Waste form development for immobilization of high level waste calcine at the Idaho Chemical Processing Plant

Since 1963 the high-level liquid waste generated at the Idaho Chemical Processing Plant (ICPP) is routinely solidified into granular calcined high level waste (HLW). A research and development program at ICPP is currently developing waste forms for immobilization of the HLW that is stored onsite. One of the waste forms that is being developed is a durable glass-ceramic, a form of material consisting of crystalline phases and a glassy matrix. The glass-ceramic waste form is a promising option because it can potentially reduce HLW volume significantly compared to glass waste forms while maintaining similar leach rates. In this paper the impact of reactants (Ti and Al) and frit additive (B{sub 2}O{sub 3}) on leach rates, microstructure and phase composition of glass-ceramic waste forms is discussed.