JPH022996A - Nuclear reactor accessory cooling facility - Google Patents

Abstract

PURPOSE:To contrive the improvement of cooling water supply reliability by providing the facility with a heat exchanger for supplying cooling water in an emergent accessory or a normal accessory, an air-actuated valve set in a piece of cooling water transport tubing of the normal accessory and a valve set in parallel to the air-actuated valve. CONSTITUTION:An emergent accessory 2 and a normal accessory 3 are connected parallelly and cooling water is supplied through a cooling water supply header 22. An emergently closing valve 23 of air-actuation is set on the header 22 for the accessory 3 and working air is supplied for the valve 23 through a valve driving air line 24 from an instrumentation air compressor which is one of the accessory 3. A motor- operated valve 25 is set in parallel to the valve 23 and the bore of a piece of tubing 25a to which the valve 25 is connected is less than that of a piece of tubing 23a. At the normal time, the valve 25 is closed, but in the case where an air source system of the valve 23 becomes nonconformity and the valve 23 failure-closes, the valve 25 is operated to close and the supply of cooling water is continued in other sound normal accessory. Further, in the case where the valve 23 automatically closes by the damage of the accessory 3, the valve 25 is closed according to need, the valve 23 is opened and the cooling function of the accessory 2 is maintained when the normal conditions are resumed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a nuclear reactor auxiliary equipment cooling system that supplies cooling water to various auxiliary equipment installed in a nuclear power plant.

(Conventional technology) At nuclear power plants, in order to cool various auxiliary machines within the power plant,
Reactor auxiliary equipment cooling equipment is installed.

A conventional nuclear reactor auxiliary cooling equipment will be explained with reference to the system diagram shown in FIG.

The reactor auxiliary equipment cooling equipment 1 uses cooling water to cool an emergency auxiliary equipment 2 that is used in a reactor emergency and a regular auxiliary equipment 3 that is used in normal times. The emergency auxiliary machine 2 and the regular auxiliary machine 3 are connected in parallel, and cooling water is supplied via a cooling water supply main pipe 4.

The cooling water that has cooled the emergency auxiliary equipment 2 and the regular auxiliary equipment 3 and has been raised in temperature is sent to a heat exchanger 7 by a cooling water pump 6 via a cooling water return main pipe 5. The cooling water exchanges heat with seawater in the heat exchanger 7, and the heat is exhausted. Seawater is supplied to the heat exchanger 7 via a seawater inlet pipe 8 by a seawater pump 9, and is discharged via a seawater outlet pipe 10.

The cooling water supply piping 4 to the regular auxiliary equipment 3 is designed to protect the emergency part even if the regular auxiliary equipment, which has a lower seismic design than the emergency auxiliary equipment (including piping that connects the regular auxiliary equipment), is damaged due to an earthquake, etc. In order to maintain functionality, an emergency shutoff valve 11 is installed to isolate commonly used parts and prevent loss of cooling water. A cooling water return check valve 12 is installed in the cooling water return main pipe 5 of the regular auxiliary equipment in order to prevent the cooling water from flowing out in correspondence with this upper stop valve 11.

The emergency closing valve IT is supplied with operating compressed air produced by an instrumentation air compressor, which is one of the regularly used auxiliary machines, as a driving source for this valve through a valve driving air line 13. For safety reasons, the emergency closing valve 11 is designed to close (fail close) when operating air is lost.

(Problem M to be solved by the invention) In such a reactor auxiliary cooling system where emergency and regular auxiliary equipment and regular auxiliary equipment are combined into one cooling system, in order to give priority to the emergency auxiliary equipment cooling function, an emergency shutoff valve is used. When closing, it can be closed using a built-in spring without the need for any external driving force, and is normally kept open using air pressure.

For this reason, it is not obvious when the normally used parts are isolated when they are damaged, but
If only the air source had a problem or malfunctioned, it would be closed, and there was a risk that cooling water would not be supplied to many other regularly used auxiliary machines. In this case, even if an attempt was made to open the emergency shutoff valve again, the valve could not be opened because cooling water was not flowing to the compressor itself, which was the air source.

An object of the present invention is to obtain a nuclear reactor auxiliary cooling equipment that can improve the reliability of cooling water supply to regular auxiliary equipment.

