Improving neutron economy of a Lead-Bismuth Eutectic-Cooled reactor using Modified-CANDLE axial fuel shuffling

LWRs do not effectively utilize natural uranium as fuel, harnessing less than 1% of its energy potential. Furthermore, initial studies show that conventional fast reactors require higher uranium enrichment and fuel reprocessing, which are expensive technology. The Modified-CANDLE strategy enables the direct use of natural uranium without enrichment or reprocessing. This study implements modified-CANDLE axial fuel shuffling in a lead-bismuth eutectic (LBE)-cooled fast reactor to examine its impact on reactor performance compared to radial fuel shuffling. The calculations use the SRAC code and the JENDL 4.0 nuclear data library. This research evaluates the effective multiplication factor (k-eff), power density, power peaking factor (PPF), and neutron leakage over a 15-year fuel cycle. The research indicates that axial fuel shuffling is more efficient at sustaining the reactor's reactivity than radial shuffling. Therefore, axial fuel shuffling can improve neutron economy compared to radial fuel shuffling.