Four first-of-a-kind 3D-printed fuel assembly brackets, produced at the US Department of Energy’s (DOE’s) Manufacturing Demonstration Facility at Oak Ridge National Laboratory (ORNL), have been installed and are now under routine operating conditions at unit 2 of Tennessee Valley Authority’s (TVA’s) Browns Ferry NPP in Alabama, ORNL said on 9 August. The components were developed in collaboration with TVA, Framatome and the DOE Office of Nuclear Energy–funded Transformational Challenge Reactor (TCR) programme based at ORNL.

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

Ryan Dehoff, ORNL section head for Secure and Digital Manufacturing noted: “ORNL offers everything under one roof: state-of-the-art printing capabilities, world-class expertise in machining, next-generation digital manufacturing technologies, plus comprehensive characterization and testing equipment.” 

ORNL used novel additive manufacturing techniques to 3D print channel fasteners for Framatome’s boiling water reactor fuel assembly, four of which were installed at Browns Ferry. ORNL said the channel fasteners’ straightforward, though non-symmetric, geometry was a good match for a first-ever additive manufacturing application for use in a nuclear reactor.

The current focus of the TCR programme is to further mature and demonstrate industry-ready technology informed by advanced manufacturing, artificial intelligence, integrated sensing and deployment of a digital platform for informed certification of 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.”

Dan Stout, TVA’s director of Nuclear Technology Innovation said: “Partnering with ORNL and Framatome in this innovative manufacturing approach could pave the path for use across the existing nuclear fleet and also in advanced reactors and small modular reactors.” Operations at Browns Ferry resumed in April, after a planned outage to replace a variety of components for continued safe, reliable operation and delivery of carbon-free electricity. The brackets will remain in the reactor for six years with regular inspections during that period.