In October, staff at Kairos Power’s testing and manufacturing facility in Albuquerque, N. M., began transferring 14 tons of molten fluoride salt coolant into an Engineering Test Unit (ETU)—the largest transfer of FLiBe (a mixture of lithium fluoride and beryllium fluoride) since the Molten Salt Reactor Experiment in 1969.

Having completed its review of the construction permit application for Kairos Power’s Hermes test reactor early last month, the Nuclear Regulatory Commission’s Advisory Committee on Reactor Safeguards (ACRS) recently submitted its conclusions to the agency, recommending approval.

Kairos Power needs a source of high-purity fluoride salt to test its molten salt reactor design and ultimately to serve as the coolant in its grid-scale fluoride salt–cooled, high-temperature reactor (KP-FHR). As part of a cooperative development agreement with Materion Corporation, Kairos Power designed a molten salt purification plant (MSPP) that has just been commissioned at Materion’s campus in Elmore, Ohio.