Development of Super-COPD code for plant dynamics, 9; Numerical simulation of natural circulation test in JOYO with MK-II core

Hiyama, Tomoyuki ; Doda, Norihiro  ; Ohshima, Hiroyuki; Iwasaki, Takashi*

As the upgrade of the Super-COPD code for plant dynamics, the analysis for natural circulation tests during JOYO MK-II core is being carried out to verify the natural circulation applicability of the code. In this study, focused on the heat exchange characteristic of the intermediate heat exchanger (IHX), the analysis has been performed to estimate the sensibility of the IHX modeling for natural circulation characteristics. We tried to analysis the momentum and the energy transport in JOYO MK-II by the IHX model with or without additional bypass channel. As a result, it is found that the reverse flow in the IHX bypass is able to simulate by the modeling of the bypass flow and this reverse flow gives effects on the natural circulation characteristics in the primary cooling system.