Computational Fluid Dynamic Studies on Gas Entrainment in Fast Breeder Reactors

Primary sodium pools in fast reactors are covered with argon. There is strong potential for argon gas entrainment into sodium and associated reactivity perturbations if the free surface velocity is large. Basic CFD studies have been carried out on ideal models and the threshold value of free surface sodium velocity that avoids gas entrainment is arrived at employing the VOF method. Subsequently, 3-D CFD studies have been carried out for PFBR hot pool and the free s urface velocity is estimated to be 1.15 m/s. To reduce this value below the threshold limit, a horizontal baffle device has been identified.