JPH06308245A - Surface pollution inspection device - Google Patents

Abstract

PURPOSE:To prevent the reduction of the measurement precision and measurement efficiency and prevent the damage of a device main body by detecting the distance between the shift tip of a smear collecting member and the surface of a subject, and keeping the smear pressure of the member constant. CONSTITUTION:When a recess 4a exists on the surface of a subject 4 during smearing, the position and shape of the recess 4a are obtained by a position measurement control circuit 22 based on the position signal from a position sensor 21a and the rotation signal of an inspection bed 5, and the corresponding surface position data are stored 24 before the recess 4a is smeared with the filter paper 6. When a wiping arm head section 7 reaches the recess 4a, a position shift control circuit 23 retreats the head section 7 in the horizontal direction (right and left direction of the paper surface) by the shift quantity corresponding to the surface position data and continuously smears the subject 4 while the smear pressure by the filter paper 6 is controlled constant. The circuit 23 controls an arm drive section 10 so that the head section 7 is correctly moved based on the surface position data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface contamination inspection apparatus for radioactive solid waste (hereinafter referred to as "inspection object") carried out from a nuclear facility.

[0002]

2. Description of the Related Art In a nuclear facility, the appearance, surface contamination, and radiation dose of an object to be taken out of the facility are measured and inspected, and only those that have no problem such as contamination are taken out of the facility. .

FIG. 2 is a block diagram showing the structure of this type of inspection process. In this inspection step, the appearance inspection apparatus 1 equipped with an ITV monitor visually inspects the subject for flaws. Next, the surface contamination inspection device 2 rubs (smears) the surface of the subject with filter paper as a smear sampling member, and
By measuring the amount of contamination of the filter paper, the presence or absence of surface contamination is inspected. Further, the radioactivity measuring device 3 measures the radiation dose using a radiation monitor.

On the other hand, an object to be inspected by such an inspection process has a considerably uneven surface because its external shape is deformed due to interference with other objects during reception or storage in the facility.

Further, of the above-mentioned inspection steps, the visual inspection mainly confirms local scratches on the subject, and therefore has the property that the unevenness on the subject surface cannot be completely inspected. For this reason,
An object that has passed the visual inspection is sent to the surface contamination measuring device 2 and inspected even if the unevenness is large.

FIG. 3 is a schematic view showing the structure of this surface contamination inspection apparatus. In this surface contamination inspection apparatus, a subject 4 having a predetermined shape is placed on an examination table 5, and the examination table 5 rotates the subject 4. Further, a wiping arm head portion 7 having a filter paper 6 as a smear collecting member for smearing the subject 4 attached to the tip, and a wiping arm head portion 7 attached to the wiping arm head portion 7 and having elasticity like rubber, for example. The arm drive unit 1 is provided with a head position correction mechanism 8 and a smear arm 9 attached to the head position correction mechanism 8 so that the smear arm can move up and down and move forward and backward.
It is set to 0.

The arm drive unit 10 has a motor 11 for driving the smear arm unit 9, and drives the smear arm under the control of the drive control unit 12. The drive control unit 12 drives the motor 11 of the arm drive unit 10 based on a predetermined procedure or a position signal to advance the smear arm unit 9 to the subject 4 side, and then controls the arm drive unit 10 to control the smear arm unit. Lower 9 As a result, the filter paper 6 at the tip of the smear arm smears the subject 4.

The unevenness of the subject 4 is absorbed by the elasticity of the head position correction mechanism section 8. When the smearing is finished, the amount of radioactive contamination adhering to the filter paper 6 after smearing is measured, the presence or absence of contamination of the subject 4 is inspected, and the subject 4 is carried out from the inspection table 5 according to the inspection result.

[0009]

However, in the surface contamination inspection apparatus as described above, when inspecting a subject 4 having large unevenness among the subjects 4 that have passed the visual inspection, the smear pressure does not become constant. There is a problem that the surface cannot be smeared uniformly.

Further, since the smear pressure set most effectively fluctuates, there is a problem that the contamination measurement accuracy and the contamination measurement efficiency decrease. Furthermore, if the unevenness is very large, the head position correction mechanism 8 cannot absorb the damage, and the wiping arm head 7 may be damaged and the inspection process may be interrupted.

The present invention has been made in consideration of the above-mentioned circumstances, and by measuring the unevenness of the surface of the subject, it is possible to prevent the deterioration of the contamination measurement accuracy and the surface contamination measurement efficiency, and to prevent the damage of the apparatus main body. An object is to provide a surface contamination inspection device.

