JPH09133789A - Radiation shielding body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a worker engaged in an activity within the radiation control area of a nuclear power plant against exposure to a radiation. SOLUTION: Rubber 3, synthetic resin or flame retarding cloth is integrated with a lead plate 2, thereby preventing lead powder or pieces from adhering to an existing facility, and enabling the lead plate 2 to be mounted on the existing facility even in such a state as in direct contact therewith. For forming the lead plate 2 to match the shape of the existing facility, at the same time, a reinforcement frame and a reinforcement plate are integrated with the lead plate 2 to form a radiation shielding body having the prescribed strength, and the shielding body is assembled with an eyelet and a fitting integrated with the arbitrary area thereof. The assembly so made is used for enhancing workability in the case of a worker's transportation or handling activity. According to this construction, the shielding body becomes practical actually for application to an activity within the radiation control area of a nuclear power plant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation shield used to protect workers engaged in a radiation controlled area of a nuclear power plant from radiation exposure.

[0002]

2. Description of the Related Art In a radiation controlled area of a nuclear power plant that handles radioisotopes, necessary measures are taken to reduce exposure.

Among them, a radiation shielding material made of a lead material is often used, and an example thereof is a radiation transmission shielding material as proposed in Japanese Utility Model Laid-Open No. 1-14959.

[0004] This is a shield in which the error stoma is applied to the lead plate with a minimum thickness of 20 to 40 microns in consideration of oxidation prevention and ease of sticking, and mosaicing can be applied to the plate or wall. It is the body.

[0005]

However, the prior art has practical drawbacks in protecting the inspection workers from radiation in the periodic inspection of the nuclear power plant in the following points and is not convenient to use. .

In a radiation controlled area of a nuclear power plant, there are a wide range of piping and equipment which are radiation sources.
It can be easily inferred that the use of curtains, boards, or walls with mosaic-like lead plates entails a huge amount of labor and exposure required for their installation and removal work.

Most of the shields used during periodic inspections need to be removed during operation of the power plant.

This is because the device to be shielded is likely to come into contact with a high temperature part exceeding 200 degrees Celsius during operation, and the mechanical properties of lead itself or its clothing material may be remarkably deteriorated, leading to damage. This is because there is a concern that it will hinder the operation of the power plant.

By the way, in the case of the proposed shield,
There are no regulations regarding strength and heat resistance, and workability for mounting and dismounting is not considered.

The shield used during the periodic inspection should be directly attached to the device or the like to be shielded as much as possible.

This is because the effect closer to the radiation source can be obtained over a wider range.

Therefore, when the surface of the shielding material is lead and lead alloy,
Lead powder or lead pieces are generated by contact with equipment,
It is necessary to prevent these from adhering to the device or peripheral devices.

As a concrete measure, it is effective to coat the surface of the lead material with a material having high flexibility, heat resistance, and strength in a sufficient thickness. In the case of the proposed shield, the surface of the lead plate is oxidized. It has a thickness of 20 to 40 microns, which is not enough to prevent lead powder or lead pieces from adhering to equipment, and therefore, as a shield during periodic inspections of nuclear power plants. Is not appropriate.

Further, the shield used during the periodic inspection is manually carried, attached and detached, and its workability should be taken into consideration.

Therefore, a structure suitable for transportation and suspension or fixing is required, but the proposed shield does not consider this point at all.

When the shield is attached near the device to be shielded, it is desirable that the shield has a shape that matches (fits) the shape of the target device.

Since the shape of the shield may be complicated in some cases, the shield must have sufficient strength so as not to cause deformation or the like due to its own weight.

However, the proposed shield does not define such a structure.

That is, it was found that there are still problems in practical use for use in the periodic inspection of nuclear power plants.

The object of the present invention is to eliminate at least one of the drawbacks from the practical point of view of practical use of the above-mentioned radiation shield as described above in the radiation controlled area of a nuclear power plant. There is

[0021]

[Means for Solving the Problems] A first means for achieving the above object is a radiation shield using a lead plate or a lead processed product as a radiation shield in a nuclear power plant. The product is a radiation shield characterized by being integrally formed with rubber or synthetic resin or a flame-retardant cloth with a thickness exceeding the film thickness that prevents the oxidation of copper material. Radiation is shielded by the material, and not only oxidation but also damage of the lead material and generation of lead pieces and lead powder are prevented by the coating formed by integrally forming rubber or synthetic resin or flame-retardant cloth.

