Systematic experimental investigation on the characteristics of molten lead-bismuth eutectic fragmentation in water

Highlights: • A series of visualized fragmentation experiments were conducted by releasing molten LBE into a subcooled water pool. • The parameter effects on the fragmentation process and debris properties are studied in detail. • A new correlation is developed by fitting the experimental data to predict the average fragment size. • The maps to predict the fragment sphericity and debris porosity based on the experimental results are established. In this study, to enhance the understanding of the thermo-hydraulic characteristics during the direct contact of molten lead-bismuth eutectic (LBE) and water, a series of visualized fragmentation experiments were conducted by releasing molten LBE into a subcooled water pool using the VTMCI (Visualized Thermo-hydraulic characteristics in Melt-Coolant Interaction) facility developed at Sun Yat-Sen University. The parameter effects, including melt temperature, water subcooling, boiling mode, penetration velocity, nozzle diameter and melt mass, on the fragmentation process and debris properties are studied in detail. A new correlation is developed by fitting the experimental data, which can simultaneously consider the effect of melt temperature, water subcooling, penetration velocity and nozzle diameter, to predict the average fragment size. The maps to predict the fragment sphericity and debris porosity based on the experimental results are established.