Analysis of core thermal hydraulics under natural circulation condition with plant dynamics analysis code Super-COPD

Hamase, Erina ; Doda, Norihiro  ; Nabeshima, Kunihiko  ; Ono, Ayako ; Ohshima, Hiroyuki

Flow re-distribution in a fuel subassembly is one of the most important phenomena under natural circulation in the sodium fast breeder reactor from the viewpoint of safety assessment. The core model of the plant dynamic code (Super-COPD) was validated through analyses using natural circulation experimental data obtained in the plant dynamics test loop (PLANDTL). The simulated sodium temperatures at the top and middle of the heated region in the subassembly showed good agreement with the experimental data. It was confirmed that the core model of Super-COPD can precisely reproduce the flow re-distribution in the subassembly.