JPH09329698A - Dual-purpose facility for storing and disposing of high-level radioactive waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to use a facility both for storage and for disposal of radioactive wastes, by suspending and supporting vitrified solids in a penetration hole so that the facility can have an air passage between an upper air exhaust space and the inner face of the part between lower air supply spaces in the penetration hole. SOLUTION: A vitrified solid 48 is inserted into a thick-wall housing tube 61 used also as an overpack placed in bedrock 39 about 500 to 1,000m below the ground so as to remove the heat of the vitrified soiled 48 by passing air outside the housing tube 61 used also as the overpack. After the heat of the vitrified solid 48 is removed, the housing tube 61 used also as the overpack is backfilled with earth and sand just as it is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for storage and disposal of high-level radioactive waste.

[0002]

2. Description of the Related Art Recently, spent nuclear fuel generated from a nuclear power plant or the like is mixed with molten glass and poured into a cylindrical metal container called a canister and solidified together with the glass to form a vitrified body. It has been considered to store the vitrified substance in a storage facility.

4 to 6 are longitudinal sectional views showing an example of a vitrified material storage facility.

In the figure, 1 is a building made of reinforced concrete built on the ground, and in the basement of this building 1, a plurality of storage tubes 3 for storing a vitrified body 2 in which spent nuclear fuel and the like are enclosed. A pit 4 is formed so as to be supported in a suspended state.

An outside air introduction passage 5 extending upward from a lower portion of the pit 4 is formed, and an outside air introduction port 6 for communicating the outside air introduction passage 5 with the outside is formed on one side of the building 1.
An air outlet channel 7 extending upward from the upper part of the pit 4 is formed, and an air outlet 8 communicating the air outlet channel 7 with the outside is formed on the other side of the building 1.

Further, a plurality of vitrified material insertion openings 1 that communicate with the pit 4 almost vertically are provided on the floor 9 on the ground floor of the building 1.
Numerals 0 are respectively opened at positions corresponding to the storage tubes 3. The vitrified body insertion port 10 is provided with a shielding plug 11
It can be closed by an airtight lid 12.

The storage tube 3 has a cylindrical shape with its lower end closed, and a plurality of vitrified bodies 2 can be stored in multiple stages in the vertical direction.

The storage tube 3 is embedded in the floor surface 9 of the ground floor which forms the ceiling of the pit 4 of the building 1 so that the upper end communicates with the above-mentioned vitrified body insertion port 10.
The portion below the portion embedded in the ceiling portion of the storage tube 3 is located inside the pit 4.

A ventilation pipe 14 having an air passage 13 is externally fitted to the outer periphery of a portion of the storage pipe 3 located inside the pit 4, and the ventilation pipe 14 is provided at a lower end thereof. Are supported by the stay 15 so as to be concentric with respect to the storage tube 3, and the outer periphery of the ventilation tube 14 is connected to each other by using a support frame 16, and the inner surface of the pit 4 is Is fixed.

Further, a plate-like lower plenum forming plate 17 is provided over the entire surface between the outer periphery near the lower part of the ventilation pipe 14 and the inner surface of the pit 4, and the pit 4 is formed near the lower part of the ventilation pipe 14. It is shut up and down.

A plate-like upper plenum forming plate 18 is provided over the entire surface between the outer periphery near the upper part of the ventilation pipe 14 and the inner surface of the pit 4, and the pit 4 is formed near the upper part of the ventilation pipe 14. It is shut up and down.

The lower end of the ventilation pipe 14 is located at the lower plenum forming plate 1.
7, and the upper end of the ventilation pipe 14 is opened at the upper part of the upper plenum forming plate 18.

In FIG. 1, reference numeral 19 denotes a transport crane for transporting the vitrified material 2 to each of the vitrified material insertion ports 10 and storing it in the storage tube 3.

In the vitrified solid storage facility shown in FIGS. 4 to 6, the air introduced from the outside through the outside air introduction port 6 descends through the outside air introduction passage 5 and is used as cooling air in the lower part of the pit 4. Be flowed in.

