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Title: Toward understanding the effect of low-activity waste glass composition on sulfur solubility

The concentration of sulfur in nuclear waste glass melter feed must be maintained below the point where salt accumulates on the melt surface. The allowable concentrations may range from 0.37 to over 2.05 weight percent (of SO 3 on a calcined oxide basis) depending on the composition of the melter feed and processing conditions. If the amount of sulfur exceeds the melt tolerance level, a molten salt will accumulate, which may upset melter operations and potentially shorten the useful life of the melter. At the Hanford site, relatively conservative limits have been placed on sulfur loading in melter feed, which in turn significantly increases the amount of glass that will be produced. Crucible-scale sulfur solubility data and scaled melter sulfur tolerance data have been collected on simulated Hanford waste glasses over the last 15 years. These data were compiled and analyzed. A model was developed to predict the solubility of SO 3 in glass based on 252 simulated Hanford low-activity waste (LAW) glass compositions. This model represents the data well, accounting for over 85% of the variation in data, and was well validated. The model was also found to accurately predict the tolerance for sulfur in melter feed for 13more » scaled melter tests of simulated LAW glasses. The model can be used to help estimate glass volumes and make informed decisions on process options. The model also gives quantitative estimates of component concentration effects on sulfur solubility. The components that most increase sulfur solubility are Li 2O > V 2O 5> CaO ≈ P 2O 5 > Na 2O ≈ B 2O 3 > K 2O. The components that most decrease sulfur solubility are Cl > Cr 2O 3 > Al 2O 3 > ZrO 2 ≈ SnO 2 > Others ≈ SiO 2. As a result, the order of component effects is similar to previous literature data, in most cases.« less
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  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. The Catholic University of America, Washington, D.C. (United States)
  3. U.S. Department of Energy, Office of River Protection, Richland WA (United States)
Publication Date:
Report Number(s):
ORP-56664 Rev.0
Journal ID: ISSN 0002-7820; TRN: US1600480
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of the American Ceramic Society
Additional Journal Information:
Journal Volume: 97; Journal Issue: 10; Journal ID: ISSN 0002-7820
American Ceramic Society
Research Org:
Hanford Site (HNF), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Environmental Management (EM)
Contributing Orgs:
Pacific Northwest National Laboratory; The Catholic University of America; Department of Energy - Office of River Protection
Country of Publication:
United States
OSTI Identifier: