JP2008170174A - Container bag for low-level radioactive waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a container bag for low-level radioactive waste which enables easy accommodation of solid low-level radioactive waste, generated from nuclear power plants and the like and to safely store the waste, without the occurrence of radiation leakage, until the volume of the waste is reduced through incineration. <P>SOLUTION: The container bag, for the low-level radioactive waste which is made of plastics-coated fabric, has an approximately square lid part, a tubular lateral face part and a substantially square-bottom part and is constituted, by fusing the lateral face part with the bottom part at the circumference of it being characterized in that the plastics coated fabric is a polyurethane-coated fabric whose base fabric is polyester fabric, with the four corners of the bottom part being round out, in that the polyurethane-coated fabric is fused by overlaying substantially over the entire surface of the bottom part, and in that the container bag is made, by laminating and fusing the polyurethane coated fabric with a part in contact with the bottom part below the lateral face part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a low level radioactive waste container bag. More specifically, the present invention can easily store solid low-level radioactive waste generated from nuclear power plants and the like and store it safely without incurring radiation leakage until it is incinerated to reduce its volume. It relates to a low-level radioactive waste container bag that can be made.

At nuclear power plants, low-level radioactive waste with low radioactive levels is generated during operation and periodic inspections. Examples of solid low-level radioactive waste include used work clothes, gloves, and paper towels. For example, research institutes also generate low-level radioactive waste derived from radioactive isotopes used as tracers. These low-level radioactive wastes are reduced in volume by incineration, solidified with cement, etc., packed in drums, transported to Japan Nuclear Fuel's low-level radioactive waste burial center, and buried in concrete pits. Will be disposed of.
Low-level radioactive waste is generated in large quantities but at a low radioactive level, and is generated at various locations in the nuclear power plant, so it is not easy to collect and store it. For this reason, means for efficiently treating low-level radioactive waste are being studied.
For example, reducing the volume of low-level radioactive waste to reduce the volume, increasing the amount stored in the carton box, reducing the number of carton boxes, and reducing the temporary storage location of the carton box. As a low-level radioactive waste disposal method, a thin board is placed on a bottomed cylindrical cartridge containing low-level radioactive waste, and the low-level radioactive waste in the cartridge is placed on the board using a compression processing unit. The low-level radioactive waste is repeatedly pressed in order, and the low-level radioactive waste is kept in a compressed state by the board, and then the storage of the low-level radioactive waste, the placement of the board, and the pressing by the compression processing device are sequentially repeated. A method has been proposed (Patent Document 1). FIG. 2 is a sectional view (a) of a cartridge used in this method and a side view (b) of a compression processing apparatus. A low-level radioactive waste 11 is stored in the cartridge 10, and a thin plate-like board 12 is placed on the cartridge 10. The low-level radioactive waste is pressed together with the board by the pressure plate 14 in the compression processing device 13. In the embodiment shown in FIG. 2A, the storage of low-level radioactive waste, the placement of the board, and the pressing by the compression processing device are repeated four times.
However, the number of compression treatment equipment that can be installed is limited, and low-level radioactive waste is generated everywhere.Therefore, low-level radioactive waste is placed between the site where low-level radioactive waste is generated and the compression treatment equipment. There is a hassle of reciprocating the stored cartridge. Also, some of the low-level radioactive waste may scatter during the cartridge reciprocation.
JP 2000-65990 A

  The present invention is a low-level radioactive material that can easily store solid low-level radioactive waste generated from nuclear power plants and the like, and can be safely stored without causing radiation leakage until it is incinerated to reduce its volume. It was made for the purpose of providing a waste container bag.

