JPH0693036B2 - Radioactive waste treatment method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive waste treatment method for burying radioactive waste in the ground or discarding it into the ocean.

[0002]

BACKGROUND OF THE INVENTION The amount of various radioactive wastes carried out from various nuclear facilities such as nuclear power plants is ever increasing. Among these radioactive wastes, medium and low level radioactive wastes are put in radioactive waste treatment containers such as drums, solidified, sealed with a lid and suitable for underground burial or ocean dumping. It is in the final form.

Various types of containers for treating radioactive waste have been proposed in the past.
For example, a radioactive waste treatment container obtained by impregnating a mild steel drum can or steel fiber reinforced concrete molded into a container shape with a polymerizable impregnating agent and polymerizing and solidifying the mixture (Japanese Patent Publication No. 56-1284).
No. 0), a radioactive waste treatment container (Japanese Patent Publication No. 57-34518) obtained by partially impregnating a steel fiber reinforced concrete molded into a container shape with a polymerizable impregnating agent and polymerizing and solidifying it, or as an outer shell. A multi-layered container having a dual structure of an outer shell and an inner shell, which is made of a metal container, concrete reinforced by an impregnating agent, which is lined on the inner surface of the metal container and reinforced with a reinforcing material. 59-8599
No. 9) has been proposed.

Then, for example, fine radioactive waste such as powdery or granular incinerated ash and other machinery contaminated with radioactive substances are filled in a radioactive waste treatment container together with a cement solidifying material and solidified. After that, the cement paste is filled on the radioactive waste layer, and an inner lid coated with an adhesive is arranged around the inner surface side, and then the outer lid is arranged with respect to the radioactive waste treatment container. It is considered to be buried underground or dumped in the ocean.

However, various radioactive wastes are filled in a radioactive waste treatment container together with a cement solidifying material and solidified, and then the radioactive waste layer is filled with cement paste, and an epoxy system is provided around the inner surface side. In the processing method in which the inner lid coated with the adhesive is arranged, and the outer lid is arranged with respect to the radioactive waste treatment container, the degree of encapsulation by the epoxy adhesive is not so good, for example, there is a pinhole,
There were cases where there was a problem with hermeticity.

[0006]

DISCLOSURE OF THE INVENTION In view of the above problems, the present inventor does not apply the adhesive to the inner surface of the lid in advance, but after covering the lid, injecting the adhesive from above the lid. However, the nozzle used for the injection filling was blocked by the adhesive remaining inside after the operation, and the nozzle could not be reused.

Therefore, in order to reuse the nozzle, it was considered to wash the nozzle with a solvent after the injection and filling work of the adhesive, but since the radioactive waste treatment work is performed in a closed space. However, the sealed space is contaminated due to the evaporation of the solvent used for this cleaning, and it is difficult to take measures against this solvent contamination, and in reality, this technical idea could not be adopted.

With respect to such a point, the present inventor has conducted further research and development, and as a result, in order to reuse the nozzle, the nozzle in which the adhesive remains is cooled,
We came to the revelation that we should prevent hardening. The present invention has been achieved based on this revelation, and its first object is to have excellent encapsulation with an adhesive,
It is an object of the present invention to provide a radioactive waste treatment method capable of treating radioactive waste with good airtightness.

A second object of the present invention is to provide a radioactive waste treatment method which can reuse the nozzle used in the bonding work and has a low treatment cost. The object of the present invention is to put a lid on a treatment container for radioactive waste, inject an adhesive from a nozzle arranged on the upper part of the lid, and cool the nozzle after the operation of injecting the adhesive to cool the inside of the nozzle. It is achieved by a method for treating radioactive waste, which is characterized by preventing the curing of the adhesive remaining in the.

[0010]

FIG. 1 is an explanatory view showing one embodiment of the radioactive waste treatment method according to the present invention. In the figure, A is the main body of the radioactive waste treatment container, and the main body A of this treatment container is
For example, a steel drum can 1 is integrally provided with a polymer-impregnated concrete layer 2 lined therein.

Reference numeral B is a polymer-impregnated concrete lid used as an inner lid of the processing container body A. The sponge tape 3 is provided around the upper surface and the lower surface of the lid B (for example, about 3 cm inside from the outer circumference). , 4 are provided. The lid B can be obtained, for example, by pouring still fiber concrete, leaving it for a predetermined time, injecting a polymerizable monomer into it, polymerizing it, and then pasting sponge tapes 3 and 4 at predetermined positions. .

