Nuclear glass corrosion mechanisms applied to the French LWR reference glass

The French LWR reference glass was leached under different experimental conditions. Analysis of the leachate together with electron microscopic examination of the leached surfaces led us to the following conclusions. The corrosion of the nuclear glasses is congruent at the hydration front, but only a fraction of the elements enters the solution; the other elements contribute to the formation of the surface layer resulting in incongruent dissolution from the standpoint of the entire sample. The leaching rate in static experiments was observed to decrease sharply in time. Specific experiments were performed to assess the protective role of the hydrolyzed layer with respect to the silica solubility limit, and the predominant effect of the solubility limit was clearly demonstrated