JP3188758U - Portable radiation shield and radiation shield device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the problem of exposure of a worker due to measurement of a radiation amount of a sample using a portable radiation shield, and to optimize the amount of radiation shielding material contained in the portable radiation shield to minimize the necessary radiation. Provided is a radiation shielding device composed of a shielding material. A probe P is inserted into a central portion of a shielding lid 4. A specified sealed plastic container 200 containing a sample is housed in the shielding body 2. The inner diameter of the shielding body 2 is slightly larger than the outer diameter of the closed container 200. The total value of the depth dimension Dth of the recess of the shielding body 2 and the thickness dimension of the shielding lid 4 is the sum of the height dimension H of the closed container 200 and the length dimension of the shielding necessary portion L of the probe P. equal. [Selection diagram] Fig. 3

Description

  The present invention relates to a portable radiation shield convenient for measuring the radiation dose of a specimen and a radiation shielding apparatus including the same.

  The accident at the Fukushima nuclear power plant caused by the 2011 off the Pacific coast of Tohoku Earthquake and the tsunami (the Great East Japan Earthquake) caused a problem of radioactive contamination over a wide area and still released a large amount of radioactive material into the environment. The result of continuing.

  While decontamination work is progressing along with the reconstruction work in the earthquake-affected areas, at the same time, work to accurately grasp the status of pollution in residential areas, farmland, forests, ponds, swamps, and river areas is also progressing.

  The inventor of the present application has proposed a portable radiation shield in Patent Document 1. Portable radiation shields are advantageous when measuring radiation doses in a target analyte or spot area using available portable instruments. This portable radiation shield has a bottom shielding lid, and when used with the bottom shielding lid removed, that is, with the bottom open, for example, the radiation dose at one point on the ground surface is measured in a state isolated from the surrounding environment. To help. In the state where the bottom shielding lid is attached, the radiation dose of the specimen can be measured in a state isolated from the surrounding environment by placing the tray on which the specimen is placed in the shielding body.

JP 2012-159517 A

  In the conventional portable radiation shield, it is necessary to place a sample brought from the field on a tray and put the tray into the shield. This specimen is a radioactive contaminant. The work of placing the sample on the tray, storing the tray in the shield, and taking out the tray from the shield after the measurement is completed, and removing the sample from the tray and discarding it in the shield container, for example. Necessary. This work is a manual work, and when measuring the radiation dose of many specimens, it is necessary to take measures against the radiation exposure of workers.

  The portable radiation shield is made mainly of lead. For this reason, the portable radiation shield is heavy. In addition, by using a portable radiation shield, this shield is also radioactively contaminated, which causes a secondary problem of lead disposal associated with the disposal of the shield.

  An object of the present invention is to provide a portable radiation shield and a shielding device that can reduce the problem of exposure of an operator due to measurement of the radiation dose of a specimen using the portable radiation shield.

  It is a further object of the present invention to provide a portable radiation shield and a shielding device that are composed of the minimum necessary radiation shielding material by optimizing the amount of radiation shielding material contained in the portable radiation shield.

The above technical problem is, according to one aspect of the present invention,
A bottomed cylindrical shield body containing a prescribed sealed container containing a specimen;
A shielding lid for closing the upper end opening of the shielding body;
A circular opening extending through a central portion of the shielding lid, the circular opening having an inner diameter substantially equal to a diameter of a cylindrical probe of the radiation measuring instrument and capable of accepting insertion of the probe;
The cross-sectional shape of the inner surface of the shielding body is similar to the cross-sectional shape of the sealed container,
The size of the cross section of the inner surface of the shielding body is set to a size such that a finger does not enter between the inner surface of the shielding body and the sealed container when the sealed container is placed in the shielding body,
The depth dimension Dth of the recess for receiving the sealed container of the shielding body is such that the sealed container is placed in the shielding body, and the probe inserted into the circular opening of the shielding lid is on the sealed container. It is set to a value obtained by subtracting the thickness dimension Th of the shielding lid from the total value of the length dimension of the necessary shielding portion L of the probe and the height dimension H of the sealed container when seated. This is accomplished by providing a portable radiation shield.