As a result of intensive research to solve the above-mentioned problems, the present inventor is made of a polyurethane stretch cloth based on a polyester fabric, and has a substantially square lid portion, a cylindrical side surface portion, and a substantially square bottom surface portion. The side surface portion is fused to the bottom surface portion at the periphery of the bottom surface portion, the four corners of the bottom surface portion are rounded, and the polyurethane stretch fabric is laminated and fused to substantially the entire surface of the bottom surface portion. The container bag formed by laminating and fusion-bonding the polyurethane stretch cloth to the part in contact with the part is found not to be perforated or torn due to wear, and to be free from damage from the bonded part. It came to complete.
That is, the present invention
(1) A low-level radioactive waste made of plastic cloth, having a substantially square lid, a cylindrical side surface, and a substantially square bottom surface, and the side surface is fused to the bottom surface at the periphery of the bottom surface. A container container bag, wherein the plastic pulling cloth is a polyurethane pulling cloth based on a polyester woven fabric, the four corners of the bottom surface portion are rounded, and the polyurethane pulling cloth is laminated and fused to substantially the entire bottom surface portion; A low-level radioactive waste container bag, characterized in that the polyurethane stretch cloth is laminated and fused to a portion in contact with the bottom surface below the side surface;
(2) The low-level radioactive waste container bag according to (1), wherein the lid part is attached to the side part so as to be opened and closed by a slide fastener having a plastic element that goes around substantially three sides of a substantially square.
(3) A low-level radioactive waste container bag according to (1), wherein a bulge prevention sheet made of a strip-like polyurethane fabric that circulates around the side surface is fused to the cylindrical side surface.
Is to provide.

  The low-level radioactive waste container bag of the present invention has high strength, does not cause perforation or tear due to wear, and does not break from the bonded portion. Therefore, as a container bag for storing and storing low-level radioactive waste. It can be used suitably. By attaching the lid part to the side part so that it can be opened and closed using a slide fastener, after the low-level radioactive waste is put in the container bag, the lid part is immediately closed to prevent the low-level radioactive waste from scattering. Can do. By making the element of the slide fastener plastic, when the container bag is full of low-level radioactive waste, it can be incinerated as it is, reducing the amount of work that touches the low-level radioactive waste and ensuring safety. And it can be easily incinerated to reduce the volume. The low-level radioactive waste container bag of the present invention can be handled stably without losing its shape by providing a bulge prevention sheet that circulates around the cylindrical side surface.

The low-level radioactive waste container bag of the present invention is made of plastic pulling cloth, has a substantially square lid, a cylindrical side surface, and a substantially square bottom surface, and the side surface is on the bottom surface at the periphery of the bottom surface. A container bag that is fused, and the plastic pulling cloth is a polyurethane pulling cloth based on a polyester woven fabric, the four corners of the bottom surface portion are rounded, and the polyurethane pulling cloth is laminated on substantially the entire bottom surface portion. This is a low-level radioactive waste container bag in which the polyurethane stretch fabric is laminated and fused to a portion that is fused and in contact with the bottom surface portion below the side surface portion.
FIG. 1 is a front view (a), a side view (b), a rear view (c) and a bottom view (d) of one embodiment of the low-level radioactive waste container bag of the present invention. The low-level radioactive waste container bag of this aspect is composed of a substantially square lid portion 1, a cylindrical side surface portion 2, and a substantially square bottom surface portion 3, and the lower end of the side surface portion is folded inward, and at the periphery of the bottom surface portion. It is fused with the bottom part.
The low-level radioactive waste container bag of the present invention is made of a polyurethane stretch cloth based on a polyester fabric. Since the polyurethane stretch fabric can be fused, a container bag can be easily manufactured with fewer man-hours than a rubber stretch fabric that requires the use of an adhesive. In addition, polyurethane stretch fabrics based on polyester fabrics have better wear resistance and fusing properties than ethylene-vinyl acetate copolymer stretch fabrics, making container bags less likely to be pierced or torn due to wear. The product life is long and there is no risk of low level radioactive waste leaking out from the container bag. Although there is no restriction | limiting in particular in the material of the polyurethane of the polyurethane stretch fabric used for this invention, Since the thermoplastic polyurethane synthesize | combined from polyester polyol and tolylene diisocyanate or diphenylmethane diisocyanate is large, it can be used conveniently.

