JPH0514879B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an opening/closing mechanism for a radiation source chamber, and more particularly to an opening/closing mechanism for a radiation source chamber equipped with a radiation shielding door that can be quickly opened and closed manually.

BACKGROUND OF THE INVENTION A passageway for people to enter and exit is provided in the shielding wall of a so-called radiation source room that uses a radiation generating device and a radioactive isotope, and a radiation shielding door is disposed in this passageway. Therefore, a conventional opening/closing mechanism for a radiation source chamber is shown in FIGS. 3 and 4, and will be described below with reference to the same figures.

As shown in FIG. 3, steps are provided on both sides and the top surface of the passage 11 of the shielding wall 1, while steps are also formed on both sides and the top surface of the radiation shielding door 2. ing. That is, the difference in level between the radiation shielding door 2 and the passage 11 eliminates any visible gap between the two. The radiation shielding door 2 is moved by a motor or the like on a rail 3 disposed in a direction perpendicular to the longitudinal direction of the shielding wall 1, as shown by arrow A in the figure, so that the passage 11 can be closed or opened. It will be done.

Further, as shown in FIG. 4, the passage 11a of the shielding wall 1a is simply rectangular;
The radiation shielding door 2a has a larger shape than the opening a. That is, the radiation shielding door 2a and the passage 1
Due to the difference in size from 1a, there is no visible gap between the two. The radiation shielding door 2a is moved by a motor or the like on a rail 3a disposed parallel to the longitudinal direction of the shielding wall 1a, as shown by arrow B in the figure, to move the radiation shielding door 2a to the passage 11a.
Increasingly, the closure and opening of

In the radiation shielding doors 2, 2a described above, since a drive source such as a motor cannot be used during a power outage, the radiation shielding doors 2, 2a are moved using a manual handle.

Problems to be solved by the invention Radiation shielding doors 2 and 2 shown in FIGS. 3 and 4
a and the passages 11, 11a have stepped portions formed on both sides and the top surface, but the rails 3, 3
The step portion is not formed in the portion a, that is, the lower surface. Therefore, since there is a visible gap between the lower surface of the shielding walls 1, 1a and the lower surface of the radiation shielding doors 2, 2a, it is said that the effect of attenuating the radiation leaking from the radiation source room to the outside cannot be effectively obtained. There were flaws.

Further, since the single radiation shielding doors 2 and 2a need to have the same thickness as the shielding walls 1 and 1a, their weight is also several tons or more. Therefore, even if manual measures are taken during power outages,
It is impossible to quickly open and close the radiation shielding doors 2, 2a. Therefore, as stated in Article 15(3)-2 of the Prime Minister's Office Ordinance of the Act on Prevention of Radiation Hazards Caused by Radioactive Isotopes, etc., the so-called Hazard Prevention Act, ``Enable persons trapped indoors to escape promptly.'' The disadvantage was that it was not possible to satisfy the requirement of "taking measures to ensure that

This invention was devised focusing on the above-mentioned circumstances, and it is possible to effectively obtain the radiation attenuation effect, and
The object of the present invention is to provide an opening/closing mechanism for a radiation source chamber that allows quick escape from the radiation source chamber.

Means for Solving the Problems In order to achieve the above object, the present invention provides a radiation shielding door consisting of an inner door and an outer door, each of which is cantilevered by hinges on a shielding wall. The passage consists of an inner opening that becomes narrower as it goes from the interior of the radiation source room to the outdoors, and an outer opening that communicates with the inner opening and becomes wider as it goes from the interior of the radiation source room to the exterior. did. Further, a step was provided on the upper surface of the passage, and a tapered step was provided on the lower surface.

Function The radiation shielding door is divided into two parts, an inner door and an outer door, to reduce the weight of each door, and these are cantilever-supported with hinges, so the inner door and outer door can be opened around the hinge. can be manually rotated to the indoor and outdoor sides of the radiation source chamber with a proportionally small force. Furthermore, since steps are formed on the inner peripheral surface of the passageway and the inner and outer doors are shaped to match the passageway, there is no visible gap between the radiation shielding door and the passageway.

Embodiment FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line AA in FIG. 1.

