Future perspective of nuclear energy in Japan and the OMEGA program Original Research Article

Nowadays, about one third of the total electricity in Japan is supplied by nuclear power plants. It is estimated that the fraction of nuclear power will be increased much more in future. The primary nuclear policy of Japan adopts a uranium and plutonium fuel cycle system. The recovered plutonium will be recycled in light water reactors as MOX fuels in near future. Vitrified high-level radioactive wastes will be stored for 30 – 50 years prior to the ultimate geological disposal. On the other hand, in order to develop future technological possibilities in management and disposal of high-level radioactive wastes, the Atomic Energy Commission of Japan initiated the first phase of the OMEGA program, which is consisting of R&D activities on partitioning processes, transmutation systems, and related underlying technologies. Results of the first phase activities show an important possibility that the radiotoxicity of the original high-level radioactive wastes can be reduced to less than one hundredth after several hundreds years by using a process based on partitioning and transmutation. An intense spallation neutron source is evaluated to be one of the most effective neutron suppliers for the transmutation process. JAERI has been making a significant effort to develop a high power proton linac for an intense spallation neutron source, which can be utilized for demonstration of the transmutation process, and more widely utilized in fields of nuclear science and technology.