JPH06324193A - Penetrating part shielding structure - Google Patents

Abstract

PURPOSE:To restrain a shielding material in proper quantity, facilitate maintenance of a member, and reduce exposure of an operator by dislocating openings little by little after the openings aligned of plural shielding bodies are and the penetrating member is inserted and installed. CONSTITUTION:A large number of shielding bodies 9 having a through-hole 12 and a shielding body 10 having a handle 11 are arranged inside of a push in sleeve 2 by fastening by a bolt and nut. In the first place, after the shielding body 10 and the large number of shielding bodies 9 are combined with each other so that the through-hole 12 is put in a straight line shape, a penetrating member 3 inserted in a protective pipe 13 is inserted/arranged. Next, when the shielding bodies 9 are twisted by the handle 11, the shielding bodies 9 are dislocated in order by being dragged by the protective pipe 13, and lastly, the through-hole 12 is formed relatively in an almost helical shape. In this way, prescribed shielding performance is secured, and a shielding effect is made variable, and installation, removal and maintenace of the penetrating member 3 or installation of the shielding bodies 9 can be facilitated, and exposure of an operator can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation shielding apparatus for radiation-related facilities such as nuclear facilities and accelerator facilities, and more particularly to a penetration portion shielding structure which facilitates installation and removal of a shielding material and maintenance of a penetration member.

[0002]

[Prior art]

(Prior art example 1) In the member penetration part of the wall in the nuclear facility, the shielding ability in the vicinity of the penetration part is lowered due to the influence of the void part in the wall caused by the penetration of the member. As a shielding measure for compensating for the deterioration of the shielding ability, there is a method of installing a shielding material having a better shielding performance than concrete in the member penetration portion.
Conventionally, as shown in FIG. 7 (see Japanese Patent Application Laid-Open No. 60-179697), a shielding device related to this method is constructed by laminating a plurality of thin steel plates having holes formed in openings formed in a wall and integrating them. It is regarded as a continuous pipe-shaped through passage of perforated thin steel plate,
This is a shield having a shielding performance equivalent to that of the wall where the penetrating portion is installed.

(Conventional Example 2) As a similar purpose of the shielding measure of the conventional example 1, as shown in FIG. 8, in a wall wall penetration portion shielding device of a pipe, a shielding block having an opening of an outer periphery open shape is formed in the penetration portion. A maze structure is formed by the combination, and the pipe is configured to penetrate along the opening of the outer peripheral open shape. As a result, the shielding block can be removed without cutting the pipe, the pipe can be easily maintained, the reliability of the related system and the exposure during the maintenance work can be reduced.

(Prior art example 3) The purpose is the same as that of the prior art examples 1 and 2, or a container in which a shielding material can be inserted and discharged is provided and is shown in FIG.

[0005]

The members in a nuclear facility are installed under severe environmental conditions of high temperature and high dose, and inspection and maintenance are required at regular intervals.
Therefore, ensuring the maintainability of the penetrating member and the equipment associated with the penetrating member even in the wall penetrating portion of the member is an essential condition for ensuring the reliability of the system related to the penetrating member.

However, in Conventional Example 1, the through pipes are inserted into the respective thin steel plates, and the thin steel plates and the through pipes cannot be separated during maintenance work. For this reason, if the thin steel plate is pulled out from the wall and left as it is, the through pipe may be damaged. Therefore, it is necessary to install a stand for supporting the pulled thin steel plate in the vicinity of the through portion in advance. However, such a preliminary space rarely exists in a nuclear facility, and in order to carry out maintenance of the through pipe in Conventional Example 1, the through pipe is cut to separate each thin steel plate and the through pipe. It becomes necessary to separate them. This may lead to not only the work of removing the shield but also the maintenance work time including the work of restoring the shield after the completion of the maintenance work, and eventually the exposure dose during the maintenance work. Further, in Conventional Example 1, since the shield is composed of a large number of thin steel plates and the number of on-site works increases, the shield is poor in installability and may lead to a long construction process. On the other hand, in Conventional Example 2, although the maintainability and the installability of the shield can be improved, there are drawbacks in timely replacement of the shield and a proper amount of the shield with a change in the radiation source. Also, the removal maintenance is not easy because the shield is not movable, and it is necessary to improve the exposure of workers.

