Computational Fluid Dynamics Analysis of Thermal Mixing in the AP600 Upper Head

Abstract

The paper discusses studies conducted to determine the extent of thermal mixing in the upper head region of the AP600 pressurized water reactor (PWR). This information is ultimately useful in the assessment of thermally-induced stresses in the upper head itself and the components adjacent to it. Coolant temperature profiles in the upper head region are also of interest in the evaluation of transients in which buoyancy forces are significant, such as natural circulation (NC) cooldown.