JP2002214394A - Geological disposal facility and its execution method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geological disposal facility and its execution method that reduce an entire underground facility part by increasing disposal density of waste bodies for disposing high level radioactive waste in nuclear power generation, reduce construction cost by moderating a restriction condition to an adequate rock mass, and improve operability in emplacing the waste bodies. SOLUTION: This geological disposal facility comprises a disposal gallery 5 having a shape allowing forming in its bottom of disposal holes in which the waste bodies are buried vertically via backfill material, and sealing bodies 30 filled with the waste bodies horizontally installed in the disposal gallery and in the crossing direction with the gallery axis. The sealing bodies are constituted with rectangular steel material made containers filled with the waste bodies under the existence of buffer material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geological disposal facility and a method of constructing the same, and more particularly to a geological disposal facility capable of facilitating the operation of disposing of waste bodies and disposing them safely and at a high density and a method of constructing the same.

[0002]

2. Description of the Related Art In a nuclear fuel cycle centered on a nuclear power plant, in order to reuse spent fuel, uranium or plutonium is transferred to a reprocessing plant directly or through a recycled fuel storage center. It is designed to collect, process into fuel and reuse it, but radioactive waste that goes out of this fuel cycle is planned to be safely sequestered.

[0003] Regarding high-level radioactive waste generated in a reprocessing plant, it is determined that the waste is stored in a high-level radioactive waste storage facility for cooling and then disposed of in a geological disposal facility. At the geological disposal facility, in order to dispose of unusable radioactive waste,
It is planned that an underground facility with a depth of 300m or less underground will be constructed as shown in (1).

[0004] The geological disposal facility 10 comprises a shaft 3 and an exhaust shaft 4 connecting the underground facility 1 to the ground receiving facility 2.
It is composed of The underground facility section 1 is composed of a plurality of disposal tunnels 5 and a main tunnel 6 connecting them, and the shaft 3 has a waste loading shaft 7, a staff and material shaft 8, and an emergency shaft 9. I have.

[0005] The geological disposal facility is designed and designed to be classified into two types of facilities: hard rock and soft rock, such as sedimentary rock, according to the type of rock. And the horizontal installation method is taken into consideration, and technical studies on each facility are being made.

In the case of soft rock, the disposal tunnel 5 is excavated by TBM or the like.
It is conceivable to support by lining using about m of lining concrete or compressed concrete segment.

In the conventional vertical placing method, as shown in FIG. 8, a disposal hole is excavated from the bottom of a disposal tunnel, and the waste is placed vertically in the pit under the intervention of backfill material.
In the case of hard rock, it is configured as shown in FIG.

[0008] The disposal tunnel 11 for hard rock based rock has a bottom 12 formed in a plane, and an upper section 13 having a half the width of the disposal tunnel 11 and a radius similar to the rising height of the vertically formed side. Of the disposal tunnel 11
And the disposal holes 14 are arranged at smaller intervals than in the case of soft rock.

[0009] For this reason, the size of the disposal tunnel is intermediate between the vertical placement of the soft rock and the horizontal placement in the tunnel, and the excavation of the disposal hole has little effect on the stability of the bedrock. Also, waste body 15
It is easy to introduce and install a machine for fixing the waste body 15 because the cross section of the tunnel is relatively large, and a high burial density of the waste body 15 can be secured.

On the other hand, in a disposal tunnel 16 for soft rock based rock shown in FIG. 8B, a bottom portion 17 and a side portion 18 are formed in an arc shape having different radii, and an upper portion 13 has a radius from the upper end of the arc of the side portion 18. The disposal tunnel 16 is constructed in a semicircular shape drawn by half the width of the disposal tunnel 16, and a lining 19 using a lining concrete or a concrete segment having a thickness of about 50 cm is constructed thereon. The arrangement with 14 is configured at a wider interval than in the case of hard rock.

Therefore, although the size of the disposal tunnel is medium, the excavation of the disposal hole has a greater effect on the stability of the bedrock. For this reason, although it is easy to introduce and install a machine for fixing the waste body 15, the waste body 15
The burial density cannot be secured very high.

