Stability of oxides on stainless steel during simulated PWR shutdown and start-up

Oxide films formed on OX18H10T Ti-stabilised stainless steel were characterised using the contact electric resistance (CER) technique and electrochemical impedance spectroscopy (EIS). The aim was to determine the effects of H2O2 injection temperature on the stability of the oxide films during simulated VVER shutdown and subsequent start-up conditions and to recognise possible changes in the thickness and structure of oxide films as a result of H2O2 injection at different temperatures. Stability of the compact part of the oxide film is not greatly influenced by the injection temperature of hydrogen peroxide during a cool-down period. On the other hand, the injection temperature had a marked influence on the deposited crystals in the outer part of the film. (orig.)