Effect of Buffering on the Electrochemical Corrosion Behavior of Alloy 800 in Sulfate Solutions Containing Hydrogen Peroxide

In current boiling water and future supercritical water-cooled nuclear reactors, water radiolysis generates appreciable levels of hydrogen peroxide and other oxygen and hydrogen containing radicals. Understanding how hydrogen peroxide affects the corrosion behavior of candidate alloys for supercritical water-cooled (SCW) reactors is essential.

In this study, the effect of hydrogen peroxide concentration, pH and temperature on electrochemical and morphological aspects of corrosion behavior of Incoloy 800HT as a potential structural alloy for SCW reactors is investigated. Potentiodynamic polarization was utilized to study the general electrochemical behavior of the alloy and electrochemical impedance spectroscopy was employed to study the response of the alloy's passive film to hydrogen peroxide and the transition from passivity to tanspassivity.