On the other hand, in the horizontal placement method, as shown in FIG. 9, the waste body 15 is excavated horizontally with the interposition of a backfill material 22 equivalent to that filled in the disposal hole of the vertical placement method. In the case of hard rock based rock, the disposal tunnel 20 is formed in a circular shape as shown in FIG. 9 (a), whereas in the case of soft rock based rock, In
As shown in FIG. 9B, the disposal tunnel 21 is formed in an elliptical shape in the vertical direction to enhance the stress.

Therefore, since the disposal tunnels are all small in diameter, the excavation of the disposal holes has no effect on the stability of the bedrock. Although the burial density of the waste body 15 can be ensured moderately, introduction and installation of a machine for fixing the waste body 15 are disadvantageous.

The waste body 1 in each disposal method as described above
The disposal work of No. 5 firstly involves disposal holes 14 and disposal tunnels 20 and 21
A backfill material 22 made of bentonite or the like is sealed in the inside of the backfill material, and then a waste body 15 is buried and fixed in the backfill material. Sealed with lid-like cushioning material.

The vertically disposed disposal hole 14 further encloses a backfill 22 made of bentonite or the like in the remaining space, and finally fills the inside of the disposal tunnels 11 and 16 with the backfill 23. Has completed the disposal work of the waste body 15.

[0016]

However, in the vertical installation method, the cross section of the disposal tunnel and the disposal hole becomes large depending on the conditions for stationary installation, so that the cost for the construction of excavation and support is bulky, This tendency becomes conspicuous in the case of a vertical method using soft rock.

Similarly, also in the case of the horizontal type, since the cross section of the disposal tunnel is small, it is necessary to reduce the size of the transporting machine. However, it is not easy to securely place the material on a soft back-fill material such as bentonite, and a countermeasure considering a proper mechanism is required. In addition, the disposal density of wastes must be matched to the axial direction of the disposal tunnel, which is disadvantageous in reducing the density.

In particular, since the disposal density of wastes affects the construction length of a plurality of disposal tunnels and main tunnels constituting the underground facility, the disposal density of the wastes is increased to increase the disposal density of the underground facilities. Reducing the construction area is an important issue because it reduces the constraints on suitable rocks and reduces construction costs.

The present invention has been made in view of the above situation, and proposes an improvement measure in the disposal of high-level radioactive waste. By increasing the disposal density of wastes, the entire underground facility can be reduced, It provides a geological disposal facility and its construction method, which alleviates the constraints on the rock mass to be used, reduces the construction cost, and improves the operability when placing the waste.

[0020]

The geological disposal facility according to the present invention basically has a closed body filled with a waste body in a disposal tunnel laid horizontally in a direction intersecting with a tunnel shaft. A closed body filled with waste bodies is held at a predetermined interval by a backfill material filled in a disposal tunnel, or a closed body is constituted by a container for filling a waste body under the intervention of a buffer material, Is formed in a rectangular shape with a steel material.

[0021] As a result, the disposal density of the waste is increased to reduce the size of the entire underground facility, and the emplacement of the closed body is improved, and the constraints on the suitable rock are reduced, thereby reducing the construction cost. I'm trying.

The method for constructing a geological disposal facility according to the present invention is a method for constructing a geological disposal facility according to the present invention, in which a sealed body filled with waste is interposed with a shaft through a buffer material in a disposal tunnel. It is arranged horizontally and is held at a predetermined interval by a backfill material.
After filling the lower part of the sealed body filled with the waste, and placing the sealed body horizontally, the upper part of the sealed body and the disposal mine to the position of the sealed body filled with the waste to be disposed next are disposed. It is characterized by filling with backfill material.

As a result, the disposal density of the wastes is increased to reduce the size of the entire underground facility, and the operability in placing the wastes is advantageous.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In a geological disposal facility according to the present invention, a closed body filled with waste bodies is placed in a disposal tunnel in a direction intersecting with a shaft of a tunnel, and specifically, a waste body is filled with the waste bodies. The sealing body is held at a predetermined interval by a backfill material filled in the disposal tunnel, or the sealing body is formed of a container in which the waste body is filled under the intervention of the buffer material, and the container is made of steel and has a rectangular shape. Has formed.

Hereinafter, embodiments of each invention will be described in detail with reference to the drawings. In order to clarify the features of the invention, parts similar to those in the related art are denoted by the same reference numerals.

FIG. 1 is a sectional view showing an embodiment of a disposal tunnel when the geological disposal facility according to the present invention is applied to a soft rock formation.

