Life prediction for HLW containers – issues related to long-term extrapolation of corrosion resistance

Traditionally, the corrosion behaviour of container materials can be predicted by extrapolation from relatively short-term experiments. Approaches to life prediction are described for two kinds of materials: carbon steel (corrosion allowance material) which must resist general corrosion, and passive materials (corrosion-resistant materials) which may suffer localized corrosion phenomena (pitting and crevice corrosion). The current theoretical and empirical basis for extrapolating the behavior of these materials to long periods emphasizes the significant gaps in understanding. To improve the credibility of life prediction, and to prove the robustness of geological disposal systems, predictive models based on mechanistic understanding are needed. This work is probably more difficult for the corrosion-resistant materials than for corrosion-allowance materials. To cite this article: J.-M. Gras, C. R. Physique 3 (2002) 891–902.