August 1, 2012.
Uranium is one of the most common and problematic contaminants at the Department of Energy legacy sites. The level of oxidative uranium, U(VI), in groundwater exceeds that of EPA standards and remains persistent. The goal of this research is to study the geochemistry of uranium in the aquifer and understand the underlining cause of the persistence of uranium plumes in groundwater. In this study, we used X-Ray fluorescence spectroscopy to determine the elemental composition of sediments collected at a former uranium mining site, Old Rifle (Colorado). The XRF results show that the naturally reduced sediments contain higher concentrations of uranium than non-naturally reduced sediments and that the uranium is highly correlated with sulfur. We will continue to examine the naturally reduced sediments for carbon content and also sulfur and uranium speciation. We also want to look
at the particle size of the sediments to see whether permeability has
an effect on the oxidation of uranium.
SLAC National Accelerator Laboratory (SLAC)
This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013 and Grant No. 0833353. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).