JP6405611B2 - Radioactive waste disposal facility and its construction method - Google Patents

Description

  The present invention relates to a radioactive waste disposal facility that geologically disposes radioactive waste generated by nuclear power generation and the like, and a construction method thereof.

  Waste generated by nuclear power generation, waste liquid generated when reprocessing spent nuclear fuel generated by nuclear power generation, etc. are planned to be buried in a deep and stable formation. The radioactive waste is buried in the geological formation as a waste body in which radioactive waste is melted together with glass raw materials and stabilized as a glass solidified body, and this glass solidified body is hermetically stored in a closed container (overpack). Is called. Then, around the waste body, an artificial barrier (buffer material) is constructed with bentonite or bentonite mixed soil, and radioactive material is contained between the artificial barrier and the natural barrier (rock) (for example, see Patent Document 1).

Several methods shown below have been proposed for the construction of an artificial barrier (buffer material).
1. Block method After placing the waste in the disposal tunnel, it is transported around the waste as a compression-molded bentonite block artificial barrier (buffer material).
2. Pre-assembled method All artificial barriers (buffer materials) and waste are packaged on the ground, transported underground, and placed.
3. In-situ compaction method After placing the waste in the disposal tunnel, powder bentonite is filled around the waste as an artificial barrier (buffer material) and compacted in-situ.
4). Pellet filling method After placing the waste body in the disposal tunnel, it is filled around the waste body as an artificial barrier (buffer material) with granular (pellet) bentonite.

Japanese Patent Application Laid-Open No. 07-294698

However, in the prior art, in the block method, the in-situ compaction method, and the pellet filling method, it is necessary to construct an artificial barrier (buffer material) after placing the waste body in the disposal tunnel, so that people approach because of radiation. First, an artificial barrier (cushioning material) must be constructed by remote control, and advanced and reliable mechanical technology is required.
Moreover, in the block method and the pre-assembly method, a gap is generated between the wall of the disposal mine where the waste is placed, that is, a natural barrier (rock) and an artificial barrier (buffer material), and this gap is a weak point as a barrier. turn into. Furthermore, the in-situ compaction method has a risk of damaging the waste during construction, and the pellet filling method may not have a sufficient density necessary for blocking.
In the prior art, since the waste is placed in the disposal tunnel using the adjacent tunnel or the disposal tunnel itself, the adjacent tunnel is generally backfilled together with the disposal tunnel. It was difficult to take out the discarded waste again.

  This invention is made | formed in view of such a situation, eliminates the above-mentioned subject, and constructs an artificial barrier (buffer material) in a disposal tunnel by manned before placing a waste body in a disposal tunnel. It is another object of the present invention to provide a radioactive waste disposal facility and a construction method for the same, which can easily take out the waste again.

The radioactive waste disposal facility of the present invention is a radioactive waste disposal facility that disposes radioactive waste as a waste body in a geological formation, and is constructed within the geological formation and disposed of a plurality of the disposals disposed at predetermined intervals. a disposal tunnel artificial barrier by cushioning material around the body is constructed, a working tunnel built in said formation keep formulation fraction mine at a predetermined distance, a plurality of the waste in the disposal tunnel and the working tunnel A plurality of construction positions are connected to each other in the formation with a predetermined interval, and used to place the waste body from the working tunnel to the disposal tunnel. It is characterized by having a waste body fixing hole backfilled.
Further, the radioactive waste disposal facility of the present invention is a radioactive waste disposal facility that disposes radioactive waste as a waste material in a geological formation, and is a buffer material around the waste material that is constructed and placed in the geological formation. Constructed in the formation by connecting the working tunnel and the disposal tunnel, the disposal tunnel in which the artificial barrier is constructed, the working tunnel constructed in the formation at a predetermined interval from the disposal tunnel, A waste body placement hole that is used to place the waste body from the working tunnel to the disposal tunnel and then backfilled with a backfill material, and the disposal tunnel and the working tunnel are parallel to each other It is built in.
Further, the radioactive waste disposal facility of the present invention is a radioactive waste disposal facility that disposes radioactive waste as a waste material in a geological formation, and is a buffer material around the waste material that is constructed and placed in the geological formation. Constructed in the formation by connecting the working tunnel and the disposal tunnel, the disposal tunnel in which the artificial barrier is constructed, the working tunnel constructed in the formation at a predetermined interval from the disposal tunnel, And a waste body placement hole that is used to place the waste body from the working tunnel to the disposal tunnel and then backfilled with a backfill material, the waste body placement hole having a section in the disposal tunnel It is characterized by being constructed smaller than the cross-sectional area.
Moreover, the construction method of the radioactive waste disposal facility of the present invention is a construction method of a radioactive waste disposal facility that disposes radioactive waste as a waste body in the geological formation, and a disposal tunnel for placing the waste body and the said waste tunnel A tunnel construction step of constructing a working tunnel for placing the waste body in the disposal tunnel at a predetermined interval in the formation, and a buffer material in the disposal tunnel before placing the waste body Artificial barrier construction step for filling and constructing an artificial barrier, waste body placement hole construction step for constructing a waste body placement hole for connecting the working tunnel and the disposal tunnel, and the disposal tunnel in which the artificial barrier is constructed A waste body placing step for placing the waste body from the working tunnel through the waste body placing hole, and a closing step for filling the waste body placing hole with a backfill material after the waste body is placed in the disposal tunnel. Have And wherein the door.
Furthermore, in the construction method of the radioactive waste disposal facility of the present invention, in the artificial barrier construction step, a dummy body having the same shape as the waste body may be embedded and filled with a buffer material.

