Evaluation of sodium magnesium silicate-based glasses for alkali waste

Na 2 O-MgO-SiO 2 glasses were evaluated as a matrix of alkali waste solidification in the plutonium-uranium redox extraction (PUREX) process.Effects of ZnO, Al 2 O 3 , and B 2 O 3 additions in small concentrations ( 4 mol%) on thermal stability against crystallization at high temperatures and water durability were studied.Infrared spectroscopy was used to evaluate the network structures of the Si-O and B-O bonds.Melt viscosity was measured by an inner rotation method in the temperature range between 1100 and 1300 C.The results revealed that the addition of B 2 O 3 and ZnO significantly contributed to respective enhancements of the thermal stability and water durability of silicate glasses with moderate melt viscosities at the operating temperatures of the glass solidification method for nuclear waste.