Experimental investigation of single helium bubbles rising in FLiNaK molten salt

State of Knowledge on Aerosols and Bubble Transport for Mechanistic Source Term Analysis of Molten Salt Reactors

“…Chavez et al [88] recently investigated single helium bubbles rising in a static column of molten FLiNaK at 600 °C to determine bubble size, rise velocity, trajectory, and shape. A high-speed camera provided images of single bubbles as they rose through a vertical quartz tube that was built into the experimental apparatus, and Particle Image Velocimetry (PIV) was applied to measure the velocity field of the liquid molten salt that surrounded the bubble.…”

“…• Gas flow rate • Bubble size, concentration, and interfacial area between bubbles and liquid • Salt temperature • Presence of impurities expected in an MSR (e.g., graphite dust, water content, oxygen content, fine metal particles from structural components, etc.) More advanced characterization techniques for discriminating bubbly flow dynamics and breakup than those employed during the MSRP have been developed and recently demonstrated for aqueous systems [120] and molten salt systems [88]. In addition, methods of determining bubble size in molten salts beyond collecting visual images have been briefly explored, including passing acoustic waves of different frequencies through the liquid and measuring absorption and employing light scattering techniques [84].…”

Development of Integrated Thermal Fluids Modeling Capability for MSRs

“…Recent experiments were performed by Chavez et al [42] that are relevant for the validation of the SAM gas transport model. In the experiments, helium bubbles were injected, one-by-one, in the bottom of a tube filled with molten, stagnant LiF-NaF-KF (46.5-11.5-42 %).…”

“…A quartz viewing chamber near the top of the tube was used to photograph the bubbles using a high-speed camera, which allowed the bubble shape and size to be determined as well as the bubble velocity. A picture of the experimental facility can be found in Chavez et al [42].…”