Design optimization of ADS plant proposed by JAERI

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

JAERI is conducting R&D on the Accelerator Driven System (ADS) to transmute minor actinides (MAs) contained in the high-level radioactive waste under the OMEGA (Options Making Extra Gains from Actinides and fission products) program. The present study discusses the design of the ADS plant and various R&D on the ADS. The reference design of ADS plant in JAERI is the 800 MWth, Pb-Bi eutectic (LBE) cooled, tank-type subcritical reactor loaded with (MA+Pu) nitride fuel. LBE is selected as a spallation target material. In our results of the optimization study on the neutronics of the ADS, we have adopted the maximum multiplication factor (k) of 0.97. From the results of the thermal-hydraulic analysis around the LBE spallation target, partition wall and flow control nozzle are required to keep the structural integrity around the core and the beam window. Feasibility of beam window was also discussed for transient conditions of proton beam.