Since the entire surface between the outer periphery of the ventilation pipe 14 and the inner surface of the pit 4 is shut off by the lower plenum forming plate 17 and the upper plenum forming plate 18, the pit 4
Flows into the air passage 13 from the lower end of each ventilation tube 14 and removes the heat of decay of the vitrified body 2 stored in the storage tube 3 while moving up the air passage 13.

The air heated by removing the heat from the vitrified body 2 rises through the ventilation pipe 14, and from the upper end of the ventilation pipe 14, the pit 4
To the upper part of the air outlet, and furthermore, the air outlet channel 7 and the air outlet 8
Through the building 1 to the outside.

The flow of air in the vitrified storage facility is of the natural ventilation type utilizing natural convection of air due to the decay heat of the vitrified material 2 and the forced ventilation type utilizing a blower or the like. There is.

When the decay heat of the spent nuclear fuel is removed from the vitrified body 2 in this manner, so-called geological disposal is performed in which the spent nuclear fuel, which is not expected to be reused, is buried in the underground rock about 500 m to 1000 m from the surface. The spent nuclear fuel will be stably stored in the underground rock for a long period of several years.

As shown in FIG. 7, the above-mentioned underground disposal facility excavates a vertical hole 22 from the ground 20 to the underground rock 21 at a position of about 500 m to 1000 m underground, and the vertical rock 22 is drilled in the underground rock 21. A container housing space 23 that extends from the lower end of the container 22 in a substantially horizontal direction is formed, and the floor surface 2 of the container housing space 23 is formed.
A plurality of cylindrical container accommodating holes 25 are formed in 4 to form an underground disposal site 26.

Then, a building 27 is installed on the ground 20 so as to surround the vertical hole 22, and a winding device 28 such as a winch is provided in the building 27, and a wire rope 29 wound by the winding device 28 is provided. The tip end is connected to an elevator 30 that is vertically movable in the vertical hole 22 to form an elevator mechanism 31.

The ceiling portion 32 of the container accommodating space 23
Although not shown in detail, a metal container called a final disposal overpack 33 that stores the vitrified body 2 in each container accommodation hole 25 is moved by moving in the front-rear direction or the left-right direction. An inserting device 34 such as an overhead crane that can be inserted is provided, and a delivery device such as a carrier truck 35 that can deliver the overpack 33 for final disposal is provided between the elevating mechanism 31 and the insertion device 34.

Further, in the container receiving hole 25, a block 36 made of a cushioning material containing bentonite as a main component is arranged in order to separate the underground rock 21 and the final disposal overpack 33.

In the figure, numeral 37 is a buffer hole cover made of a cushioning material for closing the container hole 25.

Then, the vitrified body 2 obtained by encapsulating and solidifying the spent nuclear fuel in glass is housed on the ground in a metal container called an overpack 33 for final disposal.

When the final disposal overpack 33 is formed in this way, as shown in FIG. 7, the final disposal overpack 33 is placed on the elevator 30 of the elevating mechanism 31, and the winding device 28 such as a winch is rewound. About 500m to 1000m underground from the building 27 on the ground 20 through the vertical hole 22
It is sent to the container accommodating space 23 of the underground disposal site 26 that is formed in the underground rock 21 at a certain position and extends in the horizontal direction.

Then, the final disposal overpack 33 sent to the container accommodating space 23 is received by a delivery device such as a transport carriage 35, and is delivered from the transport carriage 35 to an insertion device 34 such as an overhead crane.

Then, the insertion device 34 such as an overhead crane, which has received the final disposal overpack 33, is moved in the front-rear direction, the left-right direction, or the like to convey it to the target container accommodation hole 25, and the container accommodation hole 25. The overpack 33 for final disposal is inserted into.

Here, a block 36 made of a cushioning material containing bentonite as a main component is arranged in advance inside the container accommodation hole 25, and the final disposal overpack 33 inserted into the container accommodation hole 25. Is separated from the underground rock 21, and is stored.

When the final disposal overpack 33 is inserted into the container housing hole 25, the container housing hole 25 is covered with a housing hole lid 37 so that the housing hole lid 37 is flush with the floor 24 of the container housing space 23. To be

[0030]

However, as described above, since the storage facility and the disposal facility for high-level radioactive waste are provided separately, the construction cost of the facility becomes high and There is a problem that handling such as transportation of high-level radioactive waste becomes difficult.

