Validation of SuperMC code by simulating a Metal-cooled fast reactor - BFS-62-3A

Appraising the credibility and competency of a computer simulation can be done by verification and validation procedure. This study has been performed to validate SuperMC for precise simulation of metal-cooled fast reactors using a high profile heterogeneous critical core, the BFS-62-3A. This critical assembly - being attractive because of its multi-zoned structure with MOX fuel, high axial and radial heterogeneity, diversity of materials and their compositions, and eligibility/feasibility to benchmark the experiments and calculations - is a full scale mock-up of BN-600 hybrid core with different fuel regions and stainless steel reflector. Modeling of complex core design, calculation of desired parameters, and visualization of the complete model were all performed using SuperMC. The deviations of less than 0.4% and 0.8% appeared in the calculated values of multiplication factor and spectral indices respectively while average discrepancies for radial fission rate distributions in the fuel region and control rod worths were found to be 2.7% and less than 5% respectively that showed a good agreement of the simulation results with benchmark's measured data. Present work thus validated SuperMC's capability to precisely model a complex heterogeneous reactor core and to accurately calculate various neutron physics parameters that ultimately rendered a high level of confidence on its use in fast-spectrum and MOX-fueled nuclear fission reactors.