Surface analysis has been conducted on samples leached in a Soxhlet apparatus at 100°C in presence and in absence of air. The XPS and RBS techniques were applied to analyse the content of the silicon, iron and uranium while the nuclear reaction method was utilized to analyse the hydrogen content. The anoxic environment favours the release of iron while decreasing the dissolution of uranium. Hydrogen content is always higher in samples leached in presence of air.
Silicon depletion is evident in all cases. The diffusion process seems to regulate the growth of the layer on the glass surface. After long leaching time a detachment, at least partial, of this layer is observed.