JP2001235581A - Spent fuel storage cask support device - Google Patents

Abstract

(57) [Summary] [Problem] To prevent shaking, slipping, and falling of a storage cask during an earthquake. SOLUTION: Base units 22 are arranged at equal intervals in the circumferential direction on the upper surface of a storage facility mat 21 at equal intervals in accordance with the outer diameter of a concrete cask as a storage cask.
Buried in places. An anchor unit 23 is fixed to the outer periphery of the lower end of the concrete cask 17 so that the anchor unit 23 is arranged on each base unit 22 when the concrete cask 17 is installed. The base unit 22 is placed in contact with the anchor unit 23 from outside.
The stopper unit 24 is disposed on the upper side, and the anchor unit 23 and the base unit 2 are
2 are connected by bolts 25 and 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support device for supporting a spent fuel storage cask for storing spent fuel after being used in a nuclear power plant or the like so that it does not shake, slip, or fall. is there.

[0002]

2. Description of the Related Art Spent fuel generated in a nuclear power plant is sealed in a sealed container and strictly maintained for a long time in a required storage area until the radioactivity level falls below a reference value due to repeated natural decay. Need to be stored.

Conventionally, when storing spent fuel, as shown in FIG. 6, an example is shown in FIG. 6 in which a top end is removed from a cask pit 2 in a building 1 of a nuclear power plant with a top cover removed. The cylindrical canister 4 from which the lid and the shielding plug at the upper end have been removed is inserted into the cavity of the cylindrical metal cask 3 serving as the transport cask in an upright state. Inside, the spent fuel (aggregate) 6 collected in the spent fuel pit 5 is transferred by the refueling device 7 so that the shielding plug is attached to the upper end of the canister 4. The metal cask 3 in such a state is transported to the cleaning pit 9 using the auxiliary building crane 8, where the lid is welded to the upper end of the canister 4 so that the spent fuel 6 is transferred to the canister 4 As entrap the further, make the liquid penetrant lid welding portion of the canister 4,
A lid is attached to the upper end of the metal cask 3 to hermetically seal the inside. After that, the metal cask 3 is mounted laterally on a transport vehicle 12 that is waiting at the exit 11 of the building 1 and transported. It is designed to be carried into the receiving area 14 of the storage facility 10 by sea transportation by the ship 13 or by direct land transportation by the transportation vehicle 12.

In the receiving area 14, the canister 4 in the metal cask 3 is
Is refilled in a cylindrical concrete cask 17 as a storage cask set on a reversing device 16 and a lid 18 is placed thereon. Then, the concrete cask 17 is set up and transported to the storage area 19, and then the upright posture is set. Then, the concrete cask 17 is moved to a predetermined storage position by the air pallet 20 and stored on a storage facility mat (concrete) 21.

[0005]

However, in the storage system using the concrete cask 17 as a storage cask as described above, since the concrete cask 17 and the mat 21 are not fixed, the concrete cask 17 swings during the earthquake. There is a possibility that slipping, overturning, etc. may occur, and the seismic force is transmitted from the mat 21 to the concrete cask 17 as a non-linear input, so that the seismic design of the concrete cask 17 becomes severe.

Accordingly, the present invention is to provide a support apparatus for a spent fuel storage cask that can prevent the storage cask from shaking, slipping, and falling down during an earthquake, and can facilitate the seismic design of the storage cask. It is assumed that.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a storage facility mat on which a spent fuel storage cask is to be placed and supported by adjusting the outer diameter of the storage cask. A plurality of base units which are buried at equal intervals in the circumferential direction so that the upper surface matches the upper surface of the storage facility mat, and a lower end portion of the storage cask so as to be disposed on the base units arranged in the circumferential direction. An anchor unit fixed to the outer periphery and a stopper unit inserted from the outside so as to be in contact with the anchor unit and arranged on each of the base units, and the base unit, the anchor unit and the stopper unit are connected by bolts. Configuration.

When seismic force acts on the storage cask in the storage state, the force is transmitted from the anchor unit to the base unit via the stopper unit and received by the mat, so that the storage cask is prevented from shaking, slipping, falling, and the like.

Further, the anchor unit comprises an anchor sleeve fixed to the outer periphery of the lower end of the storage cask, and upper and lower flange plates horizontally mounted on the outer surface of the anchor sleeve, the position corresponding to the base unit. The stopper unit is inserted between the anchor unit and the base unit by notching the lower flange plate part so that the stopper unit can be placed, and the anchor unit and the base unit are easily fixed via the stopper unit. it can.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an embodiment of the present invention. A supporting apparatus for a spent fuel storage cask according to the present invention is a storage facility in which a concrete cask 17 as a storage cask is to be placed upright. The base units 22 buried in four places of the mat 21, that is, four places on the circumference corresponding to the outer diameter of the concrete cask 17, and the base units 22 arranged in a part in the circumferential direction are partially overlapped and arranged. Unit 23 fixed to the outer periphery of the lower end of the concrete cask 17 as described above, and the base unit 22 which is disposed at a position on each of the base units 22 so as to contact the anchor unit 23 from the radial outside of the concrete cask 17. Stopper unit 24 in which anchor unit 23 is connected by bolts 25 and 26
And a configuration consisting of

