SFR Breakeven Core Designs with Various Rated Powers

The conceptual design of the breakeven core with metallic fuel for a 1,200 MWe SFR is being developed under the framework of the Gen-IV SFR development program. According to the draft road map for a sodium cooled fast reactor (SFR) in Korea, the operation of a demonstrative prototype reactor will be started in 2028. There is still room to decide on the rated power and the type of core, breakeven core or TRU burner, of the commercial SFR in the future for which the prototype plant will be designed. An increased rated power generally enhances the economics of a nuclear power system, and it also changes the neutronic performances of the reactor core. Therefore, the effect of the rated power on the nuclear design has been examined for a SFR breakeven core. Same design bases were applied to the conceptual design of each core with different rated powers. It was assumed that a metallic fuel of TRU-U-10%Zr was loaded into the core with an enrichment split. All the cores under investigation were divided into three concentric regions; inner, middle, and outer core regions. The neutronic core performance of all these cores has been calculated and compared with each other. It was observed that a larger core size following the increased rated power improved the fuel economy. The axial height of the core needs to be decreased with a higher rated power in order to meet the sodium void reactivity target. The number of control rods has also to be increased as the core power rises