Similarly, in the second means, the radiation shield of the first means has a shape that fits a component product of a nuclear power plant, and the radiation shielding plate having the shape has a reinforcing frame or a reinforcing plate integrally provided. The radiation shield is fitted to the component product of the nuclear power plant to be shielded by the body having the function of the first means to enhance the shielding effect, and the radiation shield is shaped by the shape processing to fit the radiation shield. The effect of reinforcing the state in which the structural strength is lowered by the reinforcing frame or the reinforcing plate can be obtained.

Similarly, in the third means, the radiation shield of the first means or the second means is a radiation shield having eyelets or fixing metal fittings at arbitrary positions, and the first means or the second means.
In addition to having the function of the means, suspend the eyelets by hanging a rope etc., attach the radiation shield to the component products of the nuclear power plant, or connect adjacent radiation shields to each other with fixing metal fittings. It is possible to obtain a function of shielding a wide surface from radiation and suspending it.

Similarly, the fourth means is a radiation shield which is characterized in that in the first means, the second means or the third means, a gripping hole or a metal fitting for catching the gripping metal is provided. In addition to the effect of the second means or the third means, the effect that the radiation shield can be easily handled by using the grip hole or the grip fitting can be obtained. Similarly, the fifth means is characterized in that, in the first means, the second means, the third means, or the fourth means, the thickness of the rubber or synthetic resin or flame-retardant coating is 0.1 mm or more. In addition to the action of the first or second or third or fourth means, the shield is a lead material with a thickness far exceeding 20 to 40 microns which prevents oxidation. It ensures the effect of preventing damage to the product and the generation of lead pieces and lead powder.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1, 2, and 3 are a front view, a side view, and a sectional view showing a radiation shield 1 of the present invention.

FIGS. 4 and 5 are a front view and a side view showing a radiation shield 4 with a metal fitting in which the radiation shield 1 of the present invention is provided with a fixing metal fitting 5a and a fixing metal fitting 5b.

FIGS. 6 and 7 are a front view and a side view showing a radiation shield 4 with metal fittings, which is a radiation shield 1 of the present invention provided with eyelet metal fittings 6.

8 and 9, a reinforcing plate 9 is integrally formed on a lead plate 8 having a complicated shape, and the reinforcing plate 9 is covered with a covering material 3 of rubber, synthetic resin, or flame-retardant cloth, and then fixed metal fitting 5a. It is the front view and side view which show the radiation shield 7 with a reinforcement plate which fixed.

10 and 11, a lead frame 8 having a complicated shape is covered with a covering material 3 of rubber, synthetic resin or flame-retardant cloth, and a reinforcing frame 13 is integrally formed from the outside of the covering material 3. It is the front view and side view which show the radiation shield 10 with a reinforcing plate which fixed the metal fixture 5a to the integrally formed body.

FIG. 12 is a front view showing the radiation shield 14 provided with a grip metal fitting 15 which is hooked on the fixing metal fitting 5a in order to facilitate the handling work of the radiation shield 4 with the metal fitting. FIG. 13 is a front view showing the radiation shield 1 in which the radiation shield 1 of FIG. 1 is provided with a handle and a gripping hole for facilitating the handling work.

1 to 3, reference numeral 1 denotes a radiation shield according to the first embodiment.

The lead plate 2 is integrally formed with the covering material 3, and the lead plate 2 is covered with the covering material 3. Each of them has a sufficient thickness so as not to be easily damaged by contact with the peripheral or radiation shielded components of the nuclear power plant.

Regarding the thickness, specifically, the lead plate has a thickness of 3 mm to 4 mm and the coating material has a thickness of about 0.1 mm to 3 mm, which is much thicker than the antioxidant coating of 20 to 40 microns. The thickness of the material 3 is used.

As the material of the covering material 3, rubber, synthetic resin, or flame-retardant cloth is selected or used in combination.

