A Model for Droplet Size Distribution in Flashing Jets

Abstract

During some postulated accident scenarios for a CANDU PHWR, high-enthalpy coolant is released into the containment as a two-phase jet. The liquid portion of the jet atomizes into droplets due to flashing, hydrodynamic drag and instabilities. This jet may contain dissolved fission products. The fraction of jet fluid airborne as aerosol-sized droplets limits the postulated release of fission products to the outside atmosphere, and so is of interest. A model has been developed to predict the droplet size distribution produced by such a jet. It incorporates the aerodynamic and thermal fragmentation of the jet and is based on a Monte Carlo technique.