Effect of PbO on the chemical durability of low-temperature PbO–B2O3–ZnO glass for cesium immobilization

Highly reactive fission product cesium may volatilize at high temperatures. PbO–B 2 O 3 –ZnO glass with low melting temperature and excellent chemical durability can be used as a potential matrix for immobilizing Cs. In this work, five PbO–B 2 O 3 –ZnO glasses with different contents of Pb were synthesized via a melt-quenching process. These specimens were characterized with XRD , Raman, DTA and viscosity measurements . The results showed that the melting temperature decreases, viscosity decreases and structural polymerization increases with increasing lead content. Cs-doped 35PbO–60B 2 O 3 –5ZnO glasses were synthesized at low temperatures. XRD results revealed the amorphous nature of the glass solidified bodies. EDS and ICP-MS studies confirmed that Cs is retained in the glass. Clear vitrified waste products containing up to 13.6 wt% Cs were obtained. The chemical durability of the samples was evaluated via PCT-A and MCC-1 method. For the glass solidified body comprising a Cs/matrix ratio of 0.136, the leaching rate of Cs was 1.6 × 10 −1  g m −2 d −1 from the PCT test, which indicates that it has a good chemical stability. 35PbO–60B 2 O 3 –5ZnO glass was expected to be a suitable matrix for Cs immobilization.