JPH06258442A - Gate monitor - Google Patents

Abstract

PURPOSE:To allow monitoring of radioactive contamination for a person regardless of the height by providing a vertical foot driving means. CONSTITUTION:When a person A to be monitored enters into a pass gate 2, a gate monitor controller 14 controls a vertical head drive section 5 to lower a head radiation detector 3-1. When the detector 3-1 reaches a point separated by a predetermined distance L from the head part, the detector 3-1 is stopped and detectors 3-1-3-14 detect radiation under tall height mode and the monitor 14 monitors radioactive contamination of the person A. When the monitor 3-1 can not reach the point before it reaches the lower limit point, the monitor 14 decides a short height mode representative of a height shorter than a limit level. Consequently, a vertical foot drive section 11 is driven to elevate a foot detector supporting section 13. When the head part of the person A reaches a point separated by the distance L from the sensor 3-1, the monitor 14 stops the supporting section 13 and the detectors 3-1-3-14 detect dose on the body surface of the person A thus monitoring radioactive contamination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate monitor which is installed in a nuclear facility or the like and monitors radioactive contamination on the body surface of workers in the facility.

[0002]

2. Description of the Related Art Such a gate monitor is installed at the boundary of a radiation control area, for example, at the entrance of a building of a nuclear facility, and monitors radioactive contamination on the body surface of workers entering and leaving the facility to ensure the safety of workers. It is for doing.

In such a gate monitor, a plurality of radiation detectors are arranged around an operator to monitor radioactive contamination. Of these radiation detectors, the head radiation detector is used as the height of the operator. It is also structured so that it can be raised and lowered and brought close to the operator's head.

A specific structure will be described with reference to FIG. 9. A pass gate 2 is formed in the monitor body 1, and a plurality of radiation detectors 3-1 to 3-3- are formed inside the pass gate 2.
14 are arranged. Of these, the radiation detector 3-1 is a head radiation detector, and the radiation detectors 3-2 to 3-3-
Reference numeral 13 is a side radiation detector, and 3-14 is a foot radiation detector.

Of these, the head radiation detector 3-1 is constructed so as to be elevated and lowered above the passage gate 2 by the elevation mechanism 4. The elevating mechanism 4 has a configuration in which a head detector support portion 7 is screwed onto a drive shaft 6 of a head vertical drive portion 5.
The head radiation detector 3-1 is usually arranged at the uppermost position. In addition, the monitor body 1 is provided with a hand detection unit 8 for detecting the radiation dose of the worker's hand.
Workers are supposed to insert their own hands.

A gate monitor having such a configuration is shown in FIG.
As shown in the monitor flow chart shown in FIG. 5, the background (BG) radiation dose of each radiation detector 3-1 to 3-14 is detected in the standby state of step # 1.

When the person A to be measured enters the passage gate 2 in this standby state, the head vertical drive unit 5 is driven in step # 2, and the head radiation detector 3-1 descends. When the head radiation detector 3-1 descends and the distance from the head of the person A to be measured reaches a predetermined distance L, the head up-down drive unit 5 stops the head radiation detector 3-1 from descending. To do.

Next, in step # 3, the radiation detectors 3-1 to 3-14 detect the radiation dose on the body surface of the person A to be measured, and the radiation contamination of the person A to be measured based on the detection result. Is measured.

After that, in step # 4, the radioactive contamination is determined, and if it is determined that there is no contamination, the person to be measured is allowed to leave. However, as a result of the judgment of radioactive contamination,
If it is determined to be contaminated, an alarm to that effect is issued in step # 5, and the person to be measured is returned to the entrance again.

By the way, in the above gate monitor, the position of the hand detecting portion 8 is fixed, and the position of the hand of the person to be measured is substantially intermediate between the height and the height of the human body. As a result, the height range of the person to be measured that can be measured by the person in a natural posture is limited. For example, it is difficult for a person to be measured who has a short height, such as an elementary school student who visits the facility, to insert his / her hand into the hand detection unit 8.

On the other hand, the elevation range of the head radiation detector 3-1 is also limited. For example, if the maximum height of the person to be measured that can be monitored is set to 1900 mm, the size of the monitor body 1 cannot be changed, and therefore, the elevation range of the head radiation detector 13-1 is limited to 400 mm. Therefore, height 1
It becomes difficult to monitor a person under measurement of 500 mm or less. Therefore, for a person to be measured having a height of 1500 mm or less, it is necessary to facilitate a dedicated type in which the entire monitor body 1 is downsized.