The overall size is 900 mm in length and 300 mm in width.
Therefore, the total weight is about 9.5kg to about 12.5kg.
And the operator can handle it sufficiently.

Also in each of the following embodiments, the same thickness as that of the first embodiment is adopted, and the size and weight are similar.

The radiation shield 4 according to the second embodiment shown in FIGS. 4 and 5 comprises a fixing metal fitting 5a and a fixing metal fitting 5b fixed to the radiation shielding material of the first embodiment. .

The fixing metal member 5a fixed to the radiation shield protrudes further than the edge of the radiation shield, and the protruding portion is provided with a daruma-shaped hole.

The radiation shield is suspended and supported at the radiation shield position by utilizing this daruma-shaped hole, or the fixing metal fitting 5a.
A plurality of radiation shields can be connected and installed by inserting the protruding portion of the fixing metal fitting 5b into and engaging with each other.

For this reason, the fixing metal member 5b is fixed to the radiation shield and protrudes in the horizontal direction, and the middle part thereof is a protruding part which is narrower than the projecting end.

The protruding portion of the fixing metal fitting 5b is inserted into the lower hole of the dolly-shaped hole of the fixing metal fitting 5a, and the protruding portion of the fixing metal fitting 5b is inserted in the upper hole of the dolly-shaped hole of the fixing metal fitting 5a. The constricted portion of the radiation shield is caught and prevented from coming off in the horizontal direction, and a plurality of radiation shields are connected.

The radiation shield 4 according to the third embodiment shown in FIGS. 6 and 7 is one in which an eyelet metal fitting 6 is fixedly installed on the radiation shield of the first embodiment.

The eyelet fitting 6 has a hollow sleeve shape, and both ends thereof are crimped so as not to come off.

A rope-shaped member such as a rope is passed through the eyelet metal fitting 6 to support it by hanging it at a position where radiation is desired to be shielded, adjacent radiation shields 4 are connected to each other, or the rope passed through the eyelet metal fitting 6 is connected to the nuclear power. The radiation shield 4 is tied to the constituent products of the power plant and attached to the constituent products.
Is fixed.

In the radiation shield 7 according to the fourth embodiment shown in FIGS. 8 and 9, the lead plate 8 and the reinforcing plate 9 are fixed and integrated, and the integrated product is made of rubber, synthetic resin, or flame retardant. Cover with a cloth covering 3.

The lead plate 8 and the reinforcing plate 9 of the radiation shield 7 are cut in a U-shape so as to fit the shape of the equipment to be radiation shielded, and the radiation from the gap produced when the radiation shield 7 does not fit. No work to fill gaps or gaps.

A fixing metal fitting 5 having a hole is fixedly installed on such a radiation shield 7 to facilitate installation and handling.

The radiation shield 10 according to the fifth embodiment shown in FIGS. 8 and 9 is cut in a U-shape so as to fit the shape of the device to be shielded, and the lead plate 8 is made of rubber or synthetic resin. Alternatively, after covering with the covering material 3 of flame-retardant cloth, the covering material 3
A U-shaped reinforcing frame 13 is fixed and configured from the outside.

A fixing metal fitting 5 having a hole is fixedly installed on the radiation shield 10 to facilitate installation and handling.

Also with the radiation shield 10 according to the fifth embodiment, as in the fourth embodiment, a gap is created when the radiation shield 10 is cut into a U shape so as to fit the shape of the device to be radiation shielded, and does not fit. There is no radiation leakage from the area and no work to fill the gap. The radiation shield 14 of the sixth embodiment shown in FIG. 12 is a combination of the radiation shield according to the second embodiment and a fixing metal fitting 5a, and the fixing metal fitting 5a.
It consists of a holding metal fitting 15 that is detachably attached to the hole of
The radiation shield 14 is handled by using the holding metal fitting 15 hooked on the fixing metal fitting 5a as a handle, and the handleability is improved.

The grip 15 may be removed after the radiation shield 14 is installed at the shielding position, or may be used as a tool for installation.

The radiation shield 14 of the seventh embodiment shown in FIG. 13 is handled by forming a holding hole in the radiation shield 1 of the first embodiment and using the holding hole 16 as a handle.
The handleability becomes good.

