JPH09113684A - Leakage treatment device for valve bonnet of nuclear power plant - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To enable early detection of leakage from the bonnet portion of a main valve and to reliably prevent leakage to the outside of the system. SOLUTION: The main valve 31 is installed in a system including a high temperature, high pressure and high radioactive fluid of a nuclear power plant and has a bonnet part 32 having a double seal structure as a processing target.
And a leakage treatment line 3 for guiding the leakage fluid from the primary seal side of the double seal structure portion of the main valve 31 to the outside.
8 and the discharge pipe 4 connected to the leak treatment line 38
0, a stop valve 46a connected to the discharge pipe 40,
A transfer pipe 47 connected to the stop valve 46a, a condenser 48 connected to the transfer pipe 47, and a condenser 48
And a radioactive drain sump 52 for collecting condensed water condensed by the above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of treating fluid leakage from the bonnet portion of a main valve used in a system containing high temperature, high pressure, and highly radioactive fluid in a nuclear power plant, and early detection of the leakage. The present invention relates to a valve bonnet leakage processing device for a nuclear power plant.

[0002]

2. Description of the Related Art FIG. 4 is a system diagram showing, for example, a valve ground leakage processing system of two main valves among valves used in a system including a high temperature, high pressure and highly radioactive fluid in a conventional nuclear power plant. Is.

That is, as shown in FIG. 4, this system is for preventing the fluid in the system from leaking out of the system from the valve gland part 2 of the main valve 1. 2 is provided with a leak processing line 3 for guiding the leaked fluid to the outside. Each leak processing line 3
Is integrated by the transfer pipe 7 via the discharge pipe 4, the flange 5, and the stop valve 6a, and the leakage fluid from the valve gland portion 2 of each main valve 1 is integrated into the transfer pipe 7.
It joins at a and is transferred to the condenser 8 via the second stop valve 6b provided on the downstream side of the integration section 7a.

The fluid transferred to the condenser 8 is cooled by the cooling system formed by the cooling water supply pipe 9 and the cooling water return pipe 10 to become condensed water, and the fluid is transferred from the condenser 8 to the transfer pipe 11 via the transfer pipe 11. It is collected in the radioactive drain sump 12 via the stop valve 6c of No. 3.

Further, temperature detectors 13 are provided on the upstream side of the integrated portion 7a of the transfer pipe 7, and each of the temperature detectors 13 is connected to a temperature recorder of the central control panel via a detection signal transmission cable 14a. It is connected to 15. And
This temperature recorder 15 includes signal transfer cables 14b, 14
It is connected to the warning light 16 and the alarm device 17 via c.

An electromagnetic valve is generally applied to the stop valve 6a, and the stop valve 6a is connected to the remote control switch 18 of the central control panel via the operation signal cable 14d.

On the other hand, conventionally, the valve bonnet portion of the main valve 1 is not provided with the processing system as in the valve gland portion 2 described above.

That is, FIG. 5 is a sectional view showing a sealing structure of the valve bonnet portion 20 of the conventional main valve 1. This figure 5
As shown in FIG. 5, a gasket 23 is provided at the joint between the valve box 21 and the valve lid 22 that form the valve bonnet portion 20 of the main valve 1, and the inside of the valve bonnet portion 20 is sealed with this gasket 23. .

[0009]

Generally, it is sufficient for the high temperature, high pressure, high radioactive fluid flowing through the main valve 1 to be leaked in the valve gland portion 2. However, it cannot be concluded that there is no possibility that the radioactive fluid will leak out of the system from the gasket 23 portion of the valve bonnet portion 20. By any chance
Assuming that such a situation has occurred, there is a possibility that detection may be delayed in the above-described conventional equipment configuration.

The present invention has been made in view of such circumstances, and it is possible to detect the leak from the bonnet portion of the main valve at an early stage and surely prevent the leak to the outside of the system. An object of the present invention is to provide a valve bonnet portion leakage treatment device for a power plant.