  According to the present invention, since an artificial barrier in the disposal mine can be constructed before the waste body is placed, manned can be handled in the vicinity of the gap between the buffer material to be filled and the formation. It is possible to construct a simple artificial barrier and to easily take out the waste again.

It is the perspective view and sectional drawing which show the structure of embodiment of the radioactive waste disposal facility which concerns on this invention. It is sectional drawing which shows the example of arrangement | positioning of the disposal tunnel with respect to the working tunnel shown in FIG. It is explanatory drawing explaining the tunnel construction process of the construction method of the radioactive waste disposal facility which concerns on this invention. It is explanatory drawing explaining the artificial barrier construction process and waste body stationary hole construction process of the construction method of the radioactive waste disposal facility which concerns on this invention. It is explanatory drawing explaining the waste body placement process of the construction method of the radioactive waste disposal facility which concerns on this invention. It is the perspective view and sectional drawing which show the structure of other embodiment of the radioactive waste disposal facility which concerns on this invention.

  Next, modes for carrying out the present invention (hereinafter, simply referred to as “embodiments”) will be specifically described with reference to the drawings.

  With reference to FIG. 1, the radioactive waste disposal facility of the present embodiment is constructed in a stable bedrock 5 functioning as a natural barrier for containing radioactive substances, and a disposal mine 2 in which radioactive waste is stored as waste 1, A work mine 3 constructed in parallel to the disposal mine 2 at a predetermined interval is provided, and a waste body fixing hole 4 for connecting the work mine 3 and the disposal mine 2 is provided. The disposal tunnel 2 is filled with a buffer material 21 that functions as an artificial barrier for containing radioactive substances, and the waste body placement hole 4 is backfilled with a backfill material 41. In FIG. 1A, the z axis is the vertical direction, and the xy plane is the horizontal plane. Moreover, FIG.1 (b) is sectional drawing which cut | disconnected the disposal mine 2, the work mine 3, and the waste body fixing hole 4 by yz plane.

  The disposal mine shaft 2 is constructed in the x-axis direction, that is, horizontally. In the disposal tunnel 2, a plurality of waste bodies 1 are placed at predetermined intervals, and a radioactive material is placed between the buffer material 21 (artificial barrier) and the bedrock 5 (natural barrier) filled in the disposal tunnel 2. It is configured to contain. In addition, the waste body 1 is, for example, a glass solid body obtained by melting radioactive waste together with a glass raw material, and further sealed in a cylindrical sealed container (overpack). Further, the disposal tunnel 2 is larger than the waste body placement hole 4 and has an outer diameter that can secure a water permeability coefficient that requires an artificial barrier constructed by filling the buffer material 21.

  The working tunnel 3 is constructed in parallel with the disposal tunnel 2 in the x-axis direction, that is, horizontally. The work tunnel 3 is for constructing and backfilling the waste body placement holes 4, placing the waste body 1 in the disposal tunnel 2, and carrying out the waste body 1 from the disposal tunnel 2. It is constructed in a size that allows various working machines used for the above work to pass through and be installed.

  Further, the disposal mine 2 and the working mine 3 do not have to be one-to-one, and a plurality of disposal mines 2, 2a, 2b are constructed for one working mine 3 as shown in FIG. You may do it. Moreover, you may make it construct | assemble in the position where a perpendicular direction (z-axis direction) differs with respect to the working mine 3 like the disposal mine 2a.

