Section Head, Operations A1 Section, Division of Operations A, Department of Safeguards, International Atomic Energy Agency since 1991. Section Head, 1984-1991, Group Leader, 1982-1984, Safeguards Inspector, 7982, SGOC2, Division of Operations C, Department of Safeguards, International Atomic Energy Agency, Vienna. Director, Safety & Safeguards Division, 1976-1979, Section Head, Radiation Safety Section, 1973-1976, Atomic Energy Bureau, Ministry of Science & Technology, Representative of Korea.
Junior Researcher, Radiation Safety Section, Bureau of General Affairs, Office of Atomic Energy, Representative of Korea, 1966-1973. Rch Assistant, Chem Division, Atomic Energy Rch Institute, Korea, 1963-1966. Korean Air Force, 1959-1961.