[0011]

In order to achieve the above-mentioned object, the invention of claim 1 relates to a high temperature of a nuclear power plant,
It is installed in a system that contains high-pressure, high-radioactive fluid, and has a bonnet with a double-sealed structure as the main valve to be treated, and the fluid leaked from the primary seal side of the double-sealed structure part of this main valve to the outside. Leakage processing line to lead to
A discharge pipe connected to this leak treatment line, a stop valve connected to this discharge pipe, a transfer pipe connected to this stop valve, a condenser connected to this transfer pipe, and this condenser And a radioactive drain sump that collects the condensed water condensed by.

The invention according to claim 2 is the valve bonnet portion leakage treatment device for a nuclear power plant according to claim 1,
A temperature detector for detecting the temperature of the transfer pipe, a temperature recorder for recording the detected temperature, and a warning lamp for performing lighting display based on a high temperature signal of the transfer pipe due to fluid leakage. .

According to a third aspect of the present invention, there is provided a valve bonnet leakage treatment device for a nuclear power plant according to the second aspect,
It is characterized by comprising an alarm device for issuing an alarm based on a high temperature signal due to fluid leakage.

According to a fourth aspect of the present invention, in the valve bonnet leakage treatment device for a nuclear power plant according to the second or third aspect, the stop valve is a solenoid valve, and the solenoid valve is a remote switch when a warning light is displayed or an alarm is issued. It is characterized in that it can be closed by an operation.

According to a fifth aspect of the invention, in the valve bonnet portion leakage treatment device for a nuclear power plant according to any one of the first to fourth aspects, the transfer pipe is a valve of a main valve installed in the nuclear power plant. It is characterized in that it is connected to a leak treatment line for guiding the leaked fluid from the gland part to the outside, and the condenser upstream and other treatment equipment are shared.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG. FIG. 1 is a system diagram showing the leakage treatment device according to the present embodiment, and FIG. 2 is a sectional view showing the configuration of a main valve to be treated.

As shown in FIG. 2, the main valve 31 has a double seal structure in the valve bonnet portion 32. That is, an uneven step portion 35 that bends inward and outward is formed on the joint surface between the valve box 33 and the valve lid 34 that form the valve bonnet portion 32, and the joint surface inside the step portion 35 is The primary gasket 36, and the outer joint surface is the secondary gasket 37.
Each is sealed with. The primary and secondary gaskets 36 and 37 form a double seal structure.

A flow path hole bent in an L shape is formed from the position of the step portion 35 to the valve box 33 side, for example, and a leak treatment line 38 is provided. That is, since the primary gasket 36 and the secondary gasket 37 are doubly sealed against the leakage of fluid from the inside of the valve bonnet portion 32 to the outside, it is extremely strong as a leakage prevention measure. In the unlikely event that the fluid leaks from the inside, the leaked fluid is guided to the outside through the leak treatment line 38 immediately after leaking from the primary gasket 36. In this case, on the side of the secondary gasket 37, the fluid is bypassed on the inner side, that is, on the primary side, so that the secondary sealing effect is sufficiently exerted, and leakage from the sealed portion can be almost completely prevented.

As shown in FIGS. 2 and 1, the leakage treatment line 38 includes a half coupling 39.
The discharge pipe 40 is connected via. The connecting portion between the valve box 33 and the half coupling 39 and the connecting portion between the half coupling 39 and the discharge pipe 40 are hermetically sealed by welding portions 41 and 42, respectively.

FIG. 1 shows the case where there are two main valves 31. As shown in FIG. 1, each leak processing line 38
Are integrated by the transfer pipe 47 through the discharge pipe 40, the flange 45, and the stop valve 46a.
The leakage fluid from the first valve bonnet portion 32 merges at the integration portion 47a of the transfer pipe 47 and is transferred to the condenser 48 via the second stop valve 46b provided on the downstream side of the integration portion 47a. It has become so.

The fluid transferred to the condenser 48 is cooled by the cooling system formed by the cooling water supply pipe 49 and the cooling water return pipe 50 to be condensed water, which is then transferred from the condenser 48 to the transfer pipe 51 via the transfer pipe 51. It is collected in the radioactive drain sump 52 via the stop valve 46c of No.3.

