JPH08262180A - Appearance inspection device of fuel assembly - Google Patents

Abstract

PURPOSE: To reduce inspection time and to improve inspection efficiency by inspecting appearance without overlooking the mark of the halation site on the surface of a fuel rod. CONSTITUTION: A fuel assembly 1 is placed on a pad base 3 on a direct drive motor 2. The upper portion of the fuel assembly 1 is supported by an upper part support structure 4. An elevation guide device 5 is provided in parallel with the fuel assembly 1. A camera 6 is mounted to the elevation guide device 5 and a zoom lens 7, a television camera 8, and left and right light fixtures 10 and 11 are provided at the camera 6. By moving a halation position to a symmetrical position for the shaft center of a fuel rod 9, the surface state of the fuel rod 9 hidden behind the halation shade which existed at the beginning can be observed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel assembly visual inspection apparatus used in a nuclear power plant, and more particularly to a fuel assembly for inspecting the surface of a fuel rod for scratches or foreign matters. The present invention relates to a body appearance inspection device.

[0002]

2. Description of the Related Art A reactor fuel used in a nuclear power plant, that is, a fuel assembly, is carried into a nuclear power plant from a manufacturing plant and then visually inspected by an inspector.

In this visual inspection, a penlight or the like is used and an inspector approaches the fuel assembly and visually confirms it. The contents of the visual inspection include the presence of scratches, fingerprints, dirt, and foreign matter on the surface of the fuel rod, absence of missing parts, and that the fuel rod mounting position matches the record at the time of assembly. It is something to inspect.

As this type of appearance inspection apparatus, there is known an apparatus for inspecting the appearance of a fuel assembly using an underwater television camera, as disclosed in, for example, Japanese Patent Application Laid-Open No. 59-203996. In this visual inspection apparatus, an underwater television camera is installed at a position corresponding to two orthogonal surfaces of the fuel assembly. Then, a plurality of illumination sources are arranged in an arc shape in the horizontal direction of the observation surface of the fuel assembly added to the underwater television camera. In addition, two underwater television cameras are installed corresponding to two orthogonal planes.

[0005]

The visual inspection at the time of receiving a fuel assembly at a nuclear power plant, which has been conventionally performed, is carried out by a visual inspection by an inspector using a penlight as described above. Therefore, since it is necessary for the inspector to approach the inspection target portion and perform visual confirmation every time the inspection work is performed, the work is performed in the radiation control area, and there is a concern that the total radiation dose of the inspector may increase.

On the other hand, in order to perform visual confirmation using a television camera, it is necessary to illuminate the fuel rod having a glossy shape and a cylindrical shape, and this illumination always causes halation (white blur) on the surface of the fuel rod. Since it occurs, there is a problem that a flaw or the like located in the shadow of halation cannot be found.

The present invention has been made in order to solve the above problems, and when performing a visual inspection using a television camera, the visual inspection is performed without overlooking the scratches on the halation portion of the fuel rod surface caused by the illumination. It is an object of the present invention to provide a visual inspection apparatus for a fuel assembly that enables the above.

Further, the present invention aims to reduce the radiation exposure dose associated with the inspection work to reduce the total exposure dose of the inspector, and at the same time, to enable visual inspection using a television camera to inspect the fuel assembly. An object of the present invention is to provide a visual inspection apparatus for a fuel assembly, which can shorten the inspection time for approaching the site and improve the inspection efficiency.

[0009]

According to the present invention, there is provided a fuel support rotating mechanism for vertically supporting a fuel assembly and rotating the fuel assembly every 90 ° when viewed from the top of the fuel assembly, and a fuel support rotating mechanism along the fuel assembly. A TV camera elevating mechanism for elevating a TV camera with a zoom lens, and one or more arranged on the right side of the TV camera capable of causing halation at a position on the right side with respect to the axis of the fuel rods forming the fuel assembly. It is characterized by the right side illumination and the left side illumination which also causes halation at the left side position.

[0010]

According to the present invention, when the image of a specific portion of the fuel assembly displayed as the television camera moves up and down moves from the lower end (or upper end) to the upper end (or lower end) of the monitor screen, When it comes to the central part in the vertical direction of, the right side illumination (or left side illumination) is switched to the left side illumination (or right side illumination).

