The Argonne National Laboratory (Lemont, Illinois, USA) successfully swapped out a key component in its liquid metal test loop, which is being used to advance a new class of reactors.
The upgrade is the first of its kind in the United States in over 30 years, according to Argonne, and will help inform the design and operation of sodium-cooled fast reactors that are under development by several U.S. companies.
Out with the Cold (Trap)
In this upgrade, Argonne researchers replaced an aging cold trap device on the Mechanisms Engineering Test Loop (METL), which is used to purify more than 750 gallons (2,839.1 L) of reactor-grade sodium. The METL is the nation’s largest facility for sodium-cooled fast reactors, and Argonne is training a new crop of workers to operate them.
Fast reactors can be designed to run on recycled fuel from other reactors to drastically improve the fuel efficiency, waste reduction, and overall performance of nuclear power plants.
According to Argonne, the United States has not operated a fast reactor since the Experimental Breeder Reactor II shut down in the mid-1990s. However, projected increases in power demands have many companies revisiting the technology.
The METL first started operations in 2018 to help advance research on liquid metal technologies and is currently being used by industry partners to test different components.
The cold trap helps filter out oxide impurities present in the sodium that is used to cool the reactor. If not controlled, these impurities could cause accelerated corrosion of the systems and lower flow rates, resulting in degraded performance. Replacing the device was required to meet the design specifications of future experiments.
“The METL team is revitalizing and developing these key operations and maintenance techniques to ensure we are able to deploy U.S. sodium-cooled reactors,” says Matthew Weathered, Ph.D., principal nuclear engineer. “It’s exciting.”
Welded Construction Techniques
The METL facility utilizes welded construction techniques consistent with the maintenance of any advanced liquid metal reactor. The sodium was frozen and cut out before a new cold trap was welded on the piping.
Laboratory officials consulted with French Alternative Energies and the Atomic Energy Commission prior to the maintenance work.
The entire process took two weeks to complete after months of planning, while the rest of the test loop remained hot, molten, and in operation.
Coming Soon
The replacement was funded through the U.S. Department of Energy’s National Reactor Innovation Center (NRIC), which funds the METL’s operations and maintenance activities.
NRIC is tasked with building or enhancing the department’s infrastructure for the successful deployment of advanced nuclear technologies.
Going forward, METL plans to expand its testing capabilities in 2026 by activating a fifth test vessel for more liquid metal tests.
Source: U.S. Office of Nuclear Energy, www.energy.gov/ne.
