Calculation of the Neutron Distribution Function in Slabs with Extended Heterogeneous Fuel Zones

The possibility of non-physical local neutron distributions in weakly coupled systems in Monte Carlo calculations of the criticality is engendering the development of new algorithms. New possibilities of the TDMCC code for calculating neutron distribution functions in weakly coupled systems are presented. The established distribution of fission neutrons which is obtained in criticality calculations by different Monte Carlo methods – conventional method of generations, fission matrix method, and method of generations using the concept of sub-ensembles – is analyzed in supercritical slabs with extended fuel zones. The features of each method in calculations of symmetric slabs with extended heterogeneous fuel zones are analyzed.