JP2895267B2 - Reactor water purification system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor water purification system for cooling a reactor water at a high temperature and a high pressure by a heat exchanger and removing impurities by a purification device using an ion exchange resin.

[0002]

2. Description of the Related Art In a boiling water nuclear power plant, as shown in FIG.
And condensed, and then introduced again into the reactor pressure vessel 1 via the feedwater pump 3. In such a configuration, it is said that if impurities are mixed in the reactor water, the possibility that stress corrosion cracking will occur in the stainless steel used as the material is increased. A reactor water purification system 10 is installed to keep the impurity concentration of the reactor as low as possible. The reactor water purification system 10 guides the high-temperature and high-pressure water of the reactor pressure vessel 1 to the reactor water purification system heat exchanger 5 by the reactor water purification pump 4 and cools the reactor water. The reactor water purification system 6 using ion exchange resin After removing impurities in the reactor water, the temperature is raised and the system is returned to the reactor pressure vessel again. Usually, the flow rate of the system is about 2% of the flow rate of water supplied to the reactor.
Reactor water purification system pumps, heat exchangers, and purification devices included in the reactor purification system are periodically disassembled and inspected when the power plant is regularly inspected.

[0003]

In the prior art, high-temperature, high-pressure reactor water first flows into a high-pressure pump for a reactor purification system. Reactor water contains radioactive materials, some of which adhere to the reactor purification system high-pressure pump. As a result, during periodic inspections, workers may be exposed to radiation from radioactive substances attached to disassemble and inspect the contaminated reactor high-pressure pump.

[0004] In addition, rotating equipment such as a high-pressure pump is an important item for failure of equipment in a boiling water nuclear power plant, and it is desired to reduce the number of used devices in the power plant as much as possible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a reactor purifying system that does not require a reactor purifying system high-pressure pump. While reducing the amount of exposure received,
An object of the present invention is to improve the reliability of a boiling water nuclear power plant by reducing the number of rotating devices in the power plant.

[0006]

In order to achieve the above object, the present invention provides a method of cooling high-temperature and high-pressure reactor water .
Heat exchanger and this cooled reactor water into ion exchange resin
And a purified reactor water that purifies the reactor water.
Reactor water purification system piping
This reactor water purification system piping is
At least one of a water storage tank and a fuel pool purification device
It is characterized by being returned to the reactor pressure vessel via a seed .

A system having a pressure lower than that of the reactor water is a water supply system. Alternatively, the system having a lower pressure than the reactor water may be a condensate system. The system having a lower pressure than the reactor water may be a condensate storage tank. In addition, when the reactor operating pressure is low, such as when the reactor is stopped, and the reactor water after removing impurities cannot be returned to the reactor via a system with a lower pressure than the reactor water without using a pump. Alternatively, the reactor water can be passed through a fuel pool purification device before impurities are removed by a purification device using an ion exchange resin.

[0008]

In the reactor water purification system configured as described above, the pump in the system can be eliminated, so that the dose received by workers at the nuclear power plant can be reduced and the reliability of the nuclear power plant can be improved. be able to.

[0009]

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

In FIG. 1, in a boiling water reactor power plant, cooling water boiling in a reactor pressure vessel 1 is guided to a turbine 2 and then flows back into the reactor pressure vessel 1 by a feed water pump 3. I do. Part of the cooling water in the reactor pressure vessel 1
After being cooled by the reactor water purification system heat exchanger 5 and the impurities being removed by the reactor water purification device 6 using the ion exchange resin, the water is supplied to the upstream side of the feedwater pump 3 through the reactor water purification system piping 11. be introduced. Since the pressure at the outlet of the reactor water purification device 6 is higher than the pressure on the upstream side of the feedwater pump 3, the purified reactor water can flow without the power of the pump.

In FIG. 2, high-temperature and high-pressure reactor water is cooled by a reactor water purification system heat exchanger 5, and impurities are removed by a reactor water purification device 6 using an ion exchange resin. Subsequent reactor water is supplied from the reactor purification system second pipe 12 through the condensate storage tank 7, which is a system having a lower pressure than the reactor water, without using a pump, using the pressure difference of the system. Introduced upstream of

FIG. 3 shows that the reactor operating pressure is low when the reactor is stopped or the like, and the reactor is returned to the reactor via a system having a lower pressure than the reactor water without using the reactor water pump after removing impurities. In the case where the reactor water cannot be removed, the reactor water is passed through the fuel pool purification device 8 before the impurities are removed by the reactor water purification device 6 to purify the reactor water. The fuel pool purification device 8 is provided with a purification device equivalent to the purification device 6 in the reactor water purification system, and can effectively purify the reactor water.

[0013]

According to the present invention, the reactor water purification system does not require a high-pressure pump, reduces the amount of radiation received by workers at the boiling water nuclear power plant, and reduces the number of rotating devices in the power plant. By reducing it, the reliability of the nuclear power plant can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a first embodiment of a boiling water nuclear power plant atomic water purification system according to the present invention.

FIG. 2 is a conceptual diagram showing a second embodiment of a reactor water purification system for a boiling water nuclear power plant according to the present invention.

FIG. 3 is a conceptual diagram showing a third embodiment of a reactor water purification system for a boiling water nuclear power plant according to the present invention.

FIG. 4 is a conceptual diagram showing a system configuration of a conventional boiling water nuclear power plant reactor water purification system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel 2 ... Turbine 3 ... Feedwater pump 4 ... Reactor water purification system high pressure pump 5 ... Reactor water purification system heat exchanger 6 ... Reactor water purification system purification device 7 ... Condensate storage tank 8 ... Fuel Pool purification system 10 ... Reactor water purification system 11 ... Reactor water purification system piping 12 ... Reactor water purification system second piping

Claims (1)

(57) [Claims] 1. A heat exchanger for cooling high-temperature and high-pressure reactor water
And the cooled reactor water using ion exchange resin
A purification device that purifies the reactor water and the purified reactor water
Reactor water purification system piping to return inside the pressure vessel.
Reactor water purification system piping upstream of feedwater pump, condensate storage tank
A reactor water purification system characterized by being returned to the reactor pressure vessel via at least one of a fuel pool and a fuel pool purification device .