As a result, it is possible to move the position of halation, which has always occurred when a glossy cylindrical object such as a fuel rod, which has been generated conventionally, is displayed as an image of a television camera.

That is, the halation position can be moved to a symmetrical position with respect to the axial center of the fuel rod, and the surface condition of the fuel rod hidden in the shadow of the halation initially generated can be observed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the visual inspection apparatus for a fuel assembly according to the present invention will be described with reference to FIGS. 1 is an elevational view of the apparatus according to the present embodiment, FIG. 2 is a front view in which an essential part of FIG. 1 is enlarged, and FIG. 3 is a partial view showing an illumination direction of FIG.

In FIG. 1, the fuel assembly 1 has its lower portion supported by a pedestal 3 which is directly connected to a direct drive motor 2 having a function of rotating every 90 °, and its upper portion supported by an upper support mechanism 4. It is supported.

Further, an elevating guide 5 is arranged in parallel on the fuel assembly 1, a camera base 6 is supported by the elevating guide device 5, and a television camera 8 with a zoom lens 7 for remote operation is arranged on the camera base 6. It is set up. This TV camera 8
Is configured so that it can be moved up and down along the surface of the fuel rod 9 of the fuel assembly 1 by an elevating mechanism (not shown).

On the other hand, in the zoom lens 7, toward the point where the optical axes of the television camera 6 and the zoom lens 7 reach the position of the center of the fuel rod 9 constituting the fuel assembly 1.
The right side illumination 10 and the left side illumination 11 that emit light horizontally are shown in FIG.
Two of them are arranged as shown in FIG.

That is, as shown in FIG. 3, the optical axis 12 of the right side illumination and the optical axis 13 of the left side illumination can be respectively applied to the axial center 14 of the fuel rod 9 viewed from the television camera 6 in the left and right directions. It has become a structure.

Next, the operation of the above embodiment will be described. The television camera 8 moves up and down from the lower end (or the upper end) of the fuel assembly 1 along the upper end (or the lower end) to display the surface of the fuel rod 9 on the monitor screen. First, the image of the fuel rod 9 displayed on the monitor screen is The inspector observes the scratches on the surface of the fuel rod 9 by turning on only the right side illumination 10 (or the left side illumination 11).

However, since the surface condition of the fuel rod 9 at the halation position cannot be observed, the right side illumination 10 (or the left side illumination 11) is turned off and the left side illumination 11 (or the right side illumination) after observing the portion other than the halation. Turn on 10).

As a result, the halation at the right side position (or left side position) is moved to the left side position (or right side position) with respect to the shaft core 14 of the fuel rod 9, and the right side (or left side) halation that has been used so far. By observing the state of the surface of the fuel rod 9 at the position, the entire surface of the fuel rod 9 can be observed.

That is, with the construction of the embodiment in which the position where halation occurs can be moved symmetrically with respect to the axis of the fuel rod 9, the television camera 8 can be taken along one surface of the fuel assembly 1. Visual inspection can be done simply by moving it up and down.

Further, the upper and lower illuminations installed on the right and left sides of the television camera 8 (right side illumination 10 and left side illumination)
By switching 11) up, down, left and right respectively,
For the scratch on the surface of the fuel rod 9, it is possible to effectively utilize the characteristic that it is easier to find the scratch by shining light from a direction perpendicular to the scratch.

Since the fuel assembly 1 is supported so that it can rotate by 90 °, the television camera 8 is moved from the lower portion (or upper portion) to the upper portion (or lower portion) of the fuel assembly 1. After the visual inspection on one surface of the fuel assembly 1 is completed, the visual inspection can be completed by rotating the fuel assembly 1 by 90 ° and observing the same way just by reciprocating the television camera 8 twice.

According to this embodiment, since the position of the halation caused by the illumination applied to the fuel rod can be changed, the inspector can perform the inspection without directly approaching the inspection target portion of the fuel assembly. This has the effect of reducing the radiation dose to workers.

Next, a second embodiment of the present invention will be described with reference to FIG. 4, those parts that are the same as those corresponding parts in FIG. 2 are designated by the same reference numerals, and a description of the overlapping parts will be omitted. The second embodiment is different from the first embodiment in that the camera base 6 to which the television camera 8 is attached is fixed and the fuel assembly 1 can be moved up and down by an elevating mechanism.