In the conventional example 3, there was radiation leakage from the straight pipe portion.

An object of the present invention is to improve the amount of shielding material, the ease of member maintenance, and the reduction of exposure of workers.

[0009]

[Means for solving the problems] Shield installation in the conventional example,
The purpose was to make removal easier and prevent radiation leakage.

In order to simplify the attachment and detachment of the shield, and the attachment and detachment of the penetrating member such as a cable, the openings of the plurality of penetrating members are preliminarily installed so that the openings are aligned with each other. The penetration member is inserted and installed from the opening, and thereafter, the openings of the plurality of shields are slightly shifted from each other to reduce the radiation leakage of the penetration portion such as a helical shape. To remove it, reverse the procedure.

When a shielding material having fluidity is used, it is composed of two plates having openings in advance, a pipe connecting the openings and a container enclosing the whole, and a penetrating member such as a cable is passed through. After that, by changing the relative position of the two plates by twisting, a shape such as a helical shape that reduces radiation leakage is formed.

[0012]

[Function] As compared with the radiation leakage from the straight tube-shaped opening, the shielding performance becomes very high due to the helical bending. Further, at the time of installation, removal, and maintenance, it can be easily returned to the straight pipe, and can be easily performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view after the shields of the multiple plates of the present invention are installed with being offset from each other. An embedding sleeve 2 having an annular cross section is provided in a penetrating portion 4 of a wall 1, and the embedding sleeve 2 is penetrated therein. A large number of shields 9 having holes 12 and a shield 10 with a handle 11 tightened with bolt nuts 8 through bolt holes 15 are installed. The stopper 7 has a structure in which the whole does not fall off. The penetrating member 3 such as a cable is shown after the penetrating portion 12 is linearly aligned and installed, and then the handle 11 is rotated to shift the penetrating portion in a helical shape.

FIG. 2 is a detailed view of an example of the shield, in which six circular through holes 12 are arranged side by side at the same radial position from the center of the shield. The bolt hole 15 is installed at the center. The diagram on the right of FIG. 2 is a diagram of the shield with a handle. This shield may be a strip of an iron plate or the like, or may be a can in which the shielding material can be put.

3 and 4 show an example of the positional relationship between the shields. FIG. 3 shows a cable 14 in which a large number of shields 9 and a shield 10 with a handle are combined so that the through holes 12 are aligned with each other in a straight line, and the flexible shield tube 13 is made of rubber or a flexible tube. The shields 9 may be made of the same material, or may be made of a combination of different materials so that they can be shielded better. This number can be set as long as it has a thickness that satisfies the shielding performance, and thus can be prepared as a standard product.

Thereafter, as shown in FIG. 4, the handle 11
When the shield 10 is twisted by using, the shield 10 is dragged by the protective tube 13 and the shield is displaced one after another, and finally the through hole becomes relatively helical. To reduce the radiation leakage from the through holes, increase the twist. At this time, the protective tube 3 may be long in advance, or may be made of a material that stretches well. Further, the through hole 12 may be provided with a counterbore so that a shear force is not applied to the protective tube. In this way, the radiation leakage from the through hole can be changed as required.

FIG. 5 is a perspective view of a shield according to a second embodiment of the present invention. In FIG.
2 is provided so that the torsion radius can be relatively reduced. The size of the wall penetration cannot be made large,
The twist radius can be used when the material of the penetrating member 3 cannot be reduced due to the material limitation. (B) is an example in which two slits are inserted, which is effective when a multicore cable or the like having a flat cross section is installed. (C) is an example in which a large penetrating portion and a small penetrating portion are arranged at different positions from the center of the shielding plate, six in total and twelve in total. The thick cable is installed on the outside because the bending radius cannot be reduced, and the thin cable is installed on the inside because the bending radius can be reduced. Considering the radiation leakage component, it is rational because leakage can be reduced by installing a thick through hole on the outside.

