damper 6 receives the horizontal force to be compressed. Stretch. When the damper 6 is compressed, the piston 14 moves toward the casing-side bracket 12
Some of the fluid in the chamber 30 moves from the chamber 30 through the hole 18 and the three-way valve 21 while moving toward the storage pit 1.
00 and a part of the fluid in the storage pit 100 flows into the chamber 31 from the storage pit 100 through the three-way valve 20 and the hole 17. Further, when the damper 6 is extended, the piston 14 moves in the direction opposite to the direction toward the casing side bracket 12, while a part of the fluid in the chamber 31 passes from the chamber 31 through the hole 17 and the three-way valve 20. A part of the fluid in the storage pit 100 that flows out into the storage pit 100 is discharged from the storage pit 100 and the three-way valve 21 and the hole 1
It flows through 8 to the chamber 30. As a result, the force acting in the horizontal direction is transmitted to the storage unit 2 in a attenuated state from the skid 4 installed on the bottom surface of the storage pit via the damper 6. Therefore, as in the above-described embodiment, the horizontal force can be attenuated and transmitted to the storage unit 2, so that the spent fuel, the storage unit 2, and the storage pit 1 can be attenuated.
00 sides 110 can be prevented from colliding with each other. Therefore, in the present invention, it is possible to reduce the gaps between the rack portions of the storage portion and between the storage portion and the side portions of the storage pits, thereby increasing the capacity of the spent fuel that can be stored in the storage portion. be able to.

When the damper 6 receives a horizontal force and the piston 14 is displaced or displaced from the original position, that is, when the storage unit 2 is displaced or displaced with respect to the skid 4, the three-way valves 20, 21. Is the chamber 3 of the casing 13
It is set so that 1 and 30 and the high pressure fluid source 23 circulate. For example, when the piston 14 is displaced toward the casing-side bracket 12 (left side in FIG. 6) from the original position, fluid is supplied from the high-pressure fluid source 23 to the three-way valve 21 and the hole 1.
8 to feed the chamber 30 to the piston 14
Is moved to the right in FIG. Similarly, piston 1
When 4 is displaced toward the rod side bracket 10 from the original position (right side in FIG. 6), by supplying the fluid from the high pressure fluid source 23 to the chamber 31 through the three-way valve 20 and the hole 17, The piston 14 is moved to the left in FIG. As a result, the piston 14 displaced or displaced due to the horizontal force can be returned to the original position. That is, the storage 2 with spent fuel can be returned to its original position with respect to the skid. Since such a series of operations can be performed remotely, the storage unit containing the spent fuel can be quickly returned to its original position, and no additional construction period is required, and the rack cannot be used. The period can be shortened. Further, the storage unit 2 is prevented from moving beyond the designed displacement. Further, since it is not necessary to manually perform such work, the worker can be less exposed to the radiation.

FIG. 7 is a longitudinal sectional view of a damper used in a spent fuel storage rack according to the fifth embodiment of the present invention. In this embodiment, the spring 19 is arranged in the chamber 30 of the casing 13 as in the third embodiment. Therefore, in the present embodiment, the storage unit provided with the spent fuel can be quickly returned to the original position as in the above-described embodiment, and the period during which the rack cannot be used can be shortened, Workers can be less exposed to radiation. Further, in the present embodiment, similarly to the third embodiment described above, it is possible to prevent the storage unit 2 from moving beyond the designed displacement and to restore the position of the storage unit by the spring.

In the present invention, the spring is arranged in one chamber of the casing, for example, the chamber 30, but the spring is arranged in the other chamber, for example, the chamber 31, and the spring is arranged in both chambers 30, 31. Placement is within the scope of the invention. This makes it possible to prevent the storage unit 2 from moving beyond the design displacement more quickly and reliably. Further, although the storage part bracket 7 and the skid bracket 8 are adopted in the present invention, it is also possible to directly connect the rod side bracket 10 and the casing side bracket 12 of the damper 6 to the storage part or the skid respectively. It is included in the range of.

[0033]

According to the invention described in each claim, since the gap between the rack portion of the storage portion and the gap between the storage portion and the storage pit can be reduced, a large amount of spent fuel can be saved. It has the common effect of being able to store.

Further, according to the invention of claim 2,
Since it is possible to reduce the gap between the rack part of the storage part and the gap between the storage part and the storage pit, it is possible to store a large amount of spent fuel. Further, according to the invention as set forth in claim 3, there is an effect that the distribution means can be formed relatively easily.

Further, according to the invention of claim 4,
The distribution means can be formed more easily. Further, according to the invention described in claim 5, it is possible to obtain an effect that a separate fluid is not required.

