Publication Details
Geochemical Controls on Contaminant Uranium in Vadose Hanford Formation Sediments at the 200 Area and 300 Area, Hanford Site, Washington.Citation
McKinley JP, JM Zachara, J Wan, DE Mccready, and SM Heald.2007."Geochemical Controls on Contaminant Uranium in Vadose Hanford Formation Sediments at the 200 Area and 300 Area, Hanford Site, Washington."Vadose Zone Journal 6(4):1004-1017. doi:10.2136/vzj2006.0184
Abstract
differences in uranium contributed by contaminated vadose sediments at two locations was investigated. At the BX tank farms, alkaline waste was accidentally released to a thick vadose zone. At the 300 Area, waste of variable acidity was released by unintended infiltration through the base of settling ponds. The waste form at the BX site was devoid of dissolved silica, and reacted with fluids trapped in microfractures to precipitate uranyl silicates. These secondary deposits were isolated physically from the vadose pore space and are not readily leached into pore fluids. At the 300 Area, the aluminum-rich waste precipitated on the surfaces of sediment clasts, forming a microporous reservoir of solid-phase uranium. Interaction of this coating with water in transit through the vadose zone provides a persistent source of dissolved uranium to groundwater.
