Entrainment of soluble and non soluble tracers from a boiling water surface Original Research Article

The entrainment of droplets containing solid or soluble fission product simulants from the surface of a boiling water pool into a gas atmosphere was investigated at conditions, which are relevant to a severe core melt scenario. Different air–steam ratios and at pressures (2–6 bar) were considered in the model containment. Measurements carried out far above the air-liquid interface are compared with the predictions of existing correlations. Favorable agreement is obtained with the correlation of Kataoka and Ishii [Int. J. Heat Mass Transf. 27 (1984)] for the entrainment of soluble fission products into an air–steam atmosphere. Results from integral measurements however suggest that improved correlations should be based on the Froude, Weber and Rayleigh numbers, and separate between entrainment and sedimentation.