Alperin, M. J. University of North Carolina at Chapel Hill, alperin@marine.unc.edu
Suayah, I. J. University of North Carolina at Chapel Hill, suayah@email.unc.edu
Benninger, L. K. University of North Carolina at Chapel Hill, lbenning@email.unc.edu
DeVito, C. M. University of North Carolina at Chapel Hill,
Cutshall, N. H. Oak Ridge National Laboratory,

 
A COMPARISON OF FALLOUT PLUTONIUM AND CESIUM IN SEDIMENTS FROM THE NORTH CAROLINA CONTINENTAL SLOPE
 
Fallout radionuclides are widely used as tracers of modern sedimentary processes. In particular, Pu and Cs profiles are powerful tools for estimating accumulation and bioturbation rates. Although both isotopes are expected to have a similar fallout pattern, their distribution in sediments may be distinct due to the different chemical properties of the two elements. In order to test for differential deposition and mobiity, we measured detailed depth distributions of Pu and Cs in nine cores from the North Carolina continental slope. Sediment inventories of Pu and Cs were highly correlated (r2=0.92), although the activity ratio of Cs to Pu (3.3) was far below the ratio in atmospheric deposition (120). The Pu and Cs profiles were accurately simulated using a two-layer, diffusive mixing model and assuming that both isotopes were not mobile. The model suggests that the solid-liquid distriution coefficient (Kd) for Cs in these sediments is >500 mL/g.
 
Day: Friday, Feb. 5
Time: 11:15 - 11:30am
Location: Sweeney Center
 
Code: CS63FR1115S