This gripping hole 16 may be used to pass the rope through to install the radiation shield 14 in the shielded position.

The radiation shielding effect can be obtained even when the lead plate in each example is an iron plate, an alloy plate, or a synthetic plate, and the nuclear power plant also has a high temperature portion. The flame-retardant cloth coating has a heat resistance of 8 degrees Celsius.
It is preferable to use one having a temperature of 0 ° to 350 ° C.

[0056]

According to the invention of claim 1, it is possible to prevent damage to the lead material of the radiation shield and generation of lead pieces and lead powder.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, the radiation shielding body is fitted to the component product of the nuclear power plant to be shielded to enhance the shielding effect. A state in which the structural strength of the radiation shield is lowered by the shape processing for fitting can be reinforced with a reinforcing frame or a reinforcing plate.

According to the invention of claim 3, in addition to the effect of the invention of claim 1 or claim 2, a rope or the like is hung on an eyelet to hang it, or a radiation shield is attached to a component product of a nuclear power plant. Alternatively, adjacent radiation shields may be connected to each other with fixing metal fittings to shield a wide surface from radiation or to be suspended.

According to the invention of claim 4, in addition to the effect of the invention of claim 1, claim 2, or claim 3, the radiation shield can be easily handled by using the gripping hole or the gripping metal fitting. .

According to the invention of claim 5, in addition to the effect of the invention of claim 1 or claim 2 or claim 3 or claim 4, damage to the lead material and generation of lead pieces and lead powder are prevented. The action can be ensured.

[Brief description of the drawings]

FIG. 1 is a front view of a radiation shield according to a first embodiment of the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a front view of a radiation shield according to a second embodiment of the present invention.

FIG. 5 is a right side view of FIG.

FIG. 6 is a front view of a radiation shield according to a third embodiment of the present invention.

FIG. 7 is a right side view of FIG.

FIG. 8 is a front view of a radiation shield according to a fourth embodiment of the present invention.

FIG. 9 is a right side view of FIG.

FIG. 10 is a front view of a radiation shield according to a fifth embodiment of the present invention.

FIG. 11 is a right side view of FIG.

FIG. 12 is a front view of a radiation shield according to a sixth embodiment of the present invention.

FIG. 13 is a front view of a radiation shield according to a seventh embodiment of the present invention.

[Explanation of reference numerals] 1, 4, 7, 10, 14 ... Radiation shields, 2, 8, 11
... Lead plate, 3 ... Coating material, 5, 5a, 5b ... Fixing metal fittings, 6
... Eyelet metal fittings, 9 ... Reinforcing plate, 13 ... Reinforcing frame, 15 ... Grip fittings, 16 ... Holes for gripping.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Omori 3-2-2 Sachimachi, Hitachi City, Ibaraki Prefecture Hitachi Engineering Service Co., Ltd. (72) Inventor Isao Nemezawa 3-chome, Sachimachi, Hitachi City, Ibaraki Prefecture 1st-1 Hitachi Ltd. Hitachi factory (72) Inventor Masahiro Kimura 3-1-1 1-1 Saiwaicho, Hitachi city, Ibaraki Hitachi Ltd. Hitachi factory

Claims (5)

[Claims] 1. A radiation shield using a lead plate or a lead processed product as a radiation shield in a nuclear power plant, wherein the lead plate or the lead processed product has a thickness exceeding a film thickness for preventing oxidation of a copper material. A radiation shield characterized by being integrally formed with rubber, synthetic resin, or flame-retardant cloth. 2. The radiation shield according to claim 1, wherein the radiation shield has a shape that fits a component product of a nuclear power plant, and the radiation shield having the shape is integrally provided with a reinforcing frame or a reinforcing plate. 3. The radiation shield according to claim 1 or 2,
A radiation shield provided with eyelets or fixing metal fittings at arbitrary positions. 4. The radiation shield according to claim 1, 2, or 3, wherein the holding hole or the holding metal fitting is provided with a fitting. 5. The radiation shield according to claim 1, 2 or 3 or 4, wherein the thickness of the coating made of the rubber, synthetic resin or flame retardant cloth is 0.1 mm or more. body.