Method of suppressing deposition of radioactive isotope

摘要

A formic acid aqueous solution that contains Fe (II) ions is produced by dissolving metal iron in a formic acid aqueous solution. Nitrogen is supplied from a nitrogen supply device to a chemical liquid tank and then discharged from a discharge line to reduce the dissolved oxygen concentration in the aqueous solution. The chemical liquid tank is filled with the formic acid aqueous solution sealed with nitrogen, and is transferred from a factory to a nuclear reactor building designated as radiation-controlled areas. Inside the nuclear reactor building, the chemical liquid tank is installed in a film deposition apparatus connected to a reactor water recirculation pipeline. The formic acid aqueous is supplied from the chemical liquid tank to the inside of the reactor water recirculation pipeline, and then a ferrite film is formed on the inner surface of the reactor water recirculation pipeline.