Summary of studies on the anaerobic corrosion of carbon steel in alkaline media in support of the Belgian supercontainer concept

Abstract

ABSTRACTIn the Belgian supercontainer concept, a carbon steel overpack will surround high-level waste and spent fuel containers and be encased in a cementitious buffer material. A programme of research has been carried out to investigate and measure the rate of anaerobic corrosion of carbon steel in an artificial alkaline porewater that simulates the aqueous phase in the cementitious buffer material and also in solid cement matrices. This paper highlights the main features of the programme and presents some recent results from the analysis of several samples, including two 20-year-old steel in cement samples, which showed that under anoxic conditions there is no localised corrosion or incorporation of iron into the surrounding cement, even in the presence of 20 000 ppm chloride in the porewater.This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.