JPH09311193A - Inside inspecting apparatus for nuclear reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To observe cracks formed in the structure of a nuclear reactor highly reliably and quickly and easily by utilizing a camera which can provide color information. SOLUTION: In an inside inspecting apparatus for a nuclear reactor to carry out visual inspection of a pressure container of a nuclear reactor and the structure of the nuclear reactor by lowering a CCD color TV camera to the inside of the pressure container of the nuclear reactor from the outside, the CCD color TV camera 1 is installed in an air-tight cylindrical main body 3 and at the same time a mirror 6 is installed in the lower side of the camera 1. The angle of the mirror 6 is adjusted by a spiraling mechanism 7 and an angle adjusting mechanism 8 installed in the main body 3 and the pressure container of the nuclear reactor is made observed by front observation, side observation, and transverse observation through an observation glass window 24 in the horizontal direction and an observation glass window 25 in the vertical direction. The CCD color TV camera 1 is not affected by a radiation shielding body 28 and provides a clear images without generating noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-reactor inspection for visually inspecting a reactor pressure vessel, reactor internals and the like installed therein in water (charge coupled device) with a CCD color TV camera. Regarding the device.

[0002]

2. Description of the Related Art A fuel assembly, a reactor internal structure, a control rod, a steam separator, a steam dryer, a core sparger, etc. are built in a reactor pressure vessel of a boiling water reactor. The in-core structure part is composed of a shroud that forms an internal tank, a shroud head, a core support plate that supports the lateral direction of the core, and an upper support plate. An emergency core cooling system core sparger is fixed to the internal structure.

At present, the reactor pressure vessel is visually inspected as a part of in-service inspection (ISI) in a range accessible by an underwater TV camera. However, the inspection range is further expanded and the inspection accuracy is improved. Therefore, various remote inspection devices that incorporate ultrasonic flaw detection technology have been developed. In addition, a visual inspection is performed by a CCD color TV camera as an inspection sensor in water inside the reactor pressure vessel by an underwater inspection robot.

The internal structure of the reactor pressure vessel is required to have a high level of integrity and must be regularly inspected. As one of the inspections, there is a method of visually inspecting the external appearance of the internal structure of the reactor. To reduce radiation exposure, the reactor or fuel storage pool, steam dryer, shroud head storage pit, etc. are filled with water. , It is difficult to directly observe the appearance of the equipment.

Therefore, an inspection using an optical inspection device, particularly an underwater television camera, is generally carried out. Conventionally, in visual inspection using this underwater TV camera, an operator holds the signal cable of the underwater TV camera, adjusts the height and direction of the TV camera head from the reactor work floor,
The image of the subject taken by the TV camera is output on a monitor installed on the reactor work floor, and the inspector visually confirms this.

[0006]

The inspection inside the reactor by operating the signal cable of the conventional camera is simple and requires no external device, and the holding of the TV camera depends on the signal cable. However, there is a problem in that it is difficult to control due to inertia of the camera head, etc., and it is difficult to obtain a stable inspection image, and there is also a problem in that the TV camera cannot be accessed due to the structure of the nuclear reactor.

In order to confirm the soundness of the reactor internal structure, a visual inspection is carried out with a monochrome underwater TV camera by an image pickup tube system which is not so much affected by radiation, but there is no color information on the surface to be tested. Therefore, it is difficult to judge scratches, etc., and there are many problems that rely on the judgment of an inspector who is familiar.

Further, a color camera of an image pickup tube system for obtaining color information on a surface to be tested has a low resolution, and a CCD color TV camera has a high resolution, but noise is generated due to the influence of radiation. The confirmation of the soundness of internal structures has a problem of low reliability.

The present invention has been made in order to solve the above-mentioned problems, and an inspection apparatus for a reactor can be easily used by using a CCD color TV camera capable of obtaining color information on a surface to be tested. To provide.

The present invention has been made to solve the above problems, and the present invention is a CCD color TV camera which is stably provided in a narrow portion of a jet pump and a core shroud cylinder installed in a reactor pressure vessel. An object of the present invention is to provide an in-reactor inspecting apparatus that can quickly and reliably perform a highly reliable inspection on an object to be inspected in the vicinity by accessing and positioning.

