Research and development on accelerator-driven transmutation system at JAERI

Sasa, Toshinobu   ; Oigawa, Hiroyuki ; Tsujimoto, Kazufumi ; Nishihara, Kenji  ; Kikuchi, Kenji; Kurata, Yuji; Saito, Shigeru   ; Futakawa, Masatoshi  ; Umeno, Makoto*; Ouchi, Nobuo ; Arai, Yasuo; Minato, Kazuo ; Takano, Hideki

JAERI carries out research and development on accelerator-driven system (ADS) to transmute minor actinides and long-lived fission products in high-level radioactive waste. The system is composed of high intensity proton accelerator, lead-bismuth spallation target and lead-bismuth cooled subcritical core with nitride fuel. About 2500 kg of minor actinide is loaded into the subcritical core. Annual transmutation amount using this system is 250 kg with 800MW of thermal output. A superconducting linear accelerator with the beam power of 20 - 30MW is connected to drive the subcritical core. The nitride fuel without uranium, such as (Np, Am, Pu)N, is selected. The fuel irradiated in the ADS is reprocessed by pyrochemical process followed by the re-fabrication of the fuel. Many research and development activities are under way. Especially, to study and evaluate the feasibility of the ADS from physics and engineering aspects, the Transmutation Experimental Facility (TEF) is proposed under a framework of the High-Intensity Proton Accelerator Project.