The plurality of disposal tunnels 5 are formed in the same manner as the vertical disposal tunnel 16 constructed on a conventional soft rock mass, but the disposal hole 14 excavated at the bottom is not formed. Is configured.

That is, the disposal tunnel 5 has a bottom portion 17 formed in an arc shape having a predetermined radius, and a side portion 18 formed in an arc shape having a radius different from that of the bottom portion 17. The upper portion 12 continuing to the side portion 18 is formed in a semicircular shape whose radius is drawn by half the width of the disposal tunnel 5 from the upper end of the arc of the side portion 18, and the disposal tunnel 5 is arranged in a conventional manner. Similarly, they are arranged at wider intervals than in the case of hard rock.

Therefore, the disposal tunnel according to the present invention has a larger cross section than the conventional horizontal installation method,
Space allowance and the use of large machines,
The operability at the time of placing the closed body filled with the waste body is facilitated to make the operation advantageous.

Since the disposal tunnel constituting the present invention is formed in the same shape and size as the conventional vertical disposal tunnel, when the formation is hard rock, it is constructed there. The disposal tunnel to be used is formed in the same shape and size as the conventional disposal tunnel of hard rock.

The sealing body 30 filled with the waste body 15, which will be described in detail in FIG. 2, is disposed horizontally in the backfill material 23 filled in the disposal tunnel 5 as a disposal form. The direction is different from the conventional horizontal type, and is arranged to intersect with the shaft axis.

Therefore, the spacing between the sealing bodies 30 is determined according to the conventional spacing of the horizontal arrangement, so that they can be arranged at a smaller interval than in the case of the vertical arrangement.
In the case of soft rocks, the intervals are particularly narrow, and it is possible to arrange them at an interval of less than half.

As described above, the sealing body 30 is held in the backfill material 23 filling the disposal tunnel 5, and its arrangement corresponds to the lower part of the sealing body 30 first. The area to be sealed is filled with the backfill material 31 so that the position where the sealing body 30 is arranged is stably secured. Then, after the sealing body 30 is arranged horizontally, the upper part of the sealing body is Then, the backfilling material 23 is further filled up to the position of the sealing body arranged at a predetermined interval, whereby one sealing body 30 is fixed.
This is the standard form of work.

The waste 15 is formed for embedding high-level radioactive waste in a geological disposal facility. The waste liquid of the high-level radioactive waste is turned into a vitrified body, which is stored in a metal container. Things.

Conventionally, in order to dispose the waste body 15 strictly so as not to come into contact with the groundwater, the stability of the surrounding rock including the peripheral wall of the disposal hole and the bottom of the disposal tunnel is secured, An operation consisting of a plurality of steps of arranging a backfill material made of bentonite or the like and placing the waste body 15 in the backfill material has been configured.

In the case of the present invention, however, the above-described disposal hole burying specification is changed to the integral sealing member 3 as shown in FIG.
This is achieved by configuring as 0.
At the same time, the stability of the disposal of the waste body 15 is ensured, and at the same time, the work is simplified to improve the construction efficiency.

The sealing body 30 in the present embodiment is configured by previously filling a waste body 15 and a buffer material 33 for stably holding the waste body 15 in a rectangular steel container 32. In addition, it is easy to handle when disposing of burial, and at the same time, by making it a rectangular body, stability in stationary is ensured.

As described above, in the geological disposal facility according to the present invention, the closed body filled with waste in the disposal tunnel is laid horizontally in the direction intersecting with the shaft of the tunnel, so that the disposal of waste in the soft rock stratum is also possible. It is possible to increase the disposal density and reduce the size of the entire underground facility, improve the emplacement of the sealing body, and reduce the constraints on the suitable rock, thereby reducing the construction cost.

Next, the construction method of the geological disposal facility according to the present invention will be described. The method for constructing a geological disposal facility according to the present invention is a method for constructing a geological disposal facility according to the above, wherein the sealing body filled with waste is interposed with a buffer material in a disposal tunnel, and is placed horizontally in a direction to intersect with a tunnel shaft. And placing the backfill material in the disposal tunnel in the lower part of the sealed body filled with waste first, and placing the sealed body horizontally. Later, the upper part of the sealing body and the inside of the disposal tunnel up to the position of the sealing body filled with the waste to be disposed are filled with the backfill material.