According to another aspect of the present invention, the above technical problem is
A cylindrical shielding body with a bottom that accommodates a sealed plastic container having a circular shape in plan view containing a specimen, a shielding lid that is hinged to the shielding body and closes the upper end opening of the shielding body, and a shaft that is pivoted on the shielding body A portable radiation shield having a handle and a tiltable handle;
A radiation shielding device comprising a combination with a U-shaped lifting member that can be inserted into the shielding body in a side view,
The lifting member has a hook part that can be hooked with a finger on its upper end part,
The shield lid of the portable radiation shield is a circular opening extending through a central portion of the shield lid and has an inner diameter that is substantially the same as the diameter of a cylindrical probe of the radiation meter and accepts insertion of the probe A circular opening that can
The cross-sectional shape of the inner surface of the shielding body is circular,
The diameter of the inner surface of the shielding body is set to a dimension that prevents fingers from entering between the inner surface of the shielding body and the sealed plastic container when the sealed plastic container is placed in the shielding body,
The depth Dth of the recess for receiving the sealed plastic container of the shield body is such that the probe inserted into the circular opening of the shield lid is inserted into the shield body with the sealed plastic container being inserted into the shield body. When set on a value obtained by subtracting the thickness dimension Th of the shielding lid from the total value of the length dimension of the shielding necessary portion L of the probe and the height dimension H of the sealed plastic container when seated on the probe;
In the shielding body, insert the lifting member and the sealed plastic container to measure the radiation dose of the specimen in the sealed plastic container,
This is achieved by providing a radiation shielding device in which when an airtight plastic container is taken out from the shielding main body, an operator hooks a finger on a hooking portion at an upper end portion of the lifting member and pulls it up.

  The operational effects and other objects and operational effects of the present invention will become apparent from the detailed description of the preferred embodiments described later.

It is a front view of the portable radiation shielding body of an Example. It is a top view of the portable radiation shield of FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, showing a cross section of the portable radiation shield of the example. It is explanatory drawing of the usage of the portable radiation shield of an Example.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 show a portable radiation shield 100 according to an embodiment. The portable radiation shield 100 according to the embodiment includes a bottomed cylindrical shielding body 2 and a shielding lid 4 for closing the upper end opening of the shielding body 2. In order to carry the portable radiation shield 100, the handle 6 is pivotally supported by the shield body 2 so as to be tiltable. FIG. 3 is a cross-sectional view taken along line III-III in FIG.

  The shielding lid 4 is integrated with the shielding body 2 by a hinge 8 (FIGS. 2 and 3), and the shielding lid 4 can be opened and closed around the hinge 8. In order to facilitate this opening / closing operation, the shielding lid 4 is provided with a handle 10 on the opposite side of the hinge 8. It is preferable that the end of the shielding lid 4 can be fixed to the shielding body 2 by the lock 12 in order to improve the integrity of the shielding body 2 and the shielding lid 4 when the portable radiation shielding body 100 is carried. .

  The shielding main body 2 and the shielding lid 4 have a shielding material 22 surrounded by an outer skin 20 made of a stainless steel plate (FIG. 3), and lead is adopted as the shielding material 22. The thickness dimension of the lead 22 is preferably set so as to realize a desired radiation shielding effect.

  The shielding lid 4 has a circular opening 30 at the center thereof (FIG. 3), and the opening 30 penetrates the shielding lid 4 in the thickness direction, that is, in the vertical direction. A probe P of a radiation measuring instrument can be inserted into the circular opening 30. The diameter D1 of the circular opening 30 is set to a value slightly larger than the diameter Dp of the probe P of the available portable radiometer. In this embodiment, the diameter D1 of the circular opening 30 is set to a value slightly larger than the diameter of the cylindrical probe of the scintillation survey meter TCS-171B manufactured by Hitachi Aloka Medical Co., Ltd. (D1 = 48.5 mm).

  The shielding main body 2 accommodates a plastic container 200 having a hermetic shielding lid. The plastic container 200 contains a specimen S. That is, it is possible to measure the radiation dose of the specimen S by putting the sealed plastic container 200 containing the specimen S into the shielding body 2 as it is.

  The portable radiation shield 100 according to the embodiment is designed to fit into a hermetic plastic container 200 having a predetermined diameter and height and having a circular shape in plan view, and the inner diameter ID of the shielding body 2 is the outer diameter of the hermetic plastic container 200. A value slightly larger than OD is set. Specifically, the inner diameter ID of the shielding body 2 is 160 mm, and the value of the inner diameter ID is such that the sealed plastic container 200 can be accommodated in the shielding body 2 and the inner surface of the shielding body 2 and the sealed plastic container 200. The value is set so that a finger cannot be inserted between.

