was Regents’ Professor in the Department of Earth and Planetary Sciences at the University of New Mexico. During 2010-2011 he was a Visiting Professor at the Center for International Security and Cooperation at Stanford University. His professional interests are in mineralogy and materials science, and his research has focused on radiation effects in complex ceramic materials and the long-term durability of radioactive waste forms. He is a fellow of the American Association for the Advancement of Science, the Geological Society of America, and the Mineralogical Society of America, and a member of Sigma Xi. He is a past president of the International Union of Materials Research Societies and the Mineralogical Society of America. Dr. Ewing is currently a Fellow of the American Geophysical Union, the Materials Research Society, the American Ceramic Society, and the Geochemical Society. In 2006, he was awarded the Lomonosov Great Gold Medal of the Russian Academy of Sciences, and in 2007, he was awarded an Honorary Doctor of Université Pierre et Marie Curie. He received M.S. and Ph.D. degrees in geology from Stanford University.
Dr. Joonhong Ahn is a professor of radioactive waste management and nuclear fuel cycle at the University of California, Berkeley. His research interests include the performance assessment of deep geological disposal systems for high-level radioactive wastes (HLW), especially analyses of mass transport through engineered barriers and the natural geological barrier. He is also interested in the future of nuclear energy in the Asia/Pacific region. He has published papers on (1) the transport of radionuclides through a fractured geological medium; (2) the mass transport of radionuclides in a shallow-land repository for low-level wastes; (3) the sensitivity analysis of radionuclide transport through a fractured medium; (4) radionuclide diffusion in a fracture network by applying percolation theory and fractal geometry; (5) the mass transfer and transport analyses for engineered barriers; (6) bentonite expansion into fractures in a host rock surrounding the engineered barriers and mass transport in the same region; (7) analysis of the autocatalytic criticality of buried fissile materials; (8) mass-flow analysis for the nuclear fuel cycle; and (9) waste-form modeling by applying linear-programming approach. Professor Ahn currently serves as a member of the Nuclear and Radiation Studies Board of the National Academies, and the chair of the Book-Publishing Committee of the American Nuclear Society. In the past he has served as a member of the planning committee for the Atomic Energy Society of Japan (1992-1995). He was at the review committee (1992) for the first official report to the Atomic Energy Commis-