Interaction between natural convection and condensation heat transfer in the passive containment cooling condensers of the ESBWR reactor

The passive containment cooling condensers (PCCC) are the crucial part of several new reactor designs. In this paper we have developed several models to compute the heat transfer coecients for the following cases: (i) condensation in presence of noncondensable gases inside the PCCC tubes; (ii) laminar natural convection for vertical cylinders; (iii) turbulent natural convection for vertical cylinders. Thesemodels have been implemented in the TRAC-BF1 code, and we have studied the interaction between the conservation regime inside the condenser tubes and the natural convection outside