JPS6217681A - Apparatus for inspecting radioactive contamination - Google Patents

Abstract

PURPOSE:To detect contamination by rapid, safe and easy work without generating environmental pollution, by transferring a container in a shielded container and automatically inspecting the radioactive contamination of the substance of the container by a plurality of radiation detectors arranged to a transfer path in opposed relationship. CONSTITUTION:A container 13 having a radioactive contamination substance received therein is transferred by a container transfer apparatus 6 formed of a transfer stand 4, a rail 3 and a motor 5 in a state received in a radiation shielding container 1. gamma-rays are measured by radiation detectors 10a, 10b arranged to the transfer path in opposed relationship so as not to be contacted with the container 13 and gamma-rays are similary measured. By automatic measurement in a shielded chamber from which radioactive rays are not leaked to the outside, radioactive contamination can be detected without generating environmental pollution by rapid, safe and accurate work.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a radioactive contamination test for measuring the level of radioactive contamination of various solid objects located in a facility that handles radioactive materials and occurring within its radiation controlled area. Regarding equipment.

[Technical background of the invention and its problems] Generally, in facilities that handle radioactive materials, various solid objects such as paper, metal, and rags used within the controlled area are stored in certain containers. When solid objects stored in this container are transported outside the radiation controlled area, the radioactive contamination level is measured, and only those whose radioactive contamination level falls within a certain standard are transported outside the radiation controlled area. Items with radioactive contamination levels exceeding a certain standard will be stored within the facility.

Conventionally, such measurements of radioactive contamination levels have been mainly carried out manually, and there is a problem in that this measurement requires a great deal of time and effort.

Generally speaking, conventional methods of measuring radioactive contamination levels mainly measure surface contamination by measuring beta rays. It is impossible to judge which part of a person's throat contains radioactively contaminated material. In addition, if a radioactively contaminated substance is stored near the center of the thickness of the container, this beta ray measurement will detect the presence of the radioactive contaminant because the solid object itself blocks the radiation. I can't. Therefore, radioactive pollutants may be discharged into the external environment, causing environmental pollution. Furthermore, even if the radioactive contaminant is not highly contaminated, if the radioactive contaminant is contained in the same container, it must be stored in the facility with the radioactive contaminant in order to store the container together. There is a problem in that it may lead to an increase in the amount of storage within the facility.

[Object of the Invention] The present invention has been made in response to the above-mentioned conventional circumstances, and it is possible to save labor and improve the efficiency of the work in measuring the level of Fujisha contamination, and also to reduce the amount of radioactive JJ contaminants being carried out to the external environment. is used to eliminate non-radioactive contaminants without causing environmental pollution! The present invention aims to provide a radioactive contamination testing device that can be stored within a facility without causing an increase in storage ω within the facility.

[Summary of the Invention] The present invention provides a radioactive contamination inspection device for measuring the level of radioactive contamination of a solid object housed in a container, which includes a container that shields radiation from the outside and moves the container inside. a shielded container having a transfer passage; a plurality of radiation detectors disposed facing each other at intervals such that the eight detectors are movable in the container transfer passage inside the shielded container; This is a radioactive contamination testing device characterized by being equipped with a container transfer head that is movably guided.

[Embodiment 1 of the Invention] The details of the present invention will be described below with reference to an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the radioactive contamination testing apparatus of the present invention, and in the figure, reference numeral 1 indicates a shielding container made of lead. A container transfer passage 2 is formed in the center inside the shielding container 1, and the container transfer passage 2 includes a container transfer rail 3, a container transfer table 4, and a container transfer pulse motor 5. Mobile device 6 and heavy ffi measuring device
! 17 are arranged. Further, an inlet 1n8a and an outlet #a8b are arranged at both ends of the container transfer passage 2, and RN opening/closing motors 9a and 9b are arranged above the respective openings 8a and 8b. Further, near the center of the container transfer path 2, radiation detection units 510a and 10b each consisting of six Na I detectors arranged horizontally in a row in a direction perpendicular to the container transfer direction of the container transfer path 2 are installed.
are arranged to face each other vertically, and of the radiation detectors 10a and 10b, the radiation detector 10a arranged above is connected to a radiation detector moving motor 911. Furthermore, a television camera 12 is arranged above the entrance door 8a on the outside of the shielding container 1.

In the radioactive contamination inspection device configured as described above, the second
The radioactive contamination level is measured according to the configuration shown in the block diagram shown in the figure. That is, the solid object to be measured for radioactive contamination level is placed in a predetermined container 13.
First, the entrance door opening/closing motor 9a is driven, the entrance door 8a is opened, and the predetermined container 13 is transferred onto the container transfer table 4 inside the shielded container 1. Next, the entrance door opening/closing motor 9a is driven again to close the entrance door 8a. At this time, the radioactive contamination inspection device uses the television camera 12 to identify the object to be measured for the M radiation surface contamination level. After this, the radioactive contamination testing device is turned on by an external controller (not shown), and measurements are performed fully automatically.

