JPS6258478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides auxiliary machinery for a nuclear reactor auxiliary cooling system and a turbine auxiliary cooling system used in nuclear power generation, and an auxiliary cooling seawater system that supplies cooling water to these auxiliary cooling systems. This invention relates to an auxiliary cooling system for nuclear power generation, in which an auxiliary cooling system is installed in a normal auxiliary cooling system in order to periodically inspect the system's seawater pumps, etc.

FIG. 1 shows an example of an auxiliary cooling system that has been commonly used in the past. In the figure, the auxiliary cooling system is classified into three types: auxiliary cooling seawater system, reactor auxiliary cooling system, and turbine auxiliary cooling system. That is, the auxiliary equipment cooling seawater system is composed of three seawater pumps 1 and valves 16. Each of the three seawater pumps 1 has a capacity of 50% of the required flow rate, and one of them is used as a backup.
The reactor auxiliary cooling system includes reactor auxiliary cooling heat exchanger 2,
It is composed of a reactor auxiliary intermittent load machine 3, a reactor auxiliary continuous load machine 4, a reactor auxiliary machine circulation pump 5, and a valve 16. Further, the turbine auxiliary cooling system includes a turbine auxiliary cooling heat exchanger 6, a turbine auxiliary intermittent load machine 7, a turbine auxiliary continuous load machine 8, a turbine circulation pump 9, and a valve 16. Cooling water sent from seawater pump 1 via valve 16 is supplied to reactor and turbine auxiliary equipment cooling heat exchangers 2 and 6.
After being cooled, it is supplied to the intermittent load machines 3 and 7 and the continuous load machines 4 and 8 via the valve 16. The cooling water is supplied to these load machines 3,
After cooling the auxiliary equipment circulation pumps 5 and 9, the water is sent to the auxiliary equipment cooling heat exchangers 2 and 6, and is discharged to the seawater drain port 10, thereby closing the closed circuit.

Although the auxiliary cooling system is regularly inspected and repaired, the reactor continuous load machine 4 and the turbine continuous load machine 8 cannot be stopped even during periodic inspection.
For this reason, a spare seawater pump and switching each time, 1
Seawater pumps 1 were inspected one by one. In addition, since the seawater pump 1 is normally installed outdoors, its inspection work is affected by the weather.
This periodic inspection required a long period of time (60 days, for example). For this reason, the inspection period for seawater pumps, etc. becomes a critical path in the periodic inspection process for auxiliary equipment cooling systems, and improvements in this point are desired. On the other hand, the reactor auxiliary equipment cooling heat exchanger 2 and the turbine auxiliary equipment cooling heat exchanger 6 cannot be stopped even when the reactor auxiliary equipment continuous load machine 4 and the turbine auxiliary equipment continuous load machine 8 are inspected as described above. , these cannot be inspected or maintained, and even if a backup heat exchanger is used, it can only be shut down for a very short period of time.

The present invention has been proposed in view of the above circumstances, and its purpose is to greatly reduce the period and man-hours for periodic inspections of auxiliary cooling systems in nuclear power plants, particularly periodic inspections of auxiliary cooling seawater systems. In addition to removing this periodic inspection period from the critical path of the periodic inspection process of the auxiliary cooling system, it is possible to perform periodic inspections of the reactor and turbine auxiliary cooling heat exchanger, and further, during the periodic inspection period of the auxiliary cooling system. The objective of the present invention is to provide an auxiliary cooling system for nuclear power generation that greatly reduces power consumption.

