A notice of opportunity from the Nuclear Regulatory Commission was published in the November 22 Federal Register to intervene in an adjudicatory hearing on Kairos Power’s application for a construction permit to build the Hermes 2 test reactor facility in Oak Ridge, Tenn.

When it comes to advanced, high-temperature reactors—using working fluids such as molten salt, high-temperature gases, or sodium—there simply are not many qualified materials for nuclear component construction. Alloy 617 is not a new material, but it made the news after Idaho National Laboratory announced that it was recently added to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code for high-temperature nuclear applications, bringing the total number of qualified high-temperature materials to six.