  The probe P of the survey meter has a radiation detection unit at its lower end. The inventor of the present application has learned that, in practice, the influence of the radiation from the surrounding environment can be avoided by shielding the shielding required portion L having a predetermined length from the lower end of the probe P without shielding the entire probe P. . In the scintillation survey meter TCS-171B, the probe P has a cylindrical shape with a constant diameter from the lower end to the upper end, and a portion 70 mm from the lower end is the shielding required portion L. That is, if the shielding required portion L of 70 mm from the lower end is surrounded by the portable radiation shield 100, the probe P can be substantially avoided from being affected by radiation from the surrounding environment.

  With this in mind, the portable radiation shield 100 has been designed. Specifically, the sum of the depth dimension Dth of the recess of the shielding body 2 and the thickness dimension Th of the shielding lid 4 is the height dimension H of the sealed plastic container 200 and the necessary shielding part L of the probe P. The portable radiation shield 100 is designed so as to be equal to a numerical value obtained by adding together. In FIG. 3, the sealed plastic container 200 placed in the shielding body 2 is illustrated in a floating state, but this is for the reason of drawing, and actually the sealed plastic container 200 is bottomed. Of course.

{Depth dimension Dth of shielding body 2 + thickness dimension Th of shielding lid 4}
= {Height dimension H of the sealed container 200 + Length dimension of the shielding required portion L of the probe P}

  Reference numeral 14 shown in FIGS. 1 to 3 is a support cylinder made of stainless steel, and the lower end of the support cylinder 14 is welded to the upper surface of the shielding lid 4. The support cylinder 14 has a cylindrical shape and is arranged coaxially with the circular opening 30 of the shielding lid 4. The support cylinder 14 has a function of supporting the probe P inserted into the circular opening 30 of the shielding lid 4. It is arbitrary whether this support cylinder 14 is installed.

  The usage of the portable radiation shield 100 according to the embodiment will be described with reference to FIG. The radioactive contaminant that is the specimen S is carried in a state of being put in a sealed plastic container 200 having a specified size. Before the sealed plastic container 200 is put into the shielding main body 2, the removal tool 300 is put into the shielding main body 2. The removal tool 300 is composed of, for example, a relatively thin metal or relatively hard and thin plastic piece having a U-shaped cross section. Next, after the sealed plastic container 200 is placed in the shielding body 2, the upper end opening of the shielding body 2 is closed with the shielding lid 4. Of course, the sealed plastic container 200 may be placed in the shielding body 2 together with the removal tool 300 in a state where the sealed plastic container 200 is placed on the removal tool 300.

  Next, the probe P is inserted into the central circular opening 30 of the shielding lid 4, and the lower end of the probe P is seated on the sealed plastic container 200. In this state, the radiation dose is measured.

  When the measurement of the radiation dose is completed, the shielding lid 4 is opened after the probe P is removed. Then, a finger is hooked on the hook portion 300a (FIG. 4) formed by bending the two upper end portions of the tool 300 and pulled up. Thereby, the sealed plastic container 200 can be taken out from the shielding main body 2. The taken-out sealed plastic container 200 is accommodated in a box-shaped storage box having a shielding function, for example, and is carried out of the measurement site.

  In addition, a sealed plastic container 200 for storing the specimen S is defined, and the portable radiation shield 100 is designed to have a cross-sectional shape similar to the cross-sectional shape of the sealed plastic container 200, and is necessary for storing the sealed plastic container 200. Since the portable radiation shield 100 is designed with the minimum dimensions in mind, the shield 100 can be suppressed to the minimum necessary size in the cross section of the portable radiation shield 100. Further, since the height of the portable radiation shield 100 is limited to the necessary shielding portion L of the probe P of the radiation measuring instrument, the height of the portable radiation shield 100 is also the minimum necessary. Can be suppressed. Therefore, the amount of the shielding material 22 that is a main element of the portable radiation shield 100 can be minimized. That is, according to the present invention, the portable radiation shield 100 can be made compact to the minimum necessary.

  As a modified example of the above-described embodiment, if the cross-sectional shape of the sealed plastic container 200 defined to accommodate the specimen S is, for example, rectangular, the cross-sectional shape of at least the inner surface of the portable radiation shield 100 is the cross-section of the sealed plastic container 200. The shape may be similar to the shape.

