JP2003185789A - Flexible and highly plastic radiation shield - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation shield for completely shielding radiation leaking from a gap of a complex shape existing between structures by closing the gap. <P>SOLUTION: Particles made from a substance such as lead and each having a relatively small appropriate diameter are each covered with a highly viscous material having adhesiveness, such as grease, and the particles are connected together by means of the adhesiveness to appropriately inhibit the very high flowability of the particles. An aggregate of particulate matter which is flexible and highly plastic as a whole is formed in such a way that it can constitute a certain aggregate. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible and highly flexible radiation shield obtained by using a granular object such as a metal (hereinafter referred to as a "particle"). That is, by coating a granular material such as a metal with a highly viscous medium such as grease, the individual particles alone and the other particles alone are adhered to each other, and as a result, the whole is soft and highly plastic. The present invention relates to the production of a radiation shielding body using an aggregate of particles. 2. Description of the Related Art Conventionally, for shielding radiation such as X-rays, gamma rays, and neutrons, lead is used for X-rays and gamma rays, and paraffin is used for neutrons according to the characteristics of the radiation to be treated. A material capable of shielding most effectively has been selected, and a radiation shield has been manufactured by molding it into a shape required for radiation emitted linearly. In particular, to shield radiation leaking from a gap in a structure, a radiation shield made of a material corresponding to the radiation to be shielded is inserted into the gap, and the radiation shield and the structure are connected to each other. It was necessary to take a method of shielding radiation leaking from the gap of the helmet with a radiation shield of another shape. [0004] The shape of the radiation shield to be inserted into the gap is not limited to a single unit but may be divided and inserted depending on the state of attachment. Various shapes have been devised so that they can be shielded. On the other hand, when the shielding portion has a complicated shape,
The outside of this part is covered widely with a lead plate, etc., a lead block is stacked around it to shield it, or lead particles are filled in a bag etc. to keep the shape and place it at the shielding target. I've been shielding. [0006] According to the prior art, the radiation shield must be devised, such as divided and inserted, instead of a single body, depending on the state of attachment. There is a problem that requires a lot of money. In other words, lead is used as a material for radiation shielding for X-rays and gamma rays.In this case, in order to melt the lead to make an ingot and machine it to finish it to the required dimensions It is time-consuming and expensive, and has to be handled with care because it is heavy. [0007] On the other hand, a method of shielding a radiation by packing a particle such as lead in a bag and installing it in a place where the particle is to be shielded is a simple but simple method of shielding radiation by bagging a particle such as lead. Was a temporary method, and it was extremely unstable in a structure in which only bagged granules were placed, and was not recognized as being shielded by a structure. Further, when a lead plate or a lead block is used, a wide space is required around the lead plate, and since it is used in a stacked state, it is structurally unstable. Since it is a heavy object, there is a problem that special measures for safety must be considered. SUMMARY OF THE INVENTION The present invention has been proposed for the purpose of eliminating such drawbacks, and is simple, inexpensive, and can be self-supported as an aggregate of a suitable amount at the time of filling. Flexible and highly plastic radiation composed by coating granules made of a material corresponding to the type of radiation to be shielded, devised as a radiation shielding material with a viscous and highly viscous medium such as grease It is a shield. That is, the present invention relates to a method of coating a single particle of a particle made of a substance such as lead having a relatively small appropriate diameter with a highly viscous substance having a tackiness such as grease. By connecting this and other particles alone with this adhesiveness, the extremely high fluidity of the granules is appropriately inhibited, making it possible to constitute a certain aggregate, making the whole flexible and plastic Aggregates of high particulate matter. FIG. 1 shows an embodiment of the present invention. In describing the present embodiment, 1 is a single particle of lead, and 2 is grease. FIG. 2 is a plan view of an aggregate of the particles and a sticky and highly viscous substance according to an embodiment of the present invention. FIG. 3 is an embodiment of the present invention. It is a side view of the aggregate which consists of a certain highly viscous substance. More specifically, a single particle of a suitable metal or the like having a relatively small diameter is coated with a sticky medium such as grease, and the single particles are adhered and connected to each other to obtain an extremely high fluidity. The granules, which are aggregates of irregular-shaped granular materials, are relatively weakly connected by the tackiness of grease, and as a whole, are aggregates of soft and highly plastic particles. That is, the present invention is a filler for radiation shielding having high plasticity. The material of the particles is lead. The diameter of the particles is 2 mm. The material of the grease is vacuum grease, and the substance name is a compound of polyorganosiloxane and silica. Such a fluid is coated with a sticky and highly viscous grease to form a flexible and highly plastic radiation shield, which is inserted and filled into a complicated shaped gap between structures that leak radiation to fill the radiation. Shielding was performed. As a result, the shielding body and the structure wall could be brought into close contact with each other, so that radiation leaking from the gap between the structures could be completely stopped. According to the present invention, it is possible to freely form an aggregate of granules having an arbitrary shape, and to prevent radiation leaking from a gap of a structure or the like. By filling the gap with the aggregate of the particulate matter of the present invention, radiation can be shielded, and the time and cost for melting the material and forming the shield are eliminated. Further, by filling the gap with the radiation shielding body of the present invention, the structure wall and the shielding body can be brought into close contact with each other, so that the radiation leakage can be completely stopped. The radiation shielding body of the present invention is directly attached to the shielding object, and the surroundings can be covered with a sheet or the like, so that the shielding can be easily performed. On the other hand, when used as a collimator for converging radiation in an experiment or the like, an inexpensive and appropriate mold is prepared in accordance with the conditions, and the mold is easily filled with the radiation shield of the present invention. Since the collimator can be manufactured at a low cost, there is an advantage that it is not necessary to prepare collimators one by one corresponding to the conditions as in the related art, and the experiment can be performed at a low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a state in which radiation shielding particles are covered with a sticky and highly viscous substance, which is an example of the present invention. FIG. 2 is a plan view of an aggregate of radiation shielding particles and a sticky and highly viscous substance, which is an example of the present invention. FIG. 3 is a side view of an aggregate of radiation shielding particles and a sticky and highly viscous substance, which is an example of the present invention.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kazuyoshi Ishikawa             2-4, Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki Prefecture               Inside the Japan Atomic Energy Research Institute Tokai Research Institute

Claims (1)

Claims: 1. A flexible and highly plastic radiation shield obtained by adhering and connecting a radiation shielding granular material having a relatively small diameter with a medium having an appropriate viscosity.