[0012]

As described above, there is a limit to the height range of the person who can monitor the radiation contamination, and it is difficult to monitor the person whose height is 1500 mm or less. Therefore, it is an object of the present invention to provide a gate monitor capable of monitoring the radioactive contamination of a person to be measured with one device regardless of the height of the person to be measured.

[0013]

DISCLOSURE OF THE INVENTION The present invention is a gate monitor for arranging a plurality of radiation detectors around a person to be measured to monitor radioactive contamination of the person to be measured, and mounting the person to be measured on the gate monitor. A gate monitor that includes a support unit that supports a radiation detector that detects radiation from a foot of a person to be measured, and a foot up-and-down drive unit that moves the support unit up and down.

Further, according to the present invention, in a gate monitor for arranging a plurality of radiation detectors around a measured person to monitor radioactive contamination of the measured person, the measured person is placed on the gate monitor. A gate monitor, which is provided with a support portion that supports a radiation detector that detects the radiation of a foot and a holding mechanism that holds the support portion at any one of at least two height positions, to achieve the above object. is there.

[0015]

With the provision of such means, the support part for supporting the radiation detector for mounting the measurement subject and detecting the radiation of the foot of the measurement subject is adjusted to the height of the measurement subject. It moves up and down by the foot vertical drive means.

Further, by providing the above-mentioned means, the support portion for supporting the radiation detector for mounting the measurement subject and detecting the radiation of the foot of the measurement subject is adjusted to the height of the measurement subject. It is held by one of the at least two height positions by the holding mechanism.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The same parts as those in FIG. 9 are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a block diagram of a gate monitor. A foot up-and-down drive mechanism 10 is provided at the bottom of the gate monitor body 1. The foot up-and-down drive mechanism 10 mounts the person A to be measured, and raises and lowers a foot radiation detector 3-14 that detects the radiation dose of the foot of the person A to be measured.

Specifically, a foot vertical drive unit 11 is provided, and the drive shaft 12 of the drive unit 11 has a foot detector support unit 1 attached thereto.
3 is screwed together, and a foot radiation detector 3-14 is provided on the lower surface of the foot detector support portion 13.

On the other hand, when monitoring radioactive contamination, the gate monitor controller 14 drives the elevating mechanism 4 to lower the head radiation detector 3-1 and reaches the limit minimum position, so that the measured person In the short stature mode, the foot up-and-down drive unit 11 is driven to raise the foot radiation detector 3-14, and after that, each radiation detector 3
It has a function of receiving the radiation detection signals from -1 to 3-14 and determining the radioactive contamination of the measurement subject. Next, the operation of the gate monitor configured as described above will be described with reference to the monitor flow chart shown in FIG. In the standby state of step # 10, the background (BG) radiation dose of each radiation detector 3-1 to 3-14 is detected.

In this standby state, for example, when the person A to be measured enters the passage gate 2, the head vertical drive unit 5 is driven by the control of the gate monitor controller 14 in step # 11, and the head radiation detector 3-. 1 descends. When the head radiation detector 3-1 reaches the predetermined distance L from the head of the person A to be measured as described above due to this descending, the head up-and-down drive unit 5 stops the descending of the head radiation detector 3-1. To do.

When the head radiation detector 3-1 is stopped before reaching the lowest limit position in this way, the gate monitor control device 14 determines that the person A to be measured has a height of 1500 mm or more, and the height mode is set. To control.

Therefore, when the head radiation detector 3-1 stops descending, the process proceeds to step # 14 and each radiation detector 3 is moved.
-1 to 3-14 detect the respective radiation doses on the body surface of the person A to be measured, and the respective radiation detection signals are sent to the gate monitor control device 14. As a result, the gate monitor controller 14
Monitors the radioactive contamination of the person A to be measured.

However, even when the head radiation detector 3-1 descends, the distance from the head of the person A to be measured does not become the predetermined interval L, and the head radiation detector 3-1 lower limit lower limit position. When reaching, the gate monitor control device 14 determines that the height of the person A to be measured is 1500 mm or less.

Therefore, the gate monitor control device 14 judges that it is in the short stature mode, and moves to step # 13 to drive the foot up-and-down drive part 11 to raise the foot part detector support part 13. As the support 13 rises, the foot radiation detector 3
-14 rises.

