Method and device for forming corrosion protective layers in nuclear power plants

Purpose: To improve the safety and reliability by preventing the formation of radioactive nuclides and reducing the radiation dose in primary coolant circuits or equipments relevant thereto. Method: A pressurized fluid from a dissolved oxygen supply source is controlled to a predetermined oxygen concentration before nuclear heating of a reactor. Then, the fluid is sent under pressure by way of control rod driving coolant circuits to a nuclear reactor and primary coolant circuits, while the circulation pump of the reactor is driven to heat the reactor water to high temperature by the joule heat of the recycling pump, to thereby form oxide layers on the primary coolant circuits and relevant equipments. Thus, it is possible not only to reduce the radioactive nuclides but also suppress the increase in the radiation dose in the pipeway circuits or equipments of a nuclear reactor to reduce the operators exposure dose and improve the safety. (Yoshihara, H.)