An experimental parametric study of the high pressure melt ejection from two different scale reactor cavity models

A parametric study of the high pressure melt ejection(HPME) from two small-scale(1/25th and 1/41st) transparent reactor cavity models of the YoungGwang(unit 1 and 2) has been performed. Wood's metal and water have been used as melt simulants while high pressure nitrogen and carbon dioxide are used as driver gases to simulate the blowdown steam and gas from the breach of the reactor pressure vessel. Experimental data for the fraction of melt simulant retained in the cavity model(Yf) during a postulated scenario of the HPME from PWR pressure vessel have been obtained as a function of various test parameters. These data have been used to develop a correlation for Yf that fits all the data(a total of 313 data points) within the standard deviation of 0.054 by means of dimensional analysis and nonlinear least-squares optimization technique. The basic effects of important parameters used to describe the HPME accident sequence on the Yf are also determined based on the correlation obtained here and experimental evidence. (Author)