Although there is no restriction | limiting in particular in the dimension of the low level radioactive waste container bag of this invention, It is preferable that the side of a substantially square is 400-600 mm, and it is preferable that height is 600-800 mm. If the side of the substantially square is less than 400 mm and the height is less than 600 mm, the capacity of the container bag is small, and it may be difficult to efficiently treat low-level radioactive waste. If one side of the approximately square exceeds 600 mm and the height exceeds 800 mm, it may be difficult to carry and incinerate easily.
The low-level radioactive waste container bag of the present invention has rounded corners 4 at the four corners of the bottom as shown in FIG. By providing roundness at the four corners of the bottom surface portion, wear at the four corners of the bottom surface portion can be reduced and occurrence of breakage can be prevented. Although there is no restriction | limiting in particular in the curvature radius of the four corners of a bottom face part, It is preferable that it is 20-150 mm, and it is more preferable that it is 40-100 mm. When the curvature radius of the roundness at the four corners of the bottom portion is less than 20 mm, the wear reduction effect may not be sufficiently exhibited. If the curvature radius of the roundness at the four corners of the bottom portion exceeds 150 mm, the shape of the container bag may become unstable.
The low-level radioactive waste container bag according to the present invention is formed by laminating and fusion-bonding a polyurethane fabric cloth having a polyester fabric base fabric to substantially the entire bottom surface portion, and a polyester fabric base fabric portion in contact with the bottom surface portion below the side surface portion. The polyurethane stretch fabric is laminated and fused. As shown in FIG. 1 (d), a bottom surface reinforcing stretch cloth 5 made of polyurethane stretch cloth is laminated and welded to substantially the entire bottom surface portion, and a side surface lower reinforcement stretch cloth is formed at a portion in contact with the bottom surface portion below the side surface portion. 6 is laminated and fused. By laminating and fusing the bottom portion reinforcing stretch fabric and the side portion lower reinforcement stretch fabric, wear at the bottom portion and the vicinity thereof can be reduced, and the occurrence of breakage can be prevented.

In the low-level radioactive waste container bag of the present invention, it is preferable that the lid portion is attached to the side portion so as to be opened and closed by a slide fastener having a plastic element that circulates substantially three sides of a substantially square shape. In the low-level radioactive waste container bag of the embodiment shown in FIG. 1, the lid 1 is attached to the side part 2 by slide fasteners 7 that circulate around the front, both sides, and the rear end. When low-level radioactive waste is generated, the slide fastener can be moved to open the lid, and the lid can be closed immediately after being stored in a container bag, and the slide fastener can be moved to close the lid. For this reason, low-level radioactive waste can be sealed and stored safely.
In the slide fastener used for the low-level radioactive waste container bag of the present invention, the element is preferably made of plastic. By using slide fasteners with plastic elements, the container bag can be incinerated when it is full of low-level radioactive waste. Therefore, it is possible to reduce the work of touching low-level radioactive waste, and to incinerate safely and easily and reduce the volume.

In the low-level radioactive waste container bag of the present invention, it is preferable that a bulge-preventing sheet made of a strip-shaped polyurethane cloth that circulates around the side surface is fused to the cylindrical side surface. In the low-level radioactive waste container bag of the embodiment shown in FIG. 1, two bulge prevention sheets 8 made of a strip-like polyurethane stretch around the side surface are provided on the cylindrical side surface. By providing a bulge-preventing sheet on the cylindrical side surface, even if the container bag is filled with low-level radioactive waste, the side surface will not bulge and the container bag will not lose its shape, and it will retain its good appearance and be handled. Becomes easier.
The low level radioactive waste container bag of the present invention can be provided with a hanging hand. In the low-level radioactive waste container bag of the aspect shown in FIG. 1, a total of eight hanging hands 9 are provided on the bulge prevention sheet. By providing the suspension hand, it becomes easy to transport and move the container bag containing the low-level radioactive waste.
Polyurethane pulling cloth based on polyester fabric has a wear resistance of about twice that of ethylene-vinyl acetate copolymer pulling cloth, and a low-level radioactive waste container bag that is resistant to wear can be obtained. Polyurethane stretch fabric based on polyester fabric has approximately 2.5 times the adhesive strength of the fused portion compared to the ethylene-vinyl acetate copolymer drawn fabric, so there is no risk of breakage from the fused portion. A durable low level radioactive waste container bag can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1
A low level radioactive waste container bag of the embodiment shown in FIG. 1 was made.
Polyurethane produced by the reaction of butylene adipate polyol [Nippon Polyurethane Industry Co., Ltd., Nipponporan (registered trademark) 4009] and diphenylmethane diisocyanate [Nippon Polyurethane Industry Co., Ltd., MDI] is used on both sides of a polyester plain fabric with a basis weight of 300 g / m ^2. A polyurethane stretch cloth having a thickness of 0.5 to 0.6 mm was produced.
From this polyurethane stretch fabric, a substantially square bottom surface material having a side of 500 mm and rounded corners with a radius of curvature of 60 mm and a bottom side reinforcing material having a side of 460 mm and rounded corners with a radius of curvature of 40 mm are cut out and laminated together. The material shown in FIG. 1D was fused.
A material having a shape in which a rectangular side portion material of 680 mm × 1,927 mm and a rectangular lid portion material of 600 mm × 500 mm were continuously cut out from the polyurethane stretch cloth. Further, a 50 mm × 1,927 mm side portion lower reinforcing stretch fabric was cut out from the polyurethane stretch fabric, and laminated and fused with the side portion material, leaving a fusion allowance of 30 mm below the side portion material.
Cut out two 100mm x 1,927mm bulge prevention sheets from polyurethane stretch fabric and sew 8 polypropylene sheets of 1.5mm thickness and 50mm x 420mm by sewing. The center line of the bulge prevention sheet is 200mm from the bottom. Lamination was performed so that the position was 450 mm. Next, two sides of the side portion material of 680 mm were fused to form a cylindrical shape with a fusion allowance of 30 mm, and the lower fusion allowance of 30 mm was folded inward and fused at the periphery of the bottom portion portion material.
Two 80 mm × 560 mm lid side materials were cut from the polyurethane stretch cloth. A rectangular lid material of 600 mm x 500 mm is bent into a shape with a rear surface height of 50 mm, a top surface of 500 mm on one side, and a front surface height of 50 mm. A substantially square lid having a height of 50 mm and a side of 500 mm was prepared. Resin fasteners [YKK Co., Ltd., 65EY] were attached to the lid part and the side part to complete a low-level radioactive waste container bag.
The waste was stored while repeating the opening and closing of the lid of the obtained low-level radioactive waste container bag. The container bag was easy to handle, the lid was opened and closed smoothly, and the container bag maintained a substantially rectangular parallelepiped shape when filled with waste. Container bags filled with waste were put into a general waste incinerator and incinerated. The container bag burned out with the waste and did not affect the incineration of other general waste. From this result, it can be predicted that the low-level radioactive waste container bag of the present invention can be used without any trouble in the treatment of low-level radioactive waste.

