JPS62151800A - Multiple type vessel having improved soundness and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multi-type container with improved integrity for transporting hazardous materials such as low to medium level radioactive waste and a method of manufacturing the same.

In recent years, various types of radioactive waste discharged from nuclear facilities such as nuclear power plants and nuclear power plants, and hazardous heavy metal sludge discharged from chemical factories, etc., have been increasing. I am having trouble deciding how to dispose of it.

The generation of low-level radioactive waste is expected to reach 70,000 drums in 1990, and cumulatively to 1.1 million drums. Storing all of this waste would require a vast amount of land and a huge amount of money. The land is small,
European countries in Japan's history, which have a high density of entrances, are faced with the situation of having to dispose of snow by dumping it into the ocean, but in our country, there is a theory of open fields in the south! ? It is expected that it will take some time. For this reason, the government is rushing to consider implementing the 34 land disposal plan.

Unlike heavy metals, radioactive substances decay and decay with their own half-lives, so there is a finite period of time during which they must be isolated from our environment.

In the current system that uses nuclear fission, the waste that has a life of R is mainly reprocessed as nuclear fuel. I! Generated from the factory. Its lifespan is 9
If we focus on the β-γ radiation performance of 0Sr and 137Cs, it is calculated to be several hundred years, and if we focus on the α radioactivity of transuranium elements with atomic number 93 or higher, it is calculated to be several hundred thousand years.

These are typical high-level wastes, and are initially stored as liquids in a warehouse, then fixed using an appropriate method, and then engineered for storage.
A method of disposing of the waste is being considered. However, what is currently the most problematic issue is low- and medium-level waste with low iri, and it is said that this can be considered to have been in a state of flux for about 100 years. In other words, the land storage container is 10
Ideally, you will change your mind for about 0 years.

Currently, multiple containers have been proposed as containers for treatment and disposal of medium- and low-level tlitn waste.

The multi-layer container was devised to improve the drawbacks of mild steel drums as containers for the treatment and disposal of medium and low-level radioactive waste. By impregnating concrete strengthened with reinforcing materials with a polymer or B1-free impregnating agent as desired, it is possible to improve long-term durability and handleability, and to reduce the decrease in internal volume.

Since the multi-layered container of the present invention is used for transporting synthetic waste, its soundness is an extremely serious issue.In particular, cracks in the inner concrete lining and There has been a strong desire in the industry to prevent the occurrence of defects such as pinholes and improve the soundness against drop impacts during transportation.

1■ The creed to be cast on the inner surface of the multilayer container of the present invention includes cement paste made by mixing cement and water, and mortar made by mixing cement, sand, and water. For the sake of convenience, I will summarize it as ``Concrete Pa''.

The material of the "metal container" as the outer shell of the multi-layered container of the present invention may be various metals such as steel, stainless steel, aluminum, etc., and the shape may be a drum, square, hexagonal rod, etc. , they should be selected appropriately depending on the contents stored in the container, the environment and conditions under which the container is managed, etc. Metal drums are preferably used in the present invention, and particularly preferred embodiments include, for example, JIS 21600 thickness 1.2 to 1.6 #, 8
A steel open drum with a hanging capacity of 200 IL is used,
In short, it consists of a single gold 1A plate formed into a cylindrical shape, a body joined by seam welding or butt Lm welding, a base plate wrapped around the body, and a top lid tightened to the body. Regardless of the material, size, etc., as long as the drum can is well-maintained, has good welding and tightening, has no defects harmful to use such as scratches, wrinkles, or rust on the inside and outside surfaces, and maintains double density, No matter what, 1.[1-I] can also be used.

The "reinforcing material" used to reinforce the inner shell concrete of the multi-layered container of the present invention includes steel wire, glass fiber, carbon fiber or lath, reinforcing bar, etc., but especially steel!
I fiber is preferred. In the case of mm fibers, it is blended in an amount of 0.5 to 2.0% by volume. By using these reinforcing materials, the toughness of concrete 1~ is significantly improved, and impact resistance, fatigue property J3, fire resistance, etc. are improved. In the present invention, the effects obtained by using reinforcing materials are collectively referred to as "reinforcement" of concrete.

