(An) experimental study of thermal-hydraulic phenomena in the downcomer with direct vessel injection of APR1400 during LBLOCA reflood phase

Abstract

An experimental study has been performed to investigate thermal-hydraulic phenomena in the downcomer with Direct Vessel Injection (DVI), which is a new Safety Injection System (SIS) of Korea Advanced Power Reactor 1400 (APR1400). In this study, several separated experiments have been performed based on the thermal-hydraulic phenomena in the downcomer. The performed experiments are divided into two categories: steam/water interaction and boiling in the downcomer. Three experiments have been performed to investigate the steam/water interaction in the downcomer using a plane-channel type test section, which is scaled down as the 1/7 ratio of the prototype reactor (APR1400). First, the water film spreading test is performed and its results are compared with both the experiment with real size of DVI diameter in order to verify the suggested scaling law by KAERI (Korea Atomic Energy Research Institute) and the experiment with a 1/7 scaled cylindrical-type test section in order to see the cu