JP2002148386A - Storage system, and storage container and conveying apparatus for use therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage system allowing lowering of the story height of a storage housing and enabling a storage container to be easily and safely positioned, and a storage container and a conveying apparatus for use therein. SOLUTION: The storage housing of the storage system has a loading/ unloading area for loading and unloading the storage container, and a storage area for storing a number of storage containers. The storage container includes a metallic cask 80 and a concrete cask, each with a pallet mounting portion 92 at its bottom on which an air pallet 72 can be mounted. The storage area has an installation floor on which the metallic cask and the concrete cask can be placed as necessary. The storage system includes a conveying truck 100 traveling within the storage housing and having the air pallets 72. The conveying truck conveys the air pallet mounted on the pallet mounting portion of certain of the storage containers in a floated state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage system for storing and managing storage containers storing radioactive materials, a storage container used in the storage system, and a container transport device.

[0002]

2. Description of the Related Art Highly radioactive materials typified by spent fuel of a nuclear reactor are dismantled and reprocessed in order to collect useful materials such as plutonium which can be used again as fuel. These spent fuels are stored in a sealed state until reprocessing. As a method for storing such a highly radioactive substance, a dry method using a storage container such as a cask has attracted attention. There are various types of casks used for the dry method, and concrete casks or metal casks that shield spent fuel with a concrete structure are known. These casks include a cylindrical container body whose top and bottom are closed, and in the case of a concrete cask, a cylindrical metal hermetic container in which spent fuel is sealed in the container body,
A so-called canister is stored, and in the case of a metal cask, spent fuel is directly enclosed.

[0003] As such a radioactive substance, for example, spent fuel of a nuclear reactor is usually treated by the following steps. First, spent fuel is stored and sealed in a canister in a storage pool or the like of a nuclear power plant. Then, the canister is stored in a transport container, a so-called transport cask, and then transported to a storage facility by a trailer or the like.
In the storage facility, the transported canister is pulled out of the transport cask and loaded into a concrete cask prepared in advance. Then, the canister is stored in these casks for a predetermined period of time. Further, after being stored for a predetermined period, the canister is taken out of the concrete cask, loaded again into the transport cask, and transported to the reprocessing facility by a trailer or the like. A metal cask for both transportation and storage is also provided.

[0004]

In a storage facility for storing casks as described above, a storage building for arranging a large number of casks is provided. Conventionally, in such a storage building, a method of loading and unloading a cask to and from a trailer or the like by a ceiling crane installed on the ceiling portion, and transporting the cask to a predetermined position by the overhead crane has been adopted. ing.

However, when such an overhead crane is used, the floor height of the storage building increases due to the necessity of securing the traveling and lifting area of the overhead crane, and the storage building becomes large in comparison with the storage capacity of the cask. easy.

In general, concrete casks and metal casks are very heavy, about 100 to 200 tons. In order to lift and transport these casks with an overhead crane, a large overhead crane is required. There is also a risk that the cask may fall.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce the size of a storage building, in particular, to lower the floor height of a building, and to easily and safely move a storage container to a desired position. An object of the present invention is to provide a storage system that can be arranged, and a storage container and a transport device used in the storage system.

[0008]

In order to achieve the above object, a storage system according to the present invention comprises a storage system for storing a storage container containing a radioactive substance,
It has a storage building having a loading / unloading area for loading and unloading storage containers and a storage area for storing a large number of storage containers, and the storage containers each have a pallet mounting portion at the bottom portion on which an air pallet can be mounted. The storage area has an installation floor on which the metal cask and the concrete cask can be arbitrarily placed, and furthermore, is self-propelled in the storage building and is mounted on the pallet mounting section. And a container conveying device for selectively conveying the metal cask and the concrete cask by an air pallet.