An embodiment of a method for constructing a geological disposal facility according to the present invention will be described below in detail with reference to FIGS.

FIG. 3 shows a construction state of the disposal tunnel. As shown in the drawing, the disposal tunnel 5 of the geological disposal facility has a bottom portion 17 formed in an arc shape having a predetermined radius, and a side portion 18 formed in an arc shape having a different radius from the bottom portion 17.
Is excavated from the upper end of the arc of the side portion 18 into a cross-sectional shape composed of a semicircle whose radius is drawn by half the width of the disposal tunnel 5, and a lining 19 is constructed on the inner surface. ing.

Then, the adjacent disposal tunnels 5 are arranged so as to have a wider interval than in the case of hard rock as in the related art.

FIG. 4 shows a first stage of filling backfill material into a disposal tunnel. The backfill material 35 to be filled in the disposal tunnel 5 is formed so as to provide a pedestal 36 as shown in the figure. The pedestal 36 is set at a height at which the sealing body 30 is set in the disposal tunnel 5, and is leveled in a planar shape so that the sealing body 30 is stably stood still in correspondence with the rectangular shape of the sealing body 30. I have.

The pedestal 36 can be easily formed by free operation of a large machine under a wide space in the disposal tunnel, and the pedestal 36 can be used to dispose of the sealing body 30 thereafter. Very easy.

FIG. 5 shows the process of placing the blocker. The stationary body 30 can be securely placed only by placing the closed body 30 carried on the pedestal 36, and the closed body 30 is disposed inside the rectangular steel material container 32 and the waste body 15 Is preliminarily filled with the backfill material 33 that stably holds the wastewater, the waste body 15 is eventually disposed at a predetermined position of the disposal tunnel 5 and is reliably buried and disposed.

FIG. 6 shows a process of closing the fixed sealing body with the backfill material. After placing the blocker 30,
The space up to the position of the sealing body indicated by an imaginary line to be placed at a predetermined interval from the upper part of the sealing body 30 is filled with the backfill material 36, thereby completing the work process of embedding and disposing of the sealing body 30. I do.

The filling operation of the backfill material 36 is also performed as follows.
Since the rectangular steel container 32 is placed on the flat pedestal 36, there is no danger that the container 32 is moved by the backfill material 36, so that the process can be performed quickly. The operations after the sealing body 30 is continuously buried and disposed are continuously performed by repeating the above-described steps, and the disposal work of the sealing body in one disposal tunnel is completed.

As described above, according to the construction method of the geological disposal facility according to the present invention, the disposal tunnel is constructed, the backfill material is filled, and the sealing body is placed on the disposal tunnel in a direction crossing the tunnel axis. After that, the upper part of the sealed body and the inside of the disposal tunnel up to the position of the next sealed body are filled with backfill material, so the disposal density of waste is increased and the entire underground facility part is reduced At the same time, the operability when placing the waste body can be made advantageous.

As described above, the present invention has been described in detail based on the embodiments. However, the geological disposal facility according to the present invention and its construction method are not limited to the above-described embodiments.
Naturally, various modifications can be made without departing from the spirit of the present invention.

[0050]

The geological disposal facility according to the first aspect of the present invention has the following effects because the closed body filled with wastes is placed in the disposal tunnel in a direction intersecting with the shaft of the tunnel. ing. The large cross-sectional area of the disposal tunnel allows for ample space and the use of large machines, which facilitates the operability of placing the closed body filled with waste. Since the disposal hole is not excavated, the stability of the disposal tunnel is improved. Since the disposal density of wastes is increased, the entire disposal facility is made smaller, suitable sites for the disposal facility are expanded, construction costs are reduced, and economy is improved.

The geological disposal facility according to the second aspect of the present invention is the geological disposal facility according to the first aspect, wherein the closed body filled with the waste is separated by a backfill material filled in the disposal tunnel at a predetermined interval. In this case, in addition to the above-described effects, an effect of ensuring an arrangement for increasing the disposal density of the waste body is achieved.

The geological disposal facility according to the third aspect of the present invention is the geological disposal facility according to the first or second aspect, wherein the closed body filled with the waste is filled with the waste under the intervention of the buffer material. It is characterized by comprising a container that
In addition to the above effects, there is an effect that the specification for burying the waste is surely secured.

