Studies of Energetic and Nonenergetic Materials Immersed in Molten Salts

Abstract

Immersion of energetic materials into molten-salt baths is being considered as a method for their safe destruction. In the present research, a solid energetic material, 2,6-dinitrotoluene (DNT), and a solid nonenergetic material, solidified n-dodecane, were studied. Cylindrical samples initially about 1 cm in diameter were injected into salt baths, and data were taken photographically. As salt temperatures increased, surface regression rates increased. Thin gas films were observed to exist around the samples. In addition, DNT bubbles displayed sudden rapid size increases with strong increases in opacity suggesting that chemical reactions were taking place in the bubbles; these behaviors were not observed with bubbles from the dodecane samples. Temperature profiles inside the samples were measured using thermocouples; data indicate that thin thermal boundary layers existed near the sample surfaces. Estimates suggest that sample lifetimes and surface regression rates were controlled by convective heat transfer through the gas films, even for the energetic material, with radiant heat transfer being subdominant. Sample lifetimes were in the range 1-2.5 s. In addition to advancing fundamental knowledge, these results are of use for aiding in the design of molten-salt reactors.