The US Oak Ridge National Laboratory (ORNL) is partnering with Type One Energy and the University of Tennessee–Knoxville to establish a high-heat flux facility (HHF) at the Tennessee Valley Authority’s (TVA’s) Bull Run Energy Complex in Clinton, Tennessee.
The HHF will evaluate how materials react under extreme conditions in a fusion device. This will accelerate the development of plasma-facing components (PFCs), which experience the harshest operational conditions in fusion energy devices, and will enable both private and public entities to qualify and validate the materials used in fusion pilot plant designs. The facility will be only the second, and the most powerful, of its kind in the US. It will also be the only domestic facility to include pressurised helium gas cooling.
“This unique collaboration of breakthrough science, industry innovation and academic leadership will result in the creation of a national facility critical to the success of realising commercial fusion,” said ORNL Director Stephen Streiffer. “As the Oak Ridge Corridor continues to serve as the hub of nuclear and fusion energy development, ORNL is excited to play a role in this pivotal next step in the future of fusion.”
The project will use investments from DOE’s Fusion Energy Sciences programme within the Office of Science, Type One Energy and the state of Tennessee. The facility will be built at TVA’s Bull Run Energy Complex in Clinton, the site of Type One Energy’s Infinity One stellarator testbed, currently in development, and potential location of the first Infinity Two fusion power plant.
The facility will leverage the significant investments already made in fusion materials and technology in East Tennessee, including UT’s expertise in fusion materials design and ORNL’s fusion materials development programme, materials characterisation capabilities, and Manufacturing Demonstration Facility.
The facility fulfils a critical need identified in DOE’s Fusion Science & Technology Roadmap to deliver domestic HHF capabilities to advance the understanding of materials performance and lifetime limits in containing plasma hotter than the sun. This project complements ORNL’s Materials Plasma Exposure Experiment (MPEX) currently under construction, that will answer key plasma-material interaction science questions and help develop robust materials for PFCs.
The collaborative team is targeting a steady-state heat load of more than 10 megawatts per square metre on the subcomponent surface using electron-beam technology. The high-heat flux facility will also be novel for its inclusion of pressurised helium gas cooling, which is a leading candidate coolant for fusion devices, including Type One Energy’s Infinity Two fusion power plant concept. This is due to its high maximum operating temperature, stability in prototypical fusion conditions, and chemical inertness with blanket components.
The next steps in the project are to finalise the design, begin procurement and start assembly. TVA is currently conditioning the site for the facility, and the project is slated for completion at the end of 2027.
The Clinton site will function as a fusion development campus through the projects between ORNL, Type One Energy, UT, and TVA and further complement ongoing research collaborations between the institutions, marking East Tennessee as a regional hub of fusion research and future manufacturing centre for PFCs and other advanced components for future fusion plants.
“This collaboration and the high-heat flux facility at TVA’s Bull Run site further advance this region’s reputation as a leader in fusion innovation,” said Type One CEO Christofer Mowry. “The DOE, ORNL and UT are playing important roles in advancing America’s commercial fusion sector.”
Brian Wirth, UT Nuclear Engineering Department Head and UT-ORNL Governor’s Chair Professor said, “This partnership and facility will enable our students and faculty to contribute to materials and technology development to support the deployment of fusion power to the grid and provide research and career opportunities. This is yet another opportunity to expand our unique East Tennessee nuclear ecosystem, which has strong support of the local community and public-private partnerships to enable the continued development and expansion of both advanced fission and fusion energy.”
