Structure and Properties of Phosphate Glasses for Nuclear Waste Immobilization

Abstract

The leaching behavior and structure of magnesium phosphate glasses containing 45-55 mol% MgO incorporated with simulated high-level nuclear waste (HLW) were studied. The gross leach rate of the glass waste form containing 50 mol% MgO and 45 mass% simulated HLW is of the order of 10^-6 g/cm²∙day at 90˚C, which is small enough as compared with the corresponding release from a currently used borosilicate glass waste form. The isolated ions such as dimeric (P₂O₇)^4- and monomeric (PO₄)^3- increase as increasing the incorporating amount of the simulated HLW. The changes in properties can be attributed to the structure changes owing to the incorporation of the simulated HLW.