Feasibility of lead-bismuth-cooled accelerator-driven system for minor-actinide transmutation

Tsujimoto, Kazufumi ; Oigawa, Hiroyuki ; Kikuchi, Kenji; Kurata, Yuji; Mizumoto, Motoharu; Sasa, Toshinobu   ; Saito, Shigeru   ; Nishihara, Kenji  ; Umeno, Makoto*; Takei, Hayanori   

Feasibility was discussed for lead-bismuth cooled accelerator-driven system (ADS) to transmute minor actinides partitioned from high-level radioactive waste. Since lead-bismuth will cause considerable corrosion and erosion effects at high temperature, the fuel clad temperature must be kept as low as possible. Moreover, the most critical issue of ADS design is engineering viability of the high-power spallation target and the beam window. Thermal-hydraulic and structural analysis was carried out for both the fuel assembly and the beam window. In addition to the analysis in steady state, transient behaviors were also studied during typical transient and unprotected accidents. The results showed that engineering viability is reasonably achievable in nominal operation. For beam trip which will be the most frequent transient, the number of events to cause the failure of the beam window is estimated as more than . For safety aspects of ADS during unprotected accidents, estimated results showed that ULOF would cause the most significant problem, if beam operation was kept. Therefore, high reliability of the beam shutdown is required for the ADS safety.