JP3919264B2 - Radiation shield - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radiation shield useful for use in a room where radiation is radiated, such as a door of an entrance / exit of a facility, which needs to completely shield the radiation when the door is closed.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a room or facility wall where radiation is emitted is formed by a shielding wall S having a radiation shielding function, and an entrance / exit door is an iron shield formed by appropriately superposing iron plates as shown in FIG. A polyethylene block 2 formed by polymerizing an appropriate number of polyethylene plates having an excellent neutron shielding function on the outside of the body 1 and covering the outside with an iron plate is arranged, and the polyethylene block 2 is shielded with iron by a mounting bracket 3. It is integrally formed on the body 1. This is because the neutron beam cannot be shielded by the iron shield 1 alone, and the neutron beam passes through the iron shield 1 and is radiated to the outside. Even the polyethylene block 2 does not have an appropriate thickness. The neutron beam cannot be shielded reliably.
[0003]
Thus, since the polyethylene plate is limited in size, the polyethylene block 2 in FIG. 3 is divided into, for example, blocks 21, 22, and 23 so that neutron beams do not leak from their joints. In addition, the joint surfaces of the blocks 21 and 23 are formed on the step portions 21a and 23a, and the left and right joint surfaces of the block 22 are also formed on the two step portions 22a and 22b corresponding to the step portions 21a and 23a, The blocks 21, 22, and 23 are joined in steps. That is, the block 22 is formed in a plane convex shape, and the blocks 21 and 23 are formed in a single block shape by forming the step portions 21a and 23a corresponding to the block 22 so that they are joined. ing. In addition, each block 21, 22, 23 is attached to the entire surface with a mounting bracket 23 made of a large number of bolts or the like to increase the strength of each of the blocks 21 to 23 and fix each to the outer surface of the iron shield 1. Yes.
[0004]
However, since the outer surfaces of the joint surfaces m, ma, n, and na of the blocks 21, 22, and 23 are covered with an iron plate, even if they are brought into close contact with each other by tightening the mounting bracket 3, each joint surface m, ma, n, and na themselves are iron materials having no neutron beam shielding ability, gaps are present in the joint surfaces of the blocks, and mounting brackets 3 having no neutron beam shielding ability provided in the respective blocks 21 to 23 When the door is closed, the neutron beam that has passed through the iron shield 1 passes through the joint surfaces ma, m, na, n, or the gap between these joint surfaces and the mounting bracket 3. There is a risk of leaking outside and causing danger. That is, there is a possibility that a shielding defect may occur. This is because the polyethylene blocks are divided and each block 21 to 23 is covered with an iron plate, and the joining surfaces m, ma, n, na by the iron plate without polyethylene intervening are formed. This is because it is formed, or the iron mounting bracket 3 is provided through each of the blocks 21-23. In FIG. 3, 4 is a door drive unit, w is a wheel, and R is a rail laid on the floor.
[0005]
[Problems to be solved by the invention]
In view of the prior art as described above, the present invention is formed in a single plate shape or block shape as a whole without forming a joint where a gap occurs or embedding a mounting bracket. It has a high shielding function against radiation including neutrons by preventing gaps that allow neutrons to pass through. Useful radiation shielding for doors of entrances to rooms where radiation is emitted. The challenge is to provide a body.
[0006]
[Means for Solving the Problems]
Configuration of the present invention radiation shield was made in order to solve the above problems, the outer surface of the iron shield formed by a steel plate laminating a plurality, that Yusuke same width as the shield, the height with placing the iron-made box body, the front plate and the iron box body by installing a structural wall which also serves as a partition wall made of a synthetic resin comprising a neutron shielding function over a depth between the back of the iron-made box body Each chamber is fixed to the outer surface of the iron shield and partitioned by the structural wall, and filled with a synthetic resin pellet having the same function as the synthetic resin. The iron box may be provided with a back plate. In this case, the structural wall also serving as a partition is provided between the front and rear plates of the box, and the box is fixed to the front surface of the iron shield.
[0007]
Thus, as a synthetic resin having the above-described neutron beam shielding function, the use of polyethylene resin is advantageous in terms of material acquisition, production and construction costs, and cost. Further, the structural wall is opposed to the front surface of the iron shield and the inner surface of the front plate of the iron box, and the front and rear portions thereof are inserted into an attachment member formed by attaching two iron L-shaped members by welding or the like. It is fixed with fixing tools such as bolts and nuts.
[0008]
Moreover, when polyethylene resin is used as the synthetic resin, the bulk specific gravity of the polyethylene pellets filled in the iron box body with respect to the polyethylene block is 0.60 to 0.62, so the depth of the iron box body filled with the polyethylene pellets is polyethylene. When the block is used, the thickness is about 1.67 times the thickness of the block.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an example in which the radiation shielding body of the present invention is used for a door, and FIG.
