The scientific safety assessment of the Kansai Research Reactor, issued by the Science Council of Japan in 1958, was the first appearance of high technology in Japanese society, introducing 'Risk Thinking' or the first time into the scientific assessment of the professional community in Japan. Chapter 1 presents an outline of the Kansai Research Reactor and the Science Council of Japan. The citizens' movement against the Kansai Research Reactor was the first movement against a nuclear reactor in the world. Chapters 2 and 3 explore the apprehension within the Science Council of Japan concerning its safety assessment concerning the reactor, based on documents preserved by the Science Council of Japan and the Ibaraki city assembly. These chapters also analyze problems with 'Risk Thinking' that the constructor of the Kansai Research Reactor tried to use in the negotiations with residents of Ibaraki city. The paper concludes with a plan for the application of high technologies to Japanese society.