Sensitivity of measured steam oxidation kinetics to atmospheric control and impurities

The most direct means of improving the ability of water cooled reactors to withstand excessive cladding oxidation during a loss of coolant accident is to either modify or replace zirconium cladding. It is important to understand what level of agreement is to be expected as a function of systematic differences in steam oxidation testing techniques and instrumentation among testing facilities. The present study was designed to assess the sensitivities of some of the current and proposed reactor cladding materials. Steam oxidation sensitivity of Zircaloy-2, FeCrAl and Mo to O₂ impurities in steam were examined. It was shown that the effect of O₂ impurities is negligible for the two former materials while significant in the case of Mo.