A Novel High-Order Surface Characteristics Scheme for the Neutron Transport Equation in 2D Unstructured Meshes
Résumé
Monte Carlo simulation is the reference method for reactor physics applications. Yet, the use of Monte Carlo for time-dependent problems (operational or accidental reactor transients) is still in its infancy, mainly due to the inherent challenges posed by the simultaneous presence of delayed neutron precursors and neutrons: the vast separation of their typical time scales, coupled to fission-induced correlations, leads to huge fluctuations and variance jumps. We will review the variance-reduction techniques recently developed in order to cope with these issues and enable the simulation of kinetic Monte Carlo in reactor physics and present a novel systematic approach possibly leading to considerable gains in computing time for a given target accuracy.