Preliminary observations on the microstructure of nuclear waste glasses

The microstructures of simulated nuclear waste glasses prepared by the mixing of glass frit and calcined waste oxides at 1000°C are shown to contain well defined boundaries that are depleted of heavy elements. The development of small crystallites and phase separation have also been observed but no evidence of microcracking or interfacial separation at these discontinuities was found. The same glasses prepared at 1350°C were quite uniform at the microstructural level.