Operando observation of dissolution kinetics and alteration layer formation of heavy ion irradiated borosilicate glass

Abstract Borosilicate glasses are key materials for immobilizing high-level nuclear waste. The effect of self-irradiation damage on the structural integrity of the glass and its aqueous corrosion resistance is not yet fully understood. This study investigates a ternary Na borosilicate glass irradiated with ~950 MeV gold ions, producing severe damage within a ~ 50 µm layer, and subsequently corroded in a 0.5 M NaHCO₃ solution at 81.2 °C for 12.5 days. Using operando Fluid-cell Raman spectroscopy and D 2 O as a tracer for water transport through the surface alteration layer (SAL), we observed (i) a 2.5-fold increased initial forward dissolution rate of the irradiated glass, (ii) a further increase of the dissolution rate at the irradiated/non-irradiated interface, (iii) elevated residual dissolution rates, and (iv) variations in the silica ring structures correlating with the changes in the rates. These findings confirm that irradiation enhances glass reactivity and support the interface-coupled dissolution–precipitation model for SAL formation.