Publications Details

Steam Explosions of Single Drops of Core-Melt Simulants: Triggering, Work Output and Hydrogen Generation

Nelson, L.S.; Hyndman, D.A.; Duda, P.M.

We have studied triggering of fuel-coolant interactions, the work performed against the surrounding coolant during the interaction, and the generation of hydrogen produced by melt water chemical reactions with laboratory-scale experiments. We used single drops of three core-melt simulants: (a) molten stoichiometric thermite-generated iron-aluminum oxide melts to simulate the core-melt material that might be produced in the severe accident of an oxide fueled reactor; (b) molten aluminum to simulate melt that might be produced in the severe accident of a nonpower reactor; and (c) an intermediate material, aluminum-enriched iron aluminum oxide thermite, that might simulate severe meltdown of an oxide-metal dispersion fuel (cermet). As a result of these experiments, we have concluded that the peak pressure (or impulse) of the transient is not a governing parameter for the triggering of steam explosions of single drops of melt. We have observed maximum pressure-volume work outputs produced by the aluminum-rich and stoichiometric thermite melts of about 70 and 25 J/g of melt; the corresponding values for molten aluminum at 1273 and 1473 K are about 14 and 21 J/g of melt. The extent of metal-water reaction for the stoichiometric and aluminized melts were 13 and 19%. The aluminum melts at 1273 and 1473 K produced approximately 1 and 3% metal-water reaction.