In this study, modeling and simulation of two in-series UF 6 separator condensers was performed to improve the previous models for prediction of the amount of mist output, physical properties of condensing gases and condensed mass of UF 6 . These two shell and tube condensers were modeled via control volumes with finite length in axial direction of input gases. The equations of mass , energy and momentum balance were written for each of the condensers and then surface temperature of UF 6 condensed layer on the condenser tube was determined by trial and error method. The temperature,, total mass of condensed UF 6 in the condensers, gas composition and physical properties, concentrations of the mist and the mass and heat transfer parameters were calculated at each time step during the process. Comparison of the modeling predictions with Isfahan UCF industrial data in regard to important variables indicated a very good compatibility. The average error between the modeling and industrial data for the first and second condenser were calculated to be 1.39 and 2.24%, respectively. Key Words Uranium hexa fluoride, Condensation, Condenser, Modeling