As a result, the person A to be measured also sits on the foot detector support portion 13 and ascends, and the distance between the head of the person A to be measured and the head radiation detector 3-1 becomes narrower. In this way, when the distance between the head of the person A to be measured and the head radiation detector 3-1 becomes the predetermined distance L, the gate monitor control device 14
Stops driving of the foot vertical drive mechanism 10.

Next, in step # 14, each of the radiation detectors 3-1 to 3-14 detects the radiation dose on the body surface of the person A to be measured. Contamination is monitored.

After that, in step # 15, the radioactive contamination is determined, and if it is determined that there is no contamination, the person to be measured is allowed to leave. However, if the result of the radioactive contamination determination is that the contamination is determined, an alarm to that effect is issued in step # 16, and the subject is returned to the entrance again.

As described above, in the first embodiment described above, the supporter 13 on which the person A to be measured is placed and which supports the foot radiation detector 3-14 of the person A to be measured is set to the height of the person A to be measured. Since it was designed to go up and down according to
Radiation contamination can be monitored for a person A having a height of m or more without lowering the monitoring capability, and 1500
The radiation contamination monitor for the person A having a short height of less than or equal to mm can be performed without any inconvenience.

Therefore, for example, even if a visitor other than the operator of the nuclear facility, for example, an elementary school student, a short person with a height of 1500 mm or less, such as a woman, enters the nuclear facility, it is possible to monitor the radioactive contamination of these intruders. As a result, the space can be efficiently used without preparing a gate monitor exclusively for short persons, and extra maintenance work is not required. Next, as a modified example of the first embodiment, the gate control device 14 may have the following functions.

The gate control device 14 has a switch for designating the normal measurement mode and the short height measurement mode. When the short height measurement mode is designated, the foot vertical drive mechanism 10 is selected.
Is driven to raise the foot detector support portion 13 and the foot radiation detector 3-14 to a predetermined height position, and then the head up-and-down drive portion 5 is driven to drive the head radiation detector 3-1. Down,
After this, it has the function of determining radioactive contamination. The operation of the gate monitor when using the gate controller 14 will be described with reference to the monitor flowchart of FIG. In the standby state of step # 21, the radiation detectors 3-1 to 3-3-
14 background (BG) radiation doses are detected.

In this standby state, when the short stature mode is designated by the designation switch, the gate monitor controller 14
Drives the foot up-and-down drive unit 11 in step # 22 to move the foot detector support 13 and the foot radiation detector 3-1.
4 is raised to a predetermined height position.

When the person A to be measured enters the passage gate 2 in this state, the head up-and-down drive unit 5 is driven by the control of the gate monitor controller 14 in step # 23, and the head radiation detector 3-1 is activated. To descend. When the head radiation detector 3-1 reaches the predetermined distance L from the head of the person A to be measured as described above due to this descending, the head up-and-down drive unit 5 stops the descending of the head radiation detector 3-1. To do.

When the head radiation detector 3-1 stops descending, the process proceeds to step # 24 and each radiation detector 3 is moved.
-1 to 3-14 detect the radiation dose on the body surface of the person A to be measured, whereby the radioactive contamination of the person A to be measured is monitored.

After this, in step # 25, the radioactive contamination is determined, and if it is determined that there is no contamination, the person to be measured is allowed to leave. However, if the result of the radioactive contamination determination is that the contamination is determined, an alarm to that effect is issued in step # 26, and the subject is returned to the entrance again.

Even if the short height measurement mode is designated and the foot detector support portion 13 and the foot radiation detector 3-14 are raised to a predetermined height position in this manner, the same as in the first embodiment. The effect of can be produced. Next, a second embodiment of the present invention will be described.

FIG. 4 is a block diagram of the gate monitor. A detector holder 20 is provided below the gate monitor body 1. The detector holder 20 is rotatably supported on the inner wall of the gate monitor main body 1 by a hinge 21, and one surface thereof has a mounting surface on which the person A to be measured is placed, A radiation detector 3-13 for the side surface or the foot portion is provided on the surface of the.

A concrete structure is shown in FIG. The detector holding portion 20 is formed in a plate shape, and slide fixing portions 22 and 23 are provided on opposite sides so as to be slidable in the same direction as the surface direction of the detector holding portion 20.

