Effects of crystalline phases on leaching of a devitrified simulated high-level waste glass

Borosilicate glass containing 20 wt% of simulated high level waste oxides was annealed at 7000C for 1000 h to accelerate devitrification. Monolithic samples of devitrified and as-prepared glasses were subjected to the Soxhlet leach test for 2 months. The concentrations of Sr, Ba, Mo, B, Cr, Fe, Na, and Cs in leachates were analyzed. After devitrification, Sr, Ba, Mo, and B became less leachable because of low solubility of (Sr, Ba, RE)MoO/sub 4/ and (RE)BSiO/sub 5/, while the leach rate of Na corrected by the actual surface area increased by a factor of about 3 and was nearly constant throughout the test