JPS6229040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reactor internal inspection system using a television camera, which is used in a high-temperature gas atmosphere, such as in a nuclear reactor, for example, a fast breeder reactor.

BACKGROUND ART Conventionally, this type of reactor internal inspection system uses a television camera as is during periodic inspections of light water nuclear reactors and when the temperature of the reactor atmosphere is low.

However, in fast reactors that use a liquid metal coolant such as Na, the temperature inside the reactor is maintained at a high temperature of about 200°C even when output is stopped, and it is flammable in the atmosphere. Because of this, television cameras used in light water reactors cannot be inserted directly into the reactor. In other words, since the inside of a fast reactor uses a liquid metal coolant such as Na, it is dangerous for it to come into contact with the outside air, so the inside of the reactor containing the coolant is covered with an inert gas. After filling with gas, it is difficult to easily observe the inside of the furnace because it is sealed with a shielding plug.

In order to solve the above-mentioned difficulties, the present invention provides a door valve and a bellows in sequence on the shielding plug of a nuclear reactor, and provides a heat-resistant cylinder and a cooling member having a photographing window provided above the bellows so as to be able to move up and down inside the door valve. A cooling cylinder equipped with gas supply and exhaust ports is installed concentrically, and a television camera equipped with a drive device is installed at the bottom of this cooling cylinder. The purpose of this system is to enable visual observation and inspection of the inside of the reactor for long periods of time by remote control of a television camera without breaking the boundaries (boundary) and without exposing the user to radiation. This is what we provide.

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIGS. 1 to 4, reference numeral 1 denotes a reactor building in a fast breeder reactor, and this reactor building 1 is equipped with a coolant supply pipe 2 and a delivery pipe (discharge pipe) 3. A furnace vessel 4 is installed,
A reactor core 4a within this reactor vessel 4 is loaded with fuel rods 5, control rods, and the like. In addition, a coolant 6 made of liquid metal such as Na is injected into the reactor 4, and a cover gas 7 made of an inert gas is formed above the liquid surface of the coolant 6 at the opening of the reactor 4. It is sealed and filled by a shielding plug 8 provided in the section. Further, a core upper mechanism 9 is vertically installed on the shielding plug 8 located directly above the fuel rods 5 loaded in the core 4a, and a fuel exchanger is installed on the shielding plug 8 adjacent to the core upper mechanism 9. 10
is installed.

On the other hand, a door valve 11 composed of two-stage on-off valves 11a and 11b is provided at the upper part of the shielding plug 8 where the guide pipe 8a is located, and the upper opening of the door valve 11 has an inlet for cooling gas. 1
A joint tube 13 having a diameter of 2 is installed. Note that an on-off valve 1 is provided at the inlet 12 provided in this joint tube 13.
4 is provided, and by opening and closing this on-off valve 14, cooling gas can be supplied into and exhausted from the door valve 11.

In addition, a bellows is attached to the upper part of the connecting tube 13.
15 are arranged in a row in a telescopic manner, and a support plate 16 is attached to the upper part 15a of the bellows 15 in an airtight manner. Furthermore, the support plate 16 has a heat-resistant cylinder 17 made of a heat-resistant glass material.
It is located inside the bellows 15 and vertically installed in the door valve 11 so as to be able to rise and fall freely.
A photographing window (viewing window) 18 is diagonally provided in the lower part 17a of the heat-resistant cylinder 17 to maintain airtightness.

On the other hand, inside the heat-resistant cylinder 17, a cooling cylinder 19 is provided integrally and concentrically to form a cooling channel 20, and an upper part 19a of the cooling cylinder 19 is provided. A locking piece 21 is attached to a hook 23 by a hanging rope 22 of a hoisting machine (not shown).
It is attached so that it can be engaged with the or,
A cooling gas inlet 24 and an outlet 25 communicating with the cooling flow path 20 are attached to the upper part 19a of the cooling cylinder 19, and the cooling gas flowing from the inlet 24 flows into the cooling cylinder 19. descends in the direction of the arrow, flows into the cooling channel 20 through the respective flow holes 26 and 27 drilled near the photographing window 18, and rises while cooling the inner circumferential wall of the heat-resistant cylindrical body 17. It is designed to be discharged outside the machine from the discharge port 25. Furthermore, at the lower part 19b of the cooling cylinder 19, a television camera 29 is provided in the illumination device.
A driving device 28 is installed, and the television camera 29 can be moved up and down, rotated, and zoomed by this driving device 28. This drive device 28 is connected via a cable 30 to, for example, a monitor television or a control display device 31 provided outside the machine.