That is, in FIG. 4, the fuel assembly 1 is rotatably vertically supported in the pit 27 by the rotation support mechanism. At the bottom of the pit 27, a lifting device including a hoist 28, a wire rope 29, and a pulley device 31 fixed to the floor 30 at the upper end of the pit 27 is provided.

A camera base 6 is fixed to the floor 30 of the upper end so as to face the fuel assembly 1, and a zoom lens, a television camera 8 and an illumination (left illumination 11 in the figure) are attached to the camera base 6.
Is attached. One end of the wire rope 29 is connected to the hoist 28, and the other end is connected to the lower portion of the direct drive motor 2.

In the second embodiment, the fuel assembly 1 can be moved up and down by the wire rope 29 via the pulley device 31 by driving the hoist 28 in the pit 27. Therefore, the monitor image of the fuel assembly 1 displayed by the television camera 8 can be obtained similarly to the first embodiment.

Next, the third embodiment of the present invention will be described.
This will be described with reference to FIG. FIG. 5 shows only the main part of this embodiment, and the same parts as those in FIG. 1 are designated by the same reference numerals and the description of the overlapping parts will be omitted.

The present embodiment is different from the first embodiment in that when the optical axis 15 of the television camera 8 is directed in the direction of penetrating between the adjacent fuel rods 9, the space between the fuel rods 9 is transmitted. This is because the foreign matter confirmation illumination 16 which can be illuminated in the direction of the arrow is arranged above the zoom lens 7.

Thus, in this embodiment, the normal visual inspection uses the right side illumination 10 (or the left side illumination 11) and the fuel rod 9
Is observing the surface of. Therefore, although the focus of the zoom lens 7 and the right side illumination 10 (or the left side illumination 11) are aligned with the surface of the fuel rod 9, they exist between the fuel rods 9 (from the surface of the fuel rod 9 as seen from the television camera 8). A foreign object (at a distant position) cannot be judged in a clear situation (the depth of field cannot be obtained) because the right side illumination 10 (or the left side illumination 11) does not illuminate it. Therefore, the foreign matter confirmation illumination 16 is turned on to illuminate the foreign matter so that the foreign matter can be surely found.

Further, when the optical axis 15 of the television camera is directed in the direction of passing through between the fuel rods 9, the foreign matter confirmation illumination 16 is automatically turned on and the right and left illuminations are turned off (not shown). If the inspection is performed, the foreign matter can be reliably found without the inspector giving a command such as forgetting to turn on the foreign matter confirmation illumination 16.

Next, the fourth embodiment of the present invention will be described.
This will be described with reference to FIGS. 6 and 7. FIG. 6 is a plan view of an essential part of this embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals and the description of the overlapping parts will be omitted.

The present embodiment is different from the first embodiment in that the counter illumination 17 is arranged on the opposite side of the television camera 8 via the fuel assembly 1. This counter lighting 17
Is the illumination for confirming the foreign matter as in the third embodiment, and assuming that there is a black foreign matter between the fuel rods 9, it may not be possible to determine whether or not there is a foreign matter. There is. That is, by emitting the light of the opposed illumination 17 toward the fuel assembly 1, it can be confirmed that the light is blocked by an object other than the fuel rods 9, and the presence of the black foreign matter can be surely found.

Further, when the optical axis 15 of the television camera is directed in the direction of passing through between the fuel rods 9, the foreign substance confirmation illumination 16 and the counter illumination 17 are alternately turned on at a constant cycle, and the right and left illuminations are turned off. By performing the control (not shown), even if there is a black-colored foreign substance, it can be more reliably found.

Next, regarding the fifth embodiment of the present invention,
This will be described with reference to FIGS. 8 and 9. FIG. 7 shows the main parts of this embodiment, and the same parts as those in FIG. 1 are designated by the same reference numerals and the description of the overlapping parts will be omitted.

This embodiment is different from the first embodiment in that one end of the wire rope 18 is attached to the camera base 6 and the other end is connected to a position detector 19 installed on the floor side. The position detector 19 is composed of a winding drum 20 and a spring (not shown) and an encoder 21 housed inside the winding drum 20. ) When pulled, the winding drum 20 rotates, and the encoder 21 detects this rotation. This detection signal is transmitted to the control device 23 via the cable 22a.

