Dismantling nuclear waste rich in P2O5, MoO3 and ZrO2: How do these oxides incorporate in aluminoborosilicate glasses?

Dismantling nuclear facilities leads to radioactive waste less active but which may have highly variable compositions compared the high-level wastes recovered after reprocessing of spent fuel. In this work, we studied ability an alkali-rich glass matrix belonging SiO2-B2O3-Al2O3-Fe2O3-Na2O-Li2O-CaO system solubilize P2O5, MoO3, ZrO2 and Cs2O by melting at 1100°C. Phosphorus, molybdenum, zirconium cesium are present as a mixture complex compounds in real dismantling containing 137Cs considered here. To determine capacity accept wide range variations composition solubility limits ZrO2, several series were prepared mixtures raw materials (oxides, carbonates, phosphates) increasing total amount oxides representing varying their relative proportions. Their incorporation melt was analyzing microstructure quenched glasses XRD SEM-EDS. addition, phase separation crystallization tendencies during cooling cooled 1°C.min-1 from 1100°C (representative industrials steel canisters). It is shown that can without exhibiting heterogeneities. For all remained homogeneous (study samples). However, slow cooling, P2O5 MoO3 lead Na2MoO4, CsLiMoO4, NaCaPO4, NaLi2PO4, Li3PO4. Cs be partially incorporated into molybdenum-rich CsLiMoO4 when content higher than 1.3wt%. never or crystallization, possibly because existence strong connections between Zr Si through Zr-O-Si bonds whereas P Mo would PO43? MoO42? mobile entities. The order following: MoO3<P2O5<ZrO2.