JPH07218690A - Radiation shield door - Google Patents

Abstract

PURPOSE:To prevent neutron beam leaked through the gap between a lock shaft and a door body. CONSTITUTION:A space 12 is formed in a door body 9, a neutron shield material 13 is filled in the space 12, a space expansion part 14c is provided in a lock shaft 14, and the neutron shield material 13 is filled in the space expansion part 14c. A step part is formed between the penetration holes 15 by the space expansion part 14c and the straight passing of neutron beam is prevented, and thus neutron beam leak through the lock shaft 14 gap is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation shield door installed in a nuclear power plant or a radioactive material handling facility.

[0002]

2. Description of the Related Art A radiation shield door is provided on a part of a shield wall that divides a high dose area and a low dose area, and a radiation worker (hereinafter referred to as an employee) is required to enter the high dose area. , Unlocked and entered the high dose area.

Generally, a radiation shielding door is installed in a high-dose area, so that it is locked and controlled to prevent unnecessary radiation exposure. The locking and unlocking shaft penetrates inside and outside the radiation shielding door body. It is interlocked and locked and unlocked.

The structure of a conventional radiation shielding door will be described with reference to FIG. In FIG. 4, reference numeral 1 is a door body formed of a thick iron plate, and this door body 1 is a shield wall 2 in the radiation control area.
It is attached by a hinge device 3 so that it can be opened and closed.
The door body 1 is provided with a through hole 5 through which the locking / unlocking shaft 4 is inserted.

The locking / unlocking shaft 4 is provided with a lever handle 6 at both ends via lever shafts 6a and 6b, and a hook bar 7 is horizontally connected to a side surface thereof. Claw stick 7
The front end of is locked to the key plate 8 attached to the shield wall 2 and locked, and the key bar 7 and the key plate 8 form a locking device.

[0006]

Among radiation control areas in which equipment containing radioactivity is installed, especially when neutron rays are the radiation source, neutron shielding materials are considered in the radiation shielding door, and gamma rays are considered. It is constructed in combination with the shield material.

However, since the locking / unlocking shaft is made of iron or the like, it is effective for shielding gamma rays, but it is less effective for shielding neutron rays, and there is a possibility that radiation will leak due to a shield defect. However, there is a problem in leakage prevention measures. The present invention has been made to solve the above problems, and an object thereof is to provide a radiation shielding door in which neutron rays do not leak from the gap between the locking / unlocking shaft and the door body.

[0008]

According to the present invention, there is provided a door main body for opening and closing an opening of a radiation shielding wall, a hinge mechanism provided between the door main body and the shielding wall, and an insertion penetrating through the door main body. A radiation shielding door equipped with a locking / unlocking shaft that is attached and has a lever handle on the front and rear surfaces of the door body, and a locking device provided between the locking / unlocking shaft and the shielding wall. The present invention is characterized in that a hollow portion is formed, the hollow portion is filled with a neutron shielding material, the locking and unlocking shaft is provided with a hollow enlarging portion, and the hollow enlarging portion is filled with a neutron shielding material.

Further, according to the present invention, there is provided an insertion hole for a locking / unlocking shaft having a gear chamber at a substantially central portion penetrating the inner surface and the outer surface of the door body, and a pair of gears meshing with each other is provided in the gear chamber. The pair of gears are attached to each of the locking / unlocking shafts.

[0010]

According to the first aspect of the present invention, a hollow portion is formed in the door body, the neutron absorbing material is filled in the hollow portion, and the hollow enlarging portion is formed in the central portion of the locking / unlocking shaft. It is made by filling the neutron absorber.

Therefore, a step portion is formed between the door main body and the hollow enlarging portion of the locking / unlocking shaft so that the neutron beam traveling straight can be blocked and the neutron absorbing material absorbs the neutron beam. Therefore, it is possible to prevent leakage of neutron rays in the radiation controlled area.

Further, in the invention of claim 2, since the locking / unlocking shaft has an offset structure in which a pair of gears meshes on the way, the neutron beam can be intercepted by the offset structure even if the neutron beam goes straight. It is possible to prevent the neutron beam from leaking from.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the radiation shielding door according to the present invention will be described with reference to FIGS. 2 is an enlarged view of the locking / unlocking shaft of FIG. 1 and its peripheral portion.

That is, reference numeral 9 in FIG. 1 denotes a door body in this embodiment. The upper surface of the door body 9 is a thin iron plate
The lower surface is formed of a thick iron plate 11, and a hollow portion 12 is formed inside the neutron shielding material.
13 filled.

As shown in FIG. 2, a small-diameter through hole 15 for inserting the lever shafts 14a and 14b of the locking / unlocking shaft 14 is formed in the door body 9, and the middle of the through hole 15, that is, A swelled through hole 16 having a larger diameter than the through hole 15 is formed in the center of the door body 9.

The locking / unlocking shaft 14 is a lever shaft at both ends.
14a, 14b, and a hollow enlarging part 14 made of an iron plate in the center part thereof
c is formed, and the hollow expanded portion 14c is filled with a neutron shielding material 13 such as a polyethylene chip. The hollow enlarged portion 14c is inserted into the bulging through hole 16.

