Energetic Analysis of Experimental Behavior of Molten SnxLiy When Impacted by a Vertical Column of Water
Abstract The SnxLiy and PbxLiy, alloys are being considered as liquid breeding materials for fusion reactor applications. Thus, it is important to understand the safety implications associated with inadvertent contact with water used in an indirect cycle. In an effort to study this interaction, experiments have been conducted with these molten alloys when impacted with a vertical 2.4-m-tall column of water at 30 and 60°C. The qualitative behavior of Sn75Li25 was compared under similar conditions with other candidate molten metals, specifically tin, lead, and a lead-lithium alloy, Pb83Li17. Multiple pressure spikes were produced with Sn and Pb, while essentially only one initial pressurization followed by a few strongly damped minor peaks was observed with the different alloys containing lithium. Results with tin-lithium are quite similar to pure tin and lead behavior. Dynamic pressure traces from the physical and chemical reactions are discussed and used to compare the energetics associated with the two different alloys. The pressure traces were used to calculate experimental impulses, which represent the energetics of the reactions. The impulse ratio of the experimental and the theoretical values increased in the tests of alloys containing lithium. (Hydrogen production from lithium-water reactions was quite rapid and copious.) In contrast, hydrogen production with tin-lithium was modest and quite similar to the lead-lithium alloy. It was found that the metal-water interactions of Pb83Li17 and Sn75Li25 are quite similar and have significantly reduced energetics from those of pure lithium and other reactive metals being considered.
Studies with respect to the estimation of liquid metal blanket safety
Abstract One current concept in fusion blanket module design is to utilize water as the coolant and liquid lithium-lead as the breeding/neutron-multiplier material. Considering the possibility of certain off-normal events, it is possible that water leakage into the liquid metal may occur due to a tube rupture and provoke a pressure increase in the blanket module. For realistic simulation of such in-blanket events, the BLA nket S afety T est facility (BLAST) has been built. It simulates the transient event by injecting subcooled water under high pressure into a stagnant pool of liquid Li 17 Pb 83 . The reaction kinetics data required for the quantification of the chemical reaction have been measured in a separate facility. These results are more general since measurements have been performed with various LiPb-alloys. Among other results, the experiments indicate that an upper static pressure limit, which corresponds to the actual water injection pressure, was not exceeded. Current results are presented.
Inherent/passive safety for fusion
Fusion's success depends on having attractive safety and economic features. One of fusion's inherent advantages is the potential for being safer than other technologies. We should work toward making the potential become a demonstrable, cost-saving reality. Fusion safety should not be hard to prove nor require many expensive, complicated active engineered safety systems.