JPH04115194A - Apparatus for underwater observation - Google Patents

Abstract

PURPOSE:To enable execution of simultaneous observation by a plurality of observers by providing an imaging optical system which forms an image of an underwater nuclear fuel assembly in air, a waterproof member which seals hermetically the periphery of the part of this imaging optical system which is immersed in water, a color image pickup device, etc. CONSTITUTION:An outer cylinder 7a of a camera attachment 10 is fitted on the outside of an ocular element 1 of an underwater periscope device and it is fixed by tightening a fixing belt 6 provided circularly on the end part on the ocular element 1 side of the outer cylinder 7a, by a hexagonal bolt 6a, in the circumferential direction. To the end part of the outer cylinder 7a on the opposite side to the ocular element 1, an outer cylinder 7b is joined with a short-cylinder-shaped distance adjusting lever 9 interposed. The lever 9 is fixed, in the axial direction, to the outer cylinder 7a and screwed on the outer cylinder 7b, and by rotating the lever 9, the outer cylinder 7b can be moved in the axial direction without being rotated. Moreover, a color TV camera 5 is inserted inside the outer cylinder 7b, and an inner cylinder 8 is fitted in and fixed by a screw 11. A slit is provided in the end part of this inner cylinder 8 on the opposite side to the ocular element 1. After the camera 5 is inserted, a bolt 8a is tightened and thereby the camera 5 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an underwater observation device for observing the surface of a nuclear fuel assembly stored in a spent fuel storage pool in a nuclear power plant.

[Prior art] Fuel burned in a nuclear reactor is taken out for interim fuel inspection or replacement, but it contains various fission products as well as radioactive elements such as unburned uranium. include. When spent fuel is just removed from a nuclear reactor, it is extremely radioactive, but if it is left for a while, the radioactivity decreases through decay. For this purpose, spent fuel is first stored and cooled in the ice of spent fuel bits of nuclear reactors.

Conventionally, an underwater Veriscope device has been used to observe the surface conditions of nuclear fuel assemblies stored underwater. This underwater veriscope device has an imaging optical system including an objective lens and an eyepiece, and the optical system in the submerged part (objective lens side) is housed in a watertight waterproof cylinder. In use, the eyepiece side is fixed to a pedestal installed on the floor of the pool site, and the image of the nuclear fuel assembly underwater is observed from the poolside. By using an underwater Veriscope device, it is possible to observe with the naked eye, and also to take photographs of observed images with a 3511ffl camera or Polaroid.

[Problem to be solved by the invention] However, in the conventional underwater observation device as described above,
When observing with the naked eye, only one observer could confirm the observed image, and when photographing with a camera, it was difficult to accurately focus due to the shaking of water caused by the radiant heat from the nuclear fuel assembly.

For this reason, continuous observation of underwater nuclear fuel assemblies requires
A radiation-resistant underwater television camera is prepared separately, but the underwater television cameras used for this type of application are black and white cameras, and can only obtain video information without color information. This is because when using an underwater television camera, the camera must be brought close to the nuclear fuel assembly, which results in a large amount of radiation exposure, but color television cameras are much more resistant to radiation than black and white television cameras. This is because they are inferior.

This invention was made in view of the above points, and allows multiple observers to simultaneously view clear continuous color images of nuclear fuel assemblies stored in water, and is also durable. The purpose is to provide an excellent underwater observation device.

[Means for Solving the Problems] The underwater observation device of the present invention is a device for observing nuclear fuel assemblies stored underwater, and in order to achieve the above problems, an objective lens and an eyepiece are combined. an imaging optical system for forming an image of the underwater nuclear fuel assembly in the air; and an optical window in a portion of the imaging optical system corresponding to the objective lens; A waterproof member that closes around the flooded area,
A color imaging device (hereinafter referred to as a color television camera) detachably connected to the eyepiece side of the imaging optical system, and a display that displays a color image of the nuclear fuel assembly based on signals from the color television camera. It is equipped with means.

[Operation] In the present invention, the image of the underwater nuclear fuel assembly is sent into the atmosphere by the imaging optical system protected by a waterproof tube (waterproof member), so by appropriately designing the lens, it is possible to obtain clear images. A clear observation image can be obtained through the eyepiece. In addition, a color television camera is connected to the imaging optical system, and the video signal from this color television camera is used to display a color image on a color monitor (display means), so multiple observers can simultaneously view the nuclear fuel in the water. It is possible to observe and inspect the surface condition of the aggregate. At this time, since the color TV camera is connected to the eyepiece on the pool site side, radiation resistance unlike conventional underwater TV cameras is not required, and there is no need to provide a special waterproof structure to the color TV camera itself. Therefore, maintenance and management are easy.

In addition, with the present invention, nuclear fuel assemblies can be observed continuously in real time, and images can be confirmed repeatedly by connecting a video cassette recorder (video recording and reproducing device) to a color television camera. Even if the water fluctuates due to radiant heat from the body, it is possible to make accurate observations by understanding the effects.

[Example 1] FIG. 1 is a side view of an underwater Veriscope device constituting an underwater observation device according to an example of the present invention.

