JP2004085444A - Container for additionally supplying miscellaneous solid waste and additional supply method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and low-cost container for additionally supplying miscellaneous solid waste, capable of reliably and additionally supplying waste without the concern for blocking supply path etc. when conducting volume reduction processing in a fusion furnace. <P>SOLUTION: The container 1 for additional supply is formed by underlaying a combustible or thermo-softening bottom plate 12, in such a way as to block the opening on the lower side of a heat-resistant tube body 11 having upper and lower openings. The container 1 houses the miscellaneous solid waste 2 which is supplied additionally. The container 1 is suspended, transferred to directly above a canister 4 in the fusion furnace and is pulled down to the vicinity of the surface of molten metal 41. When the bottom plate 12 is heated by the molten metal 41, weakened, and drops into the canister 4 with the housed miscellaneous solid waste 2, the tube body 11 is pulled up and recovered. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a container for additionally supplying solid waste, particularly radioactive miscellaneous solid waste generated in a nuclear facility or the like, to an apparatus for melting the solid waste to reduce the volume.
[0002]
[Prior art]
Miscellaneous solid waste among low-level radioactive waste generated at nuclear power plants is buried and disposed at a designated landfill site. Wastes are packed in drums and buried as refuse with gaps filled with mortar. Since the burial site is limited, it is preferable to reduce the volume of waste and reduce the number of drums to be buried.
[0003]
As a method for reducing the volume of waste, there is a method using a melting furnace by high-frequency induction heating. In this method, waste is melted in a canister set in a melting furnace, reduced in volume and solidified, and then packed in a drum can with the canister, and a gap is filled with a solidified material such as mortar to produce a waste. It is.
As an initial load, a canister previously filled with waste is set in a high-frequency heating furnace to melt the contents. When the initially loaded waste is melted and reduced in volume, the canister has room, so that additional waste can be treated.
[0004]
There are two ways to supply additional waste: a method of dropping it from a hopper provided above the canister, and a method of pushing and supplying waste from the side above the canister. There was a problem that the waste scattered or was fused and clogged by high heat.
[0005]
Japanese Patent Application Laid-Open No. 2-298896 discloses a method of packing additional waste in a bucket, carrying the waste to a position near a storage container in a melting furnace, opening a bottom cover of the bucket, and dropping the waste into the molten metal. Have been.
In the disclosed method, the apparatus is expensive due to the complicated opening / closing mechanism of the bucket, the probability of failure is high due to the large number of movable parts, and the decontamination is not easy if the splash of molten metal is applied to the movable parts. is there.
[0006]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a simple and inexpensive waste additional supply container that can reliably supply additional waste without fear of blockage of the supply path.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an additional supply container of the present invention used for additionally supplying miscellaneous solid waste to a canister in a melting furnace is a heat-resistant cylinder having a lower bottom opened and a lower bottom opening. The bottom plate is made of a material that can be processed by melting or incineration in the canister, and when heated by the heat of the molten metal on the canister, falls into the canister together with the waste stored in the container Is characterized in that
The bottom plate may be one that burns with the heat of the molten metal or one that melts.
[0008]
When the miscellaneous solid waste is accommodated in the additional supply container of the present invention and is carried to a position immediately above the canister in which the content has become molten, the bottom plate is weakened or burned by the heat of the molten metal, and is contained. The weight of the waste becomes intolerable and the waste falls into the canister. At this time, the burnt remaining part of the damaged bottom plate falls into the canister together with the waste, but does not float on the surface of the molten metal and becomes a residue, but is drawn into the molten metal with the waste and easily melted. I do.
The container of the present invention is a cylindrical body having an opening at the bottom, there is no fear of blockage, there is no movable part, the structure is simple and inexpensive, and there is no difficulty in decontamination, and the bottom plate that is easily contaminated is Decontamination does not become a problem because it is treated with waste in a canister.
[0009]
In addition, a flange formed of a plurality of hooks formed of a shape memory alloy may be provided at the lower end of the cylindrical opening, and the flange may be deformed by the heat of the molten metal to drop the bottom plate into the canister.
Further, a circling flange may be provided inside the lower end of the cylindrical body opening, and the bottom plate may be engaged with and supported by the flange.
Further, the bottom plate may be placed on a flange and supported, and a guide ring may be placed on the bottom plate. The guide ring has a tapered surface whose inner diameter is narrowed downward, and is configured to be in contact with the inner wall surface of the cylinder so as to move up and down, so that the stored miscellaneous solid waste does not remain in the cylinder when falling.
