Microstructures of Simulated Nuclear Waste

Abstract

The microstructures of simulated tailored ceramic forms for the idaho Chemical Processing Plant (iCPP) high-level waste were characterized by TEM. The ceramic f o r m s were consolidated f r o m simulated iCPP waste calcines with either silicayttria-based or silica-lithia-based additives by hot isostatic pressing. The hot isostatically pressed ceramic waste forms are composed of cubic CaF,, monoclinic ZrO,, stabilized cubic ZrO,, tetragonal ZrSiO,, and amorphous silicate phases which can be phase separated. The phaseseparated glass is a result of phase immiscibility in the soda aluminosilicate glass to the compositions of albite and mullite. [