JP5878351B2 - Disposal of soil, sludge or incinerated ash contaminated with radioactive material - Google Patents

Description

  The present invention relates to a method for disposing of soil contaminated with radioactive substances, sludge after sewage treatment containing radioactive substances, or garbage incineration ash containing radioactive substances.

A large amount of radioactive material is released into the environment due to an accident at a nuclear power plant, contaminating the soil in the surrounding area. In addition, the released radioactive materials have fallen into areas damaged by the tsunami and contaminated houses and structures that have been destroyed.
On the other hand, radioactive materials diffused over a wide area are swept into rainwater and sewage, gathered at a sewage treatment plant, and high-concentration radioactive materials are detected from sludge after sewage treatment. Also, incineration ash left after incineration of a large amount of garbage at the garbage incineration site is concentrated in radioactive materials and emits a high concentration of radiation.
Regarding the treatment of soil and waste containing such radioactive substances, it is necessary to dispose of them so as not to affect the surrounding environment, considering that radiation is emitted over a long period of time.

  Conventionally, as described in Patent Document 1, radioactive waste is housed in a container that shields radiation as temporary disposal, and a building is constructed and the container is managed in this building.

JP 59-43398 A

However, the amount of radioactive waste such as contaminated soil, sludge, and incinerated ash caused by an accident at a nuclear power plant is enormous, and it is difficult to store it in a container and store it indoors. Moreover, in order to dispose outdoors, it is necessary to make it the state which shielded the radiation, and huge expense is needed.
The present invention has been made in view of such circumstances, and soils and radioactive wastes contaminated with a large amount of radioactive materials are placed in a state in which radiation is shielded by a simple method and disposed of in large quantities. It is intended to make possible.

In order to solve the above-mentioned problems, the invention according to claim 1 adds cement or a cement-based solidifying material to soil contaminated with radioactive substances, sludge after sewage treatment containing radioactive substances, or garbage incineration ash containing radioactive substances. The water necessary for the hydration reaction of the cement or cement-based solidified material is sprayed onto the soil, sludge or incinerated ash, and the soil, sludge or incinerated ash is formed to a predetermined size. The mold was put into a mold, applied with vibration and pressurized, and the contaminated soil molding block formed by curing the cement or cement-based solidified material was coated with a coating material that shields radiation, and coated with the coating material. The contaminated soil molding block is embedded in soil, and the step of covering the contaminated soil molding block with the covering material includes shielding a metal having a radiation shielding property into a plate shape or a sheet shape. A radiation shielding sheet having a layer and a buffer layer in which a flexible asphalt-based material is laminated on both surfaces of the shielding layer, is pressed against the contaminated soil molding block, and the radiation shielding sheet is pressed by the adhesive force of the asphalt-based material. Provided is a method for disposing of soil, sludge or incinerated ash contaminated with a radioactive material, which is to be attached to a contaminated soil molding block .

  In the above method, radioactive waste such as contaminated soil and sludge / incineration ash can be formed into blocks in a simple and inexpensive manner, and the radiation dose is shielded with a radiation shielding sheet to keep the surrounding radiation dose low. be able to. And the solidified contaminated soil molding block can be laminated and embedded in the ground. Moreover, dissipation of contaminated soil etc. can be prevented by being solidified, and it can suppress that a radioactive substance osmose | permeates groundwater by coat | covering with a radiation shielding sheet.

  Moreover, in the said method, the contaminated earth molding block used as the block shape can be easily coat | covered with a radiation shielding sheet. In particular, the asphalt material of the buffer layer of the radiation shielding sheet has an adhesive force, and the workability is improved by sticking to the contaminated soil molding block using this adhesive force. In addition, the amount of radiation emitted to the periphery is reduced by the shielding layer of the radiation shielding sheet, and the shielding layer is covered by the buffer layer, so that elution can be prevented even when heavy metals such as lead are used for the shielding layer. it can. In addition, the shielding layer of lead or the like is protected by a flexible buffer layer, and is prevented from being damaged or torn even if embedded in the soil.

  As described above, in the disposal method of soil, sludge, or incinerated ash contaminated with radioactive substances according to the present invention, a large amount of contaminated soil, sludge, incinerated ash, etc. are solidified at low cost by simple work and radiation is shielded. Can be disposed of as a finished state.

