The effect of homogenization on the neutronic parameters and transmutation of GFR-2400 fast reactor fuel assembly

Highlights: •Heterogeneous and homogeneous models of GFR2400 fuel assemblies have been designed. •Homogenization effect of GFR2400 has been quantified for open cycle operation. •Very good agreement was found between homogeneous and heterogeneous models. •The inner core operates as a breeder while the outer one operates as a burner. •The generated minor actinides amount is very small for both core assemblies. -- Abstract: Fast reactor concept like the 2400 MW GCFR is considered a promising candidate for future sustainable and economic nuclear power systems. It is a highly innovative system with advanced geometry and fuel materials (Ceramic fuel pellets of mixed uranium-plutonium carbide within fuel pins). The active fuel region of this reactor is divided radial to two core zones namely, inner core fuel assemblies (IC), and outer core fuel assemblies (OC). In the present study Monte Carlo transport code, MCNPX is used to design heterogeneous and homogeneous models for inner and outer core fuel assembly. The deigned models have been used to simulate the neutronic behavior and fuel transmutation during open cycle operation and to study the effect of Homogeneity inside the fuel assembly. The results of heterogeneous and homogeneous models were compared with each other and good agreement was found.