In view of the above situation, it is an object of the present invention to provide a high-level radioactive waste storage / disposal facility which can be used both as a storage facility and a disposal facility.

[0032]

SUMMARY OF THE INVENTION The present invention is about 500 underground.
In the underground rock located at a position of about m to 1000 m, a waste handling space, an upper air discharge space and a lower air supply space, which extend in a substantially horizontal direction, are formed at intervals in order from the top to form a waste handling space. A vertical hole for waste entry / exit with an elevating mechanism that can convey the vitrified solid that encloses high-level radioactive waste in glass is formed between the ground and the air. An outlet passage is formed, an outside air introduction path is formed between the lower air supply space and the ground, and further, a penetration penetrating between the waste handling space, the upper air discharge space and the lower air supply space. An overpack storage tube that forms a hole, can be closed at the lower end, can close the upper end, and can contain vitrified solids inside the through hole formed on the floor of the waste handling space. The upper end is locked to the solidified body insertion port, and A facility for storing and disposing of high-level radioactive waste, characterized in that it is suspended and supported in the through hole so as to have an air passage between the inner surface of the portion between the upper air discharge space and the lower air supply space in the through hole. It is a thing.

In this case, a waste handling space, an upper air discharge space and a lower air supply space may be provided in multiple stages in the underground rock.

According to the above means, the following effects can be obtained.

On the ground, spent nuclear fuel is sealed and solidified in glass to form a vitrified body, and the vitrified body is placed on an elevating mechanism, and about 50 underground underground through a vertical hole for waste entry and exit.
It is sent to either the horizontal or horizontal waste handling space formed in one or multiple steps in the underground rock at a position of 0 to 1000 m.

Then, the vitrified body sent to the waste handling space is conveyed to the position of the target vitrified body insertion port, and the vitrified body is fitted into the corresponding overpack / storage tube.

When the vitrified body insertion port is inserted into the overpack-combined storage tube, the vitrified body insertion port is covered with a shielding plug and an airtight lid, and the vitrified body is about 500 m underground.
Store in underground rock at a position of about 1000 m.

In the state where the vitrified body is stored in this manner, the air from the outside descends through the outside air introduction passage and flows into the lower air supply space as cooling air.

The air flowing into the lower air supply space enters from the lower end of each through hole into the air passage between the through hole and the overpack / combined storage pipe, and is stored in the overpack / combined storage pipe while rising in the air passage. The heat of decay of the vitrified material is removed.

The air heated by removing heat from the vitrified body rises in the through hole, flows to the upper air discharge space at the upper end of the through hole, and is further discharged to the outside of the building through the air outlet flow path. It

There are two types of air flow in the above facilities: a natural ventilation type that uses natural convection of air due to the decay heat of the vitrified body, and a forced ventilation type that uses a blower or the like.

After the heat of decay of the vitrified body is removed as described above, the overpack-combined storage tube is backfilled as it is.

As a result, the storage tube serving also as an overpack can be stably stored at a position of about 500 m to 1000 m underground for a long period of several years while being separated from the underground rock.

As described above, according to the present invention, since the storage facility and the disposal facility are used in common, the construction cost of the facility is greatly reduced, and the vitrified solid is transported from the storage facility to the disposal facility. Will be able to eliminate the problem.

Further, by providing the waste handling space, the upper air discharge space and the lower air supply space in multiple stages in the underground rock mass, it is possible to greatly increase the storage capacity of the vitrified body in one facility. .

[0046]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an example of the embodiment of the present invention.

About 38m above ground and about 500m to 1000m underground
A vertical hole 40 for entering and exiting waste is drilled toward the underground rock 39 at a certain position, and a vertical hole 4 for entering and exiting waste is inserted into the underground rock 39.
A waste handling space 41 extending from the lower end portion of 0 in a substantially horizontal direction is formed in one or more stages (four stages in the figure).

A building 42 is installed on the ground 38 so as to surround the entrance of the waste inflow / outflow vertical hole 40, and a winding device 43 such as a winch is installed in the building 42.
Elevator 45 in which the tip of the wire rope 44 wound up by the winding device 43 is arranged to be able to move up and down in the waste loading vertical hole 40.
An elevating mechanism 47 is constructed by connecting the sheave 46.

