CFD analysis of the MYRRHA primary cooling system

MYRRHA is a pool type reactor system, with all the systems immersed in the lead-bismuth eutectic coolant. Due to corrosion and solidification concerns, there is a strong incentive to know the flow patterns inside the primary cooling system. Since the flow inside the vessel is typically three-dimensional, it is simulated by the computational fluid dynamics software FLUENT. For these simulations, the Renormalization group k - ∈ turbulence model has been chosen. This turbulence model is used in combination with physical simplifications and a porous medium approach to simulate the reactor behavior. Nevertheless, these simplifications show to lead to a rather good representation of the design parameters. The simulations for nominal conditions show that, even with a high temperature margin derived from the ASCHLIM benchmark simulations, no corrosion or solidification temperature limits are exceeded. Nevertheless, some design features are found that might need some reconsideration. In addition to that, an extrapolation was made to a steady state, natural convection scoping simulation.