[0011]

According to the invention of claim 1, a reactor for visually inspecting the inside of the reactor pressure vessel and internal structures by descending a CCD color TV camera from the outside to the inside of the reactor pressure vessel. In the internal inspection apparatus, the CCD color TV camera is provided in the tubular body through a camera holder, a mirror is provided below the CCD color TV camera, and a turning mechanism and an angle for turning and adjusting the angle of the mirror are provided. An adjusting mechanism is provided, a glass window is provided on a lower side surface and a bottom surface of the main body located near the mirror, and a radiation shield for protecting the CCD color TV camera from radiation is provided on the main body. To do. According to the first aspect, it is possible to easily confirm the soundness of the reactor pressure vessel and the internal structure of the reactor under a high radiation dose, and the reliability is improved.

According to a second aspect of the present invention, the turning mechanism includes a mirror holding member that holds one end of the mirror in a swingable manner, and a rotating cylindrical body that is rotatably provided in the main body that fixes the mirror holding member. A rotary cylinder driving motor provided in the main body having a pair of upper and lower bearings provided between the rotary cylinder and the main body, and a gear meshing with a gear provided on an inner surface of the rotary cylinder It consists of and. According to the second aspect, the swivel mechanism facilitates direct view and side view of the inspection object.

According to a third aspect of the invention, the angle adjusting mechanism has an angle adjusting plate having a semicircular cutout hole that is rotatably provided so as to face the mirror holding member, and a coupling attached to the angle adjusting plate. An angle adjusting motor for connecting and rotating the coupling, an adjusting pin provided on a substantially central surface of the mirror to be inserted into the semicircular cutout, the mirror and the rotating cylinder. And an elastic body provided between and. According to the third aspect, the tilting direction of the object to be inspected can be easily viewed obliquely by the angle adjusting mechanism.

4. The radiation shield comprises a lead cylindrical body, and the lead cylindrical body is detachably screwed to the body by a cylindrical pressing member on the outer peripheral surface of the body. To do. According to claim 4, a CCD color TV
Since the camera cannot be affected by radiation, a clear image can be obtained without noise.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an in-reactor inspection apparatus according to the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 is C
CD (Charge coupled derice) color T
With a V camera, this CCD color TV camera 1 is attached to a camera holder 2, and the camera holder 2 is fixed to the inner surface of an airtight cylindrical main body 3. A camera cable 4 is connected to the upper end of the CCD color TV camera 1, and a tip portion of the camera cable 4 is branched from the middle of the cable holding member 5 and connected to a camera control and a monitor although not shown. A cable holding member 5 surrounding the camera cable 4 is connected to a wire from a fuel exchanger (not shown).

Below the main body 3, a mirror 6 is provided via a turning mechanism 7 and an angle adjusting mechanism 8. The turning mechanism 7 includes a mirror holding member 9 that holds the upper end of the mirror 6 so that the mirror 6 can swing, a rotary cylinder 10 provided in the main body 3 that fixes the mirror holding member 9 on the lower inner surface, and the rotary cylinder. A pair of upper and lower bearings 11 and 26 provided between the body 10 and the main body 3, and a large-diameter gear 12 provided on the inner surface of the rotating cylindrical body 10.
A small-diameter gear 13 that meshes with the large-diameter gear 12 and a rotary cylinder drive motor 14 that rotates the small-diameter gear 13. The rotating cylinder driving motor 14 is fixed to the inner surface of the upper portion of the main body 3.

The upper end of the mirror 6 is swingably held by a pin 15 on a mirror holding member 9, and an adjusting member is inserted into a semicircular cutout hole 17 of an angle adjusting plate 16 at a substantially middle portion of the mirror 6. It has a pin 18. The adjusting pin 18 is guided by a semicircular cutout hole 17 to adjust the angle of the mirror 6 arbitrarily, as described later.

The angle adjusting mechanism 8 of the mirror 6 has an angle adjusting plate 16 provided in a semicircular cutout hole 17 into which an adjusting pin 18 provided in an intermediate portion of the mirror 6 is inserted, and a cup connected to the angle adjusting plate 16. Provided between the ring 19, a motor 20 for angle adjustment for rotating and driving the coupling 19, a motor power source 21 for supplying electric power to the motor 20 for angle adjustment through a lead wire 22 and the mirror 6 and the rotary cylinder 10. And an elastic body 23 such as a coil spring.

