JPH02253197A - Waste storage containers and waste storage methods - Google Patents

Abstract

PURPOSE:To prevent the leakage of radioactive nuclides by forming a waterproof film and rare earth element layer on the inside surface of the steel plate concrete container embedded internally with steel plates. CONSTITUTION:The rare earth elements eluted by the dissolution of a part of the rare earth element layer 10 on the inside surface of the steel plate concrete container 1 into water by rain water are introduced together with the water through a cushion material 16 and a pipe 12 to a detector 13 even if the intrusion of the rain water into the inside of the steel plate concrete container 1 arises as the hermeticity by the concrete wall and U-shaped steels 8 of the container is gradually impaired. In such a case, the rare earth elements hardly exist in soil and, therefore, the infiltration of the water into the steel plate concrete container 2 is eventually detected by detecting the rare earth elements and the damage of the container 2 is thereby detected. The leakage of the radioactive nuclides to the outside is prevented in this way.

Description

Detailed Description of the Invention "Field of Industrial Application" This invention relates to a waste storage container used when burying a plurality of waste immobilization containers in which waste is immobilized, and a waste storage container. This relates to storage methods.

"Prior art" For example, as a method of processing low-level radioactive waste, after the radioactive waste is subjected to volume reduction treatment such as concentration and compression,
Plans are being made to store it in concrete containers and store it in the ground for a long time or semi-permanently.

For example, as shown in FIG. 4, if low-level radioactive waste is previously confined in a concrete container 1,
A plurality of these concrete containers 1 are stacked on a basic concrete layer M and buried in the soil, and in addition to the soil layer 2, a water-blocking concrete layer 3, a drainage river sand layer 4, etc. are provided as necessary. It will be established.

In this way, it is necessary to reduce radioactivity by burying radioactive waste packed in concrete for a long period of time (for example, 300 years or more), so during the period of storage, In addition to preventing the leakage of radioactive materials, monitor the presence or absence of seals, and if there is a leakage of radioactive materials due to a decline in the sealing function (barrier function), take immediate action. Concrete of that part 1・
It is desirable to replace the manufactured container 1.

``Problem to be solved by the invention'' However, when radioactive waste is buried underground in a concrete-packed state as described in ``-'', the radioactive waste is stored in a conventional concrete container. When confined in a building, it is difficult to control quality because it consists of shielding material or a single concrete wall, and safety performance is questionable.
It is difficult to prevent the intrusion of rainwater etc. for a long period of time.
Moreover, there is a problem in that it is difficult to detect when rainwater or the like enters.

This invention was made in view of the above circumstances, and is capable of effectively preventing the intrusion of rainwater, etc., and is also capable of promptly detecting the intrusion of rainwater, etc. It is an object of the present invention to provide a waste storage container and a waste storage method that can store radioactive waste in a stable condition.

"Means for Solving the Problem" The waste storage container of the present invention is a waste storage container that collectively stores a plurality of waste or immobilized waste immobilization containers, and has a steel plate embedded inside. A waterproof membrane and a rare earth element layer are formed on the inner surface of a steel plate concrete container, and a cushioning material is placed inside the steel plate concrete container.

Further, in the waste storage method of the present invention, when a plurality of waste immobilization containers in which waste is immobilized are stored together in the waste storage container, each waste immobilization container is placed around each waste immobilization container. The waste immobilization containers are fitted with cushioning material, packed into a bag made of elastic material, and stored in bales inside the bag in a waste storage container. The container is filled with an assimilating material and the waste container is hermetically sealed.

1. In the waste storage container of the present invention, a waterproof film and a rare earth element layer are formed on the inner surface of the container made of steel plate concrete 1, in which a steel plate is buried. Even if multiple waste immobilization containers are stored together and disposed of underground and are deformed due to earth pressure, it is likely that rainwater, etc. has entered the container.
-1., blocked by steel plate and waterproof membrane"2.
In the event that rainwater etc. enters the waste storage container, the intrusion of water will be immediately detected by detecting the rare earth elements dissolved from the rare earth element layer. It will be detected before it leaks back into the external pond. In addition, in this waste storage container, cushioning material is placed inside the steel plate concrete 1 container, so that when vibration is applied to the steel plate concrete 1 container from the outside, However, since the vibrations are absorbed and relaxed by the cushioning material, the waste immobilization container housed inside the container will not be damaged by the vibrations.