As shown in detail in FIGS. 3 and 4, each of the four base units 22 has a square base plate 27 having a required size, and a central portion of each base plate 27 has two front bolts. A hole 28 and two rear bolt holes 29 are provided side by side in the front-rear direction, and a front fixing nut 30 and a rear fixing are provided on the lower surface of the base plate 27 in accordance with the front bolt holes 28 and the rear bolt holes 29. Nuts 31 are fixedly provided, and shear connectors 32 extending in the left-right direction are attached to the front and rear sides of the lower surface of the base plate 27 so as to protrude therefrom. The upper surface of the mat 21 is mounted so that the upper surface of the base plate 27 is flush with the upper surface of the mat 21. It is to be embedded. In addition,
Reference numerals 30a and 31a denote covers for preventing concrete from entering the fixing nuts 30 and 31 when the base unit 22 is buried.

As shown in detail in FIGS. 2 and 3, the anchor unit 23 is provided at an outer periphery of a lower end portion of the concrete cask 17 and is fixed to the concrete cask 17 via a dowel 35. A ring-shaped upper flange plate 36 and a lower flange plate 3
7 is mounted so as to project horizontally, the upper and lower flange plates 36 and 37 are connected and fixed by web plates 38 arranged at required intervals in the circumferential direction, and the lower flange plate 37 is 90 ° in the circumferential direction. The interval position is cut into notches to form cavities 39 corresponding to the width of the base plate 27 of each base unit 22. Further, the upper flange plate 36 in a portion located above the cavities 39 is formed. , Front bolt hole 2 of base plate 27
8, two bolt holes 40 are provided.

Further, the stopper unit 24 is provided as shown in FIG.
As shown in detail in FIG. 5, an installation plate 41 having a size smaller than that of the base plate 27, and an upright standing contact with the front end of the installation plate 41 so as to come into contact with the outer peripheral surface of the anchor sleeve 34 from outside in the radial direction. A stopper plate 42 provided, and a backup rib plate 43 attached to the back side of the stopper plate 42, and the mounting plate 41 corresponds to the front bolt hole 28 and the rear bolt hole 29 of the base plate 27. The front bolt hole 44 and the rear bolt hole 45 are provided at two locations so that the bolt hole 40 of the upper flange plate 36, the intermediate nut 46, the front bolt hole 44 of the installation plate 41, and the front bolt of the base plate 27. Hole 2
8 through the long bolt 25 and the front fixing nut 30
And the intermediate nut 46 is tightened to the installation plate 41 side, and the installation plate 41 and the rear bolt holes 45 and 29 of the base plate 27 are screwed.
The anchor unit 23 and the base unit 22 can be connected to each other via the stopper unit 24 by inserting a short bolt 26 into the rear-side fixing nut 31 and screwing the bolt 26. It is.

When storing a concrete cask 17 as a storage cask, as shown in FIG. 6, the concrete cask 17 conveyed to the storage area 19 of the storage facility 10 is transferred to a storage position using an air pallet 20. Then, the mat 21 is placed on the base plate 27 of the base unit 22 embedded in the upper surface of the mat 21 at the storage position. At this time, as shown in FIG. 2, the four base units 22 are arranged at equal intervals in the circumferential direction, so that the four empty portions 39 formed in the anchor unit 23 at the lower end of the concrete cask 17 are removed. The position is adjusted to the position of the base plate 27.
That is, the bolt holes 40 of the upper flange plate 36 located above the cavities 39 of the anchor unit 23 are aligned with the positions of the front bolt holes 28 of the base plate 27.

After the above state, the anchor unit 2
The stopper units 24 are inserted into the respective base plates 27 using the cavities 39 of the third unit 3, and the stopper plate 42 at the front end is arranged so as to be in contact with the outer peripheral surface of the anchor sleeve 34 of the anchor unit 23. The front and rear bolt holes 44 and 45 of the base 41 are aligned with the front and rear bolt holes 28 and 29 of the base plate 27.

Thereafter, the long bolt 25 is inserted into the bolt hole 40 from above the upper flange plate 36 and screwed into the intermediate nut 46, and the bolt 25 is inserted into the front bolt hole 44 of the installation plate 41 and the base plate. 27
Through the front bolt hole 28 and screwed into the front fixing nut 30 to tighten it.
6 to the installation plate 41 side. Next, the short bolts 26 are sequentially inserted into the rear bolt holes 45 of the installation plate 41 and the rear bolt holes 29 of the base plate 27.
And screwed into the rear fixing nut 31 to tighten it.

In this way, the anchor unit 23 and the base unit 22 can be connected by the bolts 25 and 26 via the stopper unit 24, so that the storage position of the concrete cask 17 can be fixed and supported.

