Home-AMA: Energy Oak Ridge National Laboratory Is Using Large-Format 3D Printing to Build the Next Generation of Nuclear Reactors
WithAMA: Energy 2026just around the corner, 3D Printing Industry is taking a closer look at the role of additive manufacturing in the energy sector.
Nuclear construction is slow, expensive, and resistant to change, a combination that has constrained the industry for decades. US largest multi program science and technology laboratoryOak Ridge National Laboratoryis working to change one part of that equation, applying large-format additive manufacturing to the fabrication of structural reactor components in a way that cuts construction timelines from months to weeks while opening up geometries that conventional formwork cannot produce.
The work is led by Ahmed Arabi Hassan, group leader for the composite innovation group at ORNL’s Manufacturing Demonstration Facility. With the first molten salt reactor in the United States now underway on the historic K-25 site in Oak Ridge, the project has moved from demonstration to live deployment.
The Lab and the Scale-Up Problem
The ORNL is the largest national laboratory under theDepartment of Energy’s Office of Science, with a $2.6 billion budget and over 7,000 employees. Its history includes developing the world’s first continuously operated nuclear reactor, and today its capabilities range from two of the world’s most intense neutron sources to the 110,000‑square‑foot Manufacturing Demonstration Facility, where Hassan’s group integrates additive manufacturing, conventional composites, machining, and powder‑bed systems.
In an interview with Ryan Dehoff, Director of the MDF,the lab’s entry into nuclear additive manufacturing was described as a rapid evolution. “About six years ago, we started really getting interest from the nuclear folks on using that technology and moving quickly, trying things out, prototyping, moving to production,” he said. “It’s a pretty rapid evolution of technology, insertion, and maturation.”
All ORNL capabilities function as user facilities, accessible to industry, universities, and other national laboratories through collaborative agreements. “This structure targets the advanced manufacturing “valley of death,” the mid-scale-up stage where private investment is scarce and promising technologies often stall,” explained Hassan.
A key challenge underlying all of it, Dehoff noted, is that the industry has historically approached AM with the wrong starting point. “We took the chemistry and then just put it into 3D printers and thought everything was going to be great,” he said. “But we don’t have those same processing steps, and so we get variations in the material.” Legacy alloys optimized for casting or forging behave differently under AM conditions, and ORNL’s materials research, focused heavily on 316H stainless steel and nickel alloys, is working to close that gap by designing materials specifically for additive processes rather than adapting them from conventional ones.
Central to the group’s approach is convergence manufacturing: combining AM, subtractive, and forming processes into a unified production workflow, connected by a continuous digital thread of sensing, simulation, and data-driven optimization. This integration enables functional complexity and dimensional performance beyond the reach of any single process.
Source: 3D Printing Industry
