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Plutonium in Groundwater


Migration of plutonium and other radionuclides in groundwater is a major issue at several DOE sites. Earlier assumptions that contaminants would migrate only very slowly in the vadose and groundwater zones have been questioned based upon findings of prior monitoring programs and independent review. One explanation put forth to account for more rapid migration is the association of plutonium with groundwater colloids, which are thought to enhance transport of particle reactive compounds in groundwater. We have brought new methods developed in ocean sciences to bear on the sampling and analyses of colloids in groundwater. Our research has focused on two important DOE sites, namely the Savannah River Site (SRS) and the Hanford Site, and the project involves direct collaboration with Dr. Jim Kelley and colleagues at the Pacific Northwest labs. We have found at both a sites a low colloidal association for plutonium in groundwater, using what we feel are improved techniques, which better represent ambient groundwater speciation. In addition, at SRS, we document a new Pu source not considered in current models, namely 244Cm - another transuranuium element produced at SRS that migrates more rapidly than Pu and decays to 240Pu in groundwater.

Field sampling at Hanford site.

Selected Scientific Publications

Pike, S.M., H. Dulaiova, K.O. Buesseler (2009). Assessment of size-fractionated species of curium-244 via alpha spectroscopy in groundwater. Journal of Radioanalytical and Nuclear Chemistry, 282, 1009. DOI: 10.1007/s10967-009-0214-4.

Buesseler, Ken O., Daniel I. Kaplan, Min Han Dai and Steven Pike (2009). Source-Dependent and Source-Independent Controls on Plutonium Oxidation State and Colloid Associations in Groundwater. Environ. Sci. Technol. 2009, 43 (5): 1322-1328 DOI: 10.1021/es8028318.

Hassellöv, M., K.O. Buesseler, S.M. Pike and M. Dai (2006). Application of cross flow filtration for the determination of colloidal abundances in suboxic ferrous-rich ground waters. Science of the Total Environment, 372(2-3): 636-644.

Dai, M., K.O. Buesseler and S.M. Pike (2005). Plutonium in groundwater at the 100K-Area of the U.S. DOE Hanford Site. (PDF) Journal of Contaminant Hydrology, 76: 167-189.

Dai, M.H., J.M. Kelley and K.O. Buesseler (2002). Sources and migration of plutonium in groundwater at the Savannah River Site. (PDF) Environmental Science and Technology, 36: 3690-3699.

Buesseler, K.O., M. Dai and M. Hassellöv (2003). Commentary on: "Trace Metal Levels in Uncontaminated Groundwater of a Coastal Watershed: Importance of Colloidal Forms (PDF)" by Sañudo-Wilhelmy et al. ES&T, 37(30): 657-658.

Dai, M.H., K.O. Buesseler, J.M. Kelley, J. E. Andrews, S. Pike and J.F. Wacker (2001). Size Fractionated Plutonium Isotopes in a Coastal Environment. (PDF) J. Environ. Radioactivity, 53 (1), 9-25.

Dai, M., K.O. Buesseler, P. Ripple, J. Andrews, R. Belastock, O. Gustafsson and S.B. Moran (1998). Evaluation of two cross-flow ultrafiltration membranes for their ability to isolate marine organic colloids. (PDF) Marine Chemistry, 62, 117-136.

Conference Presentations and Posters

October 2006 Powerpoint Presentation by K. Buesseler at ERSP PI workshop in Oak Ridge
Buesseler, K., M. Dai, D. Kaplan and S. Peterson
Understanding plutonium variability and mobility in groundwater at the Savannah River site (PDF)

May 2000 Powerpoint Presentation
Speciation and isotopic composition of plutonium in the groundwater at the DOE Hanford (PDF)

Funding Agencies

We gratefully acknowledge the support of the U.S. Department of Energy.