The geological disposal facility according to the fourth aspect of the present invention is characterized in that, in the geological disposal facility according to any one of the first to third aspects, the container is formed in a rectangular shape. In addition to the above, there is an effect of securing stability when placing the waste body.

The geological disposal facility according to the fifth aspect of the present invention is characterized in that, in the geological disposal facility according to any one of the first to fourth aspects, the container is formed of a steel material. In addition, the waste is disposed of strictly so as not to come into contact with the groundwater, and at the same time, the corrosion of the steel material reduces the corrosion rate of metal containers such as overpacks that store the waste and constitute the surrounding area as a reduction zone. It has an effect.

The construction method for a geological disposal facility according to the invention according to claim 6 is the construction method for a geological disposal facility according to any one of claims 1 to 5, wherein a buffer material is interposed in the disposal tunnel. The closed body filled with waste is placed horizontally in the direction intersecting with the tunnel shaft, and it is held at a predetermined interval with backfill material, so the disposal density of waste is increased and the entire underground facility is This has the effect of reducing the size and improving the operability when placing the waste body.

The method for constructing a geological disposal facility according to claim 7 is the method for constructing a geological disposal facility according to claim 6, wherein the backfill material in the disposal tunnel is firstly disposed of by a waste body. After filling the lower part of the sealed body filled with, and placing the sealed body horizontally, filling the upper part of the sealed body and then the waste to be disposed into the disposal tunnel up to the position of the filled sealed body Therefore, in addition to the above-described effects, an effect of rapidly performing the operation of placing the sealing body is exhibited.

[Brief description of the drawings]

FIG. 1 is a sectional view of a disposal tunnel in a geological disposal facility of the present invention.

FIG. 2 is a perspective sectional view of a sealing body used in the geological disposal facility of the present invention.

Fig. 3 Construction drawing of disposal tunnel in construction method of geological disposal facility of the present invention

FIG. 4 is a diagram of filling a backfill material into a disposal tunnel in the construction method of the geological disposal facility of the present invention.

FIG. 5 is a diagram showing a stationary body installed in a disposal tunnel in the construction method of the geological disposal facility of the present invention.

FIG. 6 is a diagram of filling a backfill material into a disposal tunnel in the construction method of the geological disposal facility of the present invention.

FIG. 7 is a perspective view of a conventional geological disposal facility.

FIG. 8 is a cross-sectional view of a conventional disposal tunnel and a disposal hole using the conventional method.

FIG. 9 is a cross-sectional view of a horizontal disposal tunnel using a conventional method.

[Explanation of symbols]

1 Underground facility, 2 Ground receiving facility, 3 Shaft,
4 exhaust shaft, 5 disposal tunnel, 6 main tunnel,
7 waste loading shaft, 8 material shaft, 9 emergency shaft, 10 geological disposal facility, 11, 16 disposal tunnel,
12, 17 bottom, 13 top, 14 disposal hole, 1
5 waste, 18 side, 19 lining, 20, 21
Disposal tunnel, 22, 23 backfill material, 30 sealing body, 31, 35 backfill material, 32 steel container,
33 cushioning material, 36 pedestals,

Claims (7)

[Claims] 1. A geological disposal facility in which a closed body filled with a waste body in a disposal tunnel is placed horizontally in a direction intersecting with a tunnel shaft. 2. The geological disposal facility according to claim 1, wherein the closed body filled with the waste is held at predetermined intervals by a backfill material filled in a disposal tunnel. 3. The geological disposal facility according to claim 1, wherein the closed body filled with the waste body comprises a container for filling the waste body with a buffer material interposed therebetween. 4. The geological disposal facility according to claim 1, wherein the container is formed in a rectangular shape. 5. The geological disposal facility according to claim 1, wherein the container is formed of a steel material. 6. A closed body filled with waste bodies with a buffer material interposed in a disposal tunnel, placed horizontally in a direction intersecting with the tunnel shaft, and held at predetermined intervals by backfilling material. 6. The construction method for a geological disposal facility according to any one of 1 to 5. 7. The backfill material in the disposal tunnel is first filled in the lower part of the closure filled with waste, and after placing the closure horizontally, it is placed next to the upper part of the closure. 7. The method for constructing a geological disposal facility according to claim 6, wherein the filling is performed in a disposal tunnel up to a position of the sealing body filled with the waste body.