JPH1078498A - Simple method for disposing of radioactive waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent radioactive wastes from falling off from the surface of a solidified object, and from contaminating on the surface, and to improve the efficiency in the transportation and disposal of them by solidifying solid radioactive wastes in a built-up bottomed mold, by releasing the solidified object from the mold, and by covering the outer peripheral surface of it. SOLUTION: A mold is fabricated like a box, and radioactive wastes to be disposed of are solidified with, for example, a cementitious solidifying material. They are cured for a certain time and is solidified to shape a rectangular solidified object 4. The mold is separated from the solidified object 4, with a base plate 1b left. On this occasion, a spacer 2 is kept fixed on the solidified object 4 and a gripper 3 is fixed on a formed concavity. Then, a shield 5 is pulled up with a wire 8 to veil the solidified object 4, interlock with the base plate 1b and cover the outer peripheral surface of the solidified object 4 completely. The covering of it makes it possible to keep the radioactive wastes from falling off during transportation and prevent the contamination on the surface. The rectangular shape of the solidified object 4 improves the stability during transportation and in a fixed position and makes it possible to fix the object 4 efficiently in a limited disposal space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of solidifying and disposing solid or powdered radioactive waste, and more particularly to a method for efficiently and economically transporting and embedding solidified solids. It relates to a simple disposal method.

[0002]

2. Description of the Related Art Conventionally, low-level radioactive waste such as concrete waste contaminated by reactor cooling water and concrete waste contaminated by the action of neutron beams are dispersed to the air, surface contamination, and the like. In order to prevent members from being exposed to the radiation, they are enclosed in flexible containers specified in JIS Z 1651, and are transported and disposed of for each container.

[0003]

However, when bulk or powdered radioactive waste is stored in the container, if the container is damaged, the radioactive material contained in the radioactive waste is scattered from the damaged portion. There is a risk of doing it. In addition, since the individual radioactive waste stored in the container is not integrally solidified, in order to safely transport the container to the disposal site and set it in place,
It is necessary to consider the deformation of the container due to its own weight which differs for each stored radioactive waste.

[0004] Further, since each container has an irregular shape due to the deformation due to its own weight, when these containers are fixed in a disposal site, a gap is formed between adjacent containers, and a predetermined space in the disposal space is required. There is a problem that can not be placed efficiently. In addition, when compaction of the earth and sand filling the gap between the containers that occurs at the time of stationary installation is insufficient, there is a problem that the cover soil may collapse after these containers are buried.

[0005] In the disposal method in which the containers are stored, there is a problem that the disposal cost is increased because the containers are buried in each container and cannot be reused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a safe, efficient and low-cost transportation and disposal by solidifying and coating a massive or powdery radioactive waste. It is an object of the present invention to provide a simple radioactive waste disposal method.

[0007]

The simple disposal method of radioactive waste according to the present invention comprises the steps of: solidifying a solid or solid radioactive waste in an assembled bottomed form to form a solid; The solidified body is released from the mold, and the outer peripheral surface of the solidified body is coated. In other words, by solidifying and coating solid or powdered radioactive waste, it is possible to prevent the separation of radioactive substances from the solidified body surface and prevent surface contamination, and to efficiently carry and dispose of it. Is what you do.

Further, by using an assembling type mold as a container used for solidification, the mold can be disassembled and reused after solidification. Further, the size of the solidified body can be enlarged or reduced by changing the size of the mold, and the size and weight of the solidified body can be arbitrarily set in consideration of the transport space and the disposal space at the time of transportation.

In the above disposal method, when the coating is made by a shield made of an iron plate or a steel plate, it is possible to prevent the radioactive substance from peeling off the surface of the solidified body during transportation and to prevent surface contamination. can do.

[0010] Further, a film forming paint is applied to the inner surface of the assembled bottomed mold, a solid or radioactive solid waste is stored in the mold, and a solidified material is injected into the mold. By solidifying integrally with the paint to form a solidified body, releasing the solidified body from the mold, and applying the paint on the upper surface of the solidified body, the separation of the radioactive material and the prevention of surface contamination are prevented. In addition, the releasability from the mold can be improved.

Further, a shielding sheet is disposed on the inner peripheral surface of the assembled bottomed formwork, and a solid or radioactive solid waste is stored in the formwork and the solidified material is injected. Also, a configuration in which a shielding sheet is arranged on the upper surface of the mold, and the shielding sheet and the waste are integrally solidified to form a solidified body,
It is possible to prevent separation of the radioactive substance, prevent surface contamination, and improve releasability from the mold.

In any of the above configurations, when the solidified body is formed into a rectangular shape, that is, a cubic shape, a rectangular parallelepiped shape, and the like, the stability at the time of transportation and stationary is improved, and at the same time, the stability is improved. Since the solidified bodies can be arranged without any gaps between the solidified bodies, the solidified bodies can be placed at a high density in a predetermined transportation space and disposal space.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. First, a mold for solidifying solid or radioactive solid waste in solid form using a solidifying material will be described. FIG. 1 shows a mold 1 before assembly.
FIG. 2 shows a state in which a solidified body is formed in the assembled mold 1. In these figures, reference numerals 1 a and 1 b denote a top plate and a bottom plate, respectively.
2 is a spacer, 3 is a handle, and 4 is a solidified radioactive waste.