It is a flowchart which shows the disposal method of the soil contaminated with the radioactive substance, sludge, or incineration ash which is one Embodiment of this invention. It is a schematic perspective view which shows the state which coat | covered the contaminated earth molding block formed with the method shown in FIG. 1 with the radiation shielding sheet. It is a schematic perspective view which shows the arrangement | positioning of the soil dirt molding block formed by the method shown in FIG. 1, and arrangement | positioning of a hanging metal fitting. It is a schematic sectional drawing of the radiation shielding sheet which coat | covers the contaminated earth molding block shown in FIG. It is a schematic sectional drawing which shows an example of the bank body formed with the method of this invention. It is a schematic sectional drawing which shows the other example of the bank body formed with the method of this invention. It is a schematic sectional drawing which shows the other example of the bank body formed with the method of this invention. It is a schematic sectional drawing which shows the other example of the bank body formed with the method of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a flowchart showing an outline of a method according to an embodiment of the present invention.
In this method, soil contaminated with radioactive substances, sludge after sewage treatment containing radioactive substances, or garbage incineration ash containing radioactive substances are solidified in blocks (ST1 to ST5). Then, the formed contaminated soil forming block 1 is covered with a radiation shielding sheet 2 as shown in FIG. 2 (ST6), and after reducing the radiation dose measured in the vicinity, it is embedded in a laid body or embankment as final disposal. (ST11).

The contaminated soil molding block 1 can be formed as follows.
Radioactive waste (ST1) such as contaminated soil, sludge, or incinerated ash temporarily stored in a temporary storage site or an intermediate treatment facility is carried into the processing plant to adjust the particle size (ST2). Soil, sewage sludge, incinerated ash, etc. near the ground surface contaminated with radioactive materials released from nuclear power plants have a particle size of approximately 80 mm or less, and these can be solidified as they are. . In addition, radioactive waste includes the remains of buildings and structures destroyed by earthquakes and tsunamis. Except for combustible materials such as wood and reusable materials such as steel frames, The particle size is reduced to 80 mm or less by crushing with a crusher or the like.

  The contaminated soil whose particle size is adjusted as described above is put into a mixer, and cement or a cement-based solidifying material is added and stirred (ST3). Then, the water necessary for the hydration reaction of the cement or cement-based solidified material is supplied in the form of a mist, and the soil particles are covered with the cement or the cement-based solidified material. Contaminated soil mixed with solidifying material is put into the mold. The mold is for molding contaminated soil in the same manner as the mold that is assembled when placing concrete, but it is made stronger than the mold in order to pressurize as described later.

In the mold 3, as shown in FIG. 3, a reinforcing bar 4 is assembled in advance, and a hanging metal fitting 5 for lifting the molded contaminated soil molding block is also arranged (ST4). In this way, the contaminated soil mixed with cement or cement-based solidifying material is put into the mold 3 in which the reinforcing bars 4 and the hanging metal fittings 5 are assembled, and the mixture is compacted by applying vibration. The vibration is generated by driving a vibration exciter fixed to the mold 3, and the contaminated soil is vibrated through the mold 3. At the same time, the pressure member is pressed against the contaminated soil in the mold 3 from above to pressurize the contaminated soil and compact the volume to reduce the volume (ST5). The applied pressure can be, for example, about 50 N / cm ² to about 100 N / cm ² . After compacting in this way, curing is performed to harden the cement or cement-based solidified material to form the contaminated soil molding block 1.
The contaminated soil molding block 1 is added with cement or a cement-based solidifying material so that the strength when the contaminated soil is hardened becomes, for example, about 500 N / cm ² to 1000 N / cm ² . Moreover, the shape of the contaminated soil molding block 1 is a rectangular parallelepiped, and the size can be, for example, 1 m × 1 m × 6 m. The dimension is not limited to this value, but the length of one side in the horizontal direction is larger than twice the length of the other side in the horizontal direction, and when stacked and arranged, it can be piled up in a grid pattern. Desirable dimensions are desirable.

As shown in FIG. 2, the hardened contaminated soil molding block 1 is coated with the radiation shielding sheet 2 to reduce the emitted radiation (ST6). As the radiation shielding sheet 2, for example, a sheet having a cross-sectional configuration as shown in FIG. 4 can be used.
The radiation shielding sheet 2 includes a shielding layer 11 formed of lead in a sheet shape, a buffer layer 12 laminated on both surfaces of the shielding layer 11, a surface coating layer 13 covering one of the buffer layers 12, and a buffer layer. 12 and the release paper 14 laminated on the other surface.

