Uniform corrosion of hydrogen-charged copper and localized corrosion of non-charged copper in anoxic groundwater containing diluted sulfide

Hydrogen atom generation and permeation on nuclear waste storage canister surfaces threaten disposal safety. This study investigated the corrosion behavior of hydrogen-charged and non-charged copper in an anoxic, sulfide-containing groundwater environment simulating nuclear waste disposal conditions in Beishan, China. Chloride ions induced pitting corrosion in non-charged copper. The mass transfer rate of \(\text{Cu}{\text{Cl}}_{2}^{-}\) species within pitting pores was higher compared to that of Cu⁺ through the Cu 2 S layer, resulting in excessive thickening of corrosion products at pitting sites. By contrast, porous corrosion products on hydrogen-charged copper formed non-passivating films, leading to uniform substrate corrosion. The corrosion product thickness exhibited sub-parabolic growth over time. This predictable sub-parabolic growth pattern is crucial for reliable service life assessment of deep geological repositories rather than unpredictable pitting corrosion.