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Title: Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps tomore » formulate melter feeds for higher production rate.« less
 [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States);
  2. USDOE Office of River Protection, Richland, WA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
TRN: US1400405
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: WM2014 Waste Management Symposia, Phoenix, AZ (United States), 2-6 Mar 2014
Research Org:
Hanford Site (HNF), Richland, WA (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); USDOE Office of River Protection, Richland, WA (United States)
Sponsoring Org:
USDOE Office of Environmental Management (EM)
Country of Publication:
United States
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES Cold-Cap reactions, Evolved gas analysis, nuclear waste vitrification, glass melting