Incorporation of Nuclear Wastes in Lead-Iron-Phospate and Uranium containing LIP Glasses

Glasses in lead-iron phosphate (LIP) system loaded with simulated nuclear waste, were melted in the temperature range750-950oC. Some of the LIP glasses were mixed with uranium salt. The pH determinations of the leachate solution at normal temperature show some interesting trends. Leaching study of these glasses with a maximum time period of 300 hrs. were conducted under Soxhlet distillation condition with distilled water. Weight losses and residual activities by ‘Radiotracer technique’ were followed with respect to cumulative time period of leaching. For some LIP-glass samples containing uranium the leach rates as calculated from BET surface area measurements. They were in the range 8.2 x 10–4 to 1.8 x 10–3 g.m-2.hr-1 at 90°C. DTA endotherms occur at ~400oC and ~900oC for the LIP glasses. FTIR studies show absorptions at ~532, ~1025, ~1620-1640, ~2365 and ~3440-3490 cm–1. SEM of some selected glasses was reported. The variation of different properties was explained in terms of the changes in the ionic potentials of the different modifier ions. The model structure of glasses has been considered taking the dual role of Fe3+/2+ and Pb2+ as glass formers/ modifiers which ultimately has an effect on the chemical durability of these glasses.