The "impregnating agent" that is impregnated to strengthen the inner shell concrete of the multi-layered container of the present invention includes unsaturated polyesters such as methyl methacrylate, methyl acrylate, and ethyl acrylate, styrene, α-methylstyrene, acrylonitrile, etc. One or more mixtures of radically polymerizable monomers or one or more mixtures of polymerizable materials capable of forming thermosetting resins such as thermosetting polyesters and epoxy resins, J3 and ethyl silicate 1-, methyl silicate, Inorganic substances such as water glass and sulfur are included. When using radically polymerizable monomers, commonly available crosslinking agents such as divinylbenzene, 1-helimethylolpropane trimethacrylate, and polyethylene glycol dimethacrylate may be used, or other polymers may be added to these monomers or resins. may be used in addition. In the present invention, concrete reinforced with SiQ fibers or the like is impregnated with the above-mentioned impregnating agent to increase strength and improve water impermeability, chemical resistance, seawater resistance, acid resistance, corrosion resistance, solidity, etc. In the present invention, these effects brought about by the impregnating agent are collectively referred to as "degree strengthening" of concrete.

In the multi-layer container of the present invention, a thin preliminary separator layer of about 3 m or less made of polyethylene, polypropylene, paraffin, and oil is provided inside the outer metal container by coating, spraying, etc. , with a high-strength concrete lining formed on its inner surface.

By providing the above-mentioned preliminary separator layer, the adhesion between the concrete lining and the metal container is completely cut off, and the reinforced concrete after curing is heated at 100 to 150°C for 8 to 48 hours. J to dry
Two, Pre-IBt? The first layer of pallets melts and the concrete dries. Since there is no adhesion to any of the metal containers in the culm or the outer shell, the concrete can contract freely without being constrained by adhesion, and the occurrence of cracks in the concrete is prevented.

Also, since gaps are created by melting the preliminary separator layer,
Air removal during the drying process is facilitated, and the formation of pinholes is also prevented. In this way, defects such as cracks and pinholes in the inner concrete lining are prevented, and the integrity of the transport container is improved.

The multilayer container of the present invention has a thin preliminary separator layer of polyethylene, paraffin and oil adjacent to the interior of the outer shell metal container, and a raw material mainly consisting of cement, water, aggregate and W4 fibers. The mixture is mixed and kneaded, and a medium mold is set in a volume formed in a preliminary separator layer provided on the inner surface of a gold B container serving as an outer mold, and poured into the mold and cast. Incidentally, when mixing the raw materials, an expanding agent may be used to prevent the occurrence of cracks in the concrete. After the concrete is placed, it is steam-cured at 60°C for 3 hours. After curing, remove the medium formwork and
Dry at 150°C for 8-48 hours. During this drying process, the preliminary separator layer melts, creating gaps as the concrete shrinks as it dries. After the drying process, close the lid and reduce the pressure using a vacuum to create a vacuum inside the container. This vacuum process does not require any special equipment, just hold down the top lid. Furthermore, since the inner shell concrete has strength, there is no fear that the drum will be deformed. After the vacuum step is completed, the polymerizable monomer is directly injected using a pressure reduction means.

After completing the impregnation process and charging into the gaps such as the first layer of the preliminary lever, the excess polymerizable monomer is removed by means such as a vacuum pump, and the polymerizable upper monomer is polymerized by heating polymerization method or radiation polymerization method.゛It becomes a product after undergoing product inspection. When the impregnating agent is an organic monomer, conventionally used polymerization initiators such as autogenous nitrogen compounds such as azobisisobutyronitrile, benzoyl peroxide, t-butylhydroperoxylide are used for polymerization. Organic peroxides and the like are used. Because the polymerization process is carried out in a closed system, there is less vaporization of the monomer on the container surface, and a single layer of polymer is formed, especially in the separator E between the outer drum and the inner concrete, improving the durability of the final container. In addition, soundness can be improved. Therefore, the method of the present invention does not require any special impregnating equipment, making it possible to manufacture containers at low cost. Durability, R
This method has the advantage of being able to manufacture multi-layered containers with excellent leaching prevention properties. If the impregnating agent is an inorganic substance such as ethyl silicate, methyl silicate, water glass, or sulfur, there is no difference in the basic process as long as no special catalyst is required during polymerization.

The components and effects of the present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples.

A drum of 1.2 nm thick made of round-standing steel plate; approximately o, s on the inner surface of 1;
Preliminary separator layer of polyethylene; Ω
Install a medium frame on top of the girder. Cement 450'j
/ TrL 3, water 187 to 9/7 rL3, sand 865
Kg/TIL3, gravel 770Kg/TrL3, steel fiber 8
0Kg/TrL3, water reducing agent 3 and 'J/m3 were mixed in a mixer, poured into a mold, subjected to photographic molding, pre-incubated for 2 hours, and then steam-cured at 60℃ for 3 hours. Strained and dried at 1150°C for 12 hours, cooled. The container was placed in an impregnating device, a vacuum valve and an injection valve were attached, and the container was capped and degassed at less than IMHg for 1 hour. Methyl methacrylate monomer in which 1% azobisisobutyronitrile was dissolved was injected as a thermal catalyst, and the pressure was returned to atmospheric pressure and impregnated for 1.5 hours. After discharging the excess monomer, the mixture was heated and polymerized using steam at 90° C. for 1 hour. This method allows the inside of the drum to have a thickness of about 15#+I! A 5t PIC layer was formed.

