Simulation of Hydrogen Distribution in Containment Studies Facility: A Parametric Study Using the CFD Code FDS

Hydrogen transport behavior in the containment of NPPs is an extremely complex phenomenon and must be properly understood for the assessment of the overall plant safety under accident conditions. A case study has been carried out to predict the hydrogen concentration profile in the multi-floor multi-compartment geometry of Containment Studies Facility (CSF), to understand the complex hydrogen transport behavior in general and the influence of the location and direction of injection of hydrogen, in particular. A computer code FDS has been used for conducting these studies. The results indicate a strong possibility of stratification of the lighter gas within as well as across the compartments during both the injection and post injection phases. After the momentum effects due to the convective currents die down, stratification was noted to be more or less stabilized. Molecular diffusion was seen to have insignificant diffusion.