Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.

Nuclear thermal hydraulics—for light water reactors or advanced reactors cooled by gas, metal, or salt—is all about defining safety and performance margins as things heat up.

The Thermal Hydraulic Experimental Test Article (THETA) at Argonne National Laboratory is now operating and providing data that could support the licensing of liquid-metal fast reactor designs by validating thermal-hydraulic and safety analysis codes. The new equipment has been installed in Argonne’s Mechanisms Engineering Test Loop (METL), and its first experiments are supporting data validation needs of Oklo, Inc., by simulating normal operating conditions as well as protected and unprotected loss-of-flow accidents in a sodium-cooled fast reactor.