According to the storage system configured as described above, each of the concrete cask and the metal cask to be stored has a pallet mounting portion at the bottom. And, by the transport device that runs in the storage building,
By using an air pallet mounted on a pallet mounting portion of an arbitrary cask and transporting the cask in a floating state, a heavy cask can be easily transported to an arbitrary location. At this time, there is no danger of dropping and the like, and the cask can be safely transported as compared with the case where the cask is suspended and transported by an overhead crane or the like. Also, there is no need to provide a large overhead crane on the ceiling of the storage building, so that the floor height of the storage building can be reduced and the entire building can be reduced in size.

A storage container according to the present invention is a storage container used for a storage system for storing a radioactive substance, which is attached to a substantially cylindrical container main body capable of storing the radioactive substance, and a bottom of the container main body, It is characterized by comprising a substantially plate-shaped mount having a plane area larger than the bottom, and a pallet mounting portion formed on the mount and capable of mounting an air pallet between the mount and an installation surface. And

[0011] According to the storage container having the above structure, the base is provided at the bottom of the container body, so that the bottom area is increased.
The whole container can be stably placed. Also,
By mounting the air pallet on the pallet mounting portion provided on the gantry, the storage container can be easily transported using the air pallet.

[0012] Further, a transport device according to the present invention is a container transport device for transporting a storage container containing a radioactive substance, wherein the transport vehicle automatically or manually travels, and a bottom surface of the storage container attached to the transport vehicle. An air pallet that can be mounted between the air pallet and an installation surface, a gripper that grips the storage container on which the air pallet is mounted, and an air supply unit that supplies air to the air diaphragm of the air pallet. It is characterized by: According to the transport device having such a configuration, a heavy storage container can be easily and safely transported to an arbitrary place using the air pallet.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A storage container storage system according to an embodiment of the present invention will be described below in detail with reference to the drawings. As shown in FIGS. 1 to 3, the storage system includes, for example, a storage building 10 formed in an elongated rectangular flat, a control building 12 for controlling the temperature, humidity, operation of various devices, and the like in the storage building. It has. The storage building 10 includes a carry-in / carry-out area 14 extending across the center in the longitudinal direction at right angles, and storage areas 16 formed on both sides of the carry-in / carry-out area 14, respectively.

The storage building 10 is formed entirely of concrete walls and includes a bottom wall 20, a ceiling wall 22, and a plurality of side walls 24. In each storage area 16, an exhaust tower 2 having a large number of exhaust ports 25 at the center of the ceiling wall 22.
6 are provided and extend along the long axis direction. In each storage area 16, a large number of intake ports 27 are provided on both side edges in the longitudinal direction of the ceiling wall 22.
A partition 30 extending from the ceiling wall 22 to the vicinity of the bottom wall 20 is provided in the vicinity of the intake port 27, and the inflow passage 3 following the intake port is provided.
3 is formed.

In the carry-in / out area 14, a transport container sent from a nuclear power plant or the like, that is, a transport cask containing a canister as a sealed container in which radioactive materials are sealed, is loaded, and the storage building 10 is loaded. Of the transport cask sent to the reprocessing facility from the airport. The loading / unloading area 14 includes a transport cask 31.
A temporary storage area 32, a temporary storage area 34 of a metal cask or a concrete cask described later as a storage container, and a refilling device 36 for refilling the canister between the storage container and the transport cask. ing. The loading / unloading area 14 is provided on the side wall 24 of the storage building 10.
A loading / unloading port 37 is formed, and a trailer or the like loaded with the transport cask 31 and the like can enter and leave the loading / unloading area through the loading / unloading port 37.

Each storage area 16 has a flat installation floor 40. On the installation floor 40 of each storage area 16, a large number of metal casks and concrete casks can be installed at arbitrary positions.

Next, a metal cask and a concrete cask as storage containers used in the present storage system will be described. First, a concrete cask will be described. As shown in FIG. 4, the concrete cask 50 includes a container body 52 formed of concrete and functioning as a shielding structure.
The canister 54 is stored. The canister 54 is formed of a metal and has a cylindrical closed container whose both ends are closed. In the closed container, the spent fuel assembly 5 is supported by a basket 56.
8 are enclosed. These spent fuel assemblies 58 are, for example, spent fuel of a nuclear reactor, and contain radioactive materials that generate heat due to decay heat and generate radiation.

