The Japanese Thorium Program

Abstract

The Japanese nuclear energy policy is based on the uranium–plutonium cycle including application of a fast breeder reactor. In 2010, the Japan Atomic Energy Commission launched a council to construct a new framework of nuclear energy policy. Although progress has been halted after the Fukushima accident caused by the Great East Japan Earthquake, the application of thorium fuel is discussed as one of the alternative options for future nuclear fuel cycles and it is recommended to precede in basic research and developments. Two research working groups related to thorium-fueled reactors and the thorium fuel cycle were set up in the Atomic Energy Society of Japan in 2013. One is the “Research Committee on Nuclear Applications of Molten Salt”. The committee was established to survey molten salt technology including molten-salt-cooled reactors, molten-salt-fueled reactors, and dry reprocessing processes. The committee planned to summarize the current state of the art and issues of molten-salt-fueled systems. The other is the “Working Group for Thorium Fuel Applications in Light Water Reactors and Fast Reactors”. The objective of the working group is to summarize the current status and issues for application of solid-form thorium fuel in a U–Pu fuel cycle. Through these two different approaches, it is expected that the opinion on thorium fuel applications in Japanese nuclear fuel cycle policy will be summarized from an academic point of view. This paper summarizes the outline of activities for the two groups and introduces the application of accelerator-driven systems for thorium breeding.