  The present invention can be applied to the measurement of the radiation dose of a specimen contaminated with radioactivity.

DESCRIPTION OF SYMBOLS 100 Portable radiation shielding body 2 Shielding body Dth Depth dimension of shielding body ID Inner diameter of shielding body 4 Shielding lid Th Thickness dimension of shielding lid 6 Handle 8 Hinge 14 Supporting cylinder 20 Outer skin 22 Lead (shielding material)
30 Circular opening of the shielding lid D1 Diameter of the circular opening P Probe Dp Probe diameter L Probe shielding required part 200 Sealed plastic container to accommodate the specimen OD Outer diameter of the sealed plastic container H Height dimension of the sealed plastic container S Specimen 300 Removal tool for removing sealed plastic containers containing specimens from the shield body

Claims (9)

A bottomed cylindrical shield body containing a prescribed sealed container containing a specimen;
A shielding lid for closing the upper end opening of the shielding body;
A circular opening extending through a central portion of the shielding lid, the circular opening having an inner diameter substantially equal to a diameter of a cylindrical probe of the radiation measuring instrument and capable of accepting insertion of the probe;
The cross-sectional shape of the inner surface of the shielding body is similar to the cross-sectional shape of the sealed container,
The size of the cross section of the inner surface of the shielding body is set to a size such that a finger does not enter between the inner surface of the shielding body and the sealed container when the sealed container is placed in the shielding body,
The depth dimension Dth of the recess for receiving the sealed container of the shielding body is such that the sealed container is placed in the shielding body, and the probe inserted into the circular opening of the shielding lid is on the sealed container. It is set to a value obtained by subtracting the thickness dimension Th of the shielding lid from the total value of the length dimension of the necessary shielding portion L of the probe and the height dimension H of the sealed container when seated. Portable radiation shield. The portable radiation shield is
The portable radiation shield according to claim 1, further comprising a handle pivotally supported by the shield body and capable of tilting. The prescribed sealed container is a circular plastic container in plan view;
The portable radiation shield according to claim 1 or 2, wherein an inner surface of the shield body has a circular cross-sectional shape. The shielding lid has a support cylinder extending upward from the circular opening;
The portable radiation shield according to any one of claims 1 to 3, wherein the probe inserted into the circular opening is supported by the support cylinder.   The portable radiation shield according to claim 4, wherein the shielding lid is hinged to the shielding body.   The portable radiation shield according to claim 5, wherein the shielding lid has a handle opposite the hinged portion. A cylindrical shielding body with a bottom that accommodates a sealed plastic container having a circular shape in plan view containing a specimen, a shielding lid that is hinged to the shielding body and closes the upper end opening of the shielding body, and a shaft that is pivoted on the shielding body A portable radiation shield having a handle and a tiltable handle;
A radiation shielding device comprising a combination with a U-shaped lifting member that can be inserted into the shielding body in a side view,
The lifting member has a hook part that can be hooked with a finger on its upper end part,
The shield lid of the portable radiation shield is a circular opening extending through a central portion of the shield lid and has an inner diameter that is substantially the same as the diameter of a cylindrical probe of the radiation meter and accepts insertion of the probe A circular opening that can
The cross-sectional shape of the inner surface of the shielding body is circular,
The diameter of the inner surface of the shielding body is set to a dimension that prevents fingers from entering between the inner surface of the shielding body and the sealed plastic container when the sealed plastic container is placed in the shielding body,
The depth Dth of the recess for receiving the sealed plastic container of the shield body is such that the probe inserted into the circular opening of the shield lid is inserted into the shield body with the sealed plastic container being inserted into the shield body. When set on a value obtained by subtracting the thickness dimension Th of the shielding lid from the total value of the length dimension of the shielding necessary portion L of the probe and the height dimension H of the sealed plastic container when seated on the probe;
In the shielding body, insert the lifting member and the sealed plastic container to measure the radiation dose of the specimen in the sealed plastic container,
The radiation shielding apparatus according to claim 1, wherein when taking out the sealed plastic container from the shielding main body, an operator hooks a finger on a hooking portion of an upper end portion of the lifting member and pulls it up. The shielding lid has a support cylinder extending upward from the circular opening;
The radiation shielding apparatus according to claim 7, wherein the probe inserted into the circular opening is supported by the support cylinder.   The radiation shielding apparatus according to claim 8, wherein the shielding lid has a handle on a side opposite to the hinged portion.

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