[Structure of the invention]

(Means for Solving the Problems) ↑In order to achieve the purpose described above, the present invention provides an emergency auxiliary equipment and a regular auxiliary equipment installed in a nuclear power plant, and a supply of cooling water to these auxiliary equipment. an air-operated valve that is installed in a pipe that transports cooling water to the regular auxiliary equipment and is kept open by gas sent from the regular auxiliary equipment; and a valve that is installed in parallel with the air-operated valve. Provided is a nuclear reactor auxiliary cooling equipment characterized by comprising:

(Function) In equipment configured in this way, if the air-operated valve is closed for purposes other than its original purpose of preventing loss of cooling water from regular auxiliary equipment, the valve installed in parallel with the air-operated valve will be opened. This makes it possible to cool the regular auxiliary equipment.

(Example) An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a system diagram of a nuclear reactor auxiliary cooling equipment according to the present invention. Components that are the same as those in FIG. 2 are designated by the same reference numerals, and explanations of their structures will be omitted. The reactor auxiliary equipment cooling equipment 21 uses cooling water to cool the emergency auxiliary equipment 2 used in a reactor emergency and the regular auxiliary equipment 3 used in normal times. The emergency auxiliary equipment 2 and the regular auxiliary equipment 3 are connected in parallel, and the cooling water is supplied through the cooling water supply main pipe 22.6 The cooling water supply main pipe 22 to the regular auxiliary equipment 3 is An emergency shutoff valve 23, which is an air-operated valve, is installed. This emergency closing valve 23
Operating air is supplied from an instrumentation air compressor (not shown), which is one of the regular auxiliary machines 3, to the valve driving air line 24. Further, an electric valve 25 is installed in parallel with the emergency closing valve 23. The diameter of the pipe 25a to which the electric valve 25 is connected is set smaller than that of the pipe 23a to which the emergency closing valve 23 is connected.

Under normal conditions, cooling water is supplied from the cooling water supply main pipe 22 to the emergency auxiliary equipment 2.
And water is being passed to the regular auxiliary equipment 3. At this time.

The emergency closing valve 23 is in an open state, and the electric valve 25 is in a closed state. When the water valve fails closed due to a malfunction in the air source system M (instrumentation compressor - valve driving air line 24) of the emergency shutoff valve 23, the electric valve 25 can be opened to restore normal normal operation. Cooling water can continue to be supplied to auxiliary equipment.

In addition, for example, if the emergency closing valve automatically closes to maintain the cooling function of the emergency auxiliary equipment due to damage to the regular auxiliary equipment,
Afterwards, when the system is restored, the motorized valve can be opened as necessary to open the emergency shutoff valve.

That is, it is possible to avoid a situation in which the emergency closing valve cannot be opened because the instrumentation compressor itself that supplies the air source cannot be cooled, and cooling water cannot be sent to the regular auxiliary equipment 3. In addition, since the emergency shutoff valve can be opened after the electric valve is opened to restore the instrumentation air compressor, the diameter of the piping to which the electric valve is connected is large enough to cool the instrumentation air compressor. As long as you have the capacity. Therefore, by reducing the diameter of the pipe to which the electric valve is connected, the space inside the nuclear power plant building can be effectively utilized.

Furthermore, during normal operation, the emergency shutoff valve is open and the electric shutoff valve is closed, but the electric shutoff valve can be opened as appropriate to test the closing of the emergency shutoff valve, thereby improving safety.

〔Effect of the invention〕

According to the present invention, the regular auxiliary equipment can be cooled by opening the valve installed in parallel with the air-operated valve, so the reliability of the supply of cooling water to the regular auxiliary equipment can be improved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of a reactor auxiliary cooling film 6H according to the present invention, and FIG. 2 is a system diagram showing a conventional sub-reactor auxiliary cooling system. 2... Emergency auxiliary equipment 3... Regular auxiliary equipment 7...
Heat exchanger 21...Reactor auxiliary equipment cooling equipment 22...Cooling water supply main pipe 23...Emergency closing valve 2
5... Electric valve agent Patent attorney Nori Ken Chika Yudo Ken Daishimaru

Claims (1)

[Claims] Emergency auxiliary equipment and regular auxiliary equipment installed in a nuclear power plant, heat exchangers that supply cooling water to these auxiliary equipment, and said regular auxiliary equipment installed in piping that transports cooling water to said regular auxiliary equipment. 1. A nuclear reactor auxiliary cooling equipment comprising: an air-operated valve that is kept open by gas sent from the air-operated valve; and a valve installed in parallel with the air-operated valve.