Further, the ceiling 32 of the waste handling space 41
Although not shown in detail in particular, an overhead crane or the like capable of transporting and inserting the vitrified body 48 formed by enclosing high-level radioactive waste in glass by moving in the front-rear direction or the left-right direction. A device 49 is provided, and a delivery device such as a carriage 50 capable of delivering the vitrified body 48 is provided between the elevating mechanism 47 and the insertion device 49.

On the other hand, below the waste handling space 41 of each stage, an upper air discharge space 51 and a lower air supply space 52, which spread in a substantially horizontal direction, are vertically separated from each other to form an upper air discharge space 51 and a lower air supply space. An outer air introduction passage 55 and an air outlet passage 56 communicating with the outside air introduction port 53 and the air outlet 54 of the ground 38 are formed at a position away from the waste inlet / outlet vertical hole 40 with respect to the space 52, and the upper air discharge space 51 is filled with air. The outlet air passage 56 and the lower air supply space 52 are connected to the outside air introduction passage 55.
Connect to each. The outside air introduction passage 55 and the air outlet passage 56 may have a double structure as shown in FIG.
However, in the case of a double structure, it is preferable that both partition walls have a heat insulating structure.

Then, a plurality of through holes 58 extending substantially vertically from the floor surface 57 of the waste handling space 41 of each stage and communicating with the upper air discharge space 51 and the lower air supply space 52 are formed, and the lower end portion is formed. The closed metal overpack-combined storage tube 61 has its upper end locked to a step portion 60 formed in the vitrified material insertion port 59 at the upper end of the through hole 58, and the upper air discharge space 51 and the lower air supply space The air passage 62 is suspended and supported between the inner surface of the through hole 58 and the inner surface of the through hole 58. In addition, the storage tube 61 that also serves as an overpack is designed to withstand corrosion during long-term storage.
The thickness is about 100 mm or more.

The vitrified material insertion port 59 can be closed by a shield plug 63 and an airtight lid 64.

In FIG. 3, reference numeral 65 is a cushioning material mainly composed of bentonite or the like, which is provided so as to surround the outer periphery of the overpack / storage pipe 61 at the time of backfilling, and 66 is earth and sand for backfilling.

Next, the operation will be described.

On the ground 38, the spent nuclear fuel is sealed and solidified in glass to form a vitrified body 48, and the vitrified body 4 is formed.
8 is placed on the elevator 45 of the elevator mechanism 47, and the winding device 43 such as a winch is rewound to thereby build the building 42 on the ground 38.
From underground through vertical hole 40 for waste entry / exit approx.
It is sent to one of the waste handling space 41 which is formed in one step or multiple steps in the underground rock 39 located at a position of about 000 m and which spreads horizontally.

Then, the vitrified body 48 sent to the waste handling space 41 is received by a delivery device such as a carrier truck 50, and an insertion device 49 such as an overhead crane is received from the carrier truck 50.
Hand over to

Then, the insertion device 49 such as an overhead crane that has received the vitrified body 48 is moved in the front-rear direction, the left-right direction, or the like so that it is conveyed to the target position of the vitrified material insertion port 59 and the corresponding operation is performed. The vitrified body 48 is fitted into the storage tube 61 that also serves as an overpack.

Further, when the vitrified body 48 is inserted into the overpack-combined storage tube 61, the vitrified body insertion port 59 is formed.
The shielding plug 63 and the airtight lid 64 are attached to the
Is stored in the underground rock bed 39 at a position of about 500 m to 1000 m underground.

Note that, in view of the drawings, the vitrified body 48 is
Although it is illustrated that only one tube is accommodated in each overpack-combined storage tube 61, it is not always necessary to do so, and a plurality of vitrified bodies 48 may be stacked vertically. .

In the state in which the vitrified body 48 is stored in this way, the air from the outside introduced from the outside air introduction port 53 descends through the outside air introduction passage 55 and the lower air supply space 52.
Is supplied as cooling air.