A lever handle 6 is attached to each of the lever shafts 14a and 14b, and the lower lever shaft 14 is attached.
A key bar 7 is connected to b, and the key bar 7 is engaged with a key plate 8 provided on the shield wall 2 to form a locking device.

Therefore, in the radiation shielding door having the above-mentioned structure in the first embodiment, the neutron beam is a neutron shielding material 13
The gamma rays are shielded by the iron plates 10 and 11. When entering the radiation controlled area, the lever handle 6 of the locking / unlocking shaft 14 is turned to unlock and enter the area. When retreating to the outside of the area, the lever handle 6 which is interlocked with the inside and outside of the door body 9 is unlocked to retreat to the outside of the area.

Further, as shown in FIG. 2, since the through hole 15 has an expanded through hole 16 and the locking / unlocking shaft 14 has a hollow enlarged portion 14c, the through hole 15 and the expanded through hole are formed. Steps 17 are formed between the portions 16 and a maze is formed between the hollow enlarged portion 14c.

Therefore, even if a gap is formed between the through hole 15, the expanded through hole 16 and the hollow enlarged portion 14c, neutron rays and gamma rays which go straight by the step 17 are blocked by the step 17, so It is possible to prevent the neutron beam from leaking without leaking to the.

Next, a second embodiment of the radiation shielding door according to the present invention will be described with reference to FIG. FIG. 3 shows only the main part of this embodiment, and the other parts are similar to those of the first embodiment, and therefore omitted.

In FIG. 3, stepped through holes 15a and 15b are formed so as to bend and pass from the outer surface of the door body 9, that is, the thin iron plate 11 and the inner surface of the door body 9, that is, the thick iron plate 12, and these through holes are formed. A gear chamber 18 is formed in the bent step portion between 15a and 15b along the horizontal direction.

In the gear chamber 18, the upper lever shaft
14a and a pair of gears 19 (19a, 19b) attached to the lower lever shaft 14b are arranged. Upper through hole
An offset structure is formed between the gear 15a, the gear chamber 18, and the lower through hole 15b.

Here, by turning the handle 6 of either the upper lever shaft 14a or the lower lever shaft 14b, the lever shaft 14 is passed through the gears 19a and 19b.
The locking device can be opened and closed by rotating either a or 14b and attaching or removing the bar 7 to or from the key plate 8.

However, according to the second embodiment, the lever shafts 14a and 14b are not directly passed through the door body 9,
An offset structure is formed by bending the shield door through gears 19a and 19b to lock and unlock the locking device. Since the locking / unlocking shaft is interlocked with the inside and outside of the radiation controlled area, the entrance / exit area can be performed in the same manner as in the first embodiment, and since the door main body 9 does not penetrate straight through, The structure can prevent leakage.

[0026]

According to the present invention, the lever shaft penetrating the inner and outer surfaces of the door body is formed into a step structure, and the neutron shielding material is filled in the frame shape such as iron, which is the material of the conventional shaft, by the neutron shielding material. Leakage of neutron rays can be prevented. Further, the same effect can be expected by providing an offset structure having a step portion without directly penetrating the locking / unlocking shaft, and a rational radiation shielding door can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of a radiation shielding door according to the present invention.

FIG. 2 is an enlarged vertical sectional view showing the locking / unlocking shaft in FIG.

FIG. 3 is a vertical cross-sectional view showing the main parts of a second embodiment of the radiation shielding door according to the present invention.

FIG. 4 is a vertical sectional view showing a conventional radiation shielding door.

[Explanation of symbols]

1 ... Door body (conventional example), 2 ... Shield wall, 3 ... Hinge device, 4 ... Locking / unlocking shaft, 5 ... Through hole, 6 ... Lever handle, 6a, 6b ... Lever shaft, 7 ... Key bar, 8 ...
Key plate, 9 ... Door body (present invention), 10 ... Thin iron plate, 11 ... Thick iron plate, 12 ... Hollow part, 13 ... Neutron shielding material, 14 ... Locking / unlocking shaft, 14a, 14b ... Lever shaft, 14c ... Hollow Enlarged part, 15 ... through hole, 16 ... expanded through hole, 17 ... stepped part, 18 gear chamber, 19 gear.

Claims (2)

[Claims] 1. A door body for opening and closing an opening of a radiation shielding wall, a hinge mechanism provided between the door body and the shielding wall, and a front surface of the door body inserted through the door body. And a radiation shielding door having a locking / unlocking shaft having a lever handle on the rear surface and a locking device provided between the locking / unlocking shaft and the shielding wall, a hollow portion is formed in the door body, A radiation shielding door, characterized in that the hollow portion is filled with a neutron shielding material, the locking and unlocking shaft is provided with a hollow expanded portion, and the hollow expanded portion is filled with a neutron shielding material. 2. An insertion hole for a locking / unlocking shaft, which has a gear chamber substantially in the center and penetrates the inner surface and the outer surface of the door body, and a pair of gears meshing with each other is provided in the gear chamber. The radiation shielding door according to claim 1, wherein the pair of gears are attached to each of the lock shafts.