NMR characterization of simulated hanford low-activity waste glasses and its use in understanding waste form chemical durability

摘要

Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) spectroscopy has been used to characterize the structural and chemical environments of B, Al, and Si in model hanford low-activity waste glasses. The average ~(29)Si NMR peak position was found to systematically change with changing glass composition and structure. From an understanding of the structural roles of al and B obtained from MAS-NMR experiments, we first developed a model that reliably predicts the distribution of structural units and the average ~(29)Si chemical shift value, #delta# , based purely on glass compsition. A product consistency test (PCT) was used to determine the normalized elemental release (NL) from the prepared glasses. Comparison of the NMR and PCT data obtained from sodium boro-aluminosilicate glasses indicates that a rudimentary exponential relationship exists between the ~(29)Si chemical shift value, and the boron NL value.