The shielding layer 11 is made of lead, which has high radiation shielding performance, is inexpensive, and can be easily formed thin. The thickness of the lead sheet is appropriately determined according to the contamination concentration of the soil to be covered, but is preferably 0.1 mm or more and 5 mm or less.
In addition, as the shielding layer, tungsten or the like can be adopted as a metal having a large specific gravity. Depending on the required radiation shielding performance, metals such as aluminum steel can be used.

The buffer layer 12 is obtained by impregnating a non-woven fabric made of synthetic fiber with rubberized asphalt in which synthetic rubber is mixed with asphalt, further applying rubberized asphalt on both sides, and embedding the non-woven fabric in rubberized asphalt. Is about 0.5 mm to 5 mm. The buffer layer 12 is flexibly deformed in the direction along the surface and in the thickness direction, and protects the shielding layer 11 from being damaged even if a stone piece or the like is pressed or rubbed. It has become. Further, the nonwoven fabric is reinforced so as to be resistant to tensile force.
In addition, the said buffer layer 12 can change a thickness suitably, and can also be formed only with a rubberized asphalt layer without including a nonwoven fabric. Moreover, it can replace with a nonwoven fabric and what formed so that a woven fabric, a metal mesh, etc. may be embedded in rubberized asphalt can also be used.

  The surface covering layer 13 forms the surface of the radiation shielding sheet 2 and is formed by laminating a synthetic resin in the form of a film having a thickness of about 0.1 μm to 1 mm on the buffer layer 12. As the synthetic resin, for example, polyester, polyethylene, polypropylene, or the like can be used.

The release paper 14 is a paper that is coated with a silicone resin or silicone oil on one side of a paper that is hard to tear such as kraft paper, and is capable of suppressing the adhesive force with rubberized asphalt. Therefore, it can be laminated and adhered to the buffer layer 12 made of rubberized asphalt, but can be easily peeled off.
Such a radiation shielding sheet 2 can be stored and transported by being wound or laminated in a roll shape, and the release paper 14 can be peeled off immediately before use to utilize the adhesive strength of the rubberized asphalt. it can.

The contaminated soil molding block 1 can be coated with the radiation shielding sheet 2 as follows.
The radiation shielding sheet 2 is cut into a corresponding size at the site where the contaminated soil molding block 1 is formed, and the release paper 14 is peeled off and pressed against the surface of the contaminated soil molding block 1. The buffer layer 12 made of rubberized asphalt has an adhesive force, and the radiation shielding sheet 2 is adhered to the contaminated soil molding block 1. The vicinity of the edge of the radiation shielding sheet 2 to be attached is overlapped with the radiation shielding sheet 2 to be attached so as to be adjacent. Thus, by sticking the radiation shielding sheet 2 to the entire surface of the contaminated soil molding block 1 without a gap, radiation from the radioactive material contained in the contaminated soil molding block 1 can be shielded.

For the contaminated soil molding block 1 covered with the radiation shielding sheet 2, the radiation dose to be emitted is measured, and the contaminated soil molding block 1 is processed as follows according to the measurement result.
The radiation is measured (ST7), and if the value is equal to or less than a predetermined value, it is temporarily stored in the B accumulation site as a low radiation dose (ST10). On the other hand, when the measured radiation dose exceeds a specified value, the contaminated soil molding block is further covered with a radiation shielding sheet. Then, the radiation dose is measured again (ST8), and when it falls below a prescribed value, it is stored in the B collection station (ST10). When the measured value exceeds the prescribed value, it is stored in the A accumulation place as the amount of radiation emitted is high (ST9).

  The contaminated soil molding block 1 formed as described above is embedded in the ground, but in addition to simply excavating a hole on the ground and embedding it in a body such as a tide embankment, a river embankment or an earth dam. It may be embedded, or may be embedded in a bank built as an emergency evacuation hill for a tsunami or a road bank (ST11). And in the contaminated soil molding block etc. with a high radiation dose carried into the A collection site and the contaminated soil molding block etc. with a low radiation dose carried into the B collection site, the area where the land to be embedded, the corpse or the embankment is constructed It can be used separately. That is, it is desirable to embed a contaminated soil molding block or the like having a high radiation dose carried into the A accumulation site in a land remote from an area where a resident is present such as a mountainous area. It can also be embedded in seawalls around airports where residents are not nearby, or in river bodies. On the other hand, a contaminated soil block or the like having a low radiation dose carried into the B collection site can be embedded in a seawall, a tsunami attenuation bank, an emergency evacuation hill, a road embankment or the like constructed near the residential area.

