Evaluation of uncertainties in FEMAXI-6 calculations with MOX fuels irradiated in Halden reactor

Yamaji, Akifumi; Suzuki, Motoe; Okubo, Tsutomu

FEMAXI-6 is considered to be a powerful tool for developing an advanced LWR concept that utilizes MOX fuel rods, such as FLWR. In order to use this code, verifications with LWR MOX fuel irradiation data is necessary. In this study, the MOX fuel test data obtained from Halden reactor is used to verify FEMAXI-6. Up to about 40 GWd/t, the pellet temperature calculations through the gap conduction calculations are important to predict the fuel rod behavior. Especially, the FGR, pellet relocation, densification, and swelling are influential. These models in FEMAXI-6 have been developed based on UO irradiation experience. However, the results show that these models can also be applied to LWR MOX fuel analysis except the FGR model.