nuclear milestone graphic
Researchers load in testing device to TREAT
THOR experiment in Broad Use Specimen Transient Experiment Rig (BUSTER) being loaded into the TREAT reactor for transient testing.
Idaho National Laboratory

Researchers at Idaho National Laboratory (INL) developed a device that can test advanced reactor fuel experiments in its Transient Reactor Test (TREAT) Facility

The new experiment device is part of a joint project between the United States and Japan that will be used to perform the world’s first transient tests on fast reactor fuels in more than two decades. 

Unlocking New Testing Capabilities

INL recently completed initial testing on the newly developed capsule. The specialized device houses fuel experiments in TREAT where it can mimic the conditions of fast reactors during postulated accident conditions.  The device also hosts state-of-the-art instrumentation required to monitor the fuel’s real-time response to these conditions.

INL researcher preps experiment device
Researcher working on THOR-C-2 assembly at Idaho National Laboratory.
Idaho National Laboratory

The lab repurposed fresh legacy fuel pins from its former EBR-II reactor for experimental commissioning tests. Researchers are now shifting their focus to transient experiments on high-burnup materials archived from historic irradiation testing in EBR-II. These tests include mixed oxide fuel used by Japanese and French fast reactor designs, and metallic alloy fuel preferred by the U.S. 
The experiments will advance global fast reactor fuel safety research and are part of a four-year cost-shared facility sharing initiative being executed between the U.S. Department of Energy (DOE) and Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Research and Development Working Group.
The irradiated transient experiments will be the first of their kind in the world in more than 20 years. 
INL’s capsule also brings new testing capabilities to TREAT that will help advance fuel performance research for sodium-cooled fast reactors. 
“Execution of these unique experiments is an important step toward developing global confidence in the enhanced performance and safety of advanced nuclear reactor technologies," said Dr. Daniel Wachs, the national technical director for the U.S. Advanced Fuels Campaign. “It’s also a remarkable example of how critical international collaborations will enable the next generation of energy technology development.” 

A Multi-Decade Partnership

DOE and JAEA are performing testing to complete the development of advanced technologies first envisioned more than 30 years ago. Their work will enable deployment and provide a launching point for more collaborations with emerging reactor developers. 
Japan and the U.S. previously performed tests on high-burnup fast reactor fuels in the late '80s before EBR-II shut down and TREAT was placed on standby in 1994. 
DOE later restarted TREAT in 2017 to bring transient testing capability back to the U.S. to support the development and qualification of emerging nuclear fuel and reactor technologies.
TREAT is one of just a handful of reactors in the world designed specifically to bring nuclear fuels to failure in a controlled environment. The test reactor produces sudden bursts of energy, known as transients, that are five times more powerful than a commercial power plant to allow scientists to examine fuel performance. 

What’s Next

INL is currently working to load the first of four irradiated fuel experiments into TREAT.
The first transient test is expected to start in February.
The lab expects to complete the first three DOE/JAEA fuel experiments by early spring and wrap up U.S. testing before the end of next year. 
Learn more about TREAT.

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