Chemical and Isotopic Signatures in Nuclear Forensics

About the Topic: Analysis of environmental samples collected for nuclear forensics purposes typically involves determination of isotopic composition, which can sometimes (but not always) reveal information about nuclear events or processes that resulted in the anthropogenic radioactivity. This information is referred to as the “isotopic signature”.  Sequential extractions have been used for many years to determine chemical forms of contaminants for environmental regulatory purposes and clean-up decisions, and they can reveal “chemical signatures” about the events or processes that resulted in contamination.  Coupling sequential extractions with isotopic determinations in nuclear forensics analyses provides an opportunity to link isotopic and chemical signatures, which can improve confidence in identifying the relevant nuclear event or process. This approach shows promise, particularly when coupled with nuclear fuel cycle process knowledge.  Examples involving contaminated nuclear sites in the US and Russia will be discussed.

About the Speaker: Sue B. Clark is the regents distinguished professor of chemistry with tenure at Washington State University. She also holds an appointment to the US Nuclear Waste Technical Review Board, appointed in 2011 by President Barack Obama. Her current research areas include the environmental chemistry of plutonium and other actinides, chemistry of radioactive waste systems, and actinide separations. She has over 100 peer-reviewed publications in these areas. 

Her research support includes grants and contracts from the U.S. Department of Defense, the U.S. Department of Homeland Security, the U.S. Nuclear Regulatory Commission, and the U.S. Department of Energy's Office of Science and National Nuclear Security Administration. Prof. Clark is a fellow of the American Association for the Advancement of Science (AAAS), the American Chemical Society (ACS), and is the 2012 recipient of the ACS’s Olin-Garvan Medal. Prof. Clark is an editor for the journal Radiochimica Acta. Professor Clark holds a BS degree in Chemistry from Lander College (Greenwood, SC) and MS and PhD degrees in Chemistry from Florida State University (Tallahassee, FL).