Numerical Study of Interaction Between NPP Containment Atmosphere and Passive Autocatalytic Recombiners

The interaction of a nuclear power plant containment atmosphere with a Passive Autocatalytic Recombiner (PAR) was simulated using the Computational Fluid Dynamics code CFX4.4. The main purpose of the simulation was to observe containment atmosphere mixing phenomena, influenced by the PAR, during a postulated severe-accident scenario. A two-dimensional geometrical model of the simulation domain was developed. The containment was represented by an adiabatic rectangular box with a PAR situated at an intermediate elevation near a wall. The flow in the simulation domain was modelled as singlephase and the turbulence was modelled with a Menter modified low-Reynolds k-e model. The results of the simulation are presented and analysed.