Further, the hinge 2 in the gate monitor body 1
The holding hole 24 is provided on the inner surface opposite to the inner surface provided with 1.
Are formed. The holding hole 24 holds the detector holding portion 20 at a predetermined height position in the horizontal direction, and the slide fixing portion 23 is inserted therein. With such a configuration, the detector holding portion 20 is normally arranged on the inner wall side of the gate monitor body 1 as shown in FIG. In this state, the person A to be measured having a height of 1500 mm or more enters the gate monitor body 1 to monitor the radioactive contamination. In this case, the radiation detector 3-13 detects the radiation dose from the person A to be measured as a side radiation detector.

On the other hand, a person A whose height is 1500 mm or less
In contrast, the detector holding unit 20 is rotated about the hinge 21 to be arranged in the horizontal direction, and the slide fixing units 22 and 23 are slid in the arrow (a) direction. At this time, one slide fixing portion 23 is inserted into the holding hole 24 (shown by the broken line in FIG. 5). After being set in this way, the person A to be measured rests on the detector holder 20 as shown in FIG.

In this state, the head up-and-down drive unit 5 is driven by the control of the gate monitor control device 14, and the head radiation detector 3-1 descends. When the head radiation detector 3-1 reaches the predetermined distance L from the head of the person A to be measured as described above due to this descent, the head up-and-down drive unit 5 causes the head radiation detector 3-1.
Stop descending.

When the head radiation detector 3-1 stops descending, the radiation detectors 3-1 to 3-14 detect the radiation dose on the body surface of the person A to be measured, and the radiation amount is measured. Person A is monitored for radioactive contamination. In this case, the radiation detector 3-13 that has detected the side surface detects the radiation dose of the measurement subject A as the foot radiation detector 3-13.

After that, if radioactive contamination is determined and it is determined that there is no contamination, the subject is allowed to leave, and
If it is determined to be radioactive contamination, an alarm will be issued to that effect,
The subject is returned to the entrance again.

As described above, in the second embodiment, the detector holder 20 for holding the radiation detector 3-13 is rotatably arranged via the hinge 21 so that the person to be measured having a height of 1500 mm or less can measure the detector. Since the detector holding unit 20 is held in the horizontal direction and the radiation detector 3-13 is used as the radiation detector for the foot to perform the detection operation, as in the first embodiment, for example, a tall body of 1500 mm or more is used. The radiation contamination can be monitored for the person A to be measured without deteriorating the monitoring ability, and the radiation contamination monitor for the person A to be measured having a short height of 1500 mm or less can be performed without any inconvenience.

Even if the radiation detector 3-13 is changed from the side surface to the foot portion, since the radiation detector 3-13 used is monitored by the gate monitor control device 14, the radiation detection target is detected. Never make a mistake. Next, a third embodiment of the present invention will be described.

FIG. 6 is a block diagram of the gate monitor.
Is a front configuration diagram thereof. In addition, each radiation detector 3-1
3-14 are omitted. The foot floor fixing portion 30 is provided with respective foot floor movable pieces 31 and 32 rotatably in the arrow (B) direction.

A convex foot detector support portion 33 is arranged below the foot floor fixing portion 30, and a foot radiation detector 3-13 is provided on the back surface of the foot detector support portion 33. It is provided.

The convex foot detector support portion 33 is moved upward to move the foot floor movable pieces 31, 32.
And the foot floor movable pieces 31 and 32 are supported as support plates. In this case, each foot floor movable piece 31, 32 is provided with a lock mechanism to fix and support the foot detector support portion 33. With this configuration, for the person A to be measured having a height of 1500 mm or less, the foot detector support portion 33 is moved upward.

As the foot detector support portion 33 moves upward, the foot floor movable pieces 31 and 32 are opened, and the foot floor movable pieces 31 and 32 are supported as a support plate. This state is the state shown by the solid lines in FIGS. In this state, a step is formed by the convex foot detector support portion 33 and the foot floor movable pieces 31, 32. After being set in this way, the person A to be measured climbs the stairs and rides on the foot detector support portion 33.

In this state, the head up-and-down drive section 5 is driven by the control of the gate monitor control device 14, the head radiation detector 3-1 is lowered, and the head radiation detector 3-1 moves to the head of the person A to be measured as described above. Are arranged at a predetermined interval L. After that, the radiation detectors 3-1 to 3-14 detect the radiation dose on the body surface of the person A to be measured, whereby the radioactive contamination of the person A to be measured is monitored.

