JPH0648477Y2 - Storage container for radioactive waste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a storage container for storing radioactive waste.

[Conventional technology]

Low-level radioactive waste discharged from nuclear power plants, spent nuclear fuel reprocessing plants, etc. must be treated without creating a polluted environment in the surrounding area. Also, in the future, with the full-scale operation of the nuclear fuel cycle facility, as a method of treating such waste, conventionally, discharged low-level radioactive waste is stored in a predetermined container, It is buried in a shallow area of about 15 m and stored. Containers that store waste are durable for 200 to 300 years, such as water resistance, water permeability resistance, leaching resistance, and sealability, so that the waste does not flow into the ground due to damage or corrosion. Sex is required.

As a storage container for such radioactive waste, conventionally,
A storage container in which mortar is lined on the inner peripheral surface of a steel drum can is used. The mortar used for the inner lining of the drum must have excellent water resistance and water permeation resistance, and should have high compressive strength.

[Problems to be solved by the device]

However, the conventional mortar used in the conventional container is no different from the commonly used mortar, that is, it is composed of cement, lime, sand and the like. Therefore, its compressive strength was only about 300 kgf / cm ² , and it was questionable whether the storage container using this could maintain stable performance for a long period of 200 to 300 years.

Therefore, an object of the present invention is to provide a radioactive waste storage container capable of safely storing and storing the radioactive waste for a long period of time.

[Means for Solving the Problems]

The idea is that calcium carbonate or silica sand powder: 9.5 to 10.5 wt.%, Synthetic resin: 12.0 to 15.0 wt.
%, Curing agent: 0.24 to 0.45 wt.%, And mountain sand or river sand:
The resin-containing mortar layer consisting of the rest is formed integrally with the drum can.

Next, the resin-containing mortar layer formed on the inner peripheral surface of the drum can will be described.

The resin-containing mortar layer is composed of mountain sand, calcium carbonate, and synthetic resin.

(1) Mountain sand or river sand Mountain sand or river sand is used as fine aggregate. The reason why it is limited to mountain sand or river sand is that sea sand contains salt. The grain size of mountain sand or river sand is preferably 5 mm or less. This is because if the grain size of mountain sand or river sand exceeds 5 mm, the compactness is lacking, and the water resistance, water permeability resistance, etc. deteriorates.

(2) Calcium carbonate or silica sand powder Calcium carbonate or silica sand powder is used as an admixture.

(3) Synthetic resin A synthetic resin is used as a binder. As the synthetic resin, an acrylic resin having a small shrinkage property should be used. When the synthetic resin has a large shrinkage property, the volume change of the resin-containing mortar layer becomes large, so that the resin-containing mortar layer may be peeled off from the inner peripheral surface of the drum can or cracked.

Next, the invention will be described with reference to the drawings. FIG. 1 is a front view showing an embodiment of the storage container of the present invention in a state in which the contents are filled, FIG. 2 is a plan view, FIG. 3 is a cross-sectional view of the body, and FIG. 4 is a vertical cross-section of the body. It is a figure. In FIG. 1, the upper part is shown in a sectional view. As shown in the drawings, a resin-containing mortar layer 2 is formed integrally with the drum can 1 on the inner peripheral surface of the drum can 1. The drum can 1 has a body 3 and a canopy 4.
And a base plate 5.

The capacity of the drum can 1 is 200 liters, and the material of the drum can, the manufacturing process, and the manufacturing process of the storage container are shown below. The compounding ratio of the resin-containing mortar is shown in Table 1.

(1) Material of drum can The standard of drum can is JIS Z 1600, Class 1 H class (Steel plate thickness 1.
6 mm, 200 liter capacity steel oven drum), steel plate is 1.6 mm thick JIS G 3141 (Cold rolled steel plate and strip, SPCC
The steel plate specified in 1) is a phosphate-coated steel plate), and the canopy fastening filler is a neoprene gasket.

