Effects of Corrosion Products Deposited on 304 Stainless Steel on Reduction of Se (IV/VI) in Simulated Groundwater

Abstract

Selenium (Se) is a key mobile fission product in the geological disposal of nuclear waste. It is necessary to analyze the reductive deposition behavior of iron-based materials to Se(IV) and Se(VI) in groundwater. In the present work, the corrosion behavior of 304 stainless steel in simulated groundwater (SG) and the effects of corrosion products on the dissolution of Se were investigated by electrochemical and immersion tests. Experimental results revealed that passivation films formed on 304 stainless-steel samples were destroyed by polarization measurements, forming corrosion products consisting of Fe(II) compounds, such as Fe3O4 and FeO. Corrosion products deposited on the surface of steel samples previously treated by polarization measurements in SG + CaCl2/Na2CO3/Na2SiO3 solutions effectively reduced soluble Se(IV) and Se(VI) during immersion tests, depositing FeSe2 on sample surfaces.