In order to achieve this objective, the present invention provides an auxiliary cooling system that can supply the minimum necessary amount of cooling water to the auxiliary equipment during regular inspections. The auxiliary cooling system for nuclear power generation is characterized by a switching means that can freely switch between the auxiliary cooling system and an auxiliary auxiliary cooling system.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same items or items having the same function. The auxiliary seawater pump 11 is installed as an auxiliary separately from the seawater pump 1, and is connected to the reactor auxiliary cooling auxiliary heat exchanger 12 and the turbine auxiliary cooling auxiliary heat exchanger 1 through the valve 16.
It is connected to 4. These auxiliary heat exchangers 12 and 14 are also installed for auxiliary purposes separately from the reactor auxiliary cooling heat exchanger 2 and the turbine auxiliary cooling heat exchanger 6. The cooling water discharged from the reactor auxiliary cooling auxiliary heat exchanger 12 and the turbine auxiliary cooling auxiliary heat exchanger 14 is passed through the valve 16 to the normal reactor auxiliary continuous load machine 4 and the turbine auxiliary continuous load machine 8. Supplied. This cooling water is supplied to the reactor auxiliary equipment by the reactor auxiliary equipment auxiliary circulation pump 13 and the turbine auxiliary equipment auxiliary circulation pump 15 through bypass pipes from the outlet pipes of the reactor auxiliary equipment continuous load machine 4 and the turbine auxiliary equipment continuous load equipment 8. The water is returned to the auxiliary equipment cooling auxiliary heat exchanger 12 and the turbine auxiliary equipment cooling auxiliary heat exchanger 14, and is discharged from the seawater drain port 10 via the valve 16. These auxiliary seawater pumps and auxiliary equipment may have a capacity commensurate with the regular continuous load during periodic inspections, and normally a capacity of about 10% of the total load is sufficient. By switching cooling of the auxiliary equipment cooling system as described above, during periodic inspection, the seawater pump 1, reactor auxiliary equipment cooling heat exchanger 2, reactor auxiliary equipment intermittent load machine 3
At the same time, the reactor auxiliary equipment circulation pump 5 and the same auxiliary equipment as above for the turbine can be stopped and inspected at the same time. Since the reactor auxiliary continuous load machine 4 and the turbine auxiliary continuous load machine 8 are continuously operated by the auxiliary auxiliary cooling system, the cooling effect of the auxiliary cooling system is not affected. Switching between the auxiliary auxiliary cooling system and the normal auxiliary cooling system is performed by opening and closing the valve 16, but this switching means is not limited to manual operation, but may also be performed by remote control using a solenoid valve or the like. I don't mind. Moreover, if the load of only the continuous load machine is insufficient, it is of course possible to open the valve 16 as appropriate and use part of the normal auxiliary machine cooling system. In this embodiment, periodic inspections of the reactor auxiliary continuous load machine 4 and the turbine auxiliary continuous load machine 8 cannot be carried out; It is possible to connect the load machine 3 and the turbine auxiliary machine intermittent load machine 7 and open the reactor auxiliary machine continuous load machine 4 and the turbine auxiliary machine continuous load machine 8 for periodic inspection. As described above, by appropriately switching between the auxiliary auxiliary cooling system and the normal auxiliary cooling system, efficient periodic inspections are possible, and the seawater pump 1, reactor auxiliary cooling heat exchanger 2
etc. can be stopped at the same time, so there is no wastage of work, and even if the outdoor seawater pump 1
Even if it is not possible to inspect other auxiliary equipment, the progress of inspection work on other auxiliary equipment can be accelerated, which eliminates waste in the work process and reduces work man-hours. In the above embodiment, an auxiliary equipment cooling system for 10% load was installed, but the system is not limited to this. For example, three 50% capacity seawater pumps and auxiliary equipment were prepared, and as appropriate. It goes without saying that a method of switching the capacity, or a method of preparing four units with 33% capacity and switching as appropriate may also be adopted.

As is clear from the above explanation, according to the present invention, the periodic inspection and maintenance period of the auxiliary cooling seawater system of the auxiliary cooling system in nuclear power generation can be greatly reduced, and the critical path of the periodic inspection process can be significantly reduced. Not only can it be removed from the vehicle, but the inspection work process can also be greatly reduced. Furthermore, it is possible to achieve the effect of significantly reducing power consumption during the periodic inspection period.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the operating principle of a conventional auxiliary cooling system, and FIG. 2 is a system diagram showing the operating principle of an embodiment of the present invention. 1...Seawater pump, 2...Reactor auxiliary equipment cooling exchanger,
3... Reactor auxiliary machine intermittent load machine, 4... Reactor auxiliary machine continuous load machine, 5... Reactor auxiliary machine circulation pump, 6... Turbine auxiliary machine cooling heat exchanger, 7... Turbine auxiliary machine intermittent load machine, 8... Turbine auxiliary equipment continuous load machine, 9... Turbine auxiliary equipment circulation pump, 10... Seawater outlet, 11... Auxiliary seawater pump, 12... Reactor auxiliary equipment cooling auxiliary heat exchanger, 13... Reactor auxiliary equipment auxiliary circulation pump, 14 ...Turbine auxiliary equipment cooling auxiliary heat exchanger, 15...Turbine auxiliary equipment auxiliary circulation pump, 16...Valve.

Claims (1)

[Claims] 1. Seawater pumps, etc. are used in the normal auxiliary equipment cooling systems for both the reactor auxiliary equipment and turbine auxiliary equipment, which cool the auxiliary equipment consisting of heat exchangers, pumps, motors, etc. used in nuclear power reactors and turbines. In the auxiliary equipment cooling system of nuclear power generation, which circulates the cooling water of the auxiliary equipment cooling seawater system, the auxiliary equipment cooling system consists of at least an auxiliary seawater pump, an auxiliary heat exchanger, and an auxiliary pump, and is usually connected to the auxiliary equipment cooling system. An auxiliary cooling system for nuclear power generation, comprising: and a switching means for freely switching between this auxiliary cooling system and a normal auxiliary cooling system.