Investigation of sodium cooled fast reactors (SFR) is ongoing in France. There have been a number of experiments carried out within the framework of Generation IV reactor program at CEA. MICAS experimental facility is one of these experiments, which represents the hot pool facility of a SFR in a 1/6th scaled down model. Recent studies carried out in MICAS, explore the probability of vortex formation at one of the internal heat exchangers (IHX) nozzle, which can further lead to gasentrainment from the pool surface. Therefore, MICAS facility has extensively tested different flow conditions and the non-symmetric IHX operation.
Multi-scale calculations are carried out using Computational Fluid Dynamics (CFD) in order to better understand the vortex formation at the IHX plenum and the associated possible gas entrainment into the vortex from the hot pool free surface. This paper presents the computational analysis with focus on operation of the SFR, which tries to replicate the possibility of vortex formation, under non-symmetric operation of two out of four IHXs. The analysis was carried out with the open source code TrioCFD. This study provides valuable insight into possibilities, constrains and limitation of the used CFD calculation methodology.