In addition, the flange can also be formed by fixing a hook-shaped thing divided into several inside the lower end of the opening. With such a configuration, there is no need to use a guide ring since only a small amount of waste remains on the collar after the bottom plate has fallen.
[0010]
Further, in order to solve the above-mentioned problem, the additional supply method of the miscellaneous solid waste of the present invention includes a flammable or heat-softening bottom plate so as to close a lower opening of a heat-resistant cylinder having upper and lower openings. Lay it as an additional supply container, store additional solid waste to be supplied in this additional supply container, suspend the additional supply container containing the miscellaneous solid waste, and transport it to just above the canister in the melting furnace. Then, the additional supply container is pulled down to the vicinity of the molten metal in the canister, and the bottom plate is heated by the molten metal in the canister, and is weakened by burning or softening, and falls into the canister together with the contained miscellaneous solid waste. And is collected.
[0011]
The additional supply method of the present invention utilizes the above-described additional supply container of the present invention, and the bottom plate is dropped together with the miscellaneous solid waste into the canister, is dissolved in the molten metal, and is disposed of.
Since the release of the bottom plate directly uses the heat of the molten metal, there is no need to provide a movable mechanism. Further, the collected cylinder can be reused as it is or after decontamination.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to examples.
1 is a flowchart illustrating a method of using an additional supply container according to one embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating the additional supply container in the present embodiment, and FIG. 3 is a partially cutaway perspective view thereof. FIG. 4 is a perspective view showing a guide ring, and FIG. 5 is an enlarged sectional view showing a state where the guide ring is inserted. FIG. 6 is a plan view showing an additional supply container according to another embodiment, and FIG. 7 is a side sectional view thereof.
[0013]
The container for additional supply of miscellaneous solid waste is used to store radioactive miscellaneous solid waste generated in nuclear facilities, etc. in a canister and reduce the volume in a melting furnace. It is used to increase the disposal capacity of waste by additionally replenishing solid waste.
As shown in FIGS. 2 and 3, the additional supply container 1 of the present embodiment includes a cylindrical main body 11 and a bottom plate 12 that are largely open up and down. In addition, the flange 13 supports the bottom plate 12.
The bottom plate 12 is formed of a flammable material such as corrugated paper, and the main body 11 is formed of a nonflammable material such as stainless steel.
[0014]
FIGS. 1A to 1F illustrate a method of additionally supplying miscellaneous solid waste using the additional supply container 1 according to the present embodiment.
In the method of the present embodiment, the additional supply container 1 is formed by contacting and supporting a new bottom plate 12 on a flange 13 provided on the bottom of the cylindrical main body 11 (FIG. 1A). FIG. 1 (b). The miscellaneous solid waste 2 to be additionally supplied to the container 1 completed by applying the bottom plate 12 is accommodated (FIG. 1 (c)), and is transported to just above the canister 4 in the melting furnace by being suspended by a hanging tool 3 such as a crane. I do.
When the container 1 is gradually pulled down to approach the surface of the molten metal 41 in the canister 4 (FIG. 1D), the heat from the molten metal 41 causes the bottom plate 12 to be carbonized or burnt, and the strength is reduced (FIG. 1). (E)), the waste 2 in the container cannot withstand the weight, is broken, falls into the canister 4 together with the waste 2, burns or melts, and enters the molten metal 41.
[0015]
Since the bottom plate 12 of the container 1 is sufficiently close to the molten metal 41 when the bottom plate 12 is cracked, even when the waste 2 falls onto the molten metal 41, there is no large splash, and contaminants hardly adhere to the container 1. In addition, even when the molten metal 41 adheres, the container 1 has a simple shape, so that decontamination is easy.
After dropping the contents 2 into the canister 4, the container body 11 is recovered to the original position and reused (FIG. 1 (f)). The molten metal 41 in the canister 4 raises the liquid level by combining the new waste 2. Until the molten metal 41 is sufficiently accumulated, additional supply of miscellaneous solid waste is performed to increase the throughput.
Since the bottom plate 12 burns or melts and disappears each time it is used, it is necessary to newly attach the bottom plate 12 when reusing the container 1. It is possible to improve the work efficiency by preparing a large number of additional supply containers 1 which are assembled and contain the miscellaneous solid wastes 2 and supply the miscellaneous solid wastes 2 one after another until the canister 4 is full. It goes without saying that you can do it.
