Over his career, Dr. Sugiyama has worked on research for nuclear reactor safety and risk assessment at the Japan Atomic Energy Research Institute (JAERI) and the Japan Atomic Energy Agency (JAEA).

As a leading expert in the field of nuclear reactor and fuels, Dr. Sugiyama contributed to international activities such as the Halden Reactor Project, the Committee on the Safety of Nuclear Installations (CSNI), and the Working Group on the Analysis and Management of Accidents (WGAMA) of the Organisation for Economic Co-operation and Development/Nuclear Energy Agency (OECD/NEA).

As a seconded staff to the NRA of Japan, Dr. Sugiyama engaged in conformity review of commercial power reactors to the new regulatory requirements concerning severe accidents.