The formwork 1 is assembled in a box shape by detachably engaging a rectangular iron plate or a steel plate, and a top plate 1a is provided with a spacer 2 detachable from the top plate 1a. ing. The spacer 2 forms a recess in the solidified body 4 in order to fix the handle 3 provided for improving the operability of the solidified body 4 by a crane or the like so as not to protrude from the outer peripheral surface of the solidified body 4. Alternatively, it is assembled into a box shape by engaging a steel plate, and its open end side is detachably fixed to the top plate 1a. The handle 3 is fixed to the bottom plate 2a of the spacer 2, and the tip 3a of the handle 3 passes through the bottom plate 2a to the outside of the spacer 2 fixed to the top plate 1a, that is, the form 1 It is fixed so as to protrude inward.

Next, in order to prevent the radioactive substance from being separated from the solidified body 4 during transportation and to prevent surface contamination.
The shield 5 described above will be described. As shown in FIG. 3, the shielding body 5 is formed in a box shape by engaging a rectangular iron plate or a steel plate having the same dimensions as the formwork 1 and has an upper surface 5a.
An opening 6 is formed so that the handle 3 fixed to the solidified body 4 can be hooked from the outside by a wire or the like when the shielding body 5 is engaged with the solidified body 4. Around the periphery, a handle 7 for facilitating handling by a crane or the like is provided.

Next, a simple disposal method of radioactive waste according to the present invention will be described. First, as shown in FIG. 2, the mold 1 is assembled in a box shape, and the radioactive waste to be disposed is solidified in the mold 1 with, for example, a cement-based solidifying material. When the mixture injected into the mold 1 is cured for a certain period of time, the mixture is solidified to form a rectangular solid 4.

Next, the mold 1 is separated from the solidified body 4 while leaving the bottom plate 1b. At this time, the top plate 1a is separated from the top plate 1a while being fixed to the solidified body 4 and separated from the solidified body 4 as shown by a chain line in FIG.
Here, a recess is formed by the spacer 2 on the contact surface between the solidified body 4 and the top plate 1a, and the handle 3 is fixed to the recess without protruding from the outer peripheral surface. Next, a wire is hooked on the handle 3 and lifted, and the solidified body 4 is pulled out of FIG.
The handle 3 is rotated counterclockwise to position the handle 3 so as to face upward.

Then, as shown in FIG. 3, the shield 5 is hung by the wire 8 to cover the solidified body 4, and the shield 5 is engaged with the bottom plate 1b fixed to the solidified body 4. Thereby, the outer peripheral surface of the solidified body 4 is completely covered. As shown in FIG. 4, the coated solid body 4
It is easy to handle such as transporting. After the solidified body 4 is transported to the disposal site and set in the disposal space, the shield 5 is separated from the solidified body 4 and reused.

As described above, the outer peripheral surface of the solidified body 4 is
When coated, the radioactive material can be prevented from peeling off during transport, surface contamination can be prevented, and the product can be safely transported to a disposal site. In addition, since the solidified body 4 is formed in a rectangular shape, the stability during transportation and emplacement is improved, and the transportation and embedding work can be performed safely. There is no gap between the four, and it is possible to prevent the covering soil from being depressed after being buried, and it is possible to efficiently place the soil in a limited disposal space. When the dimensions of the disposal space are known in advance, it is possible to more efficiently place the disposal space in the disposal space by forming a mold in accordance with the dimensions and molding the solidified body.

Next, the third aspect of the present invention will be described.
According to the present invention, as shown in FIG. 5, an organic resin such as a silicone resin, a fluorine-based resin, and putty, which is cured at room temperature to form a film having a constant thickness, is coated on the inner surface of the assembled mold 1. After being applied and dried, the waste is stored in the mold 1, a solidified material is injected and solidified integrally with the paint 10 to form a solidified body 4, and the solidified body 4 is formed. As shown in FIG. 6, the outer peripheral surface of the solidified body 4 is coated by releasing the mold 1 from the mold 1 and applying the paint 10 on the upper surface of the solidified body.

With such a configuration, in addition to the function of preventing separation of radioactive substances and prevention of surface contamination, the releasability from the mold 1 can be improved. In addition, even when the solidified body 4 is molded in advance, the solidified body 4 is released from the mold 1, and then the coating material 10 is applied to the outer peripheral surface, the same radioactive substance peeling and surface contamination as described above can be obtained. Can be prevented.

