JPH0440399A - Structure of radiation shield wall - Google Patents

Abstract

PURPOSE:To eliminate the influence of scattered rays even when sufficient maze structure can not be secured by providing a movable mechanism at part of the shield wall and arranging a movable shield wall which can be stored in the shield wall when opened. CONSTITUTION:The shield wall 14 is provided so as to partition the high-dosage equivalent area 12 and low-dosage equivalent area 13 of radiation handling facilities 11 where a high-radiation source equipment 7 is arranged internally, and a maze wall 16 which prevents direct rays so as to constitute an entrance/ exit door 15 is provided to the wall 14. Further, the movable shield wall 8 which cuts off scattered rays is mounted on the wall 16 movably on a rail laid on the floor surface with casters fitted to the lower end. When the wall 8 is not used, the influence of single-time scattering from the equipment 17 extends to the area 13, which is not preferable as to exposure, but the scattered light is cut off by the wall 8 to reduce radiation reaching the door 15, thereby obtaining the same shield effect with twice scattering. Therefore, even when a sufficient maze structure can not be secured, the same shield effect is obtained and rational arrangement design is enabled.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to radiation radiation treatment facilities provided in a radiation handling facility such as a nuclear power plant, which is divided into a high dose equivalent area and a low dose area. Regarding the structure of the shielding wall.

(Conventional technology) One of these is the need for low dose equivalents in passageways, etc.

FIG. 3 is a plan view showing a labyrinth structure of a conventional radiation shielding wall. That is, the shielding wall 4 has a labyrinth wall for forming an entrance/exit door 5 to separate a high dose equivalent area 2 and a passage 3 which is a low dose area in a radiation handling facility in which a high radiation source device 7 is installed. 6 is provided.

Similarly to FIG. 3, FIG. 4 is an example showing a maze structure in a plan view, but due to structural or layout constraints of the building, the entrance/exit door 5a is located perpendicular to the maze wall 6a.

(Problem to be solved by Inventiveness S) The labyrinth wall 6 and entrance/exit door 5 configured as shown in FIG.
Although double scattering can be ensured, in the case of FIG. 4, the scattered radiation 10b reaches the passage 3 after being scattered once. −
When fishing by boat, one scattering attenuates radiation by about 1/100, so design considerations have been made so that equipment placed in areas with high dose equivalents will be scattered twice against passages and the like.

As for the maze structure, in the case of nuclear power plants, as mentioned above, there are constraints on the structure or layout of the building, and as shown in Figure 3, there are cases where it is not possible to secure a sufficient maze structure, resulting in a structure as shown in Figure 4. be.

In this case, it is conceivable to use a sliding concrete door or steel door with sufficient thickness as the entrance/exit door 5, but in the former case, it would take up a lot of space to store the door when opened and to install the concrete door itself. In the latter case, the door formwork is also made of steel, and a part of the concrete of the shielding wall 4 also needs to be made of steel to prevent streaking, resulting in a complicated structure.

The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a structure of a radiation shielding wall that can prevent the influence of scattered radiation even when a sufficient labyrinth structure cannot be secured.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a structure of a radiation shielding wall that forms a labyrinth structure to partition a high dose equivalent area and a low dose equivalent area of a radiation handling facility. The present invention is characterized in that a movable mechanism is provided in a part of the shielding wall, and a movable shield 1 is disposed so that it can be stored in the shielding wall when it is opened.

(Function) A movable mechanism is installed in a part of the shielding wall that makes up the maze wall installed in the high dose equivalent area, and when the equipment is in operation, it remains closed to prevent the contribution of radiation scattering. During maintenance inspections such as when the system is stopped, a portion of the shield wall is stored in the shield body.

The shielding wall for the maze is made of concrete, and part of the shielding wall with a movable mechanism is also made of concrete, but if it is made of metal such as iron plate instead of concrete, it can be made thinner and the structure of the movable mechanism can be made thinner. It can be simplified.

(Example) An example of the structure of a radiation shielding wall according to the present invention will be described with reference to FIGS. 1 and 2.

A shielding wall 14 is provided to separate the area 13 from the shielding wall 1.
4 is provided with a labyrinth wall 16 to form an entrance/exit door 15 to prevent a direct line.

The maze wall 16 is provided with a movable shielding wall 8 for shielding scattered radiation, and is made up of casters (not shown) attached to the lower end and rails 9 laid on the floor. The casters are placed on rails 9 and can be moved. In the structure shown in FIG. 1, the scattered radiation reaches the entrance/exit door 15 after being scattered once, which affects the contribution y passage 13 from the high radiation source equipment 7, which is not preferable in terms of reducing exposure.

FIG. 2 shows a state in which scattered radiation is shielded. That is, the movable shield 8 within the shielding wall 14 shields the scattered radiation, and the radiation reaching the entrance/exit door I5 has a shielding effect equivalent to twice scattering.

Therefore, even if it is not possible to maintain a sufficient maze structure that causes double scattering due to layout or structural constraints, it is possible to secure a maze wall that has a shielding effect, such as a radiation-reducing dirt floor.

Conventionally, concrete has been used for the radiation shielding walls for mazes, but in the present invention, iron plates can also be used for the movable shielding walls, and the use of iron plates can reduce the thickness, making the structure of the movable mechanism easier. It can be simplified with .

〔Effect of the invention〕

According to the present invention, even when a sufficient labyrinth structure cannot be maintained due to equipment layout or structural constraints, it is possible to obtain a shielding effect equivalent to that of a conventional labyrinth structure, and to design a rational layout.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the structure of the radiation shielding wall according to the present invention, FIG. 2 is a plan view showing the function of the radiation shielding wall in FIG. 1, and FIGS. 3 and 4 are the conventional radiation shielding walls. FIG. 3 is a plan view showing the structure of a radiation shielding wall. 7...Equipment 8...Movable shielding wall 9...
・Rail 14... Shielding wall 15... Entrance/exit door 16... Maze wall agent Patent attorney rules
Kensuke Chika

Claims (1)

[Claims] In the structure of a radiation shielding wall that divides a high dose equivalent area and a low dose equivalent area of a radiation handling facility by forming a labyrinth structure, a part of the shielding wall is provided with a movable mechanism so that it can be stored in the shielding wall when opened. A structure of a radiation shielding wall characterized by arranging a movable shielding wall.