The container body 52 of the concrete cask 50
Has a cylindrical shape with a closed bottom, and is formed to have a height of about 6 m and a diameter of about 4 m, for example, and a concrete wall thickness of about 1 m. Container body 52
Is closed by a concrete lid 60 whose outer surface is covered with a carbon steel plate. This lid 6
Numeral 0 is bolted to the upper end of the container body 52 by a plurality of bolts 61. In addition, a reinforcing bar (not shown) is provided in the concrete wall of the container body 52.

In the container main body 52, a cylindrical storage portion 62 is defined by the inner peripheral surface of the container main body and the lid 60. By removing the lid 60, the canister 54 can be put in and out of the storage section 62. The canister 54 is mounted on a plurality of ribs formed on the bottom surface of the storage section 62 and
And are arranged coaxially. A cylindrical liner 70 made of a metal such as carbon steel is provided on the inner peripheral surface of the container body 52. The canister 54 is housed in the housing 62 with a predetermined gap between the outer peripheral surface and the inner peripheral surface of the container body 52.

The clearance between the outer peripheral surface of the canister 54 and the inner peripheral surface of the container main body 52 forms a cooling air passage 64 through which cooling air flows. This cooling air passage 64
Is formed over the entire outer peripheral surface of the canister 54 and over the entire axial length of the outer peripheral surface.

A plurality of, for example, four intake ports 66 are formed at the bottom of the container body 52, and four exhaust ports 68 are similarly formed at the upper end of the container body 52. 64. Four intake ports 66
Are provided at equal intervals along the circumferential direction of the container body 52 and open to the outer peripheral surface of the bottom of the container body 52. The exhaust ports 68 are provided at equal intervals along the circumferential direction of the container main body 52 and open to the outer peripheral surface of the upper end portion of the container main body 52.

The intake port 66, the exhaust port 68, and the cooling air passage 64 constitute a heat removal section for removing heat from the concrete cask 50 by natural circulation cooling of air.
That is, the outside air as cooling air introduced into the container main body 52 from the intake port 66 flows around the canister 54 through the cooling air flow path 64, and during that time, removes heat and cools the canister 54 and the container main body 52. Then, the cooling air heated and heated by the heat from the canister 54 is
The gas is exhausted from the exhaust port 68 to the outside of the container body 52.

Further, a plurality of legs 5 are provided on the bottom of the container body 52.
The pallet mounting portion 74 is provided between the legs, and a pallet mounting portion 74 into which an air pallet 72 described later can be inserted and mounted is formed.

The refilling operation of the canister 54 for the concrete cask 50 thus constructed is performed by the following steps using the refilling device 36. That is, as shown in FIG. 1, the refilling device 36 installed in the loading / unloading area 14 is provided with a container placing portion 94 for placing the concrete cask 50 and the transport cask 31 side by side.
And a gripping mechanism 96 that is movably provided above the container mounting portion and grips and transports the canister.

The transport cask 31 and the empty concrete cask 50 transported by a trailer or the like
They are placed side by side on the container placement section 94. The transport cask 31 houses a canister 54 in which spent fuel is sealed in a nuclear power plant or the like. And the gripping mechanism 9
6 pulls out the canister 54 from the transport cask 31 and holds it, then moves onto the concrete cask 50, and puts the canister into the concrete cask storage section 5
Load into 2. Thereafter, by closing the lid 60 of the concrete cask 50, the loading of the canister 54 is completed.

When the canister 54 having been stored for a predetermined period is carried out, the canister 54 is taken out of the concrete cask 50 and loaded into the transport cask 31 by the refilling device 36 in the reverse process. Then, the transport cask 31 is transported to a reprocessing facility by a trailer or the like.

