JPH0454479Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a sealing device for the door of a cell handling radioactive waste. The present invention relates to a sealing device for preventing leakage from a gap.

Prior Art Nuclear facilities are equipped with various cells that handle radioactive materials, one of which is a waste handling cell. This cell is surrounded by thick concrete shielding walls on all sides to prevent radioactivity from escaping, and the upper opening is closed with a thick lead door. Inside the cell, a remote operation using a manibrator is performed, for example, to press radioactive waste, store it in a drum, and seal it. During this operation, radioactive gas is generated within the cell. However, the door that opens and closes the upper opening of the cell is
A gap is created between this door and the support member that supports it. For this reason, conventionally, when a door closes the opening of a cell, a seal is applied by placing a telescopic tube in close contact with each outside side of the door. The disadvantage was that the support in position was uncertain.

This will now be explained with reference to FIGS. 1 to 3.
In the figure, 1 is a cell that processes radioactive waste.
It is surrounded by a shielding wall 2 made of a thick concrete wall, and has an opening 3 at the top, which is opened and closed by a door 4 made of lead. The means for opening and closing the door 4 is, for example, as follows. That is, wheels 5 are provided at the bottom of both sides of the door 4, and these wheels 5 move passing through both outsides of the opening 3 (details are omitted). Reference numeral 6 denotes a drive screw shaft for opening and closing the door, and the tip end of the screw shaft 6 is screwed into a nut 7 fixed to the door 4, and is inserted into a long hole 8 that penetrates the thick part of the door 4 in the direction of movement. It is being entered.

9 is a bed installed at the upper end of cell 1;
The door 4 moves over the recess 9a of the bed 9 to open and close the opening 3 of the cell 1. The drive screw shaft 6 rotatably passes through the rising portion 9b of the bed 9, and a gear 11 provided at the end of the screw shaft 6 is interlocked with a pinion 10a of a drive motor 10.

Therefore, when the motor 10 is rotated in the forward and reverse directions, the drive screw shaft 6 is rotated in the forward and reverse directions, and the door 4 moves forward and backward in the horizontal direction, thereby opening and closing the opening 3. However, when the door 4 closes the opening 3, a gap is created between the door 4 and the opening 3, and there is a possibility that gas containing radioactive substances may leak from there. In order to prevent this, conventionally, a cover plate 12 is used as shown in FIG.
That is, the lid plate 12 has its peripheral edge hermetically fixed to the upper surface of the bed 9, and the opening 14 is formed on the plate surface of the lid plate 12.
The seal portion 13 is provided along the periphery of the opening 14, and the seal portion 13 is in close contact with each periphery of the four sides of the upper surface of the door 4. Therefore, even if there is a gap between the door 4 and the opening 3 and radioactive gas leaks from there, this radioactive gas can be confined within the cover plate 12 and will not leak outside. It is.

The detailed structure of the seal portion 13 is shown in FIG. That is, the opening periphery of the lid plate 12 has a stepped portion 15, and a frame-shaped sealing plate 12a is fixed to this stepped portion 15. At the bottom of the seal plate 12a, there is provided a recess 16 that is open at the bottom, and a tube 17 that has a bag-like cross section and expands and contracts with endless air pressure is fitted into the recess 16. A supply pipe 18 is connected. This pipe 18 is provided on a part of the seal plate 12a and the cover plate 12, and is connected to the compressor 20 via passages 19, 19a. Therefore,
When pressurized air is sent to the telescopic tube 17 in FIG. 3, the telescopic tube 17 expands as shown by the dashed line in the figure and comes into tight pressure contact with the upper surface of the four sides of the door 4. As you can see, it is endless, so close all four sides of door 4,
The cover plate 12 prevents leakage of radioactive gas from the part.
It traps it inside and prevents it from leaking outside.

However, the conventional support structure for the telescopic tube 17 within the recess 16 has the following drawbacks. That is, the inner surface of the recess 16 and the telescopic tube 1
7 was fixed with adhesive, but the adhesive deteriorates over time and the adhesive effect decreases, and if that happens,
The telescoping tube 17 falls out of the recess 16. When the telescoping tube 17 falls off from the recess 16, the telescoping tube 17 closes between the door 4 and the seal plate 12 when the door 4 is moved.
There were cases where it got caught between the a and the a and was damaged.

