JPH0511094A - Reactor water purification system - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a reactor cleaning system that does not require a reactor cleaning system high-pressure pump, to reduce the amount of exposure to workers at a boiling water nuclear power plant, and to generate power. The aim is to improve the reliability of nuclear power plants by reducing the number of rotating equipment in the plant. [Constitution] In the present invention, high-temperature and high-pressure reactor water is used as a heat exchanger 5
In the reactor water purification system 10 in which impurities are removed by the purification device 6 using an ion exchange resin, the reactor water after the impurities are removed by utilizing the pressure difference of the system,
It is characterized in that it is returned to the reactor through a system whose pressure is lower than that of the reactor water without using a pump.

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 in which high temperature and high pressure reactor water is cooled by a heat exchanger and impurities are removed 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. 4, steam generated in a reactor pressure vessel 1 is supplied to a turbine 2
After being introduced into the reactor and condensed, it was introduced again into the reactor pressure vessel 1 via the feed water pump 3. In such a structure, 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, and in order to keep the impurity concentration in the reactor water as low as possible, A reactor water purification system 10 is installed in order to keep the impurity concentration of the reactor as low as possible. The reactor water purification system 10 guides and cools the high-temperature and high-pressure water in 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 purification device 6 using ion exchange resin. After removing impurities in the reactor water by the method, the temperature is raised and the system is returned to the reactor pressure vessel again. Normally, the flow rate of the system is about 2% of the feed water flow rate to the reactor.
The reactor water purification system pump, heat exchanger, and purification device included in this reactor purification system are regularly disassembled and inspected when the power station is regularly inspected.

[0003]

In the prior art, the reactor water of the high temperature and high pressure water first flows into the reactor cleaning system high pressure pump. Reactor water contains radioactive materials, some of which adhere to the high pressure pump of the reactor cleaning system. As a result, at the time of periodic inspection, workers may disassemble and inspect the contaminated high-pressure reactor purification system pump, and there is a risk of being exposed to radiation from the radioactive substances that have adhered.

Further, rotating equipment such as a high-pressure pump is an important item as an equipment failure in a boiling water nuclear power plant, and it is desired to reduce the number of equipment used 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 cleaning system that does not require a high pressure pump for cleaning the reactor system, and a worker in a boiling water nuclear power plant While reducing the amount of exposure received,
The aim is to improve the reliability of boiling water nuclear power plants by reducing the number of rotating equipment in the power plants.

[0006]

In order to achieve the above object, in the present invention, high temperature and high pressure reactor water is cooled by a heat exchanger, and impurities are removed by a purifying device using an ion exchange resin. In the reactor water purification system, the reactor water after removing impurities is returned to the reactor through a system with a pressure lower than that of the reactor water without using a pump by using the pressure difference of the system. It is characterized by being formed.

The system whose pressure is lower than that of the reactor water is the 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. Furthermore, when the reactor operating pressure is low, such as when the reactor is shut down, and after removing impurities, the reactor water cannot be returned to the reactor through a system with a lower pressure than the reactor water without using a pump. In addition, the reactor water can be passed through the fuel pool purification device before the impurities are removed by the purification device using the ion exchange resin.

[0008]

[Function] In the reactor water purification system configured as described above, the pump in the system can be eliminated, so that the amount of exposure to workers at the nuclear power plant is reduced and the reliability of the nuclear power plant is 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 that has boiled in the reactor pressure vessel 1 is introduced into a turbine 2 and then fed into the reactor pressure vessel 1 again by a feed water pump 3. To do. A part of the cooling water in the reactor pressure vessel 1
After being cooled by the reactor water purification system heat exchanger 5 and impurities being removed by the reactor water purification system 6 using an ion exchange resin, the impurities are removed by the reactor water purification system pipe 11 to the upstream side of the feed water pump 3. 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 feed water pump 3, the purified reactor water can flow without the force 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 uses the pressure difference of the system, from the reactor purification system second pipe 12 to the water supply pump 3 through the condensate storage tank 7 which is a system having a lower pressure than the reactor water without using a pump Will be introduced upstream.

FIG. 3 shows that the reactor operating pressure is low when the reactor is shut down, etc., and impurities are removed before returning to the reactor via a system having a lower pressure than the reactor water without using the reactor water pump. This is an example in which, if it is not possible, before the impurities are removed by the reactor water purification device 6, the reactor water is passed through the fuel pool purification device 8 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, a high-pressure pump is not required in the reactor water purification system, the exposure dose to workers in a boiling water nuclear power plant is reduced, and the number of rotating equipment in the power plant is reduced. By reducing it, the reliability of the nuclear power plant can be improved.

[Brief description of 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 boiling water nuclear power plant reactor water purification system according to the present invention.

FIG. 3 is a conceptual diagram showing a third embodiment of a boiling water nuclear power plant reactor water purification system 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 ... Water supply 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)

Claims: 1. A reactor water purification system in which high-temperature and high-pressure reactor water is cooled by a heat exchanger and impurities are removed by a purification device using an ion exchange resin. A reactor water purification system characterized in that the subsequent reactor water is returned to the inside of the reactor pressure vessel via a system having a lower pressure than the reactor water without using a pump.