Further, according to the invention of claim 6,
The storage part can be prevented from moving beyond the designed displacement, and the spring can restore the position of the storage part. Further, according to the invention described in claim 7, the position of the storage section can be returned to the original position by remote control using the high-pressure fluid source, so that the period during which the rack becomes unusable is reduced and the operator is Can be prevented from being exposed to radiation.

[Brief description of drawings]

FIG. 1 is a side view of a spent fuel storage rack of the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 3 (a) is a longitudinal sectional view of a damper used in the spent fuel storage rack according to the first embodiment of the present invention. (B) It is an end view of the piston contained in the damper used for the spent fuel storage rack based on 1st embodiment of this invention. (C) Partial view of the piston included in the damper used in the spent fuel storage rack according to the first embodiment of the present invention. (D) An end view of a piston included in a damper used in a spent fuel storage rack according to another embodiment of the present invention. (E) is a partial view of a piston included in a damper used in a spent fuel storage rack according to another embodiment of the present invention.

FIG. 4 (a) is a longitudinal sectional view of a damper used in the spent fuel storage rack according to the second embodiment of the present invention. (B) A longitudinal sectional view of a damper used in a spent fuel storage rack according to the second embodiment of the present invention, in the extended position.

FIG. 5 (a) is a longitudinal sectional view of a damper used in the spent fuel storage rack according to the third embodiment of the present invention. (B) A longitudinal sectional view of a damper used in a spent fuel storage rack according to the third embodiment of the present invention, in the extended position.

FIG. 6 is a longitudinal sectional view of a damper used in the spent fuel storage rack according to the fourth embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a damper used in a spent fuel storage rack according to a fifth embodiment of the present invention.

FIG. 8 is a diagram showing a state in which a storage rack according to the related art is installed.

[Explanation of symbols]

1. Spent fuel storage rack 2 ... Storage 3 ... Seismic isolation member 4 ... Skid 5 ... spent fuel storage pit 6 ... Damper 7 ... Storage bracket 8 ... Skid bracket 10 ... Rod side bracket 11 ... Piston rod 12 ... Casing side bracket 13 ... Casing 14 ... Piston 15 ... Through hole 16 ... Notch 17, 18 ... hole 19 ... Spring 20, 21 ... 3-way valve 22, 24 ... Piping 23 ... High-pressure fluid source 30, 31 ... Room 33 ... Opening

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Daisaku Okuno             1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo             No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard

Claims (7)

[Claims] 1. A spent fuel storage rack arranged in a storage pit filled with water, comprising: a base installed on the bottom of the storage pit; and a spent fuel stored on the base for storing spent fuel. Spent fuel storage rack, comprising: a storage unit for storing the fuel; and a damper that connects the base and the storage unit and is horizontally arranged. 2. A spent fuel storage rack arranged in a storage pit filled with water, wherein a base is installed on a bottom surface of the storage pit, and a spent fuel is provided on the base and stores spent fuel. And a damper that connects the base and the storage unit and is arranged in a horizontal direction. The damper is provided with a base joint for joining to the base. A cylindrical casing that is filled with a fluid and a piston assembly that is arranged in the casing are provided, and the piston assembly divides the internal space of the casing into two chambers and slides inside the casing. A movable piston and a piston rod provided with a reservoir joint for joining to the reservoir and connected to the piston; The lid extends through an opening formed in the casing and the piston allows the fluid to flow between the two chambers when the damper is longitudinally compressed or stretched. A spent fuel storage rack including a distribution means. 3. The spent fuel storage rack according to claim 2, wherein the circulation means is a hole provided in the piston. 4. The spent fuel storage rack according to claim 3, wherein the circulation means is a notch provided in an outer peripheral portion of the piston. 5. A spent fuel storage rack disposed in a storage pit filled with water, comprising: a base installed on the bottom of the storage pit; and a spent fuel stored on the base for storing spent fuel. And a damper that connects the base and the storage unit and is arranged in a horizontal direction. The damper is provided with a base joint for joining to the base. A cylindrical casing; and a piston assembly arranged in the casing, wherein the piston assembly divides the internal space of the casing into two chambers and is slidable in the casing. And a piston rod connected to the piston, the piston rod being connected to the piston, the piston rod being formed on the casing. A spent fuel storage rack extending through the formed opening, and a hole communicating with the storage pit is formed in each of the two chambers. 6. The spent fuel storage rack of claim 5, wherein a longitudinally extending spring is disposed in at least one of the two chambers. 7. The spent fuel storage rack according to claim 5, further comprising a high-pressure fluid source, the high-pressure fluid source being connected to each of the holes via a three-way valve.