[0010]
In the figure, 1 is the same iron shield as a conventionally known iron shield, 5 is disposed on the front surface of the iron shield 1 and is attached to the iron shield 1 by a polyethylene structural wall 6 having an appropriate thickness, for example, about 50 mm. An iron box body with a fixed back plate is formed of an iron plate having a thickness of, for example, about 6 mm, and the iron box body 5 is fixed to the iron shield 1 as follows. In other words, polyethylene mounting members 7, 7, 8, and 8 made of iron L-shaped members are attached to the front surface of the iron shield 1 and the inner surface of the front plate of the iron box 5 by welding or the like. The front and rear portions of the structural wall 6 are inserted and fixed by fixing tools such as bolts 9 and nuts 10. The iron box 5 may be provided with a back plate, and the back plate may be fixed and integrated with the front surface of the iron shield 1. In the figure, 4 is a door drive unit, w is a wheel, and R is a rail laid on the floor, which is the same as that shown in FIG.
[0011]
P is a polyethylene pellet filled in the iron box 5, and since the polyethylene resin has a ratio of the resin amount when it is molded into a plate material and the resin capacity in the pellet state is 1: 0.60 to 0.62, The depth of the iron box 5 filled with the polyethylene pellets P is about 1.67 times the thickness of the polyethylene block when the polyethylene block is used. In addition, since the filling rate when the polyethylene pellet P is filled by natural dropping is 0.60 of the capacity of the iron box, and the filling rate when solidified after natural dropping is about 0.62, it is compacted after natural dropping. The neutron shielding function is enhanced.
[0012]
When the radiation shielding body of the present invention configured as described above is used for a radiation shielding door as shown in the figure, the one except the neutron beam of radiation radiated from the room is shielded by the iron shielding body 1. The neutron beam passes through the iron shield 1 and enters the layer of polyethylene pellets P filled in the iron box 5, but there is a possibility that the neutron rays are shielded by the neutron beam shielding function of the polyethylene pellets P and radiated to the outside. Absent.
[0013]
Moreover, since the junction part is not formed in the iron box 5 like the conventional polyethylene block, and the shielding defect | deletion resulting from a junction part does not arise, as a whole, safety | security becomes a very high thing.
[0014]
In the above example, an example in which the radiation shield of the present invention is used for a radiation shield door has been described. However, the radiation shield of the present invention is not limited to a door, and a wall body that needs to shield radiation including neutron beams. Even if it is used, etc., the same effect is produced.
[0015]
【The invention's effect】
The present invention is as described above, wherein an iron box is fixed to the outside of an iron shield that shields radiation other than neutrons via a structural wall made of a synthetic resin plate having a neutron beam shielding function, and the iron Since the inside of the box is filled with synthetic resin pellets with a neutron beam shielding function, even if neutrons penetrate the iron shield and enter the iron box, the iron box is filled. Since the synthetic resin pellets are shielded from this, the neutron beam does not pass through the iron box, and therefore the neutron beam is not likely to be emitted to the outside.
[0016]
In addition, if polyethylene resin is used for the synthetic resin having a neutron shielding function, it is advantageous in terms of material acquisition, production and construction costs, and cost. In addition, it is possible to construct a radiation shield using a conventional polyethylene block. It is easy and can save labor on site construction.
[Brief description of the drawings]
FIG. 1 is a perspective view of an example in which the radiation shield of the present invention is used for a door.
FIG. 2 is an enlarged plan cross-sectional view showing an installation example of a synthetic resin structural wall.
FIG. 3 is a perspective view of a conventional radiation shielding door.
[Explanation of symbols]
1 Iron shield 5 Iron box 6 Polyethylene structural wall 7, 8 Mounting member 9 Bolt
10 Nut P Polyethylene pellet

Claims (4)

On the outer surface of the iron shield formed by a steel plate laminating a plurality, as wide as the shield, along with arranging the iron-made box body that have a height between the front and back plate of the iron-made box body A structural wall also serving as a partition wall made of synthetic resin having a neutron beam shielding function over the depth of the steel box is fixed to the outer surface of the iron shielding body, and each chamber partitioned by the structural wall A radiation shield comprising a synthetic resin pellet filled with the same function as the synthetic resin.   The radiation shield according to claim 1, wherein the iron box is provided with a back plate and is also used as an outer surface plate of the iron shield.   The radiation shielding body according to claim 1 or 2, wherein the synthetic resin having a neutron beam shielding function is a polyethylene resin.   The radiation shield according to any one of claims 1 to 3, wherein the structural wall has its front and rear portions fixed to attachment members attached to the front surface of the iron shield and the inner surface of the front plate of the iron box.

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