The air flowing into the lower air supply space 52 is
A vitrified body that enters from the lower end of each through hole 58 into an air passage 62 between the through hole 58 and the storage tube 61 that also serves as an overpack, and rises in the air passage 62 while being stored in the storage tube 61 that also serves as an overpack. The decay heat of 48 is removed.

The air heated by removing heat from the vitrified body 48 rises in the through hole 58, flows into the upper air discharge space 51 at the upper end of the through hole 58, and further flows through the air outlet passage 56 and the air outlet 54. It is discharged through the building 1 to the outside.

There are two types of air flow in the above facilities: a natural ventilation type that uses natural convection of air due to the decay heat of the vitrified body 48, and a forced ventilation type that uses a blower (not shown). is there.

When the decay heat of the vitrified body 48 is removed as described above, the storage tube 61 also serving as the overpack is kept as it is.
Backfill.

That is, as shown in FIG. 3, the outer circumference of the overpack / cumulative storage tube 61 is surrounded by a cushioning material 65 containing bentonite as a main component, and the outside thereof is filled with earth and sand 66.

As a result, the storage tube 6 also serving as the overpack
1 will be stably stored at a position of about 500 m to 1000 m underground for a long period of several hundred years to several thousand years, with the buffer material 65 separating it from the underground rock 39. .

As described above, according to the present invention, since the storage facility and the disposal facility are shared, the construction cost of the facility is significantly reduced and the vitrified body 48 is transported from the storage facility to the disposal facility. You will be able to eliminate such problems.

In the underground rock 39, the waste handling space 4
By providing the first space 1, the upper air discharge space 51, and the lower air supply space 52 in multiple stages, the storage capacity of the vitrified body 48 in one facility can be greatly increased.

It should be noted that the present invention is not limited to only the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0071]

As described above, according to the facility for storing and disposing of high-level radioactive waste according to the present invention, both the storage facility and the disposal facility can be used together, and the waste can be handled in the underground rock mass. By providing the space, the upper air discharge space, and the lower air supply space in multiple stages, it is possible to achieve an excellent effect that the storage capacity of the vitrified body in one facility can be significantly increased.

[Brief description of drawings]

FIG. 1 is an overall schematic side sectional view of an example of an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a diagram showing a state in which FIG. 2 is backfilled.

FIG. 4 is a cutaway perspective view of a storage facility.

FIG. 5 is a partially enlarged view of FIG.

FIG. 6 is a partially enlarged view of FIG. 5;

FIG. 7 is a side sectional view of the disposal facility.

[Explanation of symbols]

 39 Underground rock 40 Vertical hole for waste entry / exit 41 Waste handling space 47 Lifting mechanism 49 Vitrified body 51 Upper air discharge space 52 Lower air supply space 55 Outside air introduction path 56 Air outlet flow path 57 Floor surface 58 Through hole 59 Vitrification Body insertion opening 61 Overpack storage tube 62 Air passage 63 Shielding plug 64 Airtight lid

Claims (2)

[Claims] 1. A waste handling space, an upper air discharge space, and a lower air supply space, which extend in a substantially horizontal direction, are formed in the underground rock located approximately 500 m to 1,000 m below the ground in order from the top. Then, between the waste handling space and the ground, a vertical hole for waste entry / exit with an elevating mechanism capable of transporting vitrified solids containing high-level radioactive waste in glass is formed, and the upper air discharge space is formed. An air outlet passage between the lower air supply space and the ground, and an outside air introduction passage between the lower air supply space and the ground, and between the waste handling space, the upper air discharge space and the lower air supply space. A through-hole that penetrates each other is formed, the lower end can be closed, the upper end can be closed, and an overpack-combined storage pipe that can store the vitrified body inside is formed on the floor of the waste handling space Vitrified material insertion port at the top of the through hole The upper end is locked to the through hole, and is suspended and supported in the through hole so as to have an air passage between the upper surface of the through hole and the inner surface of the portion between the upper air discharge space and the lower air supply space. Level radioactive waste storage / disposal facility. 2. The high-level radioactive waste storage / disposal facility according to claim 1, wherein a waste handling space, an upper air discharge space and a lower air supply space are provided in multiple stages in the underground rock.