Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.
TOSQAN is an experimental program undertaken by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in order to
perform thermal hydraulic containment studies. The TOSQAN facility is a large enclosure devoted to simulate typical accidental
thermal hydraulic flow conditions in nuclear Pressurized Water Reactor (PWR) containment. The TOSQAN facility, which is
highly instrumented with non-intrusive optical diagnostics, is particularly adapted to nuclear safety CFD code validation. The
present work is devoted to study the interaction of a water spray injection used as a mitigation means in order to reduce the gas
pressure and temperature in the containment, to produce gases mixing and washout of fission products. In order to have a better
understanding of heat and mass transfers between the spray droplets and the gas mixture, and to analyze mixing effects due to
spray activation, we performed detailed characterization of the two-phase flow.