In these figures, 10 is a radiation source chamber 10a.
A screening wall made of, for example, concrete. This shielding wall 10 has a passage 20 for people to enter and exit.
is formed. The passage 20 has an inner opening 21 that becomes narrower as it goes from the interior of the radiation source chamber 10a to the outside, and an outer side that communicates with this inner opening 21 and becomes wider as it goes from the interior of the radiation source chamber 10a to the exterior. It consists of an opening 22. Specifically, as shown in FIG. 1, both side surfaces of the passageway 20 have a plane perpendicular to the shielding wall 10 and a plane inclined from this plane, and therefore each side is bent in a substantially rectangular cross section. It is shaped like this. In addition, the upper surface of the shielding wall 10 has a step 23 that hangs down in a direction perpendicular to the upper surface near the center of the passage 20, as shown in FIG.
is formed, while the lower surface has a step 2 on the upper surface.
Tapered step 2 at the position corresponding to the position of 3
4 is formed. The reason why the step 24 is tapered is to allow the pulley of the transport vehicle to pass through smoothly.If the transport vehicle is not required, this step 24 can be formed in the same manner as the step 23 described above.

A radiation shielding door consisting of an inner door 30a and an outer door 30b is fitted into the inner opening 21 and outer opening 22 of the passage 20. The inner door 30a and the outer door 30b are formed in shapes that match the inner opening 21 and the outer opening 22. Specifically, the inner door 30a and the outer door 30b are made of outer shells 31a and 3 made of iron plates, for example, about 5 to 10 mm, reinforced with a reinforcing iron frame.
It has a structure in which the inside of 1b is filled with concrete, etc. The inner door 30a is supported by a cantilever on the shielding wall 10 with a hinge 40a. This hinge 4
The inner door 30a is centered on the radiation source room 1
0a can be opened to the indoor side and fitted into the inner opening 21 of the passage 20. On the other hand, the outer door 30b is supported by a cantilever on the shielding wall 10 with a hinge 40b. Centering around this hinge 40b, the outer door 30b can open the radiation source chamber 10a to the outside of the room and fit into the outer opening 22 of the passage 20.

Furthermore, the inner door 30a and the outer door 30b
are respectively provided with locking mechanisms 50a and 50b for keeping or releasing the closed state of the passage 20. This lock mechanism 50a, 50b
is a pin-on bar 51a with a male thread at one end,
51b, and handle levers 52a, 52b fixed to both ends of the pin-on bars 51a, 51b.
53a, 53b and the pin-on bars 51a, 5
Rack 54a, 54b that meshes with male screw 1b
and protrusions 541 at the ends of the racks 54a, 54b.
Lock holes 551a and 5 through which the lock holes 551a and 541b can be inserted
51b and locking members 55a and 55b.

The racks 54a and 54b are arranged parallel to the longitudinal direction of the shielding wall 10 on the outer surfaces of the inner door 30a and the outer door 30b, respectively. This rack 54a,
54b is movable in its longitudinal direction. Pin-on bars 51a and 51b are disposed in a direction orthogonal to these racks 54a and 54b, supported by bearings or the like. This pin on bar 51
Handle levers 52a, 5 on one end side of a, 51b
The handle levers 53a and 53b on the other end side of the pin-on bars 51a and 51b are attached to the inner door 30a and the outer door 30.
They are arranged in recesses 32a and 32b provided on each inner surface side of b. Handles 60c and 60b are provided in the recesses 32a and 32b, respectively, and handles 60d and 60a are also attached to the outer surfaces of the inner door 30a and the outer door 30b, respectively. Furthermore, the lock members 55a and 55b are
It is attached to the shielding wall 10.

Next, a procedure for sequentially opening the outer door 30b and the inner door 30a when entering the radiation source chamber 10a will be explained.

Rotate the handle lever 52b in the direction opposite to the moving direction of the clock hands. As a result, the rack 54b meshing with the male thread of the pin-on bar 51b
moves in the direction of arrow _a1 in FIG. 4, and the protrusion 541b at the tip of the rack 54b is removed from the lock hole 551b.

