Results of SCTF reflood tests

Two-dimensional effects on the core cooling behavior during the reflood phase of a PWR-LOCA were experimentally studied by using the Slab Core Test Facility (SCTF). Heat transfer was enhanced for the high power bundles and degraded for the peripheral low power bundles due to the effect of radial power distribution. In addition the quench propagation in the bundles corresponding to the peripheral bundles of a PWR core was suppressed by the non-uniform water accumulation in the upper plenum. It was found that the radial temperature distribution which was induced by the radial power distribution was the dominant factor of the two-dimensional thermal-hydraulic behavior in the core