On the other hand, the right side illumination 10, the left side illumination 11, the foreign substance confirmation illumination 15, and the right side illumination power source 24, the left side illumination power source 25, and the foreign substance confirmation illumination power source 26 for lighting each are connected to the control device 23 by the cable 22b. It is structured so that the lighting of can be selected.

Cable for the zoom lens 7 and the control device 23
It is connected by 22c. Accordingly, the vertical width of the fuel assembly 1 displayed on the monitor (not shown) determined by the distance between the television camera 8 and the fuel assembly 1 and the zoom ratio of the zoom lens 7 can be calculated and detected.

With these configurations, when the TV camera 8 is moved up and down along the fuel assembly 1 and the appearance is observed, the take-up drum 20 installed on the floor side is moved downward by the TV camera 8. For example, when the television camera 8 is raised by being rotated by the wire rope 18, the wire rope 18 is rotated by the force of the spring force to be wound up.

That is, with respect to the position of the TV camera 8 that moves up and down, the number of rotations (angle) is detected by the encoder 21 that rotates in the same manner as the rotation of the winding drum 20.
(The control device 23) can detect it by calculating the product of the diameter of the winding drum 20, the number of rotations, and the circular constant π.

The control performed by the controller 23 will be described below with reference to the flow chart shown in FIG. Initially, the right-side illumination 10 (or the left-side illumination 11) is turned on and the television camera 8 starts ascending / descending from an arbitrary position according to a command from an inspector.

The control device 23 calculates the ascending / descending start position of the television camera 8 which is initially stopped by the above-described calculation and stores it, and also stores the fuel assembly 1 of the fuel assembly 1 displayed on a monitor (not shown). The width in the vertical direction (elevation of the TV camera 8) is detected.

Further, the television camera 8 continues to move up and down, and the controller 23 detects the current up / down position. Next, the control device 23 determines whether the current position of the television camera 8 has reached the upper end or the lower end of the fuel assembly 1, and if it has reached, stops the raising / lowering operation of the television camera 8.

However, when the television camera 8 has not reached the upper end or the lower end of the fuel assembly 1, the control device 23 controls the vertical direction (television of the fuel assembly 1 of the fuel assembly 1 displayed on the monitor from the start / up position of the television camera 8). It is determined whether or not the camera 8 has been moved up / down (moved) by a distance half the width in the direction of up / down.

In this case, when moving up and down (moving) this distance, the right side illumination 10 (or the left side illumination 1
After turning off 1) and turning on the left side illumination 11 (or the right side illumination 10) to detect the position where the illumination is switched, the process returns to detect the current position of the television camera 8 as shown in the flow of FIG.

On the other hand, even when the vertical movement (movement) distance of the television camera 8 is not raised / lowered (moved) by a distance half the width of the fuel assembly 1 in the vertical direction (elevation movement of the television camera 8), FIG.
The flow returns to detect the current position of the television camera 8 according to the flow of.

Since the control device 23 determines and detects the flow as described above every moment according to the scan time, it is possible to switch the left and right lights to turn on until the fuel assembly 1 reaches the upper or lower end position. Therefore, it is possible to find scratches and the like in the shadow of the halation generated on the fuel rod 9 without overlooking. Furthermore, although the above embodiment has been described by raising and lowering the television camera 8, it is also possible to raise and lower the fuel assembly 1.

Next, a sixth embodiment of the present invention will be described with reference to FIG. The sixth embodiment differs from the first embodiment in that two TV cameras 8 are provided. According to this embodiment, as compared with the first embodiment in which one TV camera 8 is installed, the magnification of the zoom lens 7 on the surface of the fuel rod 9 can be increased, so that the surface of the fuel rod 9 is I am trying to observe it in more detail.

That is, if one camera 8 is to be enlarged to a width larger than the width of the fuel assembly 1 for observation, the television camera 8 must be moved in the horizontal and vertical directions with respect to the fuel assembly 1. The entire fuel assembly 1 cannot be observed.

