Effect of Mid Span Mixing Grid on EPR Core DNBR Margin

The effect of mid span mixing grid (MSMG) on the EPR core thermal-hydraulic parameters and minimum DNBR was analyzed by employing FLICA Ⅲ-F sub-channel code. The results show that DNBR margin of EPR core can be improved respectively about 24% and 28% for normal condition with cosine and AO equal to +9% power distributions by adding 4 MSMGs on AFA 3GLE fuel assembly, while thenpressure drop in EPR core increases about 10.1%.