In addition, in the waste storage method of the present invention, when storing a plurality of waste immobilization containers in which waste is immobilized in a two-part waste storage container, each waste immobilization container is Attach cushioning material around each
These waste immobilization containers are packed into bags made of elastic material,
The waste is stored in a waste storage container in a bale state inside the bag, and then the solidification material is filled into the waste storage container and the waste storage container is sealed. Even if the storage container is deformed due to landslides etc. when buried in the ground, rainwater etc. will not enter the waste storage container due to concrete, walls and internal steel plates, waterproof membranes, assimilation materials, etc. It will be blocked by multiple barriers consisting of a bag and a bag. -1 In the event that rainwater etc. enters the waste storage container,
The water is detected before it leaks into the ground again, and the waste immobilization container in the waste storage container that is at risk of leaking can be removed and replaced with a new waste storage container. For example, even when radioactive waste is immobilized in the waste immobilization container, leakage of radionuclides can be prevented.

``Example'' Hereinafter, an example in which the present invention is applied to storing a waste immobilization container in which radioactive waste is immobilized will be described with reference to FIGS. 1 to 3.

In this embodiment, a plurality of drums 5 (waste immobilization containers) in which radioactive waste is immobilized are stored together in a large waste storage container for underground burial.

The waste storage container is constructed by arranging a cushioning material 16 inside the steel plate concrete container 1.

The above-mentioned steel plate concrete container 1 has a structure that is divided into two parts: a container-shaped lower structure 6 and a similar upper structure 7 that serves as a lid, and a U-shaped steel 8 is buried inside each structure. ,
Moreover, a waterproof membrane 9 and a rare earth element layer 10 are formed on the inner surface thereof. The waterproof film 9 is formed by applying methacrylic resin or the like, and the rare earth element layer IO is made of a rare earth element such as europium, scandium, yttrium, lanthanum, cerium, praseodymium, anion, promethium, or samarium. or those that are composed of such compounds and have water solubility, and have the property of directly dissolving in water, such as complexes such as chelates, or water-soluble adhesives, and various water-decomposable adhesives. It has the property of dispersing colloidally in water, like a mixture of rare earth elements attached to pine goo.

As shown in FIG. 1, a hatch 11 is provided in the upper structure 7 of the steel plate concrete container 1, and a U-shaped pressure pipe 12 has both ends of the hatch 11 connected to the steel plate concrete container 1. A detector 13 (light electric meter) for detecting rare earth elements is provided at the upper part of the pressure tube 12. Further, hanging hardware 14 is provided at both ends of the upper part of the upper structure 7.

When storing a plurality of drums 5 using such a waste storage method, a cushioning material 16 is arranged inside the steel plate concrete container 1, and a cushioning material 17 (elastic body width)
Attach the . The lano cushioning material 16 and the cushioning material 17 are made of an elastic material such as urethane foam. After doing this, each of the drums 5 is packed into a bag 1.8 (like a comb balloon) made of an elastic material such as butyl rubber, and the steel plates are stacked in bales inside the bag 18. Concrete container 1
Store inside. In this way, the bag body 18
By closing the stopper 22 of the bag body 18 while the inside is depressurized, the gap between each drum can 5 is made into a depressurized space 23, and then the steel plate concrete IJ 1. A cement-based assimilation material 19 (solidification material) is filled into the container 1, and the container 1 made of steel plate and concrete is hermetically sealed.

In addition, when the lower structure 6 and the upper structure 7 of the steel plate concrete container 1 are connected, the U-shaped steel 8. 8 are welded together via a joint plate 20, and then, as shown in FIG. 3, the joints are grouted 21 with mortar or the like.

When the steel plate concrete container 1 containing a plurality of drums 5 is buried in the ground in this way, the steel plate concrete container 1 has a concrete wall, the U-shaped steel 8 inside it, the waterproof membrane 9, and the cement. It is composed of multiple barriers consisting of a system assimilation material 19 and a bag body 18, and the inside of the bag body 18 is a depressurized space 23, so that in the unlikely event that the radionuclide inside the drum 5 leaks due to damage etc. Even so, leakage of the radionuclide to the outside of the steel plate concrete container 1 will be suppressed to a minimum.

It is also conceivable that the airtightness of the steel plate concrete container 1 due to the concrete wall and the U-shaped steel 8 may gradually be lost, causing rainwater to enter the inside of the steel plate concrete container 1. By dissolving a part of the rare earth element layer IO on the inner surface of the container I in water,
The dissolved rare earth elements are guided together with water to the detector 13 through the cushion material 16 and the pressure pipe 12. and,
In this case, since there are almost no rare earth elements in the soil, by detecting rare earth elements, it is possible to detect water intrusion into the steel plate concrete container l. Damage to the radionuclides can be detected and leakage of radionuclides to the outside can be prevented.

