Numerical Analysis on the Scaled Air Cooled RCCS Test Facility

The Korea Atomic Energy Research Institute (KAERI) has been studying a prismatic type of High Temperature Gas cooled Reactor (HTGR) as a generation IV reactor. An HTGR may remove a residual heat without a supply of electricity under a severe accident by a Reactor Cavity Cooling System (RCCS). The RCCS uses only natural circulation of air to remove heat transferred by the radiation from the reactor pressure vessel. KAERI has been testing a scale downed RCCS to investigate the feasibility of a passive heat removal system. As the size is reduced, the non dimensional parameters are applied to maintain similarity. After the test, a Computational Fluid Dynamic (CFD) analysis is conducted to design the RCCS system. In the present study, the different types of turbulence models are applied to investigate the flow characteristics in the riser duct based on the test condition. (author)