Purpose of the invention The present invention improves the above-mentioned conventional drawbacks.The retractable tube is reliably held by vacuum suction in the recess provided in the seal plate, regardless of the deterioration of adhesive strength, and does not fall unnecessarily, causing damage to the door due to movement. An object of the present invention is to provide a sealing device for a cell door for handling radioactive waste, which is free from the risk of damage.

Composition of the invention In order to achieve the above object, the cell door sealing device according to the invention airtightly attaches a lid plate to a bed installed at the upper opening edge of the cell, and an opening is provided in the lid plate to seal the cell door. A sealing plate airtightly attached to the periphery of the opening is provided with a concave portion open at the bottom, and an endless telescopic tube that can be brought into close contact with the four sides of the upper surface of the door that opens and closes the cell opening is attached to the concave portion. In a radioactive waste handling cell door sealing device in which the tube is connected to a pressure air supply pipe, a suction groove connected to a vacuum suction device is provided at the bottom of the recess, and the expandable tube can be held by suction in this groove. It is characterized by having been provided.

Embodiment An embodiment will be described with reference to FIGS. 3 and 4. In the present invention, the recess 16 of the seal plate 12a
A suction groove 21 is provided at the bottom of the holder, and this groove 21 is connected to a vacuum pump 23 via passages 22, 22a provided in the seal plate 12a and the lid plate 12. The air pressure circuits of the air supply pipe 18 and the suction groove 21 are as shown in FIG.

That is, when expanding the telescopic tube 17, the solenoid valves 23 and 24 are opened, and the solenoid valve 25 is closed. Therefore, as the telescoping tube 17 expands, the inside of the groove 21 is also attracted, and the door portion of the telescoping tube 17 is attracted to the bottom of the recess 16, so that the telescoping tube 17 does not fall from the recess 16. Groove 2
1 suction can be performed by closing the solenoid valve 23 and opening the solenoid valve 25, and also opening the solenoid valve 24 when the telescopic tube 17 is contracted and the door 4 is moved. Even if it is not used, the telescopic tube 17 will fall off from the recess 16 and the seal plate 1 will be removed.
There is no chance of it getting stuck between the door 2a and the door 4.

Incidentally, an uneven part 26 is provided inside the recessed part 16 of the sealing plate 12a to more effectively seal the space between the recessed part 16 and the telescopic tube 17, and to ensure the suction effect from the groove 21. Even if there is a leak,
The suction holding effect of the telescoping tube 17 is lost. In order to prevent this, a spare vacuum tank 27 is installed in the suction side circuit outside the telescoping tube 17 as shown in Fig. 4, so that when a leak occurs or the vacuum pump 23 stops operating, It is set up for emergency operation.

Effects of the invention As described above, according to the invention, the shoulder of the telescoping tube that constitutes the seal part of the opening/closing door of the radioactive waste handling cell is attached to the bottom of the recess for fitting and installing the telescoping tube under vacuum. Because it is sucked in, the adhesive does not lose its adhesive strength and fall out of the recess, unlike conventional adhesives, and it eliminates the inconvenience of getting stuck between the door and the sealing plate and causing damage when moving the door. effective.

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view of a door opening/closing mechanism of a radioactive waste handling cell, FIG. 2 is an explanatory plan view, FIG. 3 is an enlarged sectional view of a sealing part, and FIG. 4 is a pneumatic circuit diagram. 1...Cell, 3...Opening, 4...Door, 9...Bed, 12...Lid plate, 13...Seal portion, 14...
...opening, 17...telescopic tube, 18...supply pipe, 21...groove, 23...vacuum pump.

Claims (1)

[Scope of utility model registration request] A lid plate is airtightly attached to the bed installed at the upper opening edge of the cell, an opening is provided in the lid plate, a recessed part with an open bottom is provided in the sealing plate airtightly attached to the periphery of the opening, and a recessed part is provided in the recessed part. This is a seal for a radioactive waste handling cell door, in which an endless telescoping tube that can be brought into close contact with the four sides of the top of the door that opens and closes the cell opening is attached, and a pressure air supply pipe is connected to the telescoping tube. A sealing device for a cell door for handling radioactive waste, characterized in that a suction groove connected to a suction device is provided at the bottom of the recess, and a telescopic tube is provided in this groove so that it can be sucked and held.