  A plurality of waste body fixing holes 4 are constructed at predetermined intervals in the y-axis direction, that is, in a direction orthogonal to the disposal mine shaft 2 and the work mine shaft 3. The waste body positioning holes 4 are holes used when the waste body 1 is placed from the work tunnel 3 to the disposal tunnel 2, and are respectively constructed corresponding to the positioning positions of the waste bodies in the disposal tunnel 2. The waste body placement hole 4 is backfilled by the backfill material 41 after the waste body 1 is placed from the work tunnel 3 to the disposal tunnel 2. Therefore, the cross section of the waste body placement hole 4 is only required to allow the waste body 1 to pass through, and the cross section area of the disposal tunnel 2 is as small as possible in consideration of the construction and backfilling work amount. It is preferable. In addition, when the disposal mine 2 and the working mine 3 are constructed in parallel as in the present embodiment, the waste body placement holes 4 that connect the disposal mine 2 and the working mine 3 are all in the same direction and What is necessary is just to construct | assemble to length, manufacture of a dedicated working machine is also easy and can improve work efficiency.

  As the buffer material 21 and the backfill material 41, for example, bentonite or bentonite mixed soil can be used. Bentonite can be suitably used as the buffer material 21 and the backfill material 41 because of its low water permeability. Further, when a soil-based material containing bentonite is used as the buffer material 21 and the backfill material 41, an effect of suppressing water intrusion is expected by swelling when contacted with water and increasing internal pressure.

Next, the construction method of the radioactive waste disposal facility of this embodiment will be described in detail with reference to FIGS.
First, as shown in FIG. 3, a tunnel construction process for constructing the disposal tunnel 2 and the work tunnel 3 in parallel is performed by excavating the stable rock 5 that performs geological disposal. Since this tunnel construction process can be performed before carrying in the waste body 1, it can be performed by manned. In the example shown in FIGS. 1 and 3, the sections of the disposal tunnel 2 and the working tunnel 3 are configured in a circular shape, but the sections of the disposal tunnel 2 and the working tunnel 3 are configured in other shapes such as a horseshoe shape and a rectangle. You may do it. Moreover, although the disposal mine 2 and the work mine 3 can be constructed in the horizontal direction, the work efficiency of the post-process can be improved. However, the disposal mine 2 and the work mine 3 may be constructed by inclining. Furthermore, the construction efficiency of the post-process can be improved by constructing the disposal tunnel 2 and the working tunnel 3 in parallel, but the disposal tunnel 2 and the working tunnel 3 are not necessarily constructed in parallel. It is sufficient if they are parallel.

  Between the working mine 3 and the disposal mine 2, a rock 5 which is a natural barrier is interposed. Therefore, the amount of radiation reaching the working tunnel 3 from the waste body 1 placed in the disposal tunnel 2 can be controlled by the distance between the working tunnel 3 and the disposal tunnel 2. For example, when the radioactive level of the waste body 1 is high, it is possible to easily reduce the amount of radiation reaching the work tunnel 3 by widening the distance between the work tunnel 3 and the disposal tunnel 2.

  Next, as shown in FIG. 4, the disposal barrier 2 is filled with the buffer material 21 to construct the artificial barrier, and the rock 5 is excavated from the working tunnel 3 toward the disposal tunnel 2. Then, a waste body placement hole construction step for constructing a waste body placement hole 4 that connects the working tunnel 3 and the disposal tunnel 2 is executed. Either the artificial barrier construction step or the waste body placement hole construction step may be executed first, or may be executed in parallel.

  The filling method of the buffer material 21 into the disposal tunnel 2 is not limited, and any of a block method, an in-situ compaction method, and a pellet filling method may be used. The artificial barrier construction step is performed before the waste body 1 is carried in. Therefore, in the artificial barrier construction step, a manned person can handle the gap between the buffer material 21 to be filled and the natural barrier (rock mass 5) in the vicinity, and a reliable artificial barrier can be constructed.

  Further, the waste body placement hole construction step is also performed before the waste body 1 is carried in. Therefore, it can be performed by manned and it becomes possible to work efficiently using the existing work machine. Furthermore, in the waste body placement hole construction step, as shown in FIG. 4, a stationary space A in which the waste body 1 is placed is formed in the cushioning material 21 filled in the disposal tunnel 2. That is, it is necessary to place the waste body 1 remotely. However, if the placement space A for placing the waste body 1 is formed in advance, the work of placing the waste body 1 can be easily performed.

  Furthermore, in the artificial barrier construction step, a dummy body having the same shape as the waste body 1 may be embedded to fill the buffer material 21. In this case, it is possible to easily form the stationary space A in which the waste body 1 is placed simply by extracting the dummy body in the waste body stationary hole construction step.