Next, the metal cask will be described. As shown in FIG. 5 and FIG. 6A, in the present embodiment, the metal cask 80 is configured as a metal cask for both transportation and storage. That is, the metal cask 80
Is a substantially cylindrical container body 82 formed of a metal such as stainless steel or carbon steel, and an outer cylinder which is arranged coaxially with the container body with a gap outside the container body and forms a cask outer surface. 83, and a resin layer 84 provided between the container body 82 and the outer cylinder 83. The resin layer 84 is formed of, for example, a polymer material containing hydrogen and functions as a neutron shield.

The lower end opening of the container body 82 is closed by a bottom plate welded to the lower end of the container body. The upper end opening of the container body 82 has a primary lid (not shown),
It is closed by the secondary lid 85 placed on the primary lid. The primary lid and the secondary lid 85 are formed of a metal such as stainless steel or carbon steel.

A large number of spent fuel assemblies 87 are accommodated in the container main body 82 thus configured while being supported by the basket 86. The basket 86 is made of a composite material of boron (B) and aluminum. The container body 82 is filled with helium gas in a negative pressure state.

When transporting the metal cask 80 having the above configuration, a shock absorber (not shown) is attached to an upper end and a lower end of the container body 82 so as to absorb a shock during transportation. However, during storage, the pair of shock absorbers are removed from the container body 82, and a pallet 88 functioning as a gantry is detachably attached to the lower end of the container body 82 instead.

More specifically, as shown in FIGS. 5 and 6, the pallet 88 is formed in a square shape having sides substantially equal to the outer diameter of the outer cylinder 83. At the center, the container body 82 is
And is located concentrically with the container body.

At the center and both side edges of the bottom surface of the pallet 88, elongated legs 90 extending parallel to each other are integrally formed. An air pallet 72, which is open to the bottom side and is described later, is formed by the gap between the legs 90.
A pallet mounting portion 92 capable of mounting the pallet is formed.

In the case of the metal cask 80 for both transportation and storage constructed as described above, after being transported from a nuclear power plant or the like, it is stored as it is without replacing the internal spent fuel. However, as described above, before storage, the shock absorber is removed and the pallet 88 is mounted. The metal cask is not limited to the one used for both transportation and storage, and a metal cask dedicated to storage may be used. In this case, like the concrete cask 50,
The canister is refilled and used by the refilling device 36.

On the other hand, the present storage system serves as a container transporting device for selectively transporting the concrete cask 50 and the metal cask 80 in the storage building 10, and a transport vehicle that can travel freely in the loading / unloading area 14 and the storage area 16. 100 is provided.

As shown in FIGS. 7 and 8, the transport vehicle 100 includes a truck 102 capable of self-propelling in the storage building 10 and on the road. The truck has four wheels 104 and drives these wheels. (Not shown). Further, an air compressor 112 functioning as an air supply unit is provided in the carriage 102.
The cart 102 has a driver's seat 106 or an operation pendant switch (not shown), and can be driven manually by an operator. Note that the cart 102 is covered with a shielding material to prevent the operator from being exposed to light.

A pair of air pallets 72 which can be inserted into the pallet mounting portion 74 of the concrete cask 50 and the pallet mounting portion 92 of the metal cask 80 are mounted at the front end of the carriage 102 via a driving portion 108. I have. These air pallets 72 are formed in an elongated rectangular shape, and protrude forward from the drive unit 108 along the floor surface. Each air pallet 72 has two
It has two circular air diaphragms 110. These air diaphragms 110 are connected to an air compressor 112 provided in the carriage 102.

The pair of air pallets 72 are driven by a driving unit 108.
Thus, the distances can be adjusted by moving in directions of coming and going with each other, and each can be driven up and down. As will be described later, each air pallet 72 is disconnected from the drive unit 108 in a state where the air pallet 72 is mounted on the pallet mounting portions 74 and 92 of the concrete cask 50 or the metal cask 80, and the degree of freedom in at least the vertical direction is reduced. It is configured to have.

Further, the transport vehicle 100 is provided with a pair of gripping arms 114 extending forward from the drive unit 108, and these gripping arms grip the cask on which the air pallet 72 is mounted from both sides. Functions as a grip.

