Photoelectrochemical study on semiconductor properties of oxide films on Alloy 600 in high temperature water with ZnO addition

Abstract Zinc addition is widely used in the primary circuit of BWR and PWR to lower radioactive adhesion of nickel base alloys. The oxide films on nickel base alloys in high temperature water indicated a duplex structure with semiconductor property. The semiconductor properties of the oxide films on Alloy 600 are changed by 650 ppb ZnO addition into the high temperature water by photoelectrochemical responses investigation. A compact structure oxide with formula Zn y Fe x Ni 1− x − y Cr 2 O 4 of the outer layer, besides the chromium enrichment of the inner layer, of the oxide film on Alloy 600 in high temperature water with 650 ppb ZnO addition is investigated. The semiconductor properties of the oxide films on Alloy 600 in high temperature water with 650 ppb ZnO addition suggest an untypical n-type semiconductor at anodic polarization with a negative movement of the flat band potential to the oxide films on Alloy 600 without ZnO addition.