Therefore, now the reactor 4 filled with the cover gas 7
When performing an internal inspection, the coolant 6 is first
Reduce the liquid to the state shown in the figure. Next, the on-off valve 14 and the on-off valves 11a and 11b of the door valve 11
At the same time as opening the respective valves, the cooling cylinder body 19
Cooling gas is forcibly supplied into the heat-resistant cylinder 17 from the supply port 24 as described above, thereby cooling the inner circumferential surface of the heat-resistant cylindrical body 17. By letting out the lifting rope 22 of the hoisting machine, the heat-resistant cylinder 17 integrated with the cooling cylinder 19 changes from the state shown in FIG. 3 to the state shown in FIG. The gas is suspended in the cover gas 7. Here, a television camera 29 is operated by a drive device 28 in response to a remote control signal from the control display device, and this television camera 29 internally inspects various equipment inside the reactor. .

On the other hand, after the inspection is completed, the above-mentioned operation is performed in reverse, so that the in-furnace observation can be carried out for a long period of time without destroying the boundary of the cover gas 7.

Incidentally, the bellows 15 in the above embodiment
It is free to change the design by removing the joint tube 13 provided with the inlet 12 and attaching it directly to the door valve 11 (see FIGS. 3 and 4).

As described above, according to the present invention, the door valve 11 is provided on the shielding plug 8 of the nuclear reactor 4, and the bellows 15 is connected to the door valve 11. A heat-resistant cylinder 17 having a photographing window 18 provided therein.
A cooling cylinder 19 equipped with cooling gas supply/exhaust ports 24 and 25 is provided concentrically, and a television camera 29 equipped with a drive device 28 is installed in the lower part 19b of this cooling cylinder 19, so that a high-temperature atmosphere can be avoided. Not only can inspections be made by observing the inside of the furnace for a long time within the cover gas 7 inside, but also the inside of the furnace can be inspected without damaging the boundaries of the cover gas 7.
Since the inspection can be performed directly with the television camera 29, reliability can be improved. Furthermore, the present invention has excellent effects such as easy handling and no leakage of cover gas or radiation.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a fast breeder reactor incorporating a visual inspection device according to the present invention, FIG. 2 is a cross-sectional view of a visual inspection device according to the present invention, and FIGS. It is each figure for explaining an effect|action. 4... Nuclear reactor, 6... Coolant, 7... Cover gas, 8... Shielding plug, 11... Door valve, 1
2...Inflow port, 13...Joint tube, 14...Opening/closing valve,
15...Bellows, 17...Heat-resistant cylinder, 18...
Photographing window, 19... Cooling cylinder body, 20... Cooling channel,
24...Inlet, 25...Outlet, 26, 27...
... Distribution hole, 28 ... Drive device, 29 ... Television camera, 30 ... Cable, 31 ... Control display device.

Claims (1)

[Claims] 1. A door valve provided on a shielding plug of a nuclear reactor, a bellows connected to the door valve,
At the top of the bellows, a heat-resistant cylinder is vertically installed so as to be able to move up and down inside the door valve, and has an imaging window provided concentrically, and a cooling cylinder is equipped with a cooling gas supply/exhaust port, and this cooling cylinder Reactor internal inspection equipment consisting of a television camera with a drive device installed at the bottom of the reactor. 2. Claim 1, characterized in that a joint tube having a cooling gas inlet is provided between the door valve and the bellows, so that cooling gas can be supplied and exhausted when the bellows expands and contracts. Furnace internal inspection equipment. 3. The in-furnace visual inspection apparatus according to claims 1 and 2, characterized in that an illumination device is provided near the television camera. 4 Claim 1, characterized in that the cable of the television camera is connected to the control display device,
3. The furnace internal inspection apparatus according to the items 2 and 3.