JPH034955Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a monitoring device for inspecting the appearance of irradiated fuel underwater.

(Conventional technology) Generally, nuclear power plants operate for a certain period of time (approximately 3 to 4 hours)
2007) A so-called visual inspection to check the deformation of the fuel after irradiation, changes in color and gloss, and the state of limescale adhesion, or to check whether the assembly was properly set in the designated position in the furnace when replacing the fuel. Underwater television equipment or binoculars are mainly used for ancillary inspections.

(Problem that the invention aims to solve) By the way, underwater television equipment requires a way to hang while protecting the camera and cord, and cannot be easily tilted, so it is necessary to raise and lower it one by one to observe each part in detail. It is difficult to handle,
In addition, binoculars cannot inspect when ripples form on the water surface; you have to wait for the waves to disappear or use a box-like tool, which is inconvenient, and underwater lighting is required in either case. It is uneconomical. Therefore, this idea provides an easy-to-handle monitoring device that allows each part to be easily observed without having to move the device up and down each time, does not require special underwater lighting, is not affected by ripples on the water surface, etc. It is.

(Means for solving the problem) Based on the above-mentioned purpose, this invention involves inserting the lower part of the photodetector tube made of a corrosion-resistant metal into a storage pool, and attaching the upper part of the photodetector tube to a crane frame in a tiltable manner. An aperture window and a reflecting mirror are provided at the lower end, and a transparent plate and an objective lens are provided in the middle part, making the lower half the objective part.An amplification tube with a built-in optical amplifier is attached to the upper end of the light receiving tube to perform amplification. A bifurcated tube consisting of a monitoring section with an eyepiece at the upper end and an imaging section with a camera connected to a television monitor at the upper end is attached to the tube, and a half mirror is disposed above the amplifier in this bifurcated tube. It is characterized by

(Function) When the light receiving tube is brought close to the fuel assembly underwater, the light emitted from the assembly enters through the opening window, is reflected by the reflector, travels upward, passes through the objective section, hits the optical amplifier, and there the light is emitted. is amplified and output upward, part of it is reflected by the half mirror and goes to the eyepiece, and the other part passes through the mirror and goes to the television camera.

(Example) Referring to the drawings, an example of this invention will be described. 1 is a light receiving tube made of water-resistant and corrosion-resistant metal such as stainless steel, with a diameter of about 5 cm and a length of about 2 m. is the pin shaft 2a on the left and right, front and back
A piece 2 having a rectangular plane is fixed, and its pin shaft 2a is supported by a bearing 11 provided so as to surround the piece 2 on a pedestal c of a bridge crane on a storage pool p. , can be tilted back and forth within a certain angle range (approximately 30 degrees on one side) as shown in chain lines, and the lower part is inserted into the pool so that it will not be exposed from the water surface even if the cylinder 1 is tilted, and the lower half The part constitutes an objective part 1a, and an opening window 3d is provided on one side of the lower end, and a reflecting mirror 3 is provided immediately behind the opening window 3d.
A transparent plate 3a and an objective lens 3b are provided above the transparent plate 3a.

On the other hand, an amplifying tube 5 is attached to the upper end of the light receiving tube 1, and inside the amplifying tube 5 there is a photoconductive film 4a such as cadmium sulfide which becomes an electrode on the input side, and a diffusion film 4 on the rear side.
b, an optical amplifier 4 consisting of a light-shielding film 4c, an electroluminescent film 4d (EL film), and a transparent film 4e serving as an electrode on the output side is housed, and a monitoring section 6a and an imaging section are installed in the upper part of the amplification tube 5. A bifurcated tube 6 consisting of 6b is attached, and within this bifurcated tube 6, a half mirror 7 is provided above the optical amplifier 4 at an angle with respect to the axis (optical axis) of the monitoring tube 1. An eyepiece lens 8 is attached, and a television camera 9 is attached to the upper end of the imaging section 6b, and this camera 9 is connected via a cord to a television monitor 10 disposed in a management room or the like.

Therefore, when using the bridge crane, the bridge crane is moved to approach the fuel assembly n placed on the inspection base in the pool, while the circuit of the optical amplifier 4 is closed and the upper and lower electrodes are closed. If a required voltage is applied between them, the light emitted from the fuel assembly n will pass through the opening window 3 at the bottom
It enters the interior from d, is reflected by a reflecting mirror 3c, and advances upward to form a transparent plate 3a of an objective section 1a and an objective lens 3b.
The photoconductive film 4a of the optical amplifier 4 enters the photoreceiver tube 1 through
At this time, the EL film 4d emits light due to the electric field corresponding to the image, and the incident light is amplified several tens to 100 times and travels upward through the transparent film 4e, which hits the half mirror 7 and a part of it. is the monitoring unit 6a
It is reflected toward the side, and the other part is transmitted and proceeds to the imaging section 6b side.

Therefore, the operator can inspect the external appearance of the fuel assembly n by looking through the eyepiece 8 on the crane mount c, and can also inspect the fuel assembly n using the camera 9 of the imaging section 6b. is displayed on the television monitor 10 and can be monitored in the control room. By appropriately tilting the light receiving tube 1 via the handle provided on the bifurcated tube 6, each part of the assembly n can be precisely inspected. Furthermore, the exchange status of the fuel assembly n for the nuclear reactor can be monitored in the same manner.

In the above example, a pin shaft was used as the tilting means for the light receiving tube 1, but it would be more convenient if the light receiving tube 1 could be tilted in all directions using a spherical bearing.

(Effects of the invention) As described above, according to this invention, since the light receiving tube can be tilted, it is possible to monitor the external appearance of the fuel assembly underwater without having to move the monitoring device up and down every time as in the past. It is also possible to fully inspect the condition of the set, and it is easy to handle and work.Also, the illuminance level underwater due to the existing lighting in the current pool is about 0.1 lux, but even at this level, the built-in light It can be amplified as required by an amplifier and can be fully monitored, and does not require special underwater lighting as in the past.

[Brief explanation of the drawing]

The drawing is a sectional view showing the usage state of the embodiment of this invention. In the figure, 1... light receiving tube, 1a... objective section, 3a...
...Transparent window, 3b...Objective lens, 3c...Reflector, 4...Optical amplifier, 5...Amplification tube, 6...Bifurcated tube, 7...Half mirror, 8...Eyepiece, 9
……camera.

Claims (1)

[Scope of utility model registration request] The lower part of the light receiving tube 1 made of a corrosion-resistant metal is inserted into a storage pool, and the upper part is tiltably attached to a crane frame c, and the lower end of the light receiving tube 1 is provided with an opening window 3d and a reflector 3c, and the middle part is provided with an opening window 3d and a reflecting mirror 3c. A transparent plate 3a and an objective lens 3b are provided to form an objective section 1a, an amplifying tube 5 having a built-in optical amplifier 4 is attached to the upper end of the light receiving tube 1, and a monitoring section having an eyepiece 8 at the upper end of the amplifying tube 5. 6a and TV monitor 1 on the top edge
This fuel assembly monitoring device includes a bifurcated tube 6 comprising an imaging section 6b having a camera 9 connected to the camera 9, and a half mirror 7 disposed within the bifurcated tube 6 above the amplifier 4.