Weathering of ancient and medieval glasses—potential proxy for nuclear fuel waste glasses. A perennial challenge revisited

Ancient and medieval glasses that have survived the deleterious attack of the environment for millennia have long since proposed as proxy to estimate and predict the corrosion mechanism of nuclear waste glasses. However, because both composition and environmental burial conditions vastly differ between hydrolytically less stable ancient glasses and modern advanced nuclear waste glasses, only semiquantitative conclusions can be drawn about the likely performance of the latter as long‐term stable immobilization matrices for high‐level radioactive nuclear waste. In this contribution, special emphasis has been devoted to the behavior of manganese, present as both iron decolorant and coloring ions in ancient Roman and medieval glasses. Study of the behavior of manganese in ancient glasses during weathering may provide some limited clues to the behavior of long‐lived radioactive technetium‐99. Knowledge of the corrosion kinetics of ancient glasses will allow, eventually, a reasonable prediction of the long‐term performance of glassy nuclear waste forms as function of their composition and environmental parameters, i.e. groundwater composition, flow rate, pH, solution volume, and surface area.