Bi2O3 doped B2O3-ZnO glass powder for immobilization of radioactive iodine waste at low temperature

Abstract

In order to research the effect of Bi2O3 doped B2O3-ZnO matrix in immobilizing iodine waste, different Bi2O3 contents were doped into B2O3-ZnO glass to immobilize iodine loaded silver-coated silica-gel (AgIs). Bi2O3 content doped B2O3-ZnO (99:1) as raw materials held the good physical and chemical property (Vickers hardness 3.07 GPa), so, the pure glass matrix was manufactured at 550 °C. SEM-EDS results gave that element I distributed homogeneously in the samples with 5 wt% AgIs at 450 °C. Meanwhile, the glass powder immobilized AgIs samples gave the glass–ceramic phases according to the XRD results, and the hightest density and Vickers hardness were 1.78 g/cm3 and 0.30 GPa, respectively. The leaking rate of iodine was 1.89–3.40 × 10−5 g∙m−2∙d−1 for 7 days, which was low and supports the stability of the immobilized AgIs with glass materials. This work highlights the well immobilized effect of Bi2O3 doped B2O3-ZnO glass as raw material to immobilize iodine waste at low temperature.