[0016]
When handling granular waste such as earth and sand and crushed concrete fragments, the waste may be left on the portion of the flange 13 supporting the bottom plate 12 after the contents are dropped. Therefore, a guide ring 14 as shown in FIG. 4 can be installed together with the bottom plate 12 in order to avoid the remaining of contaminants.
The guide ring 14 has an annular shape having a tapered surface 15 whose inner diameter narrows downward, and the upper end 16 is in contact with the inner wall surface of the main body 11. The guide ring 14 is set so that there is no dead space between the inner wall of the main body 11 and the bottom plate 12 where granular waste is accumulated. It is preferable that the inclination angle of the taper 15 is larger than the largest angle of repose of the contained particulate waste.
[0017]
Further, the flange 13 for supporting the bottom plate 12 is not a circular flange that goes around the inner wall of the opening, but may have hooks 17 provided at appropriate intervals on the circumference as shown in FIGS. 6 and 7. Good. If there is an appropriate gap in the flange 13, the granular waste falls from the gap and does not accumulate on the flange 13, and there is little risk of spreading contamination. Also, since there is an appropriate gap instead of being supported on the entire circumference, the bottom plate 12 weakened by the molten metal 41 of the canister 4 easily falls.
Note that these hooks 17 may be formed of a shape memory alloy, and the shape may be changed by the heat of the molten metal 41 so that the bottom plate 12 is dropped.
The cross section of the cylindrical body of the additional supply container main body is not limited to a circle, but may be a square or any other shape. Further, the bottom plate may not be flammable, and may have a property of being softened and deformed by heat.
[0018]
【The invention's effect】
As described above, the container for additional supply of miscellaneous solid waste of the present invention has a simple structure without moving parts, so that there is little danger of clogging and contamination, and it can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating a method of using an additional supply container according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing an additional supply container in the present embodiment.
FIG. 3 is a partially cutaway perspective view of an additional supply container of the present embodiment.
FIG. 4 is a perspective view of a guide ring used in the present embodiment.
FIG. 5 is an enlarged sectional view showing a state where a guide ring is inserted in the present embodiment.
FIG. 6 is a plan view showing an additional supply container according to another embodiment of the present invention.
FIG. 7 is a side sectional view of the additional supply container of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container for additional supply of miscellaneous solid waste 2 Miscellaneous solid waste 3 Hanging tool 4 Canister 11 Main body 12 Bottom plate 13 Flange 14 Guide ring 15 Tapered surface 16 Upper end 17 Hook

Claims (7)

A heat-resistant cylinder with an open lower bottom and a bottom plate closing the opening of the lower bottom are used to accommodate miscellaneous solid waste and to additionally supply miscellaneous solid waste to a canister in a melting furnace. A container, wherein the bottom plate is formed of a material that can be processed in the canister, and falls into the canister together with the one accommodated in the cylindrical body when heated by the heat of the molten metal on the canister. A container for additional supply of miscellaneous solid waste, characterized in that: A flange comprising a plurality of hooks formed of a shape memory alloy is provided at a lower end portion of the opening, and the flange is deformed by heat of the molten metal to drop the bottom plate into the canister. 2. The additional supply container according to 1. 2. The method according to claim 1, wherein the bottom plate is formed of a flammable material, burns when heated by the heat of the molten metal on the canister, and drops the one contained in the cylindrical body into the canister through the opening. The additional supply container as described. The bottom plate is formed of a thermo-softening material, softens when heated by the heat of the molten metal on the canister, falls into the canister together with the miscellaneous solid waste contained therein, and is melted in the canister. The additional supply container according to claim 1. The additional supply container according to claim 3 or 4, wherein a flange is provided at a lower end of the opening, and the bottom plate is engaged with and supported by the flange. A guide ring having a tapered surface whose inner diameter decreases downward and in contact with the inner wall surface of the cylindrical body and moving up and down; The additional supply container according to claim 5, wherein when the solid waste falls, the solid waste does not remain in the cylinder. A flammable or thermo-softening bottom plate is laid so as to cover the lower opening of the heat-resistant cylinder having upper and lower openings, and an additional supply container is provided. The additional supply container containing the miscellaneous solid waste is suspended and transported to a position just above the canister in the melting furnace, and the additional supply container is pulled down to near the molten metal surface in the canister. And discharging the remaining cylindrical body after dropping into the canister together with the miscellaneous solid waste accommodated by the weakening.

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