David L. Clark is a Los Alamos National Laboratory (LANL) Fellow and Director of the Laboratory’s National Security Education Center. He received a B.S. in chemistry in 1982 from the University of Washington, and a Ph.D. in 1986 from Indiana University. Clark was a postdoctoral fellow at the University of Oxford before joining Los Alamos National Laboratory as a J. Robert Oppenheimer Fellow in 1988. He became a Technical Staff Member in the Isotope and Nuclear Chemistry Division in 1989. Since then, he has held various scientific and leadership positions at Los Alamos, including Solubility Task for the Yucca Mountain Project, Source Term Test Program for the original license application of the Waste Isolation Pilot Plant (WIPP), program manager for plutonium aging and pit lifetime assessments, and Capture Manager for the Plutonium Science and Research Strategy. More recently, he co-led the chemistry investigations into the 2014 WIPP radiological release. Clark served as inaugural Director of the Glenn T. Seaborg Institute for Transactinium Science between 1997-2009. He has served the DOE as a technical advisor for environmental stewardship including the Rocky Flats cleanup and closure (1995-2005), closure of High-Level Waste tanks at the Savannah River Site (2011), and as a technical advisor to the DOE High Level Waste Corporate Board (2009-2011). He is a Fellow of the American Association for the Advancement of Science, and a Los Alamos Laboratory Fellow. He is the recipient of two ACS national awards - the Nobel Laureate Signature Award (1988) and the Glenn Seaborg Award in Nuclear Chemistry (2017). He has also been honored with several Defense Programs Awards of Excellence, the most notable in 2006 for his work on pit lifetime assessments for the nation. His research interests are in the molecular and electronic structure of actinide materials, applications of synchrotron radiation to nuclear security, behavior of actinide and fission products in the environment, the aging effects of nuclear weapons materials, and the education of judges on the methods of science. He is an international authority on the chemistry and physics of the actinides, and has published nearly 200 peer-reviewed publications, encyclopedia and book chapters. He is the co-Editor of the seven volume Plutonium Handbook, portions of which were written while a CISAC Visiting Scholar in 2015.