C is a nozzle arranged above a lid B which is closed on the container body A. Although only the tip portion of the nozzle C is shown, the main component of the two-component curing type epoxy adhesive and the curing agent are sufficiently stirred in the nozzle C using, for example, a static mixer. It is configured to be supplied later. Examples of the two-component curing type epoxy adhesive include Technodyne N86A and Technodyne N86AL manufactured by Taoka Chemical Co., Ltd.

The processing container body A having the above-mentioned structure
Explaining the processing method using the lid B and the nozzle C,
First, after putting various radioactive wastes into the processing container main body A, a paste containing water, ordinary Portland cement, etc. mixed in a predetermined ratio is filled, and then a lid B is placed on the cement paste. , An adhesive reservoir 5 formed between the drum can 1 and the sponge tape 3 provided on the lid B with an epoxy adhesive (main agent and curing agent) from the nozzle C disposed above the periphery of the lid B. Then, the adhesive filled in the adhesive reservoir 5 passes through the passage 6 between the lid B and the drum 1 to fill the space 7 formed under the lid B to the full extent, and thus the airtightness is improved. Can treat radioactive waste.

Even if the nozzle for injecting the adhesive is operated from a distance, the adhesive reservoir 5 is formed widely, so that the adhesive can be definitely injected into the adhesive reservoir 5, and thus the radiation exposure. The fear of can be reduced that much. Since the sponge tape 4 is also provided on the lower surface side of the lid B, the adhesive that has been injected and filled is not covered with the sponge tape 4.
Therefore, a large amount of the adhesive does not flow out to the side of the processing container body A filled with the radioactive waste, and the adhesive is not wasted.

After that, the main body A of the processing container (drum can 1)
Then, the outer lid is closed and the waste is transported to the disposal site, whereby the treatment of radioactive waste is completed. When the operation of injecting and filling the adhesive from the nozzle C is completed (the day of injecting and filling operation is completed), the nozzle C is cooled by an appropriate means. As the cooling method of the nozzle C, an ejector method such as a vortex scooler (trade name), an air cooling method using a low-temperature gas such as carbon dioxide and nitrogen gas, or a liquid cooling method using a liquid refrigerant is applied. it can. Therefore, even if the adhesive remains in the nozzle C, the curing does not occur in the nozzle C, and if the nozzle C is warmed during use the next day, the nozzle C and the remaining adhesive can be used. Like

This is because it is not necessary to wash the nozzle C with a solvent after the adhesive is injected and filled, so that the workplace treating the radioactive waste is not contaminated with the vaporized solvent, and no countermeasure is required for this contamination. It does not increase the cost for the treatment of radioactive waste.

[0017]

[Effect] In the radioactive waste treatment method according to the present invention, after the lid is fitted to the radioactive waste treatment container, the adhesive is injected from the nozzle disposed on the upper portion of the lid, and after the adhesive injection work is completed, The nozzle is cooled to prevent the adhesive remaining in the nozzle from hardening, so that the adhesive injected from above the lid passes through the passage between the lid and the container body and is formed under the lid. It becomes possible to seal the radioactive waste with high airtightness, can be processed without fear of pinholes, etc., and the nozzle used at the time of bonding work can be reused.
Moreover, since it is not necessary to wash the nozzle with a solvent after the adhesive injection and filling work, the action field treating the radioactive waste is not contaminated with the vaporized solvent, and no countermeasure is required for this contamination. It has features such as low processing cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of a radioactive waste treatment method according to the present invention.

[Explanation of symbols]

 A Main body of radioactive waste treatment container B Lid C Nozzle 1 Drum can 2 Polymer impregnated concrete layer 3,4 Sponge tape 5 Adhesive reservoir 6 Passage 7 Space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kanjiro Ishizaki 2-1-1 Tsukimi-cho, Kumagaya-shi, Saitama Chichibu Cement Co., Ltd. Central Research Laboratory (72) Inventor Naoaki Koyanagi, Tsukimi-cho, Kumagaya-shi, Saitama 1-1-1 Chichibu Cement Co., Ltd. Central Research Laboratory (72) Inventor Akira Asami 2-1-1 Tsukimi-cho, Kumagaya-shi, Saitama Chichibu Cement Co. Central Research Laboratory (72) Inventor Hiroyuki Yamaguchi Osaka City, Osaka Prefecture 4-21 Nishimikuni, Yodogawa-ku Taoka Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. A lid is fitted to a radioactive waste treatment container, and an adhesive is injected from a nozzle arranged on the upper portion of the lid, and the nozzle is cooled after completion of the adhesive injection work, and remains in the nozzle. A method for treating radioactive waste, characterized by preventing the curing of an adhesive that is present.