The embedment in which the contaminated soil molding block 1 is embedded can have a structure as shown in FIG. 5, for example.
This levee 31 is a seawall and is formed between two underground continuous wall bodies 32a and 32b constructed at a predetermined interval. Each underground continuous wall body 32a and 32b is connected to the coastline. Construct to be continuous in the direction along. The underground continuous wall body 32 may be formed by driving a steel sheet pile or a steel pipe sheet pile, or excavating a hole while stabilizing the wall surface with muddy water, etc., and arranging reinforcing bars or H-shaped steel, It may be formed by placing concrete so as to be embedded.
In the present embodiment, each of the sea-side underground continuous wall body 32a and the land-side underground continuous wall body 32b of the body 31 is formed by driving steel pipe sheet piles in two rows, and forms the body. Is enclosed in double.

  The ground 33 between the two underground continuous wall bodies 32a and 32b improves the ground to a predetermined depth and forms an impermeable layer 34. The ground improvement can adopt a method of mixing and solidifying cement-based solidification material into the soil, and injecting the solidification material while stirring the soil, penetrating the rotor blade having the vertical rotation center vertically downward A deep mixing method can be used. It is also possible to adopt a shallow mixing method in which the solidified material is mixed while excavating from the ground surface.

A radiation shielding sheet 35 is laid on the water-impermeable layer 34, and a waterproof sheet 36 made of a rubber-based material is further laid thereon. Wires 37 are laid on top of each other at predetermined intervals, and both ends of the wires 37 are connected to the top of the underground continuous wall body 32. A concrete retaining wall 38 is provided at the top of each of the sea-side and land-side underground continuous wall bodies 32 so as to connect steel pipe sheet piles 32 c and 32 d formed in two rows. Is connected to the top of one steel pipe sheet pile 32c within the retaining wall 38. And it winds on the saddle 39 provided in the top part of the other steel pipe sheet pile 32d, and hangs down to the surface of the layer which performed the ground improvement inside the two underground continuous wall bodies 32. On the impermeable layer 34 formed by the ground improvement, it is laid along the upper surfaces of the laid radiation shielding sheet 35 and the waterproof sheet 36. In this way, the plurality of wires 37 arranged at both ends connected to the tops of the two underground continuous wall bodies 32 are connected to each other by the connection wires 40 arranged in a direction substantially parallel to the wall surface of the underground continuous wall body 32. The wire 37 and the connecting wire 40 are meshed.
The radiation shielding sheet 35 laid on the water-impermeable layer 34 formed by ground improvement is a buffer layer made of rubberized asphalt on both sides of lead extended into a sheet shape like the radiation shielding sheet 2 shown in FIG. Can be used, and a surface coating layer can be further provided. The radiation shielding sheet 35 used here desirably covers both the buffer layers laminated on both sides of the shielding layer with a surface coating layer.
The waterproof sheet 36 may be formed of a rubber-based material, and a sheet used to prevent contaminated water from penetrating underground in a garbage disposal site or the like can be used.

The contaminated soil molding block 1 covered with the radiation shielding sheet 2 is arranged on the wire 37 and the connecting wire 40 that are mesh-shaped as described above. The blocks are arranged such that the length of one side in the horizontal direction is larger than the other side, and the long side is arranged in the width direction of the body, that is, the direction connecting the two underground continuous wall bodies 32a and 32b. The second layer is arranged such that the direction of the long side is a direction along the underground continuous wall bodies 32a and 32b, that is, a direction substantially perpendicular to the direction of the long side in the previously arranged layer. Therefore, when a plurality of layers are stacked, the contaminated soil molding block 1 or the like having one side having a large length is assembled in a cross-beam shape and stacked in a stable state. In addition, when each of the contaminated soil molding blocks 1 is arranged, it is desirable to arrange them with an interval between adjacent blocks. The interval can be set to about 3 cm to 5 cm, for example.
When the contaminated soil molding blocks 1 are stacked in a plurality of layers, it is desirable to cover the entire layer with a radiation shielding sheet for each layer.

