Research and development in Japan on long-lived nuclide partitioning and transmutation technology

Measures to treat and dispose of radioactive waste are one of the most important issues in the development and application of nuclear energy. The Atomic Energy Commission has carefully considered how to classify radioactive waste properly and how to dispose of it according to these classifications. For high-level radioactive waste (HI-W), efforts towards implementing disposal have been progressing steadily. At the same time, recognizing the nature of the radioactive nuclides contained in HLW, the aim since the early days of nuclear energy has been to develop technology either to separate useful elements and nuclides in order to reuse them effectively, or to transmute long-lived nuclides into short-lived or stable - i.e., non-radioactive - forms by irradiation. In Japan, reference to P&T technology for long-lived and other nuclides first appeared in the Long-Term Program for Nuclear Research, Development and Utilization (or long-term nuclear program) back in 1972. That program noted the need for research and development in order to ensure effective processing of radioactive waste. Under that program, in 1988, the Atomic Energy Commission's Advisory Committee on Radioactive Waste Measures issued a report entitled, Long-Term Program for Research and Development on Nuclide Partitioning and Transmutation Technology.(1) This can be considered to have been the first systematic R&D program on P&T technology in Japan. It presented a plan for R&D that ran from 1988 to 2000 and was divided into two phases: Phase I, covering the first four to nine years, which included evaluation of various concepts and R&D on key technologies; and Phase II, covering the next four to nine years, which included engineering experiments on key technologies and demonstrations. The Atomic Energy Commission's Advisory Committee on Nuclear Fuel Cycle Back-End Policy investigated and considered matters concerning P&T technology for long-lived and other nuclides, based on the evaluation schedule stated in the long-term nuclear program issued in 1994. The Committee issued a report entitled, Research and Development in Japan on Long-Lived Nuclide Partitioning and Transmutation Technology in March, 2000. The outline of this report is as follows.