JP2000028795A - Simple storage facility for radioactive matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce costs for construction and removal by being constituted of an upper radiation shield that covers the space above housing containers which stow radioactive matter and side radiation shields that are located so that can surround the containers from their side and can move freely and that form a radiation shield structure together with the upper radiation shield. SOLUTION: A ceiling shield 23 is provided in the space above pillars 21 erected on the ground 1, a storage space 25 is secured in the space below the ceiling shield 23 and housing containers C are placed at appropriate intervals in the space 25. Then, side radiation shields 27 are located to surround the group of the housing containers C. The radiation emitted from the housing containers C is blocked out by the side radiation shields 27 surrounding the containers C and the ceiling radiation shield 23. Moreover, the heat of the housing containers C is removed by the air coming in and going out at interstices. Since the pillars 21 are strong enough to support the weight of the ceiling shield 23, it is not required to shield from radiation and even the small shape and size may be effective a facility can be easily removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for storing a radioactive object such as a so-called spent fuel which has undergone a predetermined combustion in a nuclear reactor.

[0002]

2. Description of the Related Art Spent fuel emits considerable radiation and decay heat, so it is placed in a cooling pool such as a spent fuel pool of a nuclear power plant, cooled, and then transported to a fuel reprocessing facility for processing. Is done. As facilities for storing such spent fuel, there are a wet storage facility for storing spent fuel in water and a dry storage facility for exposing and storing air inside a building or the like. Since the latter does not handle water, the equipment itself is relatively simple and attracts attention. The conceptual structure is shown in FIG. In brief, a shielding wall 3 is erected on a foundation formed on the ground 1, a shielding ceiling 5 is provided thereon, and a storage room 7 is defined inside. An air supply port 9 is formed at an appropriate position below the shielding wall 3, and an exhaust port 11 is provided on the shielding ceiling 5. The storage container C containing the spent fuel is stored in the storage room 7 and is cooled by natural convection air passing through the air supply port 9 and the exhaust port 11. Of course, the loading / unloading facility for the storage container C is not shown, but is provided, and a column for supporting the shielding ceiling 5 having a large unit weight in the middle is provided as needed.

[0003]

As described above, dry storage equipment requires relatively less construction costs than wet storage equipment, and equipment operation costs are reduced if natural convection air is used for cooling. Although it is very preferable, as a facility for storing radioactive objects such as spent fuel whose storage capacity has temporarily increased, the dry storage facility of the conventional structure has a large construction cost and is a full-scale building. Removal costs are also large. It is therefore an object of the present invention to provide a simple storage facility for radioactive objects with low construction and removal costs.

[0004]

In order to solve the above problems, according to the present invention, a simple storage facility for radioactive objects comprises an upper radiation shield for covering a storage container for storing radioactive objects such as spent fuel. It comprises a body and a plurality of side radiation shields movably arranged surrounding the storage container from the side and forming a radiation shielding structure in cooperation with the upper radiation shield. The upper radiation shield is preferably formed as a column-supported ceiling structure that is open to the side without the need to fix the structure for carrying in and out the storage container, and furthermore, the upper radiation shield is individually formed. It is also suitable to form as a hat type shield placed on the upper part of the storage container.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In addition, including drawings related to the prior art,
The same parts or members are denoted by the same reference symbols throughout the drawings. First, referring to FIG. 1, a ceiling shield 23 is erected above a plurality of pillars 21 erected at appropriate places on the ground 1 and extends laterally. A storage space 25 is secured below the ceiling shield 23, and the storage containers C are arranged at appropriate intervals in the storage space 25. The storage container C contains several spent fuels and is sealed. Then, the side radiation shield 27 is placed so as to surround the group of the storage containers C arranged. A moving wheel 27a is provided below the side radiation shield 27. The shape and dimensions of the side radiation shield 27 are determined so that an appropriate gap is formed between the side radiation shield 27 and the ceiling shield 23, the radiation shield 27 has a thickness sufficient to shield radiation, and has a weight that allows movement. ing.

In the simple storage facility 20 having the above-described structure, radiation emitted from the storage container C is shielded by a plurality of side radiation shields 27 and a ceiling shield 23 surrounding the periphery, and furthermore, the radiation emitted from these gaps is prevented. The heat of the storage container C is removed by the incoming and outgoing air. In this embodiment, the column 21 needs only to have the strength to support the weight of the ceiling shield 23, and is not required to shield radiation.
Removal is simple, as small geometries are sufficient as conceptually shown in the drawings.

Next, another embodiment will be described with reference to FIG. In this embodiment, a building extending upward from the ground 1 is not provided. The ground 1 is strong enough to withstand the weight of the storage container C and the side radiation shield 27. Then, the storage containers C are arranged on the ground 1. A hat-shaped shield 31 is placed on the storage container C.
When arranging the storage containers C, the gap between the hat-shaped shields 31 adjacent to each other is set to be within a predetermined range. Then, a plurality of side radiation shields 27 are arranged around the group of storage containers C arranged in the same manner as in the case of FIG.
The side radiation shield 27 is positioned so that the gap between the hat-shaped shield 31 and the side radiation shield 27 placed on the outermost storage container C falls within a predetermined range. In this way, a plurality of hat-shaped shields 31 arranged at predetermined intervals
Functions as an upper shielding structure as a whole, so that the same radiation shielding action and heat removing action as in the embodiment of FIG. 1 can be achieved. Note that a hat-shaped shield 33 having a roof-shaped cross section as shown in FIG. 3 may be used instead of the hat-shaped shield 31.

[0008]

As described above, according to the present invention,
The use of movable side radiation shields eliminates the need for shielding buildings with thick shielding walls, while the ceiling shields are also supported by simple pillars or individual hats to be placed in individual storage containers Since it is formed of a mold shield, a necessary shielding function can be obtained and removal can be easily performed.

[Brief description of the drawings]

FIG. 1 is a conceptual vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a conceptual elevational sectional view showing another embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of a modified embodiment in which a part of FIG. 2 is modified.

FIG. 4 is a conceptual diagram showing a vertical section of a conventional dry storage facility.

[Explanation of symbols]

 Reference Signs List 20 Dry storage facility 21 Column 23 Ceiling shield 25 Storage space 27 Lateral radiation shield 27a Wheels 31,33 Hat-type ceiling shield C Storage container

Claims (3)

[Claims] An upper radiation shield covering an upper part of a storage container storing a radioactive object, and a radiation shielding structure movably disposed surrounding the storage container from a side and cooperating with the upper radiation shield. A simple storage facility for radioactive objects, comprising a plurality of side radiation shields to be formed. 2. The upper radiation shield is formed as a column-supported ceiling structure.
A simple storage facility for radioactive objects as described. 3. The facility for simple storage of radioactive objects according to claim 1, wherein the upper radiation shield is formed as a hat-shaped shield placed on top of each of the storage containers.