The motor power source 21 is fixed to the inner surface of the upper portion of the main body 3, and the angle adjusting motor 20 is fixed to the inner surface of the rotary cylinder. When voltage is applied from the motor power supply 21 to the angle adjusting motor 20, the rotation of the motor 20 causes the angle adjusting plate 16 to rotate.
Rotates, and the mirror 6 makes a pendulum motion with the pin 15 as a fulcrum.

A glass window 24 for horizontal observation is provided on the lower side surface of the main body 3, and a glass window 25 for vertical observation is provided on the bottom surface of the main body 3. Each glass window 24, 25 is made of lead glass. A lower bearing 26 is interposed between the bottom surface of the main body 3 and the bottom surface of the rotary cylinder 10. Further, a transmission hole 27 is provided on the lower side surface of the rotary cylinder 10 so as to face the horizontal observation glass window 24.

A cylindrical cylindrical radiation shield 28 is provided on the outer peripheral surface of the main body 3, and a cylindrical pressing member 29 is provided on the outer peripheral surface of the radiation shield 28 so that the radiation shield 28 is screwed to the main body 3. It is fixed by 30.

As described above, the mirror 6 performs the pendulum motion in the radial direction with the adjusting pin 18 guided along the semicircular cutout hole 17 by the rotational movement of the angle adjusting plate 16 and using the pin 15 as the fulcrum as shown by the dotted line. . The coupling 19 of the angle adjusting plate 16 is rotated by the drive of the angle adjusting motor 20, and accordingly, is rotated in the radial direction. In this way, the mirror 6 is guided by the semicircular cutout hole 17 and can be adjusted to an arbitrary angle.

Thus, according to the present embodiment, the window glass
The object to be inspected in the reactor pressure vessel is observed from 24 and 25 through the mirror 6, the image is taken by the CCD color TV camera 1, the image signal is sent to the camera controller and the monitor through the camera cable 4, and the inside of the reactor under high radiation dose. The structure can be visually inspected.

Next, a method of inspecting the internal structure of the reactor pressure vessel by the in-reactor inspection apparatus having the above-mentioned configuration will be described with reference to FIGS. 2 to 5. FIG. 2 shows a state in which the in-reactor inspecting apparatus 31 having the above-mentioned configuration is inserted into the reactor pressure vessel 32 to inspect the upper lattice plate 33 and the shroud 34 and the annular space 35 of the in-reactor structure. The camera cable 4 of the in-reactor inspection device 31 is connected to the camera controller 36, and the monitor television 37 is connected to the camera controller 36. The camera controller 36 is installed on the operation floor 38, and the fuel exchanger 39 runs on the operation floor 38. The in-reactor inspection device 31 is a refueling machine.
The cable from the auxiliary hoist 40 of 39 is connected to the cable holding member 5 and is suspended so as to move up and down in the reactor pressure vessel 32.

FIG. 3 shows an in-reactor inspection device in the upper lattice plate 33.
The state where the upper grid plate 33 is inspected by inserting 31 is shown. In this case, the in-reactor inspection device 31 is hung at the center of the upper lattice plate 33, and is inspected by rotating in a side view.

FIG. 4 shows an in-reactor inspection device 31 in an annular space 35.
4 shows a state in which the welded portion 43 between the intermediate ring 41 and the intermediate barrel 42 of the shroud 34 is inspected by inserting. The upper body 44 is connected to the middle ring 41.

In this case, the in-reactor inspection device 31 is attached to the welding part.
It is hung near 43 and the mirror 6 is a CCD color TV.
The welded portion 43 of the overring-shaped portion is inspected by setting the line of sight of the camera 1 slightly above horizontal.

FIG. 5 shows a state of inspecting the upper part of the jet pump 45 installed in the annular space 35. The jet pump 45 has a transition piece 46 and a bolt 47 on the upper side.
And has a nozzle 48 below. Below the nozzle 48, a riser pipe 49 is supported by a riser brace 50 on the inner surface of the reactor pressure vessel 32.

In this case, the in-reactor inspection device 31 is hung above the jet pump 45, and the transition piece 46, the bolt 47 and the like are inspected through the glass window 25 for vertical observation. As inspection points, not only the internal structures other than those described above but also control rods, fuel assemblies, etc. can be inspected.

