The topic of nuclear nonproliferation (both cooperative and non-cooperative) is broad, drawing upon interdisciplinary scientific, political and social sciences. At Los Alamos National Lab, as well as across the entire National Nuclear Security Administration complex, virtually all aspects of this urgent problem are being addressed. Research is ongoing in the safeguarding special nuclear materials (SNM), remote and in situ sensing of nuclear facilities, producing proliferation-resistant nuclear fuels and medical targets, technical forensics and in policy. Tracking and accounting for SNM involves not only the direct physics measurements of neutron and gamma emissions, but also the attendant accounting methodologies, much like tracking banking transactions. State-of-the-art micro-calorimeter and X-ray fluorescence techniques are improving our ability to assay plutonium. Remotely inferring reactor core burn up rates might be possible via an anti-neutrino technique that uses the containment structure itself as the sensor. New polymer ligand films are being developed that will selectively pre-concentrate plutonium into thin film geometry to increase selectivity and sensitivity for assaying actinides and their isotopes. Remote sensing can range from space-borne sensors looking at gamma, X-ray, optical and radio frequency signals to spectroscopic returns from laser induced breakdown spectroscopy inside a building. Powering reactors and manufacturing medical targets using low enriched uranium (LEU) and designing efficient fuels with taggants to identify their source all lower the proliferation risk. Social and political science play equally important roles in understanding both the problems and the solution.
Dan Holden currently serves as the program manager for nuclear nonproliferation verification science and technology at Los Alamos National Lab, a broad research portfolio that funds approximately one hundred staff members. His research interests are in radio frequency remote sensing of both natural and manmade phenomena. After earning his Bachelors’ Degree at UC Berkeley in Astronomy, he switched to physics where he earned graduate degrees at the New Mexico Institute of Mining and Technology and Clemson University specializing in lightning and thunderstorm research. He enjoys whale watching along the coast of Northern California from a sailboat that he keeps on San Francisco Bay.