[en] KNGR adopted independent four train safety injection system which injects water into the downcomer directly through the DVI line in order to enhance safety, economics, and operability. By the adoption of DVI, more complicate phenomena, compared to current cold leg injection plant, can be occurred in the downcomer during LBLOCA. Therefore, in this paper, the effect of ECC bypass and steam condensation during LBLOCA is evaluated. As the results, KNGR DVI design has sufficient margin although ECC bypass and steam condensation make some negative effect to core reflood