FIG. 6 shows a third embodiment of the present invention, which is an example when a fluid shielding material is used. Between the shields 9 and 10, four flexible penetration tubes 16 such as flexible tubes or rubber are installed,
A fluid material such as water, lead particles, iron balls, or a combination thereof is filled between the outside of the tube and the sleeve 2. Handle 12 after inserting a penetrating member such as a cable
Twist to twist the penetration. The shielding material may in this case be twisted and then inserted through the shielding material filling hole 18. Also, for materials that heat-set after mixing two liquids such as silicone elastomer, it is not possible to return it to a straight tube when removing it, but if you can reduce the twist, you can remove the cable, and if you do not need to remove it, twist the cable. It can be made larger to enhance the shielding effect.

[0020]

EFFECTS OF THE INVENTION According to the present invention, in addition to securing a predetermined shielding performance, there are the following effects.

(1) The shielding effect is variable. The transmission component can be shielded by changing the number of sheets, and can be unitized as a standard product. It is also easy to form different materials into multiple layers so as to enhance the shielding effect. In addition, the component leaking through the penetrating portion may be changed in twist angle. It is also possible to increase the shielding effect by twisting the twists in the same direction but not in the same direction. When making the radiation source large, it is only necessary to change the twist and the number, and it is not necessary to recreate the shield.

(2) Installation, removal and maintenance of the penetrating member are easy. When the penetrating member is inserted into the penetrating port, it is easy to attach because it has a straight tubular shape. It is easy because the through hole can be returned to a straight tube even when it is removed for replacement. Even when examining the radiation deterioration of the cable, it is possible to return it to a straight tube with a little force for visual inspection and the maintenance is easy.

(3) The shield can be easily installed. The shield is generally heavy, but since it is unitized, it can be assembled individually so that it can be handled lightly.

(4) A large shielding effect can be obtained as compared with a straight tubular through hole. Therefore, it is not necessary to unnecessarily increase the shielding thickness and increase the leakage distance. Only by twisting, the leakage distance can be lengthened to prevent radiation leakage.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a plurality of shields according to an embodiment of the present invention after they are installed while being offset from each other.

FIG. 2 is a perspective view of a shield used in FIG.

FIG. 3 is a perspective view in which a cable with a protective rubber tube is installed with matching through holes.

FIG. 4 is a perspective view of a helical penetrating shape.

FIG. 5 is a perspective view of an example of the shape of a shield.

FIG. 6 is a perspective view of an example in which a shield having fluidity is centrally combined.

FIG. 7 is an explanatory diagram of an example of a conventional technique.

FIG. 8 is an explanatory diagram of an example of a conventional technique.

FIG. 9 is a configuration diagram of another embodiment of the conventional technique.

[Explanation of symbols]

1 ... Wall, 2 ... Penetration part embedding sleeve, 3 ... Penetration member, 4 ...
Wall penetration part, 5 ... Low dose room, 6 ... High dose room, 7 ... Stopper, 8 ... Tightening bolt, nut, 9 ... Shield, 10 ... Shield with handle, 11 ... Handle, 12 ... Through hole, 13
... Protection tube, 14 ... Cable, 15 ... For bolt, hole, 16
... Penetrating tube, 17 ... Fluid shield, 18 ... Hole for filling shielding material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Narita 3-2-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Engineering Co., Ltd. (72) Hiroyuki Handa 3-2-1, Saiwaicho, Hitachi City, Ibaraki Prefecture No. 1 within Hitachi Engineering Co., Ltd. (72) Inventor Jun Takeuchi No. 3-2-1, Sachimachi, Hitachi City, Ibaraki Prefecture Within Hitachi Engineering Co., Ltd.

Claims (2)

[Claims] 1. A shield is provided by installing a plurality of shields having one or more openings, inserting the objects to be laid from the openings so that the openings are aligned with each other, and then shifting the relative positions of the openings from each other. A penetration part shielding structure characterized by performing. 2. The penetrating shield structure according to claim 2, wherein a fluid substance such as water or lead particles is used for a part or all of the shield.