Coupled Hydrological and Geochemical Processes Governing the Fate and Transport of Radionuclides and Toxic Metals in the Hanford Vadose Zone
At the D.O.E. Hanford Reservation, accelerated migration of radionuclides has been observed in the vadose zone underlying the tank farms. Our goal is to provide an improved understanding and predictive capability of the coupled hydrogeochemical mechanisms responsible for observed migration. Our approach is to perform a suite of experiments ranging from novel surface interrogation techniques (e.g., XAS) to miscible displacement experiments on disturbed and undisturbed sediments from the Hanford, Plio-Pleistocene and Ringold formations. Results indicate during unsaturated conditions hydrologic processes governing transport are a strong function of sediment layering in the Hanford and Ringold formations. The transport of radionuclides and toxic metals (U, Cr(VI), Cs, Sr and Co) is influenced by reactive geochemical nonequilibrium, sedimentary mineralogy and solution chemistry. This research will provide new insights into how physical and mineralogical heterogeneities (e.g. stratification, pore regime connectivity, mineral composition along flowpaths) influence contaminant retardation and degree of geochemical nonequilibrium during transport.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stanford University, Palo Alto, CA; Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC) (US)
- OSTI ID:
- 826389
- Resource Relation:
- Conference: 225th American Chemical Society Meeting, New Orleans, LA (US), 03/23/2003--03/27/2003; Other Information: PBD: 27 Mar 2003
- Country of Publication:
- United States
- Language:
- English
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Fate and Transport of Radionuclides Beneath the Hanford Tank Farms: Unraveling Coupled Geochemical and Hydrological Processes in the Vadose Zone
Fate and Transport of Radionuclides Beneath the Hanford Tank Farms: Unraveling Coupled Geochemical and Hydrological Processes in the Vadose Zone