JPS59128428A - Leak detecting apparatus for bulkhead manhole in atomic reactor equipment - Google Patents

Abstract

PURPOSE:To improve safety and efficiency of detecting work, by forming a double sealing structure between a bulkhead manhole and a lid, inputting a pressure liquid in the double sealing chamber, and detecting the leakage based on the pressure fluctuation. CONSTITUTION:At first, all valves are closed. Frist of all, a stop valve 19 is opened, and a pressure liquid is sent to a pipe 22. Thereafter a separating valve 17A is opened, and the pressure liquid flows into a double sealing chamber 16. When a pressure detector 21A indicates a specified pressure and no fluctuation is found, it is confirmed that no leak exists in double packings 12a and 12b of a bulkhead manhole 7A. Then the separating valve 17A is closed and a separating valve 17B is opened. The pressure liquid flows into the double sealing chamber 16 of a lid 11 of a bulkhead manhole 7B. The presence or absence of the leak is confirmed by the indication of a pressure detector 21B. The inspection of remaining bulkhead manholes 7C-7F can be performed by the same way. Thus safety and the efficiency of the detecting work can be improved.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a leak detection device for a bulkhead manhole in a nuclear reactor facility (in which a double seal structure is adopted for the bulkhead manhole in two reactor facilities). Technical background and problems] As shown in Fig. 1, nuclear reactor equipment surrounds a reactor pressure vessel 1 with a containment vessel 2, and the containment vessel 2 is surrounded by a concrete shielding wall 3. Between the head 4 of the container 1 and the head 5 of the containment container 2, there is a bulkhead plate 6.
A required number of bulkhead manholes 7 are provided in this bulkhead plate 6. This plurality of bulkhead manholes 7 are communicated with a common pipe 8 and are ≦double open for ventilating the chamber 9 between the pressure vessel head 4 and the containment vessel head 5 during operation of the plant.

On the other hand, the entrance of the bulkhead manhole 7 must be closed with a lid because the chamber 9 between the heads 4 and 5 is filled with water when fuel is exchanged during regular inspections. That is, as shown in Fig. 2 (2), a structure 5 in which the curve C of the manhole 7 lange lO and the connection 11 is inserted, and the plate-like rubber gasket 12 is inserted, and the lid 11 is evenly tightened with thumb screws 13 to close it.
It's two. However, the conventional ill seal structure is
- Since only the car's plate rubber gasket 12 is provided, it was necessary to check for leaks when chamber 9I was filled with water.

If a leak is about to occur when the bulkhead (77 hole 7) is closed, immediately notify the central control cab to stop filling chamber 9 with water. You will have to immediately drain the water from chamber 9 and make repairs such as replacing the rubber gasket 12 of bulkhead manhole 7.

Furthermore, since the conventional bulkhead manhole 7 did not have any leak detection mechanism, leakage must be confirmed by visual inspection.

However, this visual inspection was conducted by employees wearing full-face masks and special protective clothing, and in the interior room of containment vessel 2, which has a poor working environment.
4, I had no choice but to check for leaks from manhole 7. This visual leak detection work poses a major safety problem, as if a leak were to occur, workers would be exposed to reactor water and exposed to radiation.

[Object of the Invention] The object of the present invention is to solve the problem of leakage in bulkhead manholes of nuclear reactor equipment, which can greatly shorten periodic inspection periods, reduce man-hours, improve non-safety of work, improve efficiency, and reduce radiation exposure. The object of the present invention is to provide a detection device.

[Summary of the Invention] A leak detection device for a bulkhead manhole in a nuclear reactor facility according to the present invention includes a gasket having a double seal structure between the bulkhead manhole and the lid, and pressurized fluid flowing into the double seal chamber. It is characterized in that it is configured to detect leaks based on fluctuations in fluid pressure.

[Embodiments of the invention] The present invention will be explained below with reference to two embodiments shown in FIG.

In the present invention, first, double packing grooves 15a, 15b are provided at intervals C on the upper surface of the 7 flange 10 of the large number of bulkhead manholes 7A to 7F installed, and these packing grooves 15a, 15bI: double packing grooves 15a, 15bI: Insert the rubber gaskets 12a and 12b. Therefore, now each flange 10 (double) of bulkhead manholes 7A to 7F
1 is strongly tightened with the thumbscrew 13, a double seal structure is formed between the manhole 7 and the lid 11 by the double rubber gaskets 12α and 12b.