In the figure, an objective lens system (objective section 3) and an intermediate lens system (intermediate section 2) of an imaging optical system (not shown) are housed in a watertight waterproof cylinder 4, and the optical axis of the objective section 3 is An optical window 3a is provided above.

The length of this waterproof tube 4 is long enough to reach the nuclear fuel assembly stored at the bottom of the pool from the pool site, and the eyepiece system of the imaging optical system is attached to the waterproof tube 4.
It is disposed in an eyepiece section 1 that is connected to the upper part.

Next, Fig. 2(a) shows the eyepiece section 1 of the underwater Veriscope device.
2(b) is a sectional view taken along the line AA in FIG. 2. FIG.

In the figure, an outer cylinder 7a of a camera attachment 10 (connection member) is fitted to the outside of the eyepiece 1 (eyepiece la) of the underwater Veriscope device, and an end of the outer cylinder 7a on the eyepiece 1 side is fitted. The outer cylinder 7a is fixed by circumferentially tightening a ring-mounted fixed Heltro with a hexagonal bolt 6a. Moreover, at the end of the outer cylinder 7a opposite to the eyepiece part 1,
The outer cylinder 7b is connected via a short cylindrical distance S adjustment lever 9. The distance adjustment lever 9 is fixed to the outer cylinder 7a in the axial direction, but is screwed (threaded part 7) to the outer cylinder 7b.
By turning the distance adjustment lever 9, the outer cylinder 7b can be moved in the axial direction without rotating.

Further, an inner tube 8 into which a color television camera 5 is inserted is fitted inside the outer tube 7b and fixed with screws.

At the end of the inner cylinder 8 opposite to the eyepiece 1, there is a
), a slit is provided, and after inserting the color television camera 5, the color television camera 5 is fixed by tightening the bolt 8a.

During assembly, the color television camera 5 is fixed in the inner tube 8 and then fitted into the outer tube 7b. Furthermore, the color television camera 5 used in the present invention is an ultra-compact and lightweight CC camera.
D. It is preferable to use a so-called solid-state image pickup device.

Next, FIG. 3 is a front view of the control panel of the underwater observation device according to this embodiment.

In the figure, the color monitor 12 is a color television camera 5.
An image of the nuclear fuel assembly is displayed on the screen by receiving video signals from the The size of the image displayed on the color monitor 12 can be determined by rotating the distance adjustment lever 9 shown in FIG. It is adjusted by moving it to .

Further, focusing is performed by turning a knurled knob (FIG. 2(a)) provided on the eyepiece 1. The color television camera 5 is controlled during observation by operating the camera controller 13.

Further, the images obtained by the color television camera 5 are not only displayed on the color monitor 12, but also recorded on the video cassette recorder 14 as appropriate, and repeatedly reproduced as necessary. This makes it possible to observe and inspect underwater nuclear fuel assemblies more accurately and effectively even if there are fluctuations in the water during observation.

In the above explanation, the case where the image of the nuclear fuel assembly is displayed and observed on the color monitor 12 has been described, but as explained in FIG. 2, the color television camera 5
is detachably attached to the eyepiece section 1 by a camera attachment 10, so that the color television camera 5
Needless to say, it is also possible to remove the lens and perform naked eye observation.

[Effects of the Invention] As described above, the present invention includes a color television camera detachably connected to the eyepiece of an imaging optical system, and a display means for displaying color images using signals from the color television camera. This allows multiple observers to view clear images including color information of underwater nuclear fuel assemblies in real time.

Furthermore, in the present invention, since the color television camera is placed on the side of the pool, it is easier to maintain and manage than conventional underwater cameras, and is less susceptible to deterioration due to radiation.

Furthermore, it is possible to more accurately observe and inspect nuclear fuel assemblies by recording images from a color television camera on a self-recording and reproducing device and repeatedly reproducing them as needed.

[Brief explanation of the drawing]

FIG. 1 is a side view of an underwater periscope device constituting an underwater observation device according to an embodiment of the present invention, and FIG. 2(a) shows a connection structure between an underwater periscope device and a color television camera of an underwater observation device according to an embodiment of the present invention A sectional view of the main parts shown in Fig. 2 (
b) is a sectional view taken along line AA in FIG. 2(a), and FIG. 3 is a front view of a control panel of an underwater observation device according to an embodiment of the present invention. [Explanation of symbols of main parts] 1... Eyepiece section 1a...
・・・・・・・・・Eyepiece 2・・・・・・・・・・・・
...Intermediate section 3...Objective section 3a...Optical window 4... ...Waterproof tube 5...
・・・・・・・・・Color television camera 7a, 7b・
・Outer tube

Claims (1)

[Scope of Claims] An underwater observation device for observing nuclear fuel assemblies stored underwater, comprising an objective lens and an eyepiece, and for forming an image of the underwater nuclear fuel assemblies in the air. an imaging optical system that images an image; a waterproof member that has an optical window in a portion corresponding to the objective lens of the imaging optical system and closes around a submerged portion of the imaging optical system; and an eyepiece of the imaging optical system. An underwater observation device comprising: a color imaging device detachably connected to a lens side; and display means for displaying a color image of the nuclear fuel assembly based on a signal from the color imaging device.