Limiting Solubility of Zirconium in Aluminoborosilicate Glasses

Zirconium is one of critical high-level waste components that get into the glass and affect its properties. There are various zirconium sources such as partial corrosion damage of fuel rod clads in the course of SNF reprocessing or dissolution of the zirconium-containing refractory material of the glass-making furnace in the glass melt. Furthermore, zirconium is present in SNF as a fission product. Dissolution of zirconium in aluminoborosilicate glasses developed as a host material for high-level waste vitrification was studied by electron microscopy. The zirconium distribution between the glass and crystalline phases was studied. The optimum component ratio ensuring maximal incorporation of zirconium into the glass-containing fraction of the host material was determined. The results obtained can serve as a basis for adjusting the synthesis parameters of glass-containing borosilicate host materials used for immobilization of zirconium-containing high-level waste.