Furthermore, in the present invention, the lid 11 is provided with a double gasket 12a.
, 12b t = closed with a double seal structure, and two M1. of bulkhead manholes 7A to 7F. Seal chamber 16
pipes 18A each having isolation valves 178 to 17F;
18F are connected, and the upstream side of the isolation valves 17A to 17F is connected to a pressure fluid source 20 via a stop valve 19 via a piping 22. Furthermore, isolation valves 17 for each pipe 18A to 18F
Pressure detector 2 that detects fluid pressure on the downstream side of A to 17F
1A to 21'F are provided.

The detection function of the leak detection device for bulkhead manholes in nuclear reactor equipment according to the present invention (according to the second aspect of the present invention) configured as described above will be explained. The detection is carried out individually across each manhole 78-7F, i.e. first the stop valve 19 and each isolation valve 17A.
~17F is closed, but the stop valve 19 is first opened to send pressure fluid to the pipe 22.

Thereafter, when the isolation valve 17A is first opened, the pressure fluid flows into the double seal chamber 16. Double packing 12a.

If the seal function of 12b is healthy, the pressure detector 21
A indicates a predetermined pressure, and by this pressure instruction, it can be confirmed that there is no leakage from the closed portion of the lid 11 of the bulkhead manhole 7A.

Next, to inspect the leakage condition of the bulk head manhole 7B, close the isolation valve 17A and open the isolation valve 17B.

Pressure fluid flows into the All double seal chamber 16 of the bulkhead manhole 7B, and the presence or absence of a leak can be confirmed based on an instruction from the pressure detector 21B. The remaining bulkhead manholes 70 to 7F (7) can be inspected in the same manner by switching the isolation valves 17c to 17F.

Moreover, these isolation valves 17A to 17F1, stop valves 19, and pressure detectors 21A to 21F may be located in, for example, a central operating room outside the containment vessel 2 (both may be placed together, or may be configured to be remotely controllable). 2. Therefore, there is no need to worry about radiation exposure to workers.In addition, this leak inspection can be performed before filling room 9C with water (2), so unlike the conventional method, it is necessary to find a leak and drain the water. This will significantly improve work efficiency during periodic inspection work, etc. (Second).

[Effects of the Invention] According to the present invention as described above, when each bulkhead manhole is closed, a double seal structure is formed between the bulkhead manhole and the lid, and pressure fluid is introduced into the double seal chamber. ,
Since the system is configured to check whether there is a leak based on the fluid pressure, the leak detection work can be carried out safely and in a short time, and the efficiency of work such as periodic inspections can be significantly improved.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the head part of the reactor pressure vessel and the head part of the containment vessel in nuclear reactor equipment, Figure 2 is a partial sectional view showing the closed state of a conventional bulkhead manhole, and Figure 3 is the main part of the main body. 1 is a configuration diagram showing an embodiment of a leak detection device for a bulkhead manhole of a nuclear reactor according to the invention; FIG. 1...Reactor pressure vessel 2...Containment vessel 6...
Bulkhead plate 78-7F...Bulkhead manhole 8...Common pipe IO...Manhole flange 11...Lid I2...Rubber seals 12A, 12B...Double seals 13 River' 4 Screws 1-5A, 15B...Double packing groove 16...
・Double seal chamber 17A to 17F...Isolation valve 18A
-18F...Pipe 20...Pressure fluid 21
A~21F...Pressure detection 622...Common piping agent Patent attorney Kensuke Chika (1 person) Fig. 1/ Fig. 2 Fig. 3

Claims (2)

[Claims] (1) A leak detection device for a bulkhead manhole in a nuclear reactor facility, characterized in that a pressure detector is installed between the bulkhead manhole in the reactor facility and the lid of the bulkhead manhole. (2) A leak detection device for a bulkhead manhole in a nuclear reactor facility according to claim 1, wherein a system for inflowing pressure fluid is connected to each bulkhead manhole through an isolation valve.