[0012]

According to a first aspect of the present invention, the smear collecting member is moved while rubbing against the surface of the subject, and the amount of radioactive contamination of the smear collecting member is used to detect the subject. In a surface contamination inspection device for inspecting surface contamination, position detection means for detecting a distance from the surface of the subject at the destination of movement of the smear collection member, and the smear collection based on the detection result by the position detection means. And a smear pressure control means for controlling the position of the smear collecting member so as to keep the smear pressure of the working member constant.

According to a second aspect of the present invention, in the surface contamination inspection apparatus according to the first aspect of the invention, the detection result of the position detecting means exceeds a predetermined limit movement amount of the smear collecting member. At this time, the surface contamination inspecting device is provided with a smear stopping means for stopping the smear process to protect the device body.

[0014]

Therefore, according to the present invention, by taking the above-mentioned means, in the surface contamination inspecting apparatus, when the position detecting means detects the distance to the surface of the subject at the destination of the smear collecting member, The position of the smear collecting member is controlled by the smear pressure control means based on the detection result so that the smear pressure of the smear collecting member becomes constant. Also,
In the surface contamination inspection device, when the detection result by the position detecting means exceeds the predetermined limit movement amount of the smear collecting member,
The smear process is stopped by the smear stopping means, and the apparatus body is protected.

As described above, by measuring the unevenness of the surface of the subject, the smear pressure can be made constant and the contamination measurement accuracy and the surface contamination measurement efficiency can be prevented from deteriorating, and the device body can be prevented from being damaged.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the structure of a surface contamination inspection apparatus according to an embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals and the detailed description thereof will be omitted. Here, only different parts will be described. Describe.

That is, according to the present invention, the surface contamination inspection can be executed in correspondence with the unevenness of the subject, and specifically, the wiping arm head portion 7 has a position sensor 21a as a position detecting means. , 21b, and instead of the drive control unit 12, a position determination control circuit 22 and a position movement control circuit 23 as a smear pressure control means and a smear stop means.
And a drive determination control unit 25 including a position information storage circuit 24
Is provided. The drive determination control unit 25
In addition to the functions of the circuits 22 to 24, has a drive function of raising, lowering and advancing and retracting the smear arm portion 9 according to a predetermined procedure of the smear process.

Here, the position sensors 21a and 21b measure the distance between the surface of the subject 4 and the position sensors 21a and 21b in a non-contact manner, and the position signal corresponding to the measured amount is used as the position determination control circuit. For example, various sensors such as a high frequency oscillation type, a differential coil type, a magnetic type, a capacitance type, and an ultrasonic type can be used.

The position sensors 21a and 21b are provided on the wiping arm head portion 7, respectively. The position sensor 21a is provided at the lower portion 7 of the wiping arm head portion 7 so that the position sensor 21a can detect the distance to the subject 4 at the tip of the smear moving direction.
It is attached to a. Further, the position sensor 21b is attached to the central portion 7b of the wiping arm head portion 7 for confirming the current filter paper position.

The position determination control circuit 22 includes a position sensor 21.
a, 21b based on the position signals transmitted from the subject 4
Has a function of obtaining the surface position of the above and storing the corresponding surface position data in the position information storage circuit (memory) 24.

On the other hand, the position movement control circuit 23 obtains the movement amount of the filter paper 6 to the surface of the subject 4 based on the surface position data stored in the position information storage circuit 24, and the motor 11 is moved by this movement amount. Is driven to move the wiping arm head portion 7 at the tip of the smear arm forward and backward with respect to the subject 4. Further, the position movement control circuit 23 has a function of stopping the apparatus main body and notifying the abnormal state when the movement amount corresponding to the surface position data exceeds a predetermined limit movement amount.

Next, the operation of the surface contamination inspecting apparatus constructed as above will be described. Now, the subject 4 having the recess 4a is placed on the examination table 5, and the subject 4 is rotated by the examination table 5.

The drive determination controller 25 sends a forward command to the motor 1
1 to drive the motor 11 to drive the smear arm 9
With respect to the subject 4. The position sensor 21 a attached to the wiping arm head unit 7 sends a position signal corresponding to the distance from the subject 4 to the position determination control circuit 22. The position determination control circuit 22 obtains the surface position of the subject 4 based on the position signal, and stores the surface position data in the position information storage circuit 24.

On the other hand, the position movement control circuit 23 obtains the movement amount of the filter paper 6 to the surface of the subject 4 based on the surface position data stored in the position information storage circuit 24, and drives the motor 11 by this movement amount. By driving, the smear arm unit 9 is advanced with respect to the subject 4 and stopped.

Next, the drive determination control section 25 sends a descending command to the arm drive section 10 to cause the smear arm section 9 to move.
To lower. As a result, smearing of the surface of the subject 4 is started.

