Berkeley opens FLiNaK test bed

The University of California-Berkeley now has a forced-flow molten fluoride salt test bed that circulates molten FLiNaK-a salt mixture containing lithium fluoride, sodium fluoride, and potassium fluoride-under conditions representative of many molten-salt nuclear energy applications.

Established by Berkeley professor Guanyu Su, the facility can operate between 500°C and 700°C, reach flow rates of up to 60 liters per minute, and maintain a temperature difference of up to 100 K between its hot and cold legs, according to the university.

First experiments: The test bed was commissioned earlier this year, during which the team demonstrated force-flow operation at temperatures above 600°C.

The team is now conducting a systematic study of heat transfer between molten salt and air using a mini-channel compact heat exchanger. According to the university, the work is intended to provide experimental data to evaluate high-temperature component performance and validate models for future molten salt small reactors and microreactors.

Future research: The test bed is designed to support work in both fission and fusion, with research areas including tritium transport and recovery for fusion blanket systems; high-temperature, latent-heat thermal energy storage; additively manufactured compact heat exchangers for advanced reactors, and thermal sensors for measuring velocity profiles in molten-salt flows.