Development of a mechanistic evaluation method for wastage environment under sodium-water reaction accident

Uchibori, Akihiro ; Ohshima, Hiroyuki

For assessment of the wastage environment under tube failure accident, a mechanistic computer code called SERAPHIM calculating compressible multicomponent multiphase flow with sodium-water chemical reaction has been developed. In this study, applicability of the SERAPHIM code including the numerical model for liquid droplet entrainment and transport was investigated through the analysis of the basic experiment and the experiment under actual condition of the steam generator. In the analysis of the basic experiment, the calculated pressure variation during liquid droplet entrainment was consistent with the experimental result. In the analysis of the actual condition, the calculated temperature distribution agreed with the measurement result well. The region with higher impingement velocity of the liquid droplet was close to the wastage region confirmed in the experiment. It was demonstrated that the SERAPHIM code could predict the wastage environment under the actual condition.