Maximum wake temperature and Nusselt number behind blockages in sodium-cooled bundles

Two important correlations have been obtained to calculate the maximum coolant temperature and the Nusselt number in the wake (the flow recirculating zone) downstream of blockages in 19-pin sodium-cooled bundles. These correlations can be applied to predict the maximum temperature rise and the average heat transfer coefficient behind small non-heat-generating blockages in the fuel assemblies of the FFTF and the CRBR for the wide range of flow and power conditions. Experiments with partial blockages in simulated LMFBR fuel assemblies have been performed at the THORS facility (formerly called FFM) of the Oak Ridge National Laboratory. Nineteen-pin sodium-cooled bundles were used, which had the same pin diameter and pitch as the CRBR and the FFTF fuel assemblies