Further, temperature detectors 53 are provided on the upstream side of the integrated portion 47a of the transfer pipe 47, and each of the temperature detectors 53 is connected to a temperature recorder of the central control panel via a detection signal transmission cable 54a. Connected to 55. The temperature recorder 55 includes a signal transfer cable 54b,
It is connected to the warning light 56 and the alarm device 57 via 54c.

An electromagnetic valve is applied to the first stop valve 46a, and the stop valve 46a is connected to the remote control switch 58 of the central control panel via the operation signal cable 54d.

The operation of the embodiment having the above configuration will be described.

The fluid leaked from the primary gasket 36 of the valve box 33 and the valve lid 34 of the main valve 31 is protected by the secondary gasket 37.
The outflow to the outside of the system is stopped by the leak processing line 38
Transferred to

The fluid from the leak treatment line 38 is transferred to the discharge pipe 40 and transferred to the condenser 48 via the flange 45, the first stop valve 46a, the transfer pipe 47, and the second stop valve 46b. The fluid transferred to the condenser 48 is cooled by the cooling water supply pipe 49 and the cooling water return pipe 50 to become condensed water.

The condensed water is transferred from the condenser 48 to the condensed water transfer pipe 5
1 collects into the radioactive drain sump via the third stop valve 46c.

The temperature of the transfer pipe 47 is measured by the temperature recorder 5.
5, the temperature recorder 55 sends a high temperature signal via the cable 54b, and the warning lamp 56 is lit and displayed.

Further, since the alarm 57 is connected to the temperature recorder 55 of the central control panel, the temperature recorder 55 can be used at the time of leakage.
A high temperature signal from the device is transmitted via the cable 54c, and an alarm is issued from the alarm device 57.

Since the first stop valve 46a is an electromagnetic valve and the stop valve 46a is connected to the remote control switch 58 of the central control panel via the cable 54d,
When the warning light is displayed or the alarm is issued, the first stop valve 46a can be closed by a remote control switch as required, and thus leakage can be prevented.

According to the above-described embodiment, the fluid leaked from the bonnet portion 32 of the main valve 31 is guided from the leak treatment line 38 to the condenser 48 by the transfer pipe 47 and condensed by the condenser 48. Since water can be collected in the radioactive drain sump 52 by the condensed water transfer pipe 51, it is possible to prevent environmental pollution and reduce exposure.

Further, by providing the temperature detector 53 on the transfer pipe 47, the temperature recorder 55 of the central control panel continuously monitors the leakage, and in case of leakage, the warning lamp 56 and the alarm 57 detect the leakage. It can be detected early.

Leakage can be prevented by closing the stop valve 46a with a remote control switch.

FIG. 3 shows another embodiment of the present invention.

In this embodiment, as shown in FIG. 3, the transfer pipe 47 shown in the above-mentioned one embodiment has the same main valve 3.
The discharge pipe 62 and the flange 6 are respectively connected to the leakage treatment line 61 for guiding the leakage fluid from the gland portion 60 of No. 1.
3. Connected via stop valve 64, which allows condenser 4
8 Other processing equipment is shared.

That is, the present embodiment shown in FIG. 3 is a combination of the leakage treatment device for the valve gland portion shown in FIG. 4 and the leakage treatment device of one embodiment shown in FIG. The leaked fluid can be treated.

In the embodiment shown in FIG. 3, the stop valve 64 of the valve gland section 60 side system is also an electromagnetic valve, and the cable 6
The remote control switch 66 of the central control panel can be operated via the switch 5.

Further, the temperature detector 67 is connected to the valve gland section 60.
It is also connected to the discharge pipe 62 of the side system so that the same monitoring and alarm generation as the system of the valve bonnet section 32 side can be performed.

According to this embodiment, an efficient piping configuration
The advantage that leakage of the valve bonnet portion 32 and the valve gland portion 60 in the same main valve 31 can be prevented can be obtained.