When multiple layers of contaminated soil molding blocks 1 are stacked, the number of layers in the upper layer is reduced and the height is increased near the center between the two underground continuous wall bodies 32a and 32b so as to correspond to the shape of the levee 31. Laminate as the bodies 32a and 32b are approached.
An inspection hole 41 is provided in the gap between the arrayed contaminated soil molding blocks 1 by arranging a pipe member that reaches from the lowest layer to the uppermost layer of the stacked blocks and has a tip that reaches the surface of the body. This pipe member is assumed to have a diameter of about 100 mm and a peripheral surface in a mesh shape or provided with a large number of small holes. The inspection hole 41 enables observation of the concentration of radiation over a long period after completion of the body 1. Further, when the radiation leaks due to the damage of the radiation shielding sheet 2 covering the contaminated soil molding block 1, cement grout can be injected through the inspection hole 41.
Incidentally, the inspection hole 41 is desirably provided with a plurality, for example, 50m ² ~100m ² to preferably provided a single point.

  After the contaminated soil molding blocks 1 are stacked up to the uppermost layer, the whole is covered with a waterproof sheet made of a rubber-based material. And this is covered with the soil 42 which is not polluted with a radioactive substance, and it rolls to make the body 31. A concrete layer 43 for protecting the slope is formed on all or part of the slope of the support 31. Moreover, it is desirable to plant and protect the slope where the protective concrete layer is not provided. On the other hand, the top of the support 31 can be paved and used as a road.

Next, another example of the laid body formed by the disposal method of the present invention will be described with reference to FIG.
This levee 51 is formed by forming two rows of continuous underground wall bodies 52a and 52b in the same manner as the limb 31 shown in FIG. In this levee 51, the two underground continuous wall bodies 52a and 52b are excavated, and the bottom after the excavation is improved to form the impermeable layer 53. The formation of the water-impermeable layer 53 can be performed in the same manner as the laying body 31 shown in FIG. A radiation shielding sheet 54 and a rubber-based waterproof sheet 55 are laid on the water-impermeable layer 53, and a wire 56a and a connecting wire 56b are laid on top of each other to form a mesh. The wires 56a arranged substantially perpendicular to the wall surfaces of the two underground continuous wall bodies 52 are continuously pulled up from the position adjacent to the underground continuous wall body 52 along the wall surface of the underground continuous wall body 52, and end portions Is connected to a retaining wall 57 supported on the underground continuous wall body 52. The connection of the wire 56a to the retaining wall 57 can be performed in the same manner as the body shown in FIG. Similarly, the connecting wire 56b can be arranged in the direction along the wall surface of the underground continuous wall body 52 to connect the wire 56a.

The excavated soil 58 is spread on the wires 56a and the connecting wires 56b, and the contaminated soil molding block 1 is arranged thereon. Then, a radiation shielding sheet (not shown) is laid so as to cover the plurality of blocks arranged for each layer, and the contaminated soil molding block 1 is further arranged thereon. These contaminated soil molding blocks 1 are arranged with a gap between adjacent blocks, and the layers are alternately arranged so that the direction of the long side is substantially perpendicular to the direction of the long side in the previously arranged layer. Laminate sequentially by changing the 90 ° direction.
Further, in the gap between the contaminated soil molding blocks 1 arranged, a pipe member that reaches from the lowermost layer to the uppermost layer of the stacked blocks and whose tip reaches the surface of the laying body is arranged as an inspection hole 59.

  The contaminated soil molding blocks 1 arranged as described above are arranged with a predetermined interval between them and the wall surface of the underground continuous wall body 52, and the excavated soil 58 is backfilled and compacted in this interval. Then, the wire 56 a arranged in the vertical direction along the wall surface of the underground continuous wall body 52 is embedded in the backfilled excavated soil 58.