Therefore, by installing two TV cameras 8, it is possible to use the zoom lens 7 up to 1/2 of the width of the fuel assembly 1 to enlarge and eliminate lateral movement. 8 or observation can be performed only by raising and lowering the fuel assembly 1. Therefore, the TV camera 8
Compared with the case of using a table, inspection efficiency can be improved and more detailed observation can be performed.

In the present embodiment, an example in which two TV cameras 8 are installed has been described. However, if a plurality of TV cameras 8 are installed, the surface of the fuel assembly 1 can be further zoomed up for observation, and inspection efficiency can be improved. is there.

[0053]

According to the present invention, the visual inspection of the fuel assembly can be performed by remote control without overlooking the damage of the halation portion on the surface of the fuel rod. Further, the inspection work time for approaching the inspection target portion of the fuel assembly can be shortened, the radiation exposure dose can be reduced, and the inspection efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a first view of a visual inspection apparatus for a fuel assembly according to the present invention.
FIG.

FIG. 2 is a partially enlarged front view of a right side surface for explaining an illumination mounting position of the device in FIG.

FIG. 3 is a front view showing the direction of illumination in FIG.

FIG. 4 is an elevation view showing a second embodiment according to the present invention.

FIG. 5 is a front view showing a main part of a third embodiment according to the present invention.

FIG. 6 is a plan view showing a main part of a fourth embodiment according to the present invention.

FIG. 7 is a plan view showing a main part of a fourth embodiment according to the present invention.

FIG. 8 is an elevation view showing a partial block for explaining a fifth embodiment according to the present invention.

9 is a flowchart showing the sequence of control by the control device in FIG.

FIG. 10 is a plan view showing a sixth embodiment according to the present invention.

[Explanation of symbols]

1 ... Fuel assembly, 2 ... Direct drive motor, 3 ...
Cradle, 4 ... Upper support mechanism, 5 ... Lift guide device, 6 ...
Camera stand, 7 ... Zoom lens, 8 ... TV camera, 9 ...
Fuel rod, 10 ... right side illumination, 11 ... left side illumination, 12 ... right side illumination optical axis, 13 ... left side illumination optical axis, 14 ... fuel rod axis, 15 ... TV camera optical axis, 16 ... foreign matter confirmation illumination , 17… Counter illumination,
18 ... Wire rope, 19 ... Position detector, 20 ... Winding drum, 21 ... Encoder, 22 ... Cable, 23 ... Control device,
24 ... Right illumination power supply, 25 ... Left illumination power supply, 26 ... Foreign matter confirmation illumination power supply, 27 ... Pit, 28 ... Winding machine, 29 ... Wire rope, 30 ... Top floor, 31 ... Pulley device.

Front page continuation (72) Inventor Takao Ito 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa, Ltd. Inside Toshiba Corporation Yokohama office (72) Inventor Hiroyasu 66-2, Horikawa-cho, Kawasaki-shi, Kanagawa Within the corporation

Claims (5)

[Claims] 1. A lower portion of a fuel assembly is rotatably supported vertically by a rotation support mechanism, and an elevating guide device is arranged in parallel to face the fuel assembly, and a television camera and a zoom lens are mounted on the elevating guide device. And a visual inspection device for a fuel assembly, wherein at least one illumination is provided on the left and right of the television camera. 2. A lower part of the fuel assembly is supported by a rotation support mechanism, and an elevating mechanism for elevating and lowering the rotation support mechanism is provided. A camera base is provided facing the fuel assembly, and a television camera is provided on the camera base. A visual inspection apparatus for a fuel assembly, wherein a zoom lens is attached and at least one illumination is provided on the left and right of the television camera. 3. A system is provided in which an illumination is provided directly above the television camera, and an image of the fuel assembly displayed by the television camera is moved up and down, and the left and right illuminations are automatically switched to be turned on. Claim 1 characterized by the above.
Alternatively, the visual inspection device for the fuel assembly according to the item 2. 4. The visual inspection apparatus for a fuel assembly according to claim 1, further comprising a system for lighting an illumination disposed directly above the television camera at a position between the fuel rods. 5. A system is provided which alternately illuminates an illumination disposed directly above the television camera at a position between the fuel rods and an illumination opposed to each other through the fuel assembly. Item 1. A visual inspection apparatus for a fuel assembly according to item 1 or 2.