Spectroscopic investigation of simulated low-level nuclear waste glass

Borosilicate glasses with high sodium concentrations, formulated to simulate vitrified Hanford low-level wastes (LLW), were investigated by {sup 31}P magic angle spinning (MAS) nuclear magnetic resonance (NMR). Phase separation, glass homogeneity changes during remelting, and the form of phosphate in glass following product consistency tests (PCT) were also examined by NMR. The results show that a distinct orthophosphate phase not part of the glass network is present in the glass. The effect of glass composition on phosphate chemical environments in the glass is discussed.