Thermal- and ignition-type steam explosions of single drops of molten aluminum

The contact of aluminum-based melts with liquid water has been shown to be explosive in many experiments performed by the aluminum industry and in several nuclear reactor experiments and accidents including NRX, SL-1, and SPERT. To obtain quantitative information relating to the fuel/coolant interactions that might occur with aluminum-based fuel, a laboratory-scale experimental study is being performed at Sandia National Laboratories. The overall objective of this research program is to provide an understanding of the mechanism of steam explosions with the melt compositions expected in several hypothetical core meltdown accident scenarios in production reactors. In this program, it has been demonstrated that rapid exothermic metal-water reactions can accompany the steam explosions under certain conditions, resulting in enhanced energy release and in the concomitant generation of hydrogen