Dr. Choi is the associate director at the Berkeley Nuclear Research Center at the University of California, Berkeley. Previously, he was a visiting professor at the Tokyo Institute of Technology and a project professor for the Global-Center of Excellence Program at the University of Tokyo. Before that, Dr. Choi worked for the Lawrence Livermore National Laboratory (LLNL) for 21 years, where he remains a retired associate. Dr. Choi was also a Science Fellow at the Center for International Security and Cooperation at Stanford University and worked at the International Atomic Energy Agency. Prior to joining LLNL in 1987, Dr. Choi had 13 years of industrial experience working for Bechtel. He has a Ph.D. in Nuclear Engineering from UC Berkeley.