Radioactive High-level Waste Tank Pitting Predictions: An Investigation into Critical Solution Concentrations

A series of cyclic potentiodynamic polarization tests was performedon samples of ASTM A537 carbon steel in support of aprobability-based approach to evaluate the effect of chloride andsulfate on the steel’s susceptibility to pitting corrosion. Testingsolutions were chosen to systemically evaluate the infl uence of thesecondary aggressive species, chloride, and sulfate, in the nitratebased, high-level wastes. The results suggest that evaluating thecombined effect of all aggressive species, nitrate, chloride, andsulfate, provides a consistent response for determining corrosionsusceptibility. The results of this work emphasize the importancefor not only nitrate concentration limits, but also chloride andsulfate concentration limits.