Abstract: Understanding coupled chemical, physical, and biological processes controlling the mobility and speciation of radionuclides is critical for predicting the fate and transport of radionuclides in the environment and during waste processing. There are multiple chemical and physical mechanisms by which radionuclides can be sequestered which will minimize their potential for migration and reduce the risk to human and environmental health during waste disposition or environmental remediation. This presentation will focus on the chemical mechanisms of sequestration including sorption, ion exchange, complexation, oxidation/reduction, and precipitation/co-precipitation. Laboratory and field-based experiments will be discussed with specific examples involving sequestration of uranium, neptunium, and plutonium. 

Biography: Dr. Brian A. Powell holds the Fjeld Professorship in Nuclear Environmental Engineering and Science and is jointly appointed in the Department of Environmental Engineering and Earth Sciences, School of Civil and Environmental Engineering and Earth Sciences as well as the Department of Chemistry at Clemson University. Dr. Powell is also a joint appointee at the Savannah River National Laboratory with the objective of building research collaborations between Clemson and SRNL. Dr. Powell’s research focuses on the treatment and storage of radioactive waste and the migration of heavy metals and radionuclides in the environment from natural or engineered systems. He has conducted sponsored research in a wide range of projects dealing with topics of environmental chemistry, radiochemistry, geochemical reaction modeling and thermodynamic database development, evaluation of nanoparticle behavior, subsurface migration of actinides and fission products, and related topics. Dr. Powell was awarded the 2014 South Carolina Governor’s Young Researcher Award for Excellence in Scientific Research, a U.S. Department of Energy Early Career Research Award, and named the 2022 Clemson University Senior Researcher of the Year.