Chemical Stability of Sintered Modified SYNROC B Ceramics Containing Simulated High Level Wastes

Abstract

Sintered Modified SYNROC-B ceramics containing 10 wt% and 15 wt% simulated high level radioactive waste (PW-4b) were prepared by a subsolidus sintering technique. The chemical stability of the samples was determined by conducting leaching experiments for long periods at different temperatures and pressures. The compositions of the leaching solutions correspond to those of the groundwater (brine) at various possible geologic disposal sites. Analyses were performed by atomic absorption and neutron activation analysis. Leach rates are given for specific elements in terms of μg cm^-2 day^-1 and also as fractional release. Results indicate that the system described is very stable, with leach rates several orders of magnitude lower than those reported for other solid waste forms for radioactive waste disposal material.