By pulling the handle 60a in this state,
The outer door 30b rotates about the hinge 40b in the direction of arrow b in FIG. ₁ . In other words, radiation source room 1
The outer door 30b opens on the outdoor side of 0a. In addition, when the outer door 30b is about 4 tons, the outer door 30b can be opened with a force of about 10 kg. Needless to say, this also applies to the inner door 30a described below.

And the handle lever 53 of the inner door 30a
Rotate a in the same direction as the clock hands. As a result, the rack 54a moves in the direction of arrow _c1 in FIG. 1 via the pin-on bar 51a, and the protrusion 541a at the tip of the rack 54a is disengaged from the lock hole 551a.

By pressing the handle 60c in this state,
The inner door 30a rotates about the hinge 40a in the direction of arrow _d1 in FIG. In other words, radiation source room 1
The inner door 30a opens on the indoor side of 0a.

On the other hand, a procedure for sequentially closing the inner door 30a and the outer door 30b when exiting from the radiation source room 10a to the outside will be explained.

Pull the handle 60c of the inner door 30a and release the hinge 4.
Centering on 0a, move the inner door 30a in the direction of arrow d ₂ in Figure 1.
rotate in the direction. Thereby, the inner door 30a is fitted into the inner opening 21. Thereafter, the handle lever 53a is rotated in a direction opposite to the moving direction of the clock hands. As a result, the pin-on bar 51a
The rack 54a engaged with the male screw moves in the direction of arrow _c2 in FIG. 1, and the protrusion 541a at the tip of the rack 54a is inserted into the lock hole 551a and locked.

Push the handle 60a of the outer door 30b and release the hinge 4.
Centering on 0b, move the outer door 30b along the arrow b ₂ in Figure 1.
rotate in the direction. Thereby, the outer door 30b is fitted into the outer opening 22. Thereafter, the handle lever 52b is rotated in the same direction as the moving direction of the clock hands. As a result, the pin-on bar 51
The rack 54b moves in _{the two} directions of arrow a in FIG.
b is inserted into the rack hole 551b and locked.

Note that, of course, the shape of the passage 20 and the shapes of the inner door 30a and the outer door 30 are not limited to those in the above embodiment. Further, lock mechanisms 50a, 5
0b is also not limited to the above configuration.

Effects of the Invention As explained above, according to the present invention, steps are formed on the upper and lower surfaces of the passage, and the inner opening of the passage is made narrower as it goes from the interior of the radiation source chamber to the outside. The opening communicates with the inner opening and becomes wider from the inside of the radiation source room toward the outside, while the inner door and the outer door are shaped to match the inner opening and the outer opening. There is no visible gap between the outer door and the inner door, resulting in an effective radiation attenuation effect. In addition, the weight was reduced by dividing the conventional single radiation shielding door into two, and by supporting them cantilevered on hinges, there was no need to use a drive source such as a motor. You can quickly open and close the door manually. Therefore, there is no need to take measures against power outages, which were required in the past, and a quick escape as required by law becomes possible. Moreover, since it is manual, there is no need to worry about failure of a drive source such as a motor, as in the conventional case, and there is no need for electric power to be supplied to the drive source.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention;
Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is an explanatory diagram showing a conventional opening/closing mechanism of a radiation source chamber, and Fig. 4 is an explanatory diagram showing another conventional opening/closing mechanism of a radiation source chamber. It is. 10... Shielding wall, 10a... Radiation source room, 20
...Passway, 21...Inner opening, 22...Outer opening, 30a...Inner door, 30b...Outer door, 4
0a, 40b...Hinge, 50a, 50b...Lock mechanism.

Claims (1)

[Claims] 1. An inner opening that is provided in the shielding wall of the radiation source room and becomes narrower as it goes from the interior of the radiation source room to the outside; A passage consisting of a wide outer opening, an inner door that matches the inner opening and is supported by a shielding wall so as to be openable to the indoor side of the radiation source chamber, and an inner door that matches the outer opening. and an outer door supported by a shielding wall so as to be openable to the outside of the radiation source room, and an inner door blocking the passage from inside and outside the radiation source room when the passage is blocked by the inner door. and a lock mechanism that can maintain or release the closed state of the passage with the outer door from inside and outside the radiation source room when the passage is closed with the outer door. An opening/closing mechanism for a radiation source chamber characterized by: