JPH0454474Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an apparatus for measuring the presence or absence of radioactive contamination of an object to be measured.

[Technical background of the invention and its problems]

A conventional example of this type of radioactive contamination measuring device is shown in FIG. An endless wire mesh belt 2 made of metal mesh is rotated in the direction of the arrow by driving rollers 3 placed at both ends. 4 is a drive device.
Above and below the upper wire mesh belt are radiation detectors 5 for measuring radioactivity from the object to be measured 1.
a and 5b are installed. The object to be measured 1 is placed on a wire mesh belt 2, and when it passes between radiation detectors 5a and 5b, the presence or absence of radioactive contamination is measured.

However, this device has the following drawbacks.

[a] Since a part of the object to be measured 1 is blocked by the wire mesh belt 2, detection efficiency is reduced and accurate measurement cannot be performed.

[b] If the object to be measured 1 is contaminated with radioactivity,
Radioactive contamination also occurs on the wire mesh belt 2 and drive roller 3 on which the contaminated material is placed. For this reason,
The wire mesh belt 2 and drive roller 3 must be cleaned or replaced.

[c] The object 1 to be measured may be caught or caught in the wire mesh belt 2 or the driving roller 3, and the object 1 to be measured may be damaged.

[Purpose of invention]

An object of the present invention is to provide a radioactive contamination measuring device that does not cause a decrease in detection efficiency or spread of radioactive contamination from an object to be measured, and also eliminates the risk of damage to the object to be measured.

[Summary of the idea]

The present invention includes a feed roller unit in which a pair of feed rollers are arranged with their rotation axes parallel to each other and their outer circumferential surfaces close to each other, and are rotated in opposite rotational directions by a drive device, and each of the feed rollers in this feed roller unit. A flexible sheet is fed out from a feeding drum, which is provided with a feed roller and a rotating shaft parallel to each other, and is wound around the feeding roller and moves in the opposite direction, so that the feeding drum and rotating shaft are approximately parallel to each other. A contamination prevention unit that is wound up on a winding drum arranged in parallel and a pair of feed rollers of the feed roller unit are placed on both sides of the workpiece that is fed out and close to the workpiece. A pair of radiation detectors are placed facing each other and measure the radioactive contamination of the object to be measured, and the amount of radioactive contamination of the object to be measured is determined by receiving the detection signals from the pair of radiation detectors and compared with the allowable value. A radioactive contamination measuring device is realized, which is equipped with a measuring section that determines the presence or absence of radioactive contamination, and a pair of radiation detectors placed oppositely on both sides of an object to be measured sent out from a feed roller unit performs measurement. As a result, there is no obstruction between the object to be measured and the radiation detector, so there is no reduction in detection efficiency, and the feed roller is isolated from the object to be measured by a flexible sheet, preventing contamination. Moreover, since the flexible sheet is stored in the winding drum, post-treatment is easy if it becomes contaminated, and furthermore, the object to be measured is transported by the feed roller unit, so there is no possibility of damage. It has achieved its intended purpose, such as eliminating the fear of

[Example of idea]

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

FIG. 1 shows a radioactive contamination measuring device according to an embodiment of the present invention. As shown, a pair of feed rollers 12
A and 12B are arranged with their rotational axes parallel to each other and their outer peripheral surfaces close to each other, and drive devices 13A and 13B, respectively.
Upper feed roller units 11 are provided which are rotated in opposite rotational directions as shown by arrows. A flexible sheet 16A made of synthetic resin is fed out from a feeding drum 15A arranged with its rotating shaft parallel to the feeding roller 12A.
The contamination prevention unit 1 is wound around the winding drum 17A, which reverses the direction of travel and is wound around the winding drum 17A, which is arranged with the rotating shaft parallel to the feeding drum 15A.
4A is provided. The feeding drum 15A and the winding drum 17A are provided with driving devices 18A and 19A, respectively.

Further, a contamination prevention unit 14B consisting of a feeding drum 15B, a flexible sheet 16B, a winding drum 17B, and driving devices 18B and 19B is similarly provided for the feeding roller 12B.

Upper feed roller unit 1 configured as above
A lower feed roller unit 21 is provided for receiving the workpiece 1 sent out from the workpiece 1 and moving it further downward. The lower feed roller unit 21, like the upper feed roller unit 11, includes a pair of feed rollers 22A, 22B and drive devices 23A, 23B.
It becomes more. As with the pollution prevention unit 14A, the feed roller 22A is connected to the feed drum 25.
A pollution prevention unit 24A is provided which includes a flexible sheet 26A, a winding drum 27A, and drive devices 28A and 29A. In addition, the feed roller 22
For B, similar to the pollution prevention unit 14B, a feeding drum 25B, a flexible sheet 26
B, winding drum 27B, drive devices 28B, 29B
A pollution prevention unit 24B is provided.

In addition, in the space between the upper feed roller unit 11 and the lower feed roller unit 21, a pair of radiation detectors 30A, which are placed close to and opposite to the object to be measured 1, are installed.
30B is placed. The object to be measured 1 receives the detection signals from the pair of radiation detectors 30A and 30B.
A measurement unit 31 is provided that determines the amount of radioactive contamination and compares it with an allowable value to determine the presence or absence of radioactive contamination.

In the radioactive contamination measuring apparatus according to one embodiment of the present invention constructed as described above, the object to be measured 1 is inserted between the feed rollers 12A and 12B of the upper feed roller unit 11 from above the apparatus. feed roller 12
The object to be measured 1 is moved downward by the rotation in the direction of the arrow A, 12B, and the pair of radiation detectors 30A, 3
It is measured while passing between 0B, is received by the feed rollers 22A and 22B of the lower feed roller unit 21, and is transferred downward. Measured object 1
The radiation detectors 30A and 30B
The detection signal sent from the measurement unit 31 is processed to determine the amount of radioactive contamination of the object to be measured 1.
1 is the measured object 1 compared with the stored tolerance value.
Determine whether there is radioactive contamination.

On the other hand, the flexible sheet 16A fed out from the feeding drum 15A of the pollution prevention unit 14A moves with the rotation of the feed roller 12A and is stored in the winding drum 17A. As a result, the feed roller 12A does not come into direct contact with the object 1 to be measured, so even if the object 1 to be measured is contaminated, it will not be contaminated. Similarly, the feed roller 12B is protected from contamination by the interposition of the flexible sheet 16B of the contamination prevention unit 14B. The feed rollers 22A and 22B of the lower feed roller unit 21 are similarly prevented from being contaminated by the interposition of flexible sheets 26A and 26B of the contamination prevention units 24A and 24B, respectively.

In the radioactive contamination measuring device according to one embodiment of the present invention, the object to be measured is kept in a constant transfer line from the upper feed roller unit 11 to the lower feed roller unit 21 by a pair of feed rollers 12A and 12B. be transferred. By arranging a pair of radiation detectors 30A, 30B between the upper feed roller unit 11 and the lower feed roller unit 21 and facing each other on both sides of the transfer line, the object to be measured 1 and the radiation detectors 30A, 30B There is no obstruction in between, and the transfer line of the object to be measured 1 is maintained constant by the upper and lower feed roller units 11 and 21, so there is little variation in the measurement space, and these two effects make it easy to detect. Accurate measurements can be made without loss of efficiency. Furthermore, since each feed roller is isolated from the object to be measured by a flexible sheet, it is prevented from being contaminated. In addition, post-treatment in case of contamination is easy. Furthermore, since the object to be measured is transported by the feed roller unit, there is no risk of damage.

Next, a modification of the present invention will be explained.

[a] The modification shown in FIG.
The object to be measured 1 is located below the transfer line.
A sorting gate mechanism 32 and its driving device 33 are installed to sort the waste according to the presence or absence of contamination. The separation gate mechanism 32 is driven by the measuring section 3.
This is done by the signal from 1.

[b] The modification shown in FIG. 3 is a simplified version in which the object 1 to be measured is transferred downward by the upper feed roller unit 11 and the contamination prevention units 14A and 14B, and is placed below the upper feed roller unit 11. Radioactive contamination is measured by a pair of radiation detectors 30A and 30B. (The measurement unit 31 is not shown.) [c] The modification shown in FIG.
1 is provided in two stages to stabilize the transfer line and ensure reliable transfer of the object to be measured 1.
There are two configurations below the pair of radiation detectors 30A and 30B: one in which no lower feed roller unit is provided as shown in the figure, and one in which a lower feed roller unit 21 is provided as shown in FIG. Of course, you can take the following.

[d] In the modification shown in FIG. 5, the flexible sheets 16A,
Radiation detectors 34A and 34B are installed near the winding path of sheet 16B to measure radioactive contamination transferred from the contaminated object to be measured 1 to flexible sheets 16A and 16B. be. Although only the upper feed roller unit 11 and its contamination prevention units 14A and 14B are shown in FIG. 5, the lower feed roller unit 21
Of course, a radiation detector for detecting contamination of the flexible sheet can be attached to the contamination prevention unit of other feed roller units as well.

[e] It is also possible to arrange the feed roller units side by side in the horizontal direction and to transport the object to be measured in the horizontal direction.

[Effect of idea]

As detailed above, according to the present invention, the radioactive contamination measuring device is configured so that the object to be measured is transported by the feed roller of the feed roller unit,
As a result, the object to be measured is transported while maintaining a constant transfer line, and radiation detectors installed close to each other on both the front and back sides of the object sent out from the feed roller unit measure the object. , there is no obstruction between the object to be measured and the radiation detector, and the object to be measured is maintained in a constant transfer line, so there is little variation in the measurement space, and these two effects prevent detection efficiency from decreasing. , accurate measurements are possible. In addition, the feed roller unit is provided with a contamination prevention unit for each feed roller, and the flexible sheet fed out from the feed drum is wound around the feed roller, moves as the feed roller rotates, and is stored in the take-up drum. With this configuration, each feed roller does not come into direct contact with the object to be measured due to the flexible sheet, which prevents the feed roller from being contaminated by the object to be measured, making it easier to clean and replace the feed roller. Troublesome work becomes unnecessary. Further, since the flexible sheet is stored in the winding drum, post-processing of the contaminated flexible sheet is easy. Furthermore, since the object to be measured is transported by the feed roller unit, there is no risk of damage.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a radioactive contamination measuring device according to an embodiment of the present invention, FIGS. 2 to 5 are elevational views showing different modifications of the radioactive contamination measuring device according to the present invention, and FIG. 6 1 is a perspective view showing a conventional example of a radioactive contamination measuring device. 1...Object to be measured, 11...Upper feed roller unit, 12A, 12B...Feed roller, 13A,
13B... Drive device, 14A, 14B... Contamination prevention unit, 15A, 15B... Feeding drum, 16A, 16B... Flexible sheet, 17A,
17B... Winding drum, 18A, 18B... Drive device, 19A, 19B... Drive device, 21... Lower feed roller unit, 22A, 22B... Feed roller, 23A, 23B... Drive device, 24A,
24B...Pollution prevention unit, 25A, 25B...
...Feeding drum, 26A, 26B... Flexible sheet, 27A, 27B... Winding drum, 28A,
28B... Drive device, 29A, 29B... Drive device, 30A, 30B... Radiation detector, 31...
Measuring section, 32... Separation gate mechanism, 33... Drive device, 34A, 34B... Radiation detector.

Claims (1)

[Claims for Utility Model Registration] (1) A feed roller unit in which a pair of feed rollers are arranged with their rotation axes parallel and their outer peripheral surfaces close to each other, and are rotated in opposite rotational directions by a drive device; A flexible sheet is fed out from a feeding drum provided for each feeding roller of the roller unit and arranged with the feeding roller and the rotating shaft parallel to each other, and is wound around the feeding roller and moved in the opposite direction. A contamination prevention unit is wound up on a winding drum, which is arranged so that the feeding drum and the rotating shaft are almost parallel to each other, and the object to be measured is fed out while being sandwiched between the pair of feed rollers of the feed roller unit. A pair of radiation detectors, each of which is placed close to and facing the object to be measured, measures radioactive contamination of the object to be measured, and detects the amount of radioactive contamination of the object by receiving detection signals from the pair of radiation detectors. A radioactive contamination measuring device comprising: a measurement unit that determines the presence or absence of radioactive contamination by comparing the obtained value with an allowable value. (2) The radioactive contamination measuring device according to claim (1) of the utility model registration, characterized in that a pair of feed rollers are arranged side by side in a horizontal direction. (3) The radioactive contamination measuring device according to claim (1) of the utility model registration, characterized in that a pair of feed rollers are arranged side by side in the vertical direction. (4) Radioactive contamination according to claim (1) of the utility model registration claim, characterized in that the feed roller unit is provided at least one stage upstream of the pair of radiation detectors in the feeding direction of the object to be measured. measuring device. (5) Utility model registration claim (1) characterized in that the feed roller unit is provided at least one stage upstream and one stage downstream of the pair of radiation detectors in the feeding direction of the object to be measured. Radioactive contamination measurement device described.