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U.S. Department of Energy
Office of Scientific and Technical Information

Borosilicate based glasses for immobilization of plutonium-bearing materials

Conference ·
OSTI ID:518691
; ;  [1]
  1. Pacific Northwest National Lab., Richland, WA (United States); and others
Simulated plutonium glasses were studied to determine the effect of glass composition on the solubility limits of Cl, F, P{sub 2}O{sub 5}, SO{sub 3} and Cr{sub 2}O{sub 3}. The solubility of phosphate in glass with alkalis were much greater than in alkali-free glass. The effect of melt redox on the solubility limit of cerium (simulant for plutonium) in glass was also explored. The more reducing the melt, the higher the solubility of cerium (i.e., Ce is more soluble than Ce{sup IV}). Phosphate increased the melt viscosity, while the opposite effect was found for fluorine. Component effect on phase separation or crystallization varied, depending on glass composition. Suppression of CePO{sub 4} phase segregation by alkalis in the melt was suggested. The 7-day product consistency tests (PCTs) showed that the presence of F, SO{sub 3} and Cr{sub 2}O{sub 3} in glass had a negligible effect on glass durability. No evidence was found to suggest that the redox ratio of Ce{sup III}/Ce{sup IV} influences glass durability. The normalized concentrations of Ce and Gd in the PCT solution were substantially higher in glasses with phosphate at all concentration levels. In addition, phosphate induced phase separation in glass significantly increased the normalized PCT release of sodium.
DOE Contract Number:
AC06-76RL01830
OSTI ID:
518691
Report Number(s):
CONF-9604124--
Country of Publication:
United States
Language:
English