Performance evaluation of UO2/graphene composite fuel and SiC cladding during LBLOCA using MARS-KS

The fuel rod performance of enhanced thermal conductivity on UO2/graphene composites and SiC cladding was investigated through a LBLOCA (Large Break Loss of Coolant Accident) analysis using the MARS-KS (Multi-dimensional Analysis of Reactor Safety-Korean Standard). The benefits increased monotonically with increasing thermal conductivity in terms of reduced radial fuel rod temperature and PCT (Peak Cladding Temperature). The performance of the UO2/graphene composite fuel and SiC cladding was assessed in an OPR-1000 (Optimized Power Reactor-1000) during a LBLOCA. The UO2/graphene composite fuel is to increase the power density and maximum allowable fuel burnup. Graphene can be a promising material for developing advanced nuclear fuel, because of its properties of high thermal conductivity and low absorption cross section. SiC cladding material has been proposed as the replacement for the traditional Zircaloy4 and Zirlo, as SiC has excellent resistance to the high-temperature and high-radiation environment. The results confirmed the LBLOCA performance related to PCT of the UO2/graphene composite fuel and SiC cladding, while maintaining safety margins.