First 3D Printed Parts Installed in Nuclear Reactor

After announcing the project in October 2020, Oak Ridge National Laboratory (ORNL) has completed the installation of four 3D printed brackets at the Tennessee Valley Authority (TVA)’s Browns Ferry Nuclear Plant Unit 2 in Athens, AL. These fuel assembly brackets represent a major step forward for the use of additive manufacturing (AM) in the nuclear sector, as 3D printed parts have never been used in a reactor application.

To extend the lives of U.S. nuclear power plants and speed up development of new nuclear power technologies, TVA’s French fuel supplier Framatome commissioned ORNL to develop the brackets as a foray into the use of AM for nuclear reactor parts. Because the channel fasteners have a straightforward, but non-symmetric design, they were deemed to be a good entry point for 3D printing in such an application. The parts were then designed by ORNL in collaboration with TVA, Framatome, and the Department of Energy Office of Nuclear Energy–funded Transformational Challenge Reactor (TCR) program.

ORNL used novel additive manufacturing techniques to 3D print channel fasteners for Framatome’s boiling water reactor fuel assembly. Four components, like the one shown here, were installed at the TVA Browns Ferry nuclear plant. Credit: Framatome

“Deploying 3D-printed components in a reactor application is a great milestone,” said ORNL’s Ben Betzler, TCR program director. “It shows that it is possible to deliver qualified components in a highly regulated environment. This program bridges basic and applied science and technology to deliver tangible solutions that show how advanced manufacturing can transform reactor technology and components.”

The parts were 3D printing using laser powder bed fusion on a GE Additive/Concept Laser M2 Cusing system using 316 stainless steel. They were designed and produced to comply with safety regulations. 3D data was captured during the printing process at every layer to certify the components.

“Collaborating with TVA and ORNL allows us to deploy innovative technologies and explore emerging 3D printing markets that will benefit the nuclear energy industry,” said John Strumpell, manager of North America Fuel R&D at Framatome. “This project provides the foundation for designing and manufacturing a variety of 3D-printed parts that will contribute to creating a clean energy future.”

After a planned outage, in which a number of parts were replaced for the site, the 3D printed fasteners were installed and operations at Browns Ferry resumed on April 22, 2021. The 3D printed parts are now under routine operating conditions and will remain in the reactor for the next six years, undergoing continual inspections throughout that period.

Though this may be the first set of 3D printed parts inside of a reactor, others have been looking into the technology for other nuclear reactor components. Idaho National Laboratory uses the technology to fabricate parts for its research endeavors. The University of Pittsburgh was awarded $1 million to study the 3D printing of components for nuclear reactors. In 2017, Siemens had already installed a 3D printed part in a nuclear reactor, which pushed Westinghouse to pursue a similar initiative. In Russia, RusAT, a subsidiary of the Russian State Atomic Energy Corporation Rosatom, is exploring the use of 3D printing for nuclear power parts.

Framatome initiated its research in the use of AM for nuclear fuel applications in 2015, focusing on stainless steel and nickel alloys. Now that it has produced a comparatively simple, yet critical component, it will begin looking at more complex geometries.