Manufacturing process <1> The body is made by forming a steel plate with a thickness of 1.6 mm into a cylindrical shape and then joining them by seam welding to press out two ring zones. The canopy and base plate are formed by pressing a steel plate with a thickness of 1.6 mm.

<2> The body, canopy, and ground plate are subjected to chemical conversion treatment.

<3> Epoxy / phenolic paint is baked on the inner surface of the body, canopy, and ground plate. The film thickness is 30 ± 5μm.

<4> Combine the base plate with the body, inject the winding filler, and then tighten.

<5> Wrap the melamine resin paint around the outer surface of the body and the canopy with the bottom plate fastened. The film thickness is 30 ± 5μm.

Canopy lever tightening band Use a 2.0 mm thick steel plate specified in JIS G 3141 and zinc-plated.

(2) Mortar layer containing resin (3) Manufacturing process of storage container The fine aggregate and admixture shown in Table 1 are sufficiently stirred.

Next, a synthetic resin liquid (a curing agent is added immediately before charging and well stirred) is charged and sufficiently stirred.

As for the body of the mortar with a microwave oven, the resin-containing mortar is charged while the drum set in the mold is rotated at low speed by a centrifugal molding machine.

After adding the resin-containing mortar until the specified thickness can be secured, apply high speed rotation to sufficiently compact and perform sufficient solidification and curing.

As for the bottom of the mortar with a microwave oven, while vibrating the drum after the step with a vibrator, the mortar with a resin is charged from the top and compacted, and sufficient solidification curing is performed.

The thickness of the resin-containing mortar layer is typically 20 mm at the body.
And 40mm at the bottom.

(4) Casting the canopy The casting of the canopy is performed after filling the contents (radioactive waste) 6, and filling the contents solidifying agent 7 from the upper side while vibrating to the upper end of the resin-containing mortar layer. Then, after a predetermined curing period, it is placed by using a canopy molding mortar. The canopy molding mortar uses a material having the same composition as the body and the bottom.

When the compressive strength of the resin-containing mortar lined on the inner peripheral surface of the drum of the storage container manufactured as described above was measured, the compressive strength was 800 kgf / cm ² or more. From the above, the storage container of the present invention is superior to the conventional storage container in which the inner peripheral surface of the drum can is lined with the conventional mortar in terms of water permeability, leaching resistance, water resistance, and sealing property. I know that

[Effect of device]

As described above, according to the present invention, radioactive wastes can be safely stored for a long period of time without making the surroundings a polluted environment, so that an industrially useful effect is brought about.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the storage container of the present invention in a state in which the contents are filled, FIG. 2 is a plan view, FIG. 3 is a partial cross-sectional view of the body, and FIG. 4 is a longitudinal section of the body. It is a side view. In the drawings, 1 ... Drum can, 2 ... Resin-containing mortar, 3 ... Body, 4 ... Canopy, 5 ... Main plate, 6 ... Contents, 7 ... Contents solidifying agent.

Front page continued (72) Inventor Toshiaki Tanaka Marunouchi 1-2-2 Nihon Steel Pipe Co., Ltd. (72) Inventor Hidehisa Yamagishi 8-11-11 Ginza, Chuo-ku, Tokyo Steel pipe drum Incorporated (72) Inventor Ishii Lighting 8-11-11 Ginza, Chuo-ku, Tokyo Steel tube drum Co., Ltd. (72) Inventor Toshinobu Fujita 2 315 Hara, Numazu-shi, Shizuoka Toyo Pile Fume Tube Co., Ltd. (56) Reference JP 62-251700 (JP, A) JP 63-32399 (JP, A) JP 1-223399 (JP, A)

Claims (2)

[Scope of utility model registration request] 1. Calcium carbonate or silica sand powder: 9.5 to 10.5 wt.%, Synthetic resin: 12.0 to 15.0 wt.% On the inner peripheral surface of a drum can.
%, Curing agent: 0.24 to 0.45 wt.%, And mountain sand or river sand: balance, a resin-containing mortar layer is integrally formed with the drum can. . 2. The container for radioactive waste according to claim 1, wherein the synthetic resin is an acrylic resin.