About the Author

Dr. CHARLES E. TILL received his Ph.D. in nuclear engineering from the Imperial College, University of London, in 1960. Early in his career he worked on a variety of reactor concepts, including the U.K. gas-cooled reactor, the Canadian heavy water reactor and the U.S. light water reactor upon joining Argonne National Laboratory in 1963. There, after a year or two, Dr. Till became been deeply involved in the development of the fast breeder reactor. From 1980 onward, as Associate Laboratory Director for Engineering Research, Till led the large Argonne reactor development program for seventeen of its most innovative and productive years. He created the Integral Fast Reactor concept and spearheaded the development of its underlying technologies. An advanced reactor technology with revolutionary improvements in safety, nuclear waste disposal, and resource usage, this was a major effort involving a thousand to two thousand engineers and supporting staff and carried out over the ten year period from 1984 to 1994 at Argonne's two sites, its main laboratory in Illinois, and its big reactor facilities on the desert in Idaho. A Fellow of American Nuclear Society and recipient of its Walker Cisler Medal for distinguished contributions to fast reactor development, he was elected to the National Academy of Engineering in 1989. Dr. YOON IL CHANG received his Ph.D. in nuclear science from the University of Michigan in 1971. After a short time at Nuclear Assurance Corporation working on nuclear fuel cycle services, he joined Argonne National Laboratory in 1974, hired initially by Till as a reactor analyst. With the initiation of the Integral Fast Reactor program in 1984, as Till's deputy and as the program's General Manager, he managed the program through its ten years of development. Bringing all the many parts on IFR program together in a coherent and focused program, it was Chang who saw to its progress day by day, month by month. Upon Till's retirement in 1998, Dr. Chang succeeded him as Associate Laboratory Director for Engineering Research, and also served as Interim Laboratory Director. The recipient of outstanding alumni awards from the University of Michigan and Seoul National University, a Fellow of American Nuclear Society and recipient of its Walker Cisler Medal, he received the Department of Energy's Ernest Orlando Lawrence Award in 1994 for his technical leadership role in the IFR development.