Fast Reactor Research and Development Programme in Japan

The present paper reviews the fast reactor research and development programme, with the stress on fast reactor physics and related safety problems. The first part of the paper deals with the research and development programme, which was prepared by a Special Committee for Power Reactor Development Project in compliance with the request of the Japan Atomic Energy Commission. The 100-MW(th) fast experimental reactor and fast prototype reactor are to be sodium-cooled. The former is scheduled to be critical in 1972, and some of the related R and D activities have already commenced. The prototype is to be developed at the latest by the early 1980s. A prototype advanced converter project is also now under way in Japan, and a new organization was established in October 1967 to develop both the fast reactor and the advanced converter. The second part of the paper describes the research and development programme connected with fast reactor physics and safety problems related to the fast reactor project, and also outlines the present state of activities in Japan. The JAERI fast critical assembly, which attained criticality at the end of April 1967, is scheduled to play an important role in obtaining information on the reactivity effects in large fast reactors, and will be used to check designs of the experimental fast reactor and the prototype fast reactor. Also, other establishments plan to prepare additional experimental facilities for research on this subject. In many establishments theoretical research is increasing on the following topics: nuclear data for fast reactors, fast neutron energy spectrum, reactivity coefficients, design study of large fast reactors, analysis of fast reactor kinetics and accidents. The study of fast reactor safety in Japan is so far mainly confined to the theoretical approach;' however, the experimental research programme is also being prepared on such subjects as containment system design studies, sodium technology and fuel development. (author)