Unravelling the corrosion processes at steel/bentonite interfaces in in situ tests

Microscopic and spectroscopic analyses were conducted on steel/bentonite interface samples removed from four in situ experiments that carried out three underground research laboratories at different temperatures under hydraulic geochemical conditions. The results provide valuable information about the corrosion processes occurring high-level radioactive waste repositories. Systematic patterns can be deduced results, irrespective of carbon steel grade, type bentonite its degree compaction, environment or experimental setup. Thus, a clear dependence rates temperature exposure period, as well availability H2O O2 provided by surrounding buffer, is observed. Furthermore, Fe(II) ions released interact with structural Fe clay. Recent developments highlight usefulness reactive transport modelling understanding coupled Fe–clay interaction processes.