In-situ electrochemical study of zirconium alloy in high temperature hydrogenated Water conditions

Abstract

The electrochemical characteristics of a Zr-Nb-Sn zirconium alloy have been investigated at 360 degrees C in simulated primary water condition of pressurized water reactor with two different dissolved hydrogen contents. In-situ electrochemical impedance spectroscopy experiment was performed for 100 d, and the thickness and resistivity of the zirconium oxide films were measured as function of time. The results show that there is a difference in oxide resistivity as function of dissolved hydrogen content in the environment. The resistivity of the oxide film on Zr-Nb-Sn alloy is lower at higher dissolved hydrogen condition, resulting in a higher corrosion rate at that condition.