When the concrete cask 50 is transported by the transport vehicle 100 having the above-described configuration, as shown in FIGS.
2 is inserted into the pallet mounting portion 74 of the concrete cask 50, and is disposed between the bottom surface and the floor surface of the concrete cask. In this state, after the connection of each air pallet 72 is released, the air diaphragm 112
Supply air to 10. Thereby, each air diaphragm 110 is inflated, and air is exhausted from a number of exhaust holes of the air diaphragm toward the floor. As a result, an air bearing is formed between each of the air diaphragms 110 and the floor, and the concrete cask 50 is maintained in a state of slightly rising from the floor.

Further, the concrete cask 5 in a floating state
0 is gripped from both sides by a pair of gripping arms 114,
The concrete cask and the carriage 102 are connected. By moving the carriage 102 in this state, the concrete cask 50 can be transported to an arbitrary position.

After the concrete cask 50 is conveyed to the predetermined position, the gripping of the concrete cask 50 by the gripping arm 114 is released, and the supply of air from the air compressor 112 is stopped and the concrete cask 50 is landed. Can be placed on Subsequently, after connecting each air pallet 72 to the driving unit 108,
The transport operation is completed by retracting the carriage 102 and pulling out the air pallet 72 from the pallet mounting section 74 of the concrete cask 50.

When the metal cask 80 is transported by the transport vehicle 100, the same operation as described above is performed. However,
In this case, a pair of air pallets 7 is
After adjusting the interval between the two to match the pallet mounting portion 92 of the metal cask 80, these air pallets 72 are inserted and mounted in the pallet mounting portion 94.

In the above-described embodiment, the transport vehicle 1
00 is a manual type driven by an operator,
As shown in FIG. 9, this carrier may be configured as an automatic operation type or a remote operation type. Such a transport vehicle 10
0 is the same as the carrier described above except for the driver's seat, and includes a cart 102 having wheels 104 and an air compressor 11.
2, a drive unit 108, a pair of air pallets 72, and a pair of gripping arms 114.

According to the storage system configured as described above, the concrete cask 50 and the metal cask 80 to be stored are both provided at the bottom thereof with the pallet mounting portion 7.
4 and 92 are provided. Then, an air pallet 72 provided on a transport vehicle 100 that is self-propelled in the storage building 10 is mounted on a pallet mounting portion 74 or 92 of an arbitrary cask, and the air pallet is transported in a state where the cask is floated. The heavy cask can be easily transported to any place. At this time, compared with the case where the cask is suspended and transported by an overhead crane,
There is no danger of falling or the like, and the cask can be transported safely. Therefore, the concrete cask 50 and the metal cask 80 can be freely arranged and stored in a mixed state.

According to such a configuration, it is not necessary to provide a large overhead crane on the ceiling of the storage building 10, so that the floor height of the storage building can be reduced, and the entire building can be reduced in size. Furthermore, by mounting the pallet 88 on the bottom of the metal cask 80, the bottom area of the metal cask is increased, and the metal cask can be stably placed.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the pallet 88 attached to the metal cask is provided with the pallet mounting portion 92, and the air pallet 72 of the transport vehicle 100 is mounted on the pallet mounting portion and transported. The pallet 88 itself may be provided with the air pallet 72 attached to the pallet mounting portion 92. In this case, the transport vehicle 100 has a configuration in which the air pallets 72 are omitted. When transporting the metal cask 80, the transport vehicle 1
In the state 00, the air compressor 112 is connected to the air pallet 72 of the metal cask 80 to supply air, and the metal cask is transported while being gripped by the gripping arm 114. Also, in such a configuration, the same operation and effect as those of the above-described embodiment can be obtained.

[0047]

As described above in detail, according to the present invention, it is possible to reduce the size of the storage building, in particular, to lower the building floor height, and to easily and safely arrange the storage container at a desired position. Storage system, and a storage container and a transport device used for the storage system can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an entire storage system and a part of a storage building according to an embodiment of the present invention.

FIG. 2 is a plan view showing the storage building partially broken away.