Air Leak Test The containers formed according to the above examples were tested in accordance with the air leak test method and apparatus described in Japanese Patent Application Laid-Open No. 105534/1983 filed by the same applicant as the present application.

Compared to the otherwise similar container without the preliminary separator layer, the crack occurrence rate of the container of the present invention was improved to about 115.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a multiple container according to the present invention. Patent applicant: Chichibu Cement Co., Ltd. (1 other person) (4 other people)

Claims (1)

[Claims] 1. A metal container as an outer shell, a high-strength concrete lining as an internal structure formed on the inner surface of the metal container,
The concrete lining is reinforced with reinforcing material and reinforced with impregnating material, and consists of a triple structure of hardened impregnating material as a separator layer formed between the metal container and the concrete lining, with the hardened impregnating material being A multilayer container that is integrally constructed with a separator layer interposed therebetween, and has self-supporting properties against external stress, long life, and solidity even if the outer shell metal corrodes over time. 2. A container according to claim 1, wherein the concrete lining is formed from a cement paste consisting of a mixture of cement and water and optionally sand, aggregate and additives. 3. The container according to claim 1, wherein the reinforcing material is selected from the group consisting of steel fibers, carbon fibers, glass fibers, polymer fibers, laths, and reinforcing bars. 4. The reinforcement material is 0.5 to 2 of the total capacity of concrete.
Container according to claim 1, consisting of steel fibers present in the concrete lining in an amount of 0% by volume. 5. The impregnating material is methyl methacrylate, methyl acrylate,
One or two or more radically polymerizable monomers such as ethyl acrylate, styrene, α-methylstyrene, and acrylonitrile, or one or two polymerizable materials capable of forming thermosetting resins such as thermosetting polyester and epoxy resin. The container according to claim 1, which is a mixture of more than one species. 6. A container according to claim 1, wherein the impregnating material is an inorganic material selected from the group consisting of ethyl silicate, methyl silicate, water glass and sulfur. 7. The container according to claim 1, wherein the metal container serving as the outer shell is a steel drum. 8. (a) A thin preliminary separator layer consisting of polyethylene, polypropylene, paraffin and fat is provided adjacent to the interior of the outer shell metal container; (b) Raw materials consisting mainly of cement, water and reinforcing materials are blended and kneaded. (c) A medium formwork is installed inside a container formed by a preliminary separator layer provided on the inner surface of a metal container serving as an outer formwork to produce reinforced concrete; (d) After curing, the medium formwork is removed, the reinforced concrete is heated and dried, and at the same time the polymer resin, paraffin or oil in the preliminary separator layer is removed, and then cooled; (e) Insert the core into the volume formed by the concrete lining, close it with a top lid, and reduce the pressure inside the container with a vacuum pump; (f) Inject the impregnating material into the container under reduced pressure beyond the upper limit of the inner shell concrete. Then, the pressure is returned to atmospheric pressure or further pressurized to impregnate the inner shell concrete and simultaneously fill the gaps in the preliminary separator layer; (g) Next, the core is removed and excess impregnated material is removed; (h) curing the impregnating material to integrally adhesively bond the outer shell metal container, the inner shell reinforced impregnated concrete, and the intermediate shell hardened impregnant separator layer therebetween; Production method. 9. The manufacturing method according to claim 8, wherein the raw materials include cement, water, sand, gravel, additives, and reinforcing materials. 10. The manufacturing method according to claim 8, wherein the reinforcing material is selected from the group consisting of steel fibers, carbon fibers, glass fibers, polymer fibers, laths, and reinforcing bars. 11. Reinforcement material is 0.5 to 2 of the total capacity standard of concrete
．． 9. A method according to claim 8, comprising steel fibers present in the concrete lining in an amount of 0 container %. 12. The impregnating material is methyl methacrylate, methyl acrylate, ethyl acrylate, styrene, α-methylstyrene,
One or a mixture of two or more radically polymerizable monomers of acrylonitrile, or thermosetting polyester,
Claim 8 is one or a mixture of two or more polymerizable materials capable of forming a thermosetting resin of epoxy resin.
The manufacturing method described in section. 13. The impregnating material is ethyl silicate, methyl silicate,
The manufacturing method according to claim 8, wherein the inorganic material is selected from the group consisting of water glass and sulfur. 14. The manufacturing method according to claim 8, wherein the metal container serving as the outer shell is a steel drum.