As described above, in the third embodiment, since the convex foot detector support portion 33 is moved upward and disposed at the predetermined height position, it is the same as in the above embodiments. It goes without saying that it works. In particular, by setting the convex foot detector support portion 33 upward,
A staircase is formed so that even a person A to be measured having a short height of 150 mm or less can easily mount it on the foot detector support portion 33. Next, a fourth embodiment of the present invention will be described.
The same parts as those in FIGS. 6 and 7 are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 8 is a block diagram of the gate monitor. This gate monitor automates the raising and lowering of the convex foot detector support portion 33. A foot vertical drive unit 40 is provided, and a drive arm 42 is screwed onto a rotary shaft 41 of the foot vertical drive unit 40. This drive arm 42 is fixed to the upper surface of the convex foot detector support portion 33.

With such a structure, the foot vertical drive unit 40
The foot detector support portion 33 is moved up and down by driving. Here, when the foot detector support portion 33 moves upward, the foot floor movable pieces 31 and 32 open along with this movement. Then, the foot detector support portion 33 is provided with the foot floor movable piece 3
The support plates 1 and 32 are supported at predetermined height positions. This state is the same as the state shown by the solid lines in FIGS. 6 and 7. In this state, a step is formed by the convex foot detector support portion 33 and the foot floor movable pieces 31, 32.

Thereafter, similarly to the above, the person A to be measured climbs the stairs and rides on the foot detector support portion 33, and in this state, the head up-and-down drive portion 5 is controlled by the gate monitor control device 14.
Is driven, and the head radiation detector 3-1 is lowered, and the head radiation detector 3-1 is arranged at a predetermined distance L from the head of the person A to be measured as described above. After that, the radiation detectors 3-1 to 3-14 detect the radiation dose on the body surface of the person A to be measured, whereby the radioactive contamination of the person A to be measured is monitored. In this way, the fourth
It goes without saying that the embodiment is one in which the elevation of the convex foot detector support portion 33 is automated, and has the same effect as each of the above embodiments.

[0055]

As described above in detail, according to the present invention, it is possible to provide a gate monitor capable of monitoring the radioactive contamination of the person to be measured by one unit regardless of the height of the person to be measured.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a gate monitor according to the present invention.

FIG. 2 is a flowchart showing a monitoring operation of the gate monitor.

FIG. 3 is a flowchart showing another example of the monitoring operation of the gate monitor.

FIG. 4 is a configuration diagram showing a second embodiment of a gate monitor according to the present invention.

FIG. 5 is a specific configuration diagram of the gate monitor.

FIG. 6 is a configuration diagram showing a third embodiment of a gate monitor according to the present invention.

FIG. 7 is a front configuration diagram of the gate monitor.

FIG. 8 is a configuration diagram showing a fourth embodiment of the gate monitor according to the present invention.

FIG. 9 is a configuration diagram of a conventional gate monitor.

FIG. 10 is a monitor flowchart of the gate monitor.

[Explanation of symbols]

1 ... Monitor main body is 2 ... Passage gate, 3-1 to 3-14
... radiation detector, 4 ... elevation mechanism, 5 ... vertical head drive unit,
7 ... Head detector support part, 8 ... Hand detection part, 10 ... Foot up / down drive mechanism, 11 ... Foot up / down drive part, 12 ... Drive shaft, 13
… Foot detector support, 14… Gate monitor controller, 2
0 ... Detector holding part, 21 ... Hinge, 22, 23 ... Slide fixing part, 24 ... Holding hole, 30 ... Foot floor fixing part, 3
1, 32 ... Foot floor movable piece, 33 ... Foot detector support portion, 4
0 ... Foot up / down drive unit, 41 ... Rotating shaft, 42 ... Drive arm.

Claims (2)

[Claims] 1. A gate monitor for arranging a plurality of radiation detectors around a measured person to monitor radioactive contamination of the measured person, wherein the measured person is placed on the foot part of the measured person. A gate monitor, comprising: a support portion that supports the radiation detector that detects the radiation of the above; and a foot up-and-down driving means that raises and lowers the support portion. 2. A gate monitor for arranging a plurality of radiation detectors around a measured person to monitor radioactive contamination of the measured person, wherein the measured person is placed on the foot part of the measured person. A monitor for supporting the radiation detector for detecting the radiation, and a holding mechanism for holding the support at any one of at least two height positions.