| 摘要 |
PROBLEM TO BE SOLVED: To provide a dosage reduction method for an atomic power plant constitution member that can suppress stress corrosion cracking and also suppress the taking of radioactive nuclides into a ferrite coating. SOLUTION: A coating formation device is connected to a recirculation-system pipe as an object of coating formation in a stop period of the atomic power plant (S1), a coating formation liquid which includes ferric (II) ions, hydrogen peroxide, and hydrazine and has pH of 5.5 to 9.0 is supplied to the recirculation-system pipe. A ferrite coating is formed on an inner surface of the recirculation-system pipe (S3). The coating formation device is detached from the recirculation-system pipe, and the atomic power plant is actuated. Furnace water which includes oxidizing chemical species produced through radiolysis of furnace water during temperature raising and pressure raising comes into contact with a surface of the ferrite coating, and a hematite coating is formed on the surface of the ferrite coating. Then a first state in which a corrosion potential of the recirculation-system pipe is -0.5 V and a second state in which the corrosion potential is -0.2 to + 0.2 V are alternated (S12, S13). COPYRIGHT: (C)2013,JPO&INPIT |
