Experimental Study for Evaluation of Spreading Behavior of Free-Falling Molten Core With Floor Impingement

Understanding the spreading behavior of the molten core is important for predicting the progress of severe accidents and for smooth decommissioning work. In this study, we performed molten metal drop experiments using Sn and Cu to obtain fundamental data and its uncertainties that can be used to verify the analysis model and to evaluate the effect of scaling parameters on the spreading and deposition behaviors. We obtained spreading area and deposition thickness of the metals after floor impingement. The standard deviation on average were 6.0% and 6.7% for the thickness and the area, respectively. In addition, the correlation with each dimensionless number was confirmed, and strong correlations were obtained between the deposition behavior and the Re number, and between the spreading behavior and the Pe number. We constructed a correlation equation using our experimental data as a function of Re number, We number, Fr number, Pe number, and dimensionless length (L/d). The errors for our experimental data were within 30%.