Patent Number: 051475979
Section: claims

1. A method for retarding buildup of radioactive materials on a water exposed steel surface of a pipe which forms a part of a water system of a light water nuclear reactor, comprising the steps of: preparing said water exposed steel surface to obtain a clean base metal starting surface;  depositing a chromium film at least five hundred Angstroms thick on said pipe surface from a solution of chromic acid and sulfuric acid under controlled electrochemical deposition conditions;  exposing said deposited chromium film and said underlying base metal to a gaseous oxygen source at temperatures between 150.degree. C. and 450.degree. C. to obtain a thin stabilized chromium-rich oxide film on the exposed surface of said deposited chromium film; and,  using said chromium-coated pipe with an oxide film as a portion of the water system of the light water nuclear reactor. 2. A method as in claim 1 wherein said oxygen source comprises air. 3. A method as in claim 1 wherein said oxygen source further comprises a minor amount of water vapor.