In the storage state of the concrete cask 17, the horizontal load and the vertical load when an earthquake occurs are transmitted from the anchor unit 23 to the mat 21 via the stopper unit 24 and the base unit 22. It is possible to prevent the cask 17 from shaking, slipping, falling, and the like. That is, the horizontal load acting on the concrete cask 17 is mainly transmitted to the shear connector 32 of the base unit 22 as a shear load, and is received by being transmitted from the shear connector 32 to the mat 21. On the other hand, the vertical load acting on the concrete cask 17 is, as a tensile load,
Mainly transmitted to the dowel 33 of the base unit 22,
It is received by being transmitted from the dowel 33 to the mat 21. Therefore, in the seismic analysis of the concrete cask 17, the seismic force from the mat 21 can be used as a linear input, so that the seismic design of the concrete cask 17 can be facilitated.

In the above, each unit 22, 23, 2
Reference numeral 4 denotes a connection structure using bolts 25 and 26, and the base plate 27 of the base unit 22 is
The concrete cask 17 should be easily moved even if it is necessary to carry out the concrete cask 17 for any reason, such as in the event of an abnormality, because it is made so as to be flush with 1 and has no steps or protrusions. And quick response is possible.

The concrete cask 17 during storage is
Assuming that seismic force is input from all directions, at least four support positions at the lower end are required at the front, rear, left and right.
And the like are shown in four places, but it is needless to say that the number can be arbitrarily increased and various changes can be made without departing from the scope of the present invention.

[0022]

As described above, according to the apparatus for supporting a spent fuel storage cask of the present invention, the storage cask is placed on the upper surface of the storage facility mat where the spent fuel storage cask is to be placed and supported. A plurality of base units which are buried at equal intervals in the circumferential direction in accordance with the outer diameter so that the upper surface matches the upper surface of the storage facility mat, and the storage unit is arranged on the base units arranged in the circumferential direction. An anchor unit fixed to the outer periphery of the lower end of the cask, and a stopper unit inserted from the outside so as to be in contact with the anchor unit and arranged on each of the base units, wherein the base unit, the anchor unit and the stopper unit are bolted together. The seismic force acting on the storage cask is transferred from the anchor unit to the stopper unit. Can be transmitted to the base unit through the mat and transmitted to the mat, thereby preventing the storage cask from shaking, slipping, overturning, etc., and the seismic force is transmitted to the storage cask as a linear input. Therefore, the seismic design of the storage cask can be made easier, and furthermore, the upper surface of the base unit and the upper surface of the mat are formed flush with each other, which in combination with the bolt connection structure enables We can deal with discharge work,
Still further, the anchor unit is constituted by an anchor sleeve fixed to the outer periphery of the lower end portion of the storage cask, and upper and lower flange plates horizontally attached to the outer surface of the anchor sleeve, and a lower portion corresponding to the base unit is provided. Since the stopper unit is placed by notching the flange plate part, the lower flange plate of the anchor unit is cut out at the position corresponding to the base unit, and the stopper unit can be easily set in this part, An excellent effect such as that the anchor unit and the base unit can be fixed via the stopper unit is exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of a spent fuel storage cask support device of the present invention.

FIG. 2 is a view in the direction of arrows AA in FIG. 1;

FIG. 3 is an enlarged view of a portion B in FIG. 1;

FIG. 4 is a plan view of the base unit as viewed from the direction of arrows CC in FIG. 3;

FIG. 5 is a plan view of the stopper unit as viewed from a direction DD in FIG. 3;

FIG. 6 is a schematic diagram showing an example of a handling flow when storing spent fuel.

[Explanation of symbols]

 10 Storage Facility 17 Concrete Cask (Storage Cask) 21 Mat 22 Base Unit 23 Anchor Unit 24 Stopper Unit 25,26 Bolt 34 Anchor Sleeve 36 Upper Flange Plate 37 Lower Flange Plate

Claims (2)

[Claims] An upper surface of a storage facility mat on which a spent fuel storage cask is to be placed and supported is buried at equal intervals in a circumferential direction in accordance with an outer diameter of the storage cask, and an upper surface of the storage facility mat is provided. A plurality of base units adapted to coincide with the upper surface, an anchor unit fixed to the outer periphery of the lower end of the storage cask so as to be arranged on the base units arranged in the circumferential direction, and an outer unit in contact with the anchor unit And a stopper unit to be inserted from one side and disposed on each of the base units, wherein the base unit, the anchor unit, and the stopper unit are connected by bolts. Support device. 2. An anchor unit comprising: an anchor sleeve fixed to an outer periphery of a lower end portion of a storage cask; and upper and lower flange plates mounted horizontally on an outer surface of the anchor sleeve, the position corresponding to the base unit. 2. A supporting apparatus for a spent fuel storage cask according to claim 1, wherein the stopper unit can be placed by notching a portion of the lower flange plate.