Note that as the cement solidifying material 17 described in 1., ordinary cement paste, mortar, concrete, lightweight mortar, etc. may be used, but non-shrinkage lightweight mortar is preferably used. This non-shrinkable lightweight mortar is made by mixing non-shrinkable cement such as ordinary Portland cement with an expanding material such as a calcium sulfur aluminate-based expanding material, and a lightweight aggregate such as a silica-based porous hollow balloon and water. In addition, there are products made by kneading, and the specific gravity thereof is about 0.5 to 1.8. When such non-shrinkage lightweight mortar is used, it is possible to reduce the weight, which makes it easier to handle when buried, and prevents cracks from occurring due to shrinkage. It is also possible to prevent leakage of radionuclides.

"Effects of the Invention" According to the waste storage container of the present invention, a waterproof membrane and a rare earth element layer are formed on the inner surface of the steel plate concrete container in which a steel plate is embedded, so that the waste can be disposed of in the waste storage container. Even if a container is deformed due to landslides when it is disposed of by storing multiple containers together in the ground, concrete, steel plates, and waterproof membranes can prevent rain water from entering the container. In addition, even if rainwater or the like intrudes into the waste storage container, the intrusion can be quickly detected by detecting the rare earth elements dissolved from the rare earth element layer. This allows the water to be detected before it leaks into the ground again. In addition, in this waste storage container, a cushioning material is placed inside the steel plate concrete container, so even if vibrations are applied to the steel plate concrete container from the outside, the cushioning material absorbs the vibrations. , it is possible to prevent damage to the waste immobilization container stored therein.

Further, according to the waste storage method of the present invention, when a plurality of waste immobilization containers in which waste is immobilized are stored together in the waste storage container, each waste immobilization container is The waste immobilization containers are each fitted with Kunonkong material around the surroundings, packed in a bag made of elastic material, and stored in bales inside the bag in a waste storage container. By filling the waste storage container with a solidifying material and sealing the waste storage container, even if the waste storage container is deformed due to landslides etc. when disposed of by burying it in the ground, there will be no damage to the inside of the container. Concrete walls, internal steel plates, waterproof membranes, solidifying materials, etc. prevent rainwater from entering.
This can be prevented by multiple barriers consisting of a bag and a bag. -1 In the event that mountain water, etc. enters the waste storage container, it can be detected before the water leaks into the ground again, and the waste that is likely to leak can be stored. By taking out the waste immobilization container inside the container and replacing it with a new waste storage container, for example, even if radioactive waste is immobilized in the waste immobilization container, leakage of radionuclides can be prevented. It can be prevented.

[Brief explanation of drawings]

Figures 1 to 3 are views showing one embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional view of a waste storage container, and Figure 2 is a view of the joint of a steel plate concrete container before grouting. Detailed sectional view, FIG. 3 is a detailed sectional view after grouting. FIG. 4 is a front sectional view showing a radioactive waste burial plan. 1...Steel plate concrete container, 5...Waste immobilization container (drum can), 6. Lower structure, 7...Two-part structure, 8... Steel plate ( U-shaped steel), 9. Waterproof membrane, 10. Rare earth element layer, 11. Hatch, 12.. Pressure pipe, 13.. Detector, ■4. Hanging fittings, I6, I7.. Cushioning material 18 --Bag body, 19 - Assimilation material (cement solidified side) 20 - Joint plate, 2I... Grout, 22 - Plug, 23 - Decompression space.

Claims (2)

[Claims] (1) A waste storage container that stores multiple waste immobilization containers in which waste is immobilized, with a waterproof membrane and rare earth element layer on the inner surface of the steel plate concrete container with a steel plate embedded inside. A waste storage container characterized by forming a steel plate concrete container and arranging a cushioning material inside the steel plate concrete container. (2) When storing a plurality of waste immobilization containers containing immobilized waste in the waste storage container described in paragraph 1, attach a cushioning material around each waste immobilization container. Then, the waste immobilization containers are packed in a bag made of an elastic material, and stored in a waste storage container in bales inside the bag, and then solidified in the waste storage container. 1. A waste storage method comprising filling the waste storage container with material and sealing the waste storage container.