Method of reducing radioactivity in nuclear plant.

摘要

57 The present invention is concerned with a method of reducing radioactivity in a nuclear plant by preliminarily forming oxide films (15,16) on the surfaces of metallic structural members (17) to be in contact with high-temperature and high-pressure reactor water containing radioactive substances before said metallic members (17) are exposed to said reactor water. The method is characterized by the steps of subjecting said structural members (17) to a first-step oxidation treatment of heating said structural members (17) in an environment of a high temperature, and further subjecting the thus treated structural members (17) to a second step oxidation treatment of heating said treated structural members (17) in an environment having a higher oxidizing capacity than that of said environment in said first-step oxidation treatment to form a denser oxide film (15,16) than an oxide film (15) obtained in said first step oxidation treatment.