The weight of the container 13 housed in the shielded container 1 is first measured by the coulometric measuring device 7, and then the pulse motor 5 for container transfer is driven, and the container transfer table 4 and the container transfer table 4 are moved on the container transfer rail 3 by the radiation detector 10a. , 10b. The ends of the container 13 are radiation detectors 10a and 10b.
When the container is located in the middle, the pulse motor 5 for transferring the container is temporarily stopped, and after that, the gamma ray radiation is measured by the radiation detectors 10a and 10b for a preset time.

When this measurement is completed, the pulse motor 5 for container transfer is activated again.
is driven, the container 13 is further transferred 101, and gamma ray measurement is performed again by the radiation detectors 10a and 10b. In this way, ten gamma ray measurements are repeated every 10 CII. Note that the height of the radiation detector 10a is adjusted by the detector moving motor 11 according to the size of the container to be measured at this time. The radioactive contamination level measurement data of the container 13 measured in this way is led to an external data processing device (not shown), and after data processing, it is determined that the radioactive contamination level of the container 13 is outside the radiation control area. Items that can be transported to
is driven, and the exit door 8b is opened. After this, the workers will carry it out of the radiation controlled area. In addition, if the radioactive contamination level is higher than a certain standard, the entrance door 8a
direction, the simultaneous opening/closing motor 9a is driven, and the opening/closing motor 9a is driven.
will be opened and returned to the radiation controlled area.

On the other hand, the measured data is printed out as shown in FIG. 3, for example. In the figure, the squares divided vertically and horizontally are
Each indicates the part of the 10C11 square container 13, and the number shown in this square indicates the measured radiation Matsuyama at the medium level of microcue, and the pattern of dots shown in the square is measured by its density. It represents the degree of radiant IQ. The numbers and letters shown at the bottom of the figure represent the measurement conditions, the radioactivity concentration of the measurement analysis results, the maximum surface 1!1 til rate, etc.

As a result of measuring the radioactive contamination level in this way, the container 13 was returned to the radiation control area because the radioactive contamination level exceeded a certain standard. It can be seen whether a part contains material with a high level of radioactive contamination. Therefore, in some cases, by removing only the material with a high level of ll1tA contamination from the container 1a13, it may be possible to transport the materials contained in other containers 13 outside the radiation controlled area. .

In other words, the radioactive contamination inspection device configured as described above can fully automatically measure the radioactive contamination level of various solid objects taken out of the radiation controlled area, which greatly reduces the labor and efficiency of this work. In addition, when measuring the level of radioactive contamination of a solid object contained in a container, it is possible to determine which part of the container contains the substance and the level of radioactive contamination. Therefore container 13
Only solid objects with high levels of radioactive contamination can be removed from inside, and other solid objects with low levels of radioactivity can be transported outside the radiation controlled area. Therefore, solid objects with a low level of radioactive contamination are not unnecessarily stored in the radiation controlled area, and the amount of stored materials m can be reduced. Also,
In this example, since the radioactive contamination level is measured by gamma ray measurement, it is possible to detect solid objects with a high radioactive contamination level that are present near the center of the container 13. It can also prevent solid objects from being transported outside the radiation controlled area.

In this example, the radioactive contamination level is measured by gamma ray measurement, but the present invention is not limited to this example, and the radiation detectors IOA and IOB are used.
Of course, surface contamination can also be measured by beta ray measurement by replacing the .

[Effects of the Invention] As described above, the radioactive contamination inspection device of the present invention can fully automatically measure the radioactive contamination level of solid objects being carried out from radiation controlled areas, resulting in significant labor savings and In addition to improving efficiency, materials with high radioactive contamination levels are not carried out outside the radiation control area, without causing external environmental contamination, and low radioactive contamination level materials that are mixed with high radioactive contamination level materials are unnecessary. It is stored in a radiation-controlled area, and does not cause an increase in the amount of storage.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the radioactive contamination inspection device of the present invention, FIG. 2 is a book diagram showing the configuration of FIG. 1,
FIG. 3 is an explanatory diagram showing an example of a launch pattern as a result of measurement.

Claims (1)

[Claims] (1) In a radioactive contamination inspection device that measures the radioactive contamination level of a solid object housed in a container, a shielding container that shields radiation from the outside and has a container transfer path for moving the container inside; a plurality of radiation detectors disposed opposite to each other at intervals such that the container can be moved in the container transfer path inside the shielding container; and a container moving device that movably guides the container along the container transfer path. A radioactive contamination testing device characterized by: