Analysis of FLECHT and FLECHT-SEASET Reflood Tests with RELAP5/MOD2

Simulations of FLECHT and FLECHT-SEASET, unblocked forced flow reflood tests, were performed using RELAP5/MOD2 code reflood capabilities. The predictions of the high flooding injection rate and steam cooling tests were in good agreement with the measurements. The low flooding rate tests showed a tendency to predict lower peak cladding temperatures than the data and unrealistic void fraction oscillations. The spikes in void fraction histories were flow-regime dependent. The prediction for the quench times at the upper bundle elevations was overestimated.