Dissolution behavior and mechanism of oxides on stainless steel 316LN during electrochemical decontamination

Electrochemical decontamination is a promising technique for removing oxide films from stainless steel surface in nuclear power plants. The present study investigates the dissolution behavior of oxides on stainless steel 316LN after pre-oxidation in high-temperature pressurized water during electrochemical decontamination. The decontamination efficiency of electrolytes based on the HNO 3 -NaNO 3 system and their impacts on metal substrate are analyzed. Results indicate that pure HNO 3 effectively removes surface oxides but also causes significant corrosion of substrate. Addition of NaNO 3 improves electrolysis efficiency due to its strong ionization capability. Glycerol facilitates oxide detachment through hydrogen bonding and increases viscosity and protect surface from damage. The mechanism of oxide removal in HNO 3 -NaNO 3 electrolytes is discussed.