A groundbreaking achievement in additive manufacturing has emerged from the Department of Energy’s Oak Ridge National Laboratory (ORNL), where an innovative team has been honored with the prestigious 2026 SME Aubin Additive Manufacturing Case Study Award. This accolade recognizes not only exceptional technical prowess but also transformative real-world applications of 3D printing technology, marking a significant milestone in industrial additive manufacturing applied to the energy sector. The awarded project centers around the utilization of large-format additive manufacturing (LFAM) to fabricate precision molds that are instrumental in the construction of advanced nuclear reactors, potentially revolutionizing how nuclear plants are built and accelerating the timeline of their deployment.
At the core of this pioneering effort is ORNL’s Manufacturing Demonstration Facility (MDF), which spearheaded collaborations with a variety of industrial and academic partners including the University of Maine and Kairos Power. Together, they developed composite molds through digital manufacturing techniques that utilize LFAM to produce exceptionally large and intricate concrete forms. These molds play a critical role in shaping the bio-shield strongback columns and radiation shielding wall panels — vital components for modular nuclear reactor shielding. This advancement addresses one of the nuclear industry’s most persistent challenges: the protracted and costly construction phases that commonly delay reactor projects.
Traditional nuclear reactor construction is plagued by extended schedules and high costs, primarily due to the demanding requirements for safety, precision, and durability of concrete shielding structures. These massive concrete components can represent up to 60 percent of construction schedule risk, often creating bottlenecks that impede project completion and inflate budgets. The ORNL-led team’s application of LFAM technology greatly mitigates these challenges by enabling faster production of molds that meet rigorous nuclear safety standards while offering the flexibility to adapt designs swiftly during the construction process, an improvement that is critical when responding to changing project requirements.
The LFAM-produced molds themselves represent an extraordinary engineering accomplishment. Designed with high-fidelity digital computer models, the molds are printed in modular sections that are subsequently machined and sealed to achieve tolerances as fine as one-sixteenth of an inch. This level of precision ensures that the molds maintain their structural integrity and dimensional stability under the immense pressures applied during concrete casting, which involves pouring wet concrete to heights reaching 12 feet. The capability to endure such stresses without deformation is essential for producing reliable and safe nuclear shielding components.
One of the most compelling advantages of this technology lies in the rapid production timeline and reuse potential of the molds. Traditional steel molds require six to eight weeks to fabricate and are notoriously difficult to modify once constructed. In stark contrast, the LFAM molds created by the ORNL team were designed, printed, and delivered within approximately two weeks, with modular sections facilitating quick updates in response to design refinements. Furthermore, these composite molds are significantly lighter than conventional steel counterparts, dramatically simplifying handling, installation, and repositioning on construction sites.
The application of these composite molds was demonstrated through full-scale casting cycles for Kairos Power’s modular reactor shielding components. The successful execution of four bio-shield strongback column castings and three shielding wall panel castings, all without perceptible loss of mold quality or dimensional accuracy, showcases the durability and repeatability of the printed molds. Notably, some of the fabricated shielding panels measured an impressive 27 feet in length and incorporated complex interlocking joints. These joints are engineered to diminish or eliminate the reliance on grout between segments, enhancing structural integrity and streamlining assembly.
Crucially, the Kairos Power system operates at low pressure, which alleviates the necessity for the concrete structures to be airtight or containment-rated. This operational parameter permitted the team to focus on optimizing mold precision and manufacturability rather than demands related to pressure containment, thereby expediting development without compromising safety or structural performance. Such an approach aligns with current energy strategies to support small modular reactors (SMRs), designed to be scalable and more economically viable than traditional large-scale nuclear reactors.
The implications of this project extend beyond immediate technical successes; it exemplifies how digital and additive manufacturing technologies can converge with the nuclear energy sector to bolster the nation’s energy security. By harnessing the reliability and repeatability of LFAM-produced tooling, construction timelines can be compressed, costs lowered, and the scalability of advanced reactors enhanced. This is especially relevant in light of the United States’ strategic emphasis on expanding its portfolio of SMRs as part of a broader clean energy future.
Looking ahead, the ORNL team is actively engaging with major U.S. precast concrete manufacturers to scale up LFAM tooling usage for broader nuclear infrastructure applications. The integration of this technology into mainstream precast manufacturing could herald a paradigm shift in nuclear plant construction, enabling faster deployment of advanced reactors and supporting the country’s commitment to energy innovation and decarbonization goals. The project also underscores the value of cross-sector collaboration, involving academia, government, and private industry in tackling complex engineering problems.
Underpinning this success is the DOE’s Advanced Materials and Manufacturing Technologies Office (AMMTO), which funded the research as part of a wider program known as SM²ART, in partnership with the University of Maine. This funding framework champions the development of transformative manufacturing technologies aimed at reinforcing the United States’ industrial base and addressing critical technological challenges connected to energy and manufacturing. The project also highlights ORNL’s leadership role in large-scale additive manufacturing, reflecting a growing trend toward applying advanced composites and digital design tools in high-stakes, safety-critical infrastructure projects.
The award-winning team includes a wide array of contributors from ORNL, the University of Maine, Kairos Power, and Seaboard Services of Virginia, Inc., demonstrating the power of multidisciplinary collaboration and expertise. The collective effort has not only manifested a novel technical achievement but has also established a replicable model for integrating additive manufacturing into nuclear reactor construction on an industrial scale. As Ahmed Hassen, ORNL group leader and project lead, articulated, this work dispels the misconception that additive manufacturing is confined to prototypes, providing compelling evidence of its reliability and effectiveness for fabricating full-scale, safety-critical nuclear infrastructure.
In conclusion, the success of ORNL’s LFAM-based mold fabrication sets a new benchmark in additive manufacturing applications for nuclear energy, showing that complex, large-scale, and precision molds can be produced rapidly, cost-effectively, and to stringent quality standards. This progression promises to shorten construction schedules, reduce costs, and accelerate the deployment of advanced nuclear reactors—critical steps toward achieving resilient, clean, and reliable energy systems for the future.
Subject of Research: Advanced manufacturing techniques for nuclear reactor construction, large-format additive manufacturing (LFAM) for precision concrete mold fabrication.
Article Title: ORNL’s Large-Format 3D Printed Molds Revolutionize Nuclear Reactor Construction, Winning Prestigious SME Award
News Publication Date: April 14, 2026
Web References:
- https://www.ornl.gov/news/3d-printing-reshapes-construction-nuclear-energy
- https://www.rapid3devent.com/event/celebrating-am-achievement
Keywords: large-format additive manufacturing, LFAM, Oak Ridge National Laboratory, nuclear reactor construction, small modular reactors, SMRs, composite molds, digital manufacturing, nuclear energy infrastructure, Kairos Power, DOE Advanced Materials and Manufacturing Technologies Office, SM²ART program
