Fundamental Study on Two-Phase Flow Characteristics in Chimney of Pb-Bi Cooled Direct Contact Boiling Water Fast Reactor

The lead-bismuth-steam two-phase flow in the chimney of the lead-bismuth cooled direct contact boiling water fast reactor (PBWFR) was simulated experimentally using water-air two-phase flow system and analytically using the multi-dimensional two-fluid model computer program ACE-3D for the design of the ring header nozzles and chimney of the PBWFR. It has been found that the downward flow appeared in the chimney according to the analytical results. The analytical simulation will be verified by the experiment data, and the air injection flow rate, and the number, caliber and arrangement of injection nozzles in the ring header will be chosen adequately to improve the performance of the lift pump. Also, the analytical program will be extended for the simulation of a steam-Pb-Bi flow system.