Next, the invention of claim 4 will be described.
According to the present invention, as shown in FIGS. 7 and 8, a resin or fiber sheet 11 such as a polypropylene sheet, a polyethylene sheet, a vinyl chloride sheet, or a water-impermeable cotton cloth is provided on the inner surface of the mold 1. Place and end 1
1a, the waste is stored in the mold 1 and a solidified material 4 is formed by injecting a solidified material and solidifying integrally with the sheet 11, as shown in FIG. By releasing the solidified body 4 from the mold 1, the outer peripheral surface of the solidified body 4 is coated.

Even with such a configuration, the radioactive substance can be prevented from peeling off and surface contamination, and the releasability from the mold can be improved. In addition, as shown in FIG. 11, if the suspension wire 12 is provided on the sheet 11, even if the handle 3 as shown in FIG. 10 is not provided, as shown in FIG. Operability in the transportation work of the vehicle can be improved.

[0024]

As is apparent from the above description, the following effects can be obtained according to the simple radioactive waste disposal method of the present invention. (A) By solidifying and coating solid or radioactive solid or radioactive waste, the workability of transportation and disposal is improved, and the separation of radioactive substances from the solidified surface and the prevention of surface contamination are prevented. Work safety can be ensured. (B) Since a prefabricated mold is used as a container used for solidification, the mold can be disassembled and reused after solidification, and disposal costs can be reduced. In addition, the size of the solidified body can be expanded or reduced by changing the size of the formwork. Transportation and disposal. (C) In the disposal method according to claims 3 and 4, in addition to the functions of preventing the radioactive substance from peeling and preventing surface contamination, the releasability from the mold can be improved, and the disposal work can be shortened. Can be achieved. (D) In the disposal method according to the fifth aspect, since the stability during transportation or stationary is improved, the safety of work can be ensured, and the solidified bodies can be arranged without gaps. Therefore, transportation and disposal can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state before assembling a mold in a disposal step showing an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state following the state of FIG. 1 in which radioactive waste is solidified in an assembled mold with a solidifying material to partially separate the mold.

FIG. 3 is a cross-sectional view showing a state in which a shield is placed on the released solidified body, following the state shown in FIG. 2;

FIG. 4 is a cross-sectional view showing a state where the solidified body covered with the shield is transported following the state of FIG. 3;

FIG. 5 is a cross-sectional view showing a state in which a film-forming paint is applied to a mold in advance to form a solidified body in a disposal step of the present invention.

FIG. 6 is a cross-sectional view showing a state in which the mold is released, following the state of FIG. 5;

FIG. 7 is a plan view showing an example of a state in which a shielding sheet arranged on the inner peripheral surface of the mold is arranged on the mold before assembly in the disposal step of the present invention.

FIG. 8 is a cross-sectional view showing a state in which the radioactive waste stored in the assembled form is solidified integrally with the shielding sheet with a solidifying material, following the state of FIG.

FIG. 9A is a cross-sectional view showing a state following the state shown in FIG. 8, in which the mold is separated after the handle is fixed to the solidified body. (B) is a plan view of (a).

FIG. 10 is a cross-sectional view showing a state in which the released solidified body is suspended and transported by a wire, following the state of FIG. 9;

FIG. 11 shows a shielding sheet to which a hanging wire is fixed.
It is a top view which shows an example of the state arrange | positioned on the formwork before assembling.

FIG. 12 shows a state in which the radioactive waste stored in the assembled form is solidified integrally with the shielding sheet using a solidifying material, and then the solidified product released from the mold is transported, following the state of FIG. It is sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Formwork 4 Solidified body 5 Shield 10 Film-forming paint 11 Shield sheet

Continued on the front page (72) Inventor Hisashi Tateyashiki 1-3-25 Koishikawa, Bunkyo-ku, Tokyo Koishikawa Daikoku Building Mitsubishi Materials Corporation Environmental Recycling Business Center

Claims (5)

[Claims] The solid radioactive waste in a lump or powder is solidified in a prefabricated bottomed mold to form a solidified body, and the solidified body is released from the mold to form a solidified body. A simple disposal method for radioactive waste, characterized in that a coating is applied to the outer peripheral surface. 2. The simple disposal method of radioactive waste according to claim 1, wherein said coating is applied by a shield made of an iron plate or a steel plate. 3. A film forming paint is applied to the inner surface of the assembled bottomed formwork, and a solid or radioactive solid waste is stored in the formwork, and a solidification material is injected into the formable solid form waste. A simple method of disposing of radioactive waste, comprising: solidifying integrally with a paint to form a solid; releasing the solid from the mold; and applying the paint to an upper surface of the solid. 4. A shielding sheet is disposed on the inner peripheral surface of the assembled bottomed formwork, and a solid or radioactive solid waste is stored in the formwork and solidified material is injected. Disposing a shielding sheet on the upper surface of the mold, solidifying the shielding sheet and the waste to form a solid, and releasing the solid from the mold. Simple disposal method for things. 5. The simple disposal method for radioactive waste according to claim 1, wherein the solidified body is solidified into a rectangular body and molded.