FIG. 3 is a cross-sectional view of the storage building along a line AA and a line BB in FIG. 1;

FIG. 4 is a perspective view showing a concrete cask used in the storage system, partially broken away.

FIG. 5 is a perspective view showing a metal cask used in the storage system, partially cut away.

FIG. 6 is a sectional view of the metal cask taken along a line CC and a line DD in FIG. 5;

FIG. 7 is a perspective view showing a transport vehicle in the storage system.

FIG. 8 is a perspective view showing a state where the concrete cask is transported by the transport vehicle.

FIG. 9 is a perspective view showing a state in which the metal cask is transported by a transport vehicle according to a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Storage building 14 ... Loading / unloading area 16 ... Storage area 36 ... Refilling apparatus 40 ... Installation floor 50 ... Concrete cax 52 ... Container main body 54 ... Canister 58 ... Spent fuel assembly 62 ... Storage part 72 ... Air pallet 74 ... Pallet mounting section 80 ... Metal cask 82 ... Container main body 88 ... Pallet 92 ... Pallet mounting section 100 ... Carriage vehicle 102 ... Bogie 110 ... Air diaphragm 112 ... Air compressor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G21F 9/36 531 G21C 19/06 S G21F 5/00 TF term (reference) 3F022 BB03 CC05 EE02 EE05 LL05 LL12 MM01 3F333 AA01 AB20 AE02 AE23 AE38 BA01

Claims (9)

[Claims] 1. A storage system for storing storage containers containing radioactive materials, comprising: a storage building having a loading / unloading area for loading / unloading storage containers and a storage area for storing a large number of storage containers. The storage container includes a metal cask and a concrete cask each having a pallet mounting portion capable of mounting an air pallet at the bottom thereof, and the storage area has an installation floor on which the metal cask and the concrete cask can be arbitrarily placed. Further, a storage device, comprising: a container transporting device that travels by itself in the storage building and selectively transports the metal cask and the concrete cask by an air pallet mounted on the pallet mounting portion. Container storage system. 2. The metal cask according to claim 1, wherein said metal cask is attached to a cylindrical metal container main body in which a radioactive substance is sealed, and is attached to a bottom of said metal container main body. The storage system according to claim 1, further comprising a base having a portion. 3. The concrete cask has a cylindrical concrete container main body for accommodating an airtight container filled with a radioactive substance, and the concrete container main body has the pallet mounting portion provided at the bottom thereof. The storage system for a storage container according to claim 1, wherein: 4. The container transport device according to claim 1, wherein the trolley travels automatically or manually, an air pallet attached to the trolley and mountable on a pallet mounting portion of the metal cask and the concrete cask; 4. The air supply device according to claim 1, further comprising: a gripper for gripping the metal cask or the concrete cask mounted thereon; and an air supply unit for supplying air to an air diaphragm of the air pallet. A storage system for a storage container according to claim 1. 5. A refilling device provided in the carry-in / out area and refilling a closed container filled with a radioactive substance between the transport container conveyed to the carry-in / out area and the concrete cask. The storage system of a storage container according to any one of claims 1 to 4, wherein: 6. A storage container used for a storage system for storing a radioactive substance, comprising: a substantially cylindrical container main body capable of storing the radioactive substance; and a flat plate attached to the bottom of the container main body and larger than the bottom. A storage container comprising: a substantially plate-shaped mount having an area; and a pallet mounting portion formed on the mount and capable of mounting an air pallet between the mount and an installation surface. 7. A container transporting device for transporting a storage container containing a radioactive substance, wherein the trolley runs automatically or manually, and is mounted between the bottom surface and the installation surface of the storage container. A transfer device comprising: a possible air pallet; a gripper for gripping the storage container on which the air pallet is mounted; and an air supply unit for supplying air to the air diaphragm of the air pallet. 8. The transport apparatus according to claim 7, wherein the carriage has a driver's seat on which an operator can ride, and is covered with a shielding material for shielding radioactive substances. 9. The transfer device according to claim 7, wherein the air pallet is formed in a plate shape protruding forward from the carriage along the installation surface of the storage container.