  Next, as shown in FIG. 5, a waste body placement step is performed in which the waste body 1 is placed in the placement space A formed in the disposal tunnel 2 from the work tunnel 3 through the waste body placement hole 4. For example, as shown in FIG. 5B, the waste body 1 is placed in the stationary space A formed in the disposal tunnel 2, and supports the waste body 1, and is transported to the stationary space A through the waste body stationary hole 4. This can be done using a work machine 6 with a possible arm 61. In addition, since the waste body positioning process handles the waste body 1, it cannot be performed by manned, and the work machine 6 can be operated by radio.

  Next, the buffer material 21 is filled in the periphery of the waste body 1 from the work tunnel 3 through the waste body placement hole 4, thereby constructing an artificial barrier on the waste body placement hole 4 side of the waste body 1, and the waste body placement hole. A closing step of closing 4 with the backfill material 41 is executed. By executing the closing process, the state shown in FIG. 1 is obtained. Since the closing process is a work after the waste body 1 is placed, it cannot be performed by manned work and is performed using a work machine (not shown) that can be operated wirelessly.

  After closing the waste emplacement hole 4, the radiation amount in the work tunnel 3 is reduced by the natural barrier (rock 5) between the disposal tunnel 2 and the work tunnel 3, so it is necessary to refill the work tunnel 3 There is no. In other words, the distance between the disposal mine 2 and the work mine 3 may be set so that the radiation dose in the work mine 3 is reduced to a level where there is no problem. As a result, maintenance such as inspection of the state of the waste body 1 placed in the disposal tunnel 2 from the work tunnel 3 can be performed, and the waste body 1 can be easily taken out again by using the work tunnel 3. It can be carried out. In addition, it is easy to selectively take out a plurality of waste bodies 1 placed in the disposal tunnel 2.

  In the present embodiment, as shown in FIG. 1, an example in which the shaft of the waste body 1 that is cylindrical is placed in a direction orthogonal to the construction direction of the disposal tunnel 2 is illustrated in FIG. 6. Thus, you may make it place the axis | shaft of the waste body 1 which is cylindrical shape in the construction direction of the disposal tunnel 2a. The shape of the waste body 1 is usually set such that the axial length is longer than the diameter. When placing the axis of the waste body 1 in the construction direction of the disposal tunnel 2, compared to the case of placing the axis of the waste body 1 in a direction orthogonal to the construction direction of the disposal tunnel 2 a, The area can be reduced. However, the cross-sectional area of the waste body placement hole 4a needs to be set large, and the interval for placing the waste body 1 in the disposal tunnel 2a needs to be wide. Therefore, although it depends on the state of the bedrock 5 and the like, it is considered effective to place the cylindrical waste body 1 in a direction orthogonal to the construction direction of the disposal tunnel 2.

As described above, the present embodiment is a radioactive waste disposal facility that disposes radioactive waste as the waste body 1 in the rock 5 (the formation) that is a natural barrier, and is constructed and placed in the rock 5. Disposal tunnel 2 in which an artificial barrier is constructed around buffer 1 by buffer material 21; work tunnel 3 built in bedrock 5 at a predetermined interval from disposal tunnel 2; work tunnel 3 and disposal tunnel 2 Are constructed in the bedrock 5 and used to place the waste body 1 from the work mine 3 to the disposal mine 2, and then are provided with a waste body placement hole 4 that is backfilled by a backfill material 41. Yes.
With this configuration, since an artificial barrier in the disposal tunnel 2 can be constructed before the waste body 1 is placed, a manned person can take care of the gap between the buffer material 21 to be filled and the natural barrier (rock mass 5). This can be done and a reliable artificial barrier can be constructed. Moreover, it is not necessary to backfill the working mine 3 by the bedrock 5 (natural barrier) between the disposal mine 2 and the working mine 3. As a result, maintenance such as inspection of the state of the waste body 1 placed in the disposal tunnel 2 from the work tunnel 3 can be performed, and the waste body 1 can be easily taken out again by using the work tunnel 3. It can be carried out.

Furthermore, in this embodiment, the disposal tunnel 2 and the work tunnel 3 are constructed in parallel.
With this configuration, since the waste body placed in the disposal tunnel 2 is in the same direction and the same distance from the work tunnel 3, it can be easily maintained and taken out again.

Further, in the present embodiment, the waste body placement hole 4 is constructed so that the cross section is smaller than the cross sectional area of the disposal tunnel 2.
With this configuration, the disposal tunnel 2 needs to have a cross section including a size of the waste body 1 and an artificial barrier constructed by filling the buffer body 21 around the waste body 1. As long as the waste body can pass through, the loss of the barrier function due to the waste body fixing hole 4 can be reduced, and the bedrock 5 (natural barrier) between the disposal tunnel 2 and the working tunnel 3 can be effectively used. Can be used.