[0030]

According to the present invention, a clear image and color information can be obtained at the same time even when confirming the soundness of a furnace internal structure or the like in a furnace area where radiation is high. It also contributes to shortening the periodic inspection and reducing radiation exposure, improving reliability. Further, since the mirror is provided with the turning mechanism and the angle adjusting mechanism, it is possible to easily perform the direct view, the side view, and the perspective view of the inspection object.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an in-reactor inspection apparatus according to the present invention.

FIG. 2 is a schematic diagram for explaining a method for inspecting the inside of a reactor pressure vessel with the in-reactor inspection device in FIG.

FIG. 3 is a perspective view showing an example of inspecting an upper lattice plate in FIG.

FIG. 4 is a vertical cross-sectional view showing an example of inspecting a welded portion of a shroud in FIG.

5 is a vertical cross-sectional view showing an example of inspecting the jet pump in FIG.

[Explanation of symbols]

1 ... CCD color TV camera, 2 ... camera holder, 3 ...
Main body, 4 ... Camera cable, 5 ... Cable holding member, 6
... Mirror, 7-swivel mechanism, 8 ... Angle adjusting mechanism, 9 ... Mirror holding member, 10 ... Rotating cylinder, 11 ... Upper bearing, 12
… Large gear, 13… small gear, 14… Cylinder drive motor,
15 ... Pin, 16 ... Angle adjustment plate, 17 ... Semi-circular cutout hole, 18 ...
Adjustment pin, 19 ... Coupling, 20 ... Angle adjustment motor, 21 ... Motor power supply, 22 ... Lead wire, 23 ... Elastic body, 24 ...
Horizontal observation glass window, 25 ... Vertical observation glass window, 26 ... Lower bearing, 27 ... Transmission hole, 28 ... Radiation shield, 29 ... Cylindrical holding member, 30 ... Screw, 31 ... Nuclear reactor inspection device , 32 ... Reactor pressure vessel, 33 ... Upper lattice plate, 34 ... Shroud, 35 ... Annular space, 36 ... Camera control, 37 ...
Monitor TV, 38 ... Operation, 39 ... Refueling machine,
40 ... Auxiliary hoist, 41 ... Intermediate ring, 42 ... Intermediate barrel, 43
… Welded part, 44… Upper body, 45… Jet pump, 46… Transition piece, 47… Bolt, 48… Nozzle, 49… Riser tube, 50… Riser brace.

Claims (4)

[Claims] 1. A CCD from the outside to the inside of the reactor pressure vessel.
In the in-reactor inspecting apparatus for visually inspecting the inside of the reactor pressure vessel and the in-reactor structures by descending a color TV camera, the CCD color TV camera is provided in a cylindrical body via a camera holder and the CCD A mirror is provided below the color TV camera, a turning mechanism and an angle adjusting mechanism for turning and adjusting the angle of the mirror are provided, and a glass window is provided on a lower side surface and a bottom surface of the main body located near the mirror. An in-reactor inspecting apparatus, characterized in that the main body is provided with a radiation shield for protecting the CCD color TV camera from radiation. 2. The turning mechanism includes a mirror holding member that holds one end of the mirror so that the mirror can swing, a rotary cylinder that is rotatably provided in the main body that fixes the mirror holding member, and the rotary cylinder. It comprises a pair of upper and lower bearings provided between the body and the main body, and a rotary cylinder driving motor provided in the main body having a gear that meshes with a gear provided on the inner surface of the rotary cylinder. The in-reactor inspection device according to claim 1. 3. The angle adjusting mechanism has an angle adjusting plate having a semicircular cutout hole rotatably provided facing the mirror holding member, a coupling attached to the angle adjusting plate, and the cup. An angle adjusting motor for connecting and rotating a ring, an adjusting pin provided on the mirror to be inserted into the semicircular cutout hole, and an elastic body provided between the mirror and the rotating cylindrical body. The in-reactor inspecting apparatus according to claim 1, comprising: 4. The radiation shield comprises a lead cylinder, and the lead cylinder is detachably screwed to the body by a cylindrical pressing member on the outer peripheral surface of the body. The nuclear reactor inspection apparatus according to claim 1.