Preparation and Characterization of Sintered Glass-Ceramics from Calcined Simulated High-Level Waste

Simulated high-level commercial fluidized-bed calcine was treated to form sintered glass-ceramics (SGC) by sintering compacted mixtures of calcine with aluminosilicate fluxes at temperatures ranging from 965 to 1070°C. Products are resistant to impact and thermal shock and exhibit leach rates of 10⁻⁵ to 10⁻⁹ g/(cm² day). Up to 67 wt% calcine is used, giving waste volumes as low as 0.040 m³ /MTU reprocessed. Storage centerline temperatures up to 800°C appear feasible. A conceptual process in which SGC is molded into thin-walled containers for processing and canister loading is proposed.