METHOD FOR FORMING FERRITE FILM ON CARBON STEEL MEMBER IN ATOMIC POWER PLANT AND FILM FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a ferrite film on a carbon steel member in an atomic power plant that may reduce a time for forming the ferrite film on the carbon steel member of the power plant.SOLUTION: A film forming apparatus is connected to a water piping made of a carbon steel while an atomic power plant is halt (S1). An oxidative decontamination and a reductive decontamination of a chemical decontamination on an inner surface of the water piping is carried out (S2). After the reductive decontamination, a part of a reductive decontamination agent contained in a reductive decontamination liquid is decomposed (S3b) and a reductive decontamination liquid containing an oxidant and a pH adjusting agent having a pH of 5.5 or more is formed by adding the oxidant and the pH adjustment agent (S4). The reductive decontamination liquid is brought into contact with the inner surface of the water piping and a magnetite film is formed on the inner surface of the water piping by a chemical reaction of iron eluted from the water piping and the oxidant by an action of the oxidant. Injection of the oxidant and the pH adjustment agent is stopped (S7) and the reductive decontamination agent and the pH adjusting agent injected in S4 are decomposed (S3c).