REFLOOD INVESTIGATION OF MODEL FUEL ASSEMBLIES OF LIGHT-WATER REACTORS FOR A LOSS-OF-COOLANT ACCIDENT

摘要

The results of a reflood investigation of model WER and PWR fuel assemblies for maximum design-basis and beyond design-basis accidents performed on the RBHT, SVD, and PARAMETR stands are presented. The variation ranges of the regime parameters are: initial temperature of fuel element 460-1600℃; mass velocity of water 47-160 kg/(m~2-sec), underheating at the entry into the model fuel assembly 11-108℃; pressure 0.14-0.42 MPa; and, linear heat flux density simulating the residual heat release 0-2.3 kW/m. A colligating relation describing the experimental data to within 30% is obtained for the wetting front of model fuel assemblies, which makes it possible to calculate the cool-down time of model fuel assemblies with different designs and evaluate the reflooding time of WER and PWR.