  The low-level radioactive waste container bag of the present invention has high strength, does not cause perforation or tear due to wear, and does not break from the bonded portion. Therefore, as a container bag for storing and storing low-level radioactive waste. It can be used suitably. By attaching the lid part to the side part so that it can be opened and closed using a slide fastener, after the low-level radioactive waste is put in the container bag, the lid part is immediately closed to prevent the low-level radioactive waste from scattering. Can do. By making the element of the slide fastener plastic, when the container bag is full of low-level radioactive waste, it can be incinerated as it is, reducing the amount of work that touches the low-level radioactive waste and ensuring safety. And it can be easily incinerated to reduce the volume. The low-level radioactive waste container bag of the present invention can be handled stably without losing its shape by providing a bulge-preventing sheet that circulates around the cylindrical side surface.

1 is a front view, a side view, a rear view, and a bottom view of one embodiment of a low-level radioactive waste container bag of the present invention. FIG. It is explanatory drawing of an example of the processing method of the conventional low level radioactive waste.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover part 2 Side part 3 Bottom part 4 Roundness 5 Bottom part reinforcement pulling cloth 6 Side part downward reinforcement pulling cloth 7 Slide fastener 8 Swelling prevention sheet 9 Lifter 10 Cartridge 11 Low level radioactive waste 12 Board 13 Compression processing apparatus 14 Addition Pressure plate

Claims (3)

  A low-level radioactive waste container bag made of a plastic cloth, having a substantially square lid portion, a cylindrical side surface portion, and a substantially square bottom surface portion, the side surface portion being fused to the bottom surface portion at the periphery of the bottom surface portion. The plastic fabric is a polyurethane fabric based on a polyester fabric, the four corners of the bottom surface are rounded, and the polyurethane fabric is laminated and welded to substantially the entire surface of the bottom surface. A low-level radioactive waste container bag, characterized in that the polyurethane stretch cloth is laminated and fused to a portion in contact with a lower bottom portion.   The low-level radioactive waste container bag according to claim 1, wherein the lid portion is attached to the side portion so as to be opened and closed by a slide fastener having a plastic element that goes around substantially three sides of a substantially square.   The low-level radioactive waste container bag according to claim 1, wherein a bulge-preventing sheet made of a strip-shaped polyurethane cloth that circulates around the side surface portion is fused to the cylindrical side surface portion.

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