Alternative Electrochemical Salt Waste Forms, Summary of FY2010 Results

Technical Report · Tue Aug 31 00:00:00 EDT 2010

DOI:https://doi.org/10.2172/1033467· OSTI ID:1033467

Riley, Brian J. ^[1]; Rieck, Bennett T. ^[1]; Crum, Jarrod V. ^[1]; Matyas, Josef ^[1]; McCloy, John S. ^[1]; Sundaram, S. K. ^[1]; Vienna, John D. ^[1]

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1. Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

In FY2009, the Pacific Northwest National Laboratory (PNNL) performed scoping studies to down-select two candidate waste forms for spent electrochemical salt, tellurite (TeO₂-based) glasses and high-halide minerals. Both candidates showed promise with acceptable Product Consistency Test (PCT) responses (i.e., an assessment of chemical durability) and immobilization of at least 10 mass% fission product waste stream. These candidates were investigated in FY2010. Sodalite was successfully synthesized by the sol-gel method. The vast majority of the dried sol-gel consisted of sodalite with small amounts of alumino-silicates and unreacted salt. Upon firing the powders made by sol-gel, the primary phase observed was sodalite with the addition of various amounts of nepheline, carnegieite, lithium silicate, and lanthanide oxides. The amounts of sodalite, nepheline, and carnegieite varied with firing temperature, as did the bulk density of the fired pellets, sol-gel process chemistry, and the amount of glass sintering aid added to the batch. As the firing temperature was increased from 850°C to 950°C, chloride volatility increased, the fraction of sodalite decreased, and the fractions of nepheline and carnegieite increased. This indicates that the sodalite structure is not stable and begins to convert to nepheline and carnegieite under these conditions at 950°C. Density has an inverse relationship with firing temperature. The addition of NBS-1, a borosilicate glass sintering aid, had a positive effect on bulk density and increased the stability of the sodalite structure. A summary data table for FY2010 halide mineral investigations is presented in Table S1.1.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1033467
• Report Number(s): PNNL--19690; FCRD-WAST-2010-000129; AF5805000
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BULK DENSITY
CHEMISTRY
CHLORIDES
CRUCIBLES
FISSION PRODUCTS
GLASS
HALIDE MINERALS
LITHIUM SILICATES
MELTING
PELLETS
RARE EARTHS
SINTERING
SOL-GEL PROCESS
STABILITY
TESTING
VOLATILITY
WASTE FORMS
WASTES
cancrinite
electrochemical
halide minerals
sodalite
tellurite
tellurite glasses