Reactor core and actinide production evaluation based on different loading material of recyled spent nuclear fuel of LWR in FBR

Reactor core analysis is one of the important factor for evaluating reactor operation and safety concern as well as the evaluation on fuel breeding of nuclear fuel to show nuclear fuel sustainability. Actinide compositions including plutonium and minor actinides production are also evaluated for estimating the plutonium non-proliferation aspect as well as for nuclear fuel breeding aspect. Loaded initial fuels in fast breeder reactor (FBR) are based on the spent nuclear fuel (SNF) of light water reactor (LWR). Those SNF of LWR will vary depending on LWR operation such as fuel burnup levels as well as cooling time process after the reactors are shutdown. In order to optimize the analysis of FBR design, a large FBR type with core and blanket fuel arrangements as driver fuels and breeding fuel regions as well as adopted some specific fuel batches and cycle length systems were adopted as a basic analysis case. Some obtained results are showing that reactor core performance such as criticality and breeding ratio are depending on the loaded fuel composition as well as operating reactor operation. Less criticality condition and higher breeding ratio are obtained by longer cooling time process of loaded SNF LWR. In addition, higher burnup of loaded SNF LWR achieves less criticality condition, while fuel breeding ratio profile is obtained higher for higher burnup. Loaded fuel composition of U-TRU fuel gives higher breeding ratio and its breeding ratio become higher for longer cooling time of loaded fuels. Actinide element compositions become less at end of equilibrium cycle (EOEC) of FBR, except for plutonium (Pu) and curium (Cm) which obtains higher composition. It shows the utilization of trans-uranium fuel type such as U-TRU type gives a significant production of minor actinide which can be estimated to contribute for reducing the excess reactivity as well as to increase nuclear fuel breeding capability. Less criticality is effective to reduce the excess reactivity at beginning of cycle for safety concern and higher breeding profile is indicating that more fuel sustainability aspect of nuclear fuel is gained.