The contaminated soil molding block 1 is laminated to a position lower than the top of the retaining wall 57 provided on the underground continuous wall body 52, and the excavated soil 58 is backfilled and compacted thereon, and the upper surface of the retaining wall 57 is The height is almost the same as the top. On top of this, a reinforcing bar is placed and a top end concrete 60 is placed, and a lid is placed so as to contain the contaminated soil molding block 1 embedded between the two continuous underground walls 52.
In such a pedestrian 51, a contaminated soil molding block 1 containing soil, sludge, incinerated ash, etc. contaminated with radioactive substances, an underground continuous wall body 52, and an impermeable layer 53 formed by ground improvement at the bottom, The radiation can be shielded by being accommodated inside the ceiling concrete 60. Further, in this laying body 51, a part of the weight of the stacked block group is supported by the top of the underground continuous wall body 52 by the wire 56a, and is stacked when a large horizontal force such as an earthquake acts. The block group is allowed to swing between the underground continuous wall bodies 52 formed on both sides. Therefore, the horizontal force acting on the body is relaxed, and the stable body 51 is stable even during an earthquake. Such a levee can be used for a long time as a river bank, a seawall, or the like.

The embedment in which the contaminated soil molding block 1 is embedded is not limited to one in which wires are arranged between the tops of two underground continuous walls as shown in FIG. 5 or FIG. Depending on the state of the ground, the state of land use, etc., blocks can be embedded as other forms.
For example, as shown in FIG. 7, a waterproof sheet 62 is laid on the ground 61, and the contaminated soil molding block 1 is arranged thereon, and the embankment 63 is applied so as to embed these blocks, thereby forming a support 64. can do. In addition, as shown in FIG. 8, two underground continuous wall bodies 71 formed opposite to each other or an inside of the underground continuous wall body formed so as to surround a predetermined range are excavated, and contaminated soil is included in the excavated range. It is also possible to arrange the molding blocks 1 and embed them with excavated soil 72 to form the slats 73.
In addition, the code | symbol 74 shown in FIG. 8 shows a water-impermeable layer, and the code | symbol 75 shows the retaining wall supported on the underground continuous wall 71. FIG.

In addition, the present invention is not limited to the embodiments described above, and can be implemented in various forms within the scope of the present invention.
For example, the shape and size of the contaminated soil molding block can be appropriately set in consideration of the position of the embedding position, workability, and the like.
In addition, the radiation shielding sheet may use other materials within the scope of the present invention, and may be one in which layers other than the layers described in the above embodiment are further laminated.

1: Contaminated soil molding block, 2: Radiation shielding sheet, 3: Mold, 4: Rebar, 5: Hanging bracket,
11: shielding layer, 12: buffer layer, 13: surface coating layer, 14: release paper,
31: Hidden, 32: Underground continuous wall body, 33: Ground between underground continuous wall bodies, 34: Impervious layer, 35: Radiation shielding sheet, 36: Waterproof sheet, 37: Wire, 38: Retaining wall, 39: Saddle, 40: Connecting wire, 41: Inspection hole, 42: Soil not contaminated with radioactive material, 43: Concrete layer protecting slope
51: Body, 52: Continuous underground wall, 53: Impervious layer, 54: Radiation shielding sheet, 55: Waterproof sheet, 56a: Wire, 56b: Connecting wire, 57: Retaining wall, 58: Excavated soil, 59: Inspection hole 60: Top concrete
61: Ground, 62: Tarpaulin, 63: Filling, 64: Body
71: underground continuous wall, 72: excavated soil, 73: levee, 74: impermeable layer, 75: retaining wall

Claims (1)

Cement or cement-based solidifying material is added to and mixed with soil contaminated with radioactive material, sludge after sewage treatment containing radioactive material, or garbage incineration ash containing radioactive material.
Injecting the water necessary for the hydration reaction of the cement or cement-based solidified material into a mist to the soil, sludge or incinerated ash,
Put the soil, sludge or incineration ash into a mold formed in a predetermined size, give vibration and pressurize,
The contaminated soil molding block formed by curing the cement or cement-based solidifying material is coated with a coating material that shields radiation,
The contaminated soil molding block covered with the covering material shall be embedded in soil ,
The step of coating the contaminated soil molding block with the covering material includes a shielding layer in which a metal having radiation shielding properties is formed into a plate shape or a sheet shape, and a buffer layer in which flexible asphalt materials are laminated on both surfaces of the shielding layer. And a radiation shielding sheet having a radioactive substance characterized in that the radiation shielding sheet is pressed against the contaminated soil molding block, and the radiation shielding sheet is adhered to the contaminated soil molding block by the adhesive force of the asphalt material. To dispose of soil, sludge or incinerated ash.

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