[0040]

As described above, according to the present invention, even if the radioactive fluid leaks from the bonnet portion of the main valve, the leaked fluid is guided to the condenser through the transfer pipe and condensed. By collecting in the radioactive drain sump, it is possible to completely prevent leakage to the external system and prevent the possibility of environmental pollution, and further improve the reliability of the nuclear power plant.

Further, by providing a temperature detector in the transfer pipe, the temperature recorder of the central control panel continuously monitors the leakage, and in the unlikely event that radioactive fluid leaks, a warning light and an alarm will prevent the leakage. It can be detected early, or leakage can be reliably prevented by closing the stop valve with a remote control switch.

Further, when the transfer pipe from the leak processing line is connected to the transfer pipe of the leak processing system from the valve gland portion installed in the nuclear power plant, the processing equipment is shared so that the efficiency is improved. With a good configuration, it is possible to prevent leakage from each position.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a processing apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing the configuration of the valve bonnet portion shown in FIG.

FIG. 3 is a system diagram showing another embodiment of the processing apparatus according to the present invention.

FIG. 4 is a sectional view showing a configuration of a conventional valve bonnet portion.

FIG. 5 is a system diagram showing a conventional valve gland leakage processing device.

[Explanation of symbols]

 31 Main Valve 32 Valve Bonnet Part 33 Valve Box 34 Valve Lid 35 Stepped Part 36 Primary Gasket 37 Secondary Gasket 38 Leakage Treatment Line 39 Half Coupling 40 Discharge Pipe 41, 42 Welded Part 45 Flange 46a First Stop Valve 46b Second Stop valve 46c Third stop valve 47 Transfer pipe 47a Integrated part 48 Condenser 49 Cooling water supply pipe 50 Cooling water return pipe 51 Transfer pipe 52 Radioactive drain sump 53 Temperature detector 54a Detection signal transmission cable 54b, 54c Signal transfer cable 54d Operation signal cable 55 Temperature recorder 56 Warning light 57 Alarm device 58 Remote control switch 60 Ground section 61 Leakage treatment line 62 Discharge piping 63 Flange 64 Stop valve 65 Cable 66 Remote control switch 67 Temperature detector

Claims (5)

[Claims] 1. A main valve to be treated, which is installed in a system containing high temperature, high pressure and high radioactive fluid of a nuclear power plant and has a bonnet part having a double seal structure, and a double seal structure of this main valve. A leakage treatment line for guiding the leakage fluid from the primary seal side of the part to the outside, a discharge pipe connected to this leakage treatment line, a stop valve connected to this discharge pipe, and a stop valve connected to this stop valve Transfer piping,
A valve bonnet leakage treatment device for a nuclear power plant, comprising: a condenser connected to the transfer pipe; and a radioactive drain sump for collecting condensed water condensed by the condenser. 2. The valve bonnet leakage treatment device for a nuclear power plant according to claim 1, wherein a temperature detector for detecting the temperature of the transfer pipe, a temperature recorder for recording the detected temperature, and a transfer pipe for fluid leakage. And a warning lamp for performing lighting display based on the high temperature signal of the above. A leakage processing device for a valve bonnet part of a nuclear power plant. 3. The valve bonnet leakage treatment device for a nuclear power plant according to claim 2, further comprising an alarm device for issuing an alarm based on a high temperature signal due to fluid leakage. Bonnet leakage processing device. 4. The valve bonnet leakage treatment device for a nuclear power plant according to claim 2 or 3, wherein the stop valve is a solenoid valve, and the solenoid valve is closed by a remote switch operation when a warning light is displayed or an alarm is issued. A valve bonnet leakage treatment device for a nuclear power plant, which is characterized by being made possible. 5. The valve bonnet leakage treatment device for a nuclear power plant according to any one of claims 1 to 4, wherein the transfer pipe is leaked from a valve gland of a main valve installed in the nuclear power plant. A valve bonnet leakage treatment device for a nuclear power plant, which is connected to a leakage treatment line for guiding a fluid to the outside and shares the condenser upstream and other treatment facilities.