Experimental Behavior of Molten Sn_xLi_y When Impacted by a Vertical Column of Water

Sn_xLi_y and Pb_xLi_y eutectic alloys are being considered as liquid breeding materials for nuclear fusion applications. Thus, it is important to understand the interactions that might occur if this alloy were inadvertently to contact water. In an effort to study this interaction, experiments have been conducted with the molten alloys when impacted with a vertical 2.4 m tall column of water at 30°C. The qualitative behavior of Sn₇₅Li₂₅ was compared with similar impacts of other candidate molten metals, specifically a lithium-lead alloy, Pb₈₃Li₁₇¹. Multiple pressure spikes were produced with Sn and Pb, while essentially only one initial pressurization followed by a few strongly damped minor peaks were observed with the different lithium alloys. Hydrogen production from the lithium water interaction was measured and used to determine the extent of the chemical reaction. Dynamic pressure traces from the physical and chemical reactions are discussed and used to compare the energetics associated with the two different eutectics. It was found that the water/eutectic interactions of Pb₈₃Li₁₇ and Sn₇₅Li₂₅ are quite similar and significantly reduced from that of pure lithium and other reactive metals.