Further, the present embodiment is a construction method of a radioactive waste disposal facility that disposes radioactive waste as a waste body 1 on a rock 5 (geosphere) that is a natural barrier, and a disposal tunnel 2 for placing the waste body 1 in place. And a tunnel construction step for constructing a work tunnel 3 for placing the waste body 1 in the disposal tunnel 2 at a predetermined interval in the rock 5, and in the disposal tunnel 2 before the waste body 1 is placed. An artificial barrier constructing step for constructing an artificial barrier by filling the buffer material 21 with a waste material embedding hole constructing step for constructing a waste embedding hole 4 for connecting the working tunnel 3 and the disposal tunnel 2 and an artificial barrier is constructed. A waste body placing step for placing the waste body 1 from the work tunnel 3 through the waste body placement hole 4 in the disposed disposal tunnel 2, and a backfilling material 41 for filling the waste body placement hole 4 after placing the waste body 1 in the disposal tunnel 2 And a backfilling process.
With this configuration, in the artificial barrier construction step, a manned person can handle the gap between the buffer material 21 to be filled and the natural barrier (rock mass 5) in the vicinity, and a reliable artificial barrier can be constructed.

Furthermore, in this embodiment, in the artificial barrier construction step, a dummy body having the same shape as the waste body 1 is embedded and the buffer material 41 is filled.
With this configuration, it is possible to easily form the stationary space A in which the waste body 1 is placed simply by extracting the dummy body in the waste body stationary hole construction step.

  The present invention has been described above based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to combinations of the respective components and the like, and such modifications are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Waste body 2, 2a, 2b Disposal tunnel 3 Working tunnel 4, 4a Waste body setting hole 5 Rock bed 6 Work machine 21 Buffer material 41 Backfill material 61 Arm A Stationary space

Claims (5)

A radioactive waste disposal facility that disposes radioactive waste as a waste material in the geological formation,
A disposal mine constructed in the formation and constructed with an artificial barrier made of cushioning material around the plurality of waste bodies placed at predetermined intervals, and
A working tunnel constructed in the formation at a predetermined interval from the disposal tunnel;
A plurality constructed at a predetermined interval and respective stationary positions of the plurality of the waste in each connection to the earth layer in the disposal tunnel and the work tunnels, the waste from the working mines to the disposal tunnels A radioactive waste disposal facility comprising waste disposal holes which are used for the placement of the waste and then backfilled with a backfill material. A radioactive waste disposal facility that disposes radioactive waste as a waste material in the geological formation,
A disposal mine constructed in the formation and constructed with an artificial barrier made of cushioning material around the disposed waste,
A working tunnel constructed in the formation at a predetermined interval from the disposal tunnel;
The waste emplacement constructed by connecting the working mine and the disposal mine in the formation and used for the placement of the waste material from the working mine to the disposal mine, and then backfilled with a backfill material. With holes,
The radioactive waste disposal facility, wherein the disposal mine and the working mine are constructed in parallel. A radioactive waste disposal facility that disposes radioactive waste as a waste material in the geological formation,
A disposal mine constructed in the formation and constructed with an artificial barrier made of cushioning material around the disposed waste,
A working tunnel constructed in the formation at a predetermined interval from the disposal tunnel;
The waste emplacement constructed by connecting the working mine and the disposal mine in the formation and used for the placement of the waste material from the working mine to the disposal mine, and then backfilled with a backfill material. With holes,
The radioactive waste disposal facility, wherein the waste body mounting hole has a cross section smaller than a cross sectional area of the disposal tunnel. A method of constructing a radioactive waste disposal facility that disposes radioactive waste as a waste body in the geological formation,
A mine construction step of constructing a disposal mine for placing the waste and a work mine for performing the work of placing the waste in the disposal mine at a predetermined interval in the formation;
An artificial barrier construction step of constructing an artificial barrier by filling a buffer material in the disposal mine before placing the waste body,
A waste body positioning hole construction step for constructing a waste body positioning hole connecting the working tunnel and the disposal tunnel;
A waste body placement step of placing the waste body from the working tunnel through the waste body placement hole in the disposal tunnel where the artificial barrier is constructed;
A method for constructing a radioactive waste disposal facility, comprising: a closing step of backfilling the waste body placement hole with a backfilling material after placing the waste body in the disposal tunnel.   5. The construction method of a radioactive waste disposal facility according to claim 4, wherein in the artificial barrier construction step, a dummy body having the same shape as the waste body is embedded and filled with a buffer material.

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