Ashanti J. Pyrtle, Ursula S. Wilborn, Ellery D. Ingall, Meg Grantham, and W. Crawford Elliott 2003. Radionuclide Distribution and Geochemistry of the Savannah (Georgia) Aquatic Environment.

The Savannah River drainage basin spans parts of North Carolina, South Carolina and Georgia (USA). This riverine-estuarine-marine system receives both airborne and land-derived material including naturally occurring and anthropogenic radionuclides. For those radionuclides that are not permanently sequestered at their introduction site, the aquatic system often becomes the major mechanism by which the radionuclides are transported. As such, riverine, marsh and estuarine sediments from the Savannah region were examined in order to identify processes affecting the local radionuclide distribution. In addition to examining ¹³⁷Cs and ²¹⁰Pb_xs activities, clay mineralogy, grain-size characteristics as well as elemental cesium (Cs) and manganese (Mn) concentrations were determined. Preliminary results indicate that ¹³⁷Cs activities in the Savannah area sediments range from below detection limits to 3.42 dpm/g. Radiogeochemistry patterns suggest that in the marsh, steady-state particle mixing primarily controls downcore particulate ¹³⁷Cs distribution and burial processes whereas in the local riverine and estuarine environments, non-steady state physical transport processes govern post-depositional ¹³⁷Cs distribution. In addition to physical processes, clay mineralogy and grain-size differences may also influence the ¹³⁷Cs retention ability of the Savannah area aquatic sediments. This research is apart of a larger on-going investigation of Savannah area aquatic radiogeochemistry.