Caustic Waste Soil Weathering Reactions and their Impacts on Trace Contaminant Migration and Sequestration

Mueller, Kart T.

Pennsylvania State University, University Park, PA (United States)

关键词: Storage;    12 Management Of Radioactive Wastes, And Non-Radioactive Wastes From Nuclear Facilities;    Sediments;    36 Materials Science;    Radioactive Wastes;   

DOI  :  10.2172/838394
RP-ID  :  EMSP-86984--2003a
RP-ID  :  FG07-99ER15012
RP-ID  :  838394

美国|英语

来源: UNT Digital Library

【 摘 要 】

Waste produced during the production and purification of weapons-grade nuclear material is stored in underground tanks at the Hanford site in Washington state. Since their burial, many of the storage tanks have leaked caustic nuclear waste contaminated with radioactive Cs-137, Sr- 90, and I-129 into the surrounding soils. The effects on the natural soils of these particular radionuclides in a highly caustic solution are largely unknown, as are the transport properties. Recent work has shown that zeolite-type aluminosilicate phases form in clay mineral systems weathered under near-field exposure to Hanford-type nuclear waste. The transport and sequestration of Cs-137, Sr-90, and I-129 in the sediments is partially controlled by the cation adsorption-exchange properties of the parent clay minerals and these zeolitic neophases. This project seeks to isolate the effects of these new phases on contaminant adsorption by identifying the contaminant binding structures, assisting in the identification of neoformed phases, probing the kinetics of phase formation and contaminant uptake, and investigating the mobility of these specific radionuclides in silicon-induced precipitates from synthetic tank waste representative of that at the Hanford site. In work at Penn State University, these objectives are being accomplished through the use of solid-state nuclear magnetic resonance (NMR) spectroscopy.