Lanthanide-aluminoborosilicate (LABS) glass is one option for immobilizing rare earth (RE) oxide fission products generated during reprocessing of pyroprocessed fuel. This glass system can accommodate a high loading of RE oxides and has excellent chemical durability. The present study describes efforts to model equilibrium crystallinity as a function of glass composition and temperature as well as liquidus temperature (T L) as a function of glass composition. The experimental method for determining T L was ASTM C1720-11. Typically, three crystalline phases were formed in each glass: Ce-borosilicate (Ce 3 BSi 2 O 10), mullite (Al 10 Si 2 O 19), and corundum (Al 2 O 3). Cerianite (CeO 2) was a common minor crystalline phase and Nd-silicate (Nd 2 Si 2 O 7) occurred in some of the glasses. In the composition region studied, T L decreased as SiO 2 and B 2 O 3 fractions increased and strongly increased with increasing fractions of RE oxides; Al 2 O 3 had a moderate effect on the T L but, as expected, it strongly affected the precipitation of Al-containing crystals.

No abstract

No abstract

No abstract