When there is a concave portion 4a on the surface of the subject 4 in the smear, before the concave portion 4a is smeared by the filter paper 6, the position determination control circuit 22 receives a position signal from the position sensor 21a and a predetermined signal of the inspection table 5. The position and shape of the recess 4a are obtained based on the rotation speed, and the corresponding surface position data is stored in the position information storage circuit 24.

As a result, when the wiping arm head portion 7 reaches the concave portion 4a, the position movement control circuit 23 advances and retracts the wiping arm head portion 7 in the horizontal direction by the moving amount corresponding to the surface position data, and the filter paper 6 is moved. The smearing of the subject 4 is continued while controlling the smearing pressure by the constant.

Further, the position movement control circuit 23 confirms whether or not the wiping arm head portion 7 is correctly moved based on the current surface position data obtained in the same manner from the position signal from the position sensor 21b. According to this result, the arm drive unit 10 is controlled so that the wiping arm head unit 7 is moved correctly.

The position movement control circuit 23 stops the smear process by stopping the surface contamination inspection device when the movement amount corresponding to the surface position data exceeds the limit movement amount.

Further, the position movement control circuit 23 outputs an abnormality notification signal indicating the abnormal state to the outside. As described above, according to the present embodiment, when the position sensor 21a attached to the wiping smear head unit 7 detects the distance from the surface of the subject 4, the drive determination control unit 25 determines the distance based on the detection result. The position of the wiping smear head portion 7 is controlled so that the smear pressure by the filter paper 6 is kept constant. Also,
In the surface contamination inspection device, when the detection result of the position sensor 21a exceeds a predetermined limit movement amount, the position determination control circuit 22 stops the smear process to protect the device body.

By measuring the unevenness of the subject 4 from the distance from the surface of the subject 4 in this manner, the smear pressure is kept constant and the contamination measurement accuracy and the surface contamination measurement efficiency are prevented from deteriorating, and the device body is damaged. Can be prevented.

Further, by outputting the abnormality notification signal indicating the abnormal state, the operator can quickly know the abnormal state, so that the inspection can be restarted smoothly. Further, since smearing is performed according to the measured object shape, it is not necessary to set the position of the wiping arm head portion 7, so that operability can be improved.

Further, it is not necessary to confirm the presence or absence and the degree of unevenness of the subject 4 before the surface contamination inspection is carried out, and the appearance inspection and the surface contamination inspection can be processed at the same time, so that the operation rate of the whole inspection process is improved. You can

In the above embodiment, the position sensor 21a
Although the case where the movement amount of the wiping smear head portion 7 is obtained based on the position signal received from is described, the present invention is not limited to this, and the outer dimension of the subject 4 is obtained based on the position signal,
Even when the measurement and inspection accuracy is improved by using the external dimensions as a parameter in another inspection, the present invention can be similarly implemented and the same effect can be obtained.

Further, in the above embodiment, the position sensor 21a
The above description is for the case where the above is attached to the lower portion 7a and the central portion 7b of the wiping arm head portion 7. However, the present invention is not limited to this and the present invention can be similarly implemented if the position sensor is provided at the tip of the smear advancing direction. The same effect can be obtained.
In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0036]

As described above, according to the present invention, by measuring the unevenness of the surface of the subject, it is possible to prevent the contamination measurement accuracy and the surface contamination measurement efficiency from deteriorating, and prevent the apparatus body from being damaged. An inspection device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a surface contamination inspection device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional inspection process.

FIG. 3 is a schematic diagram showing a configuration of a conventional surface contamination inspection device.

[Explanation of symbols]

4 ... Subject, 4a ... Recess, 5 ... Inspection table, 6 ... Filter paper, 7 ...
Wiping arm head part, 8 ... Head position correction mechanism part, 9
... smear arm part, 10 ... arm drive part, 11 ... motor, 21a, 21b ... position sensor, 22 ... position determination control circuit, 23 ... position movement control circuit, 24 ... position information storage circuit, 25 ... drive determination control part.

Claims (2)

[Claims] 1. A surface contamination inspection apparatus for inspecting the surface contamination of the subject based on the amount of radioactive contamination of the smear collecting member while rubbing the smear collecting member against the surface of the subject. Position detecting means for detecting the distance to the surface of the subject at the moving destination of the sampling member, and the smear so as to make the smear pressure of the smear collecting member constant based on the detection result by the position detecting means. And a smear pressure control means for controlling the position of the sampling member. 2. The surface contamination inspection apparatus according to claim 1, wherein when the detection result by the position detection means exceeds a predetermined limit movement amount of the smear collecting member, the smear process is stopped and the apparatus main body is moved. A surface contamination inspecting device, characterized in that a smear stopping means for protection is added.