3D Printing: Revolutionising Nuclear Build

Revolutionising Nuclear Construction with 3D-Printed Concrete Forms

A groundbreaking collaboration between the Department of Energy’s Manufacturing Demonstration Facility (MDF) at Oak Ridge National Laboratory, Kairos Power, and Barnard Construction has yielded a significant advancement in nuclear infrastructure development. The team has successfully created and validated large-scale, 3D-printed polymer composite forms for casting intricate, high-precision concrete structures. These structures would be exceptionally difficult and expensive to produce using traditional construction methods.

These innovative concrete forms are currently being utilised at Kairos Power’s Oak Ridge site, where the Hermes Low-Power Demonstration Reactor is under construction. This project represents a crucial step forward for the future of nuclear energy in America.

The 3D-printed forms are designed for the Janus shielding demonstration and serve as precursors to those that Kairos Power and Barnard will use to build components of the Hermes reactor facility. Each section measures approximately 10 feet by 10 feet and is stacked three units high to form a column.

A Leap Forward in Infrastructure-Scale Construction

The adoption of 3D-printed forms signifies a significant leap forward in infrastructure-scale construction, an area Kairos Power intends to exploit on a larger scale for its future commercial plants. These composite forms dramatically reduce production timelines, enabling the “cast-in-place” construction of complex structural components with unique geometries in a matter of days, rather than weeks. This represents a considerable improvement over traditional methods that rely on steel or wood forms, which can be costly, imprecise, and time-consuming to fabricate.

Ryan Dehoff, director of the Manufacturing Demonstration Facility, stated, “At ORNL, we’re demonstrating that the future of nuclear construction doesn’t need to resemble the past. We’re combining the capabilities of a national laboratory with the MDF’s history of pursuing ambitious goals – moonshots that transform bold ideas into practical solutions – to accelerate the development of new commercial nuclear energy.”

Over the past decade, the MDF has spearheaded numerous pioneering initiatives, from 3D printing automobiles and houses to developing digital tools for real-time part qualification. These ambitious projects have redefined the boundaries of what is possible in manufacturing, and they are now being applied to address the challenges of modernising nuclear energy.

Collaboration and Rapid Learning Cycles

Edward Blandford, co-founder and chief technology officer of Kairos Power, emphasised the long-standing relationship with the MDF. “We’ve had a relationship with MDF since Kairos Power’s inception. They operate quickly, think creatively, and have proven their ability to deliver transformative results when conventional manufacturing methods fall short.”

Blandford explained that while exploring options for precast concrete systems, Kairos Power received a recommendation from a commercial partner to engage with the MDF. “It’s rare to receive industry advice to contact a national laboratory because of their speed and efficiency.”

The MDF’s collaborative approach aligns with Kairos Power’s emphasis on using rapid learning cycles to accelerate technology deployment. “This project aligns perfectly with our iterative development approach,” Blandford said. “By constructing and testing the moulds for the columns first, we can refine our methods, engage with regulators early, and mitigate risk before scaling up the construction method for Hermes and future plants. This has been a core element of our strategy from the outset.”

Demonstrating Innovation and Design

Kairos Power’s Janus column demonstrates a key element of the company’s innovative design for the Hermes bioshield – the thick concrete structure surrounding a nuclear reactor that absorbs radiation during operation, protecting workers.

The project was supported by a number of industry partners, including Airtech, TruDesign, Additive Engineering Solutions, and Haddy, who collectively established a new supply chain for nuclear infrastructure enabled by additive manufacturing. Barnard Construction played a crucial role in implementing and adapting the 3D-printed formwork, providing real-time feedback, and incorporating design changes swiftly to enhance constructability and enable rapid deployment. Dehoff highlighted that the project’s success stemmed from effective communication between the partners. “It’s a genuine example of national lab innovation in action,” he said.

Mechanical Resilience and Innovative Design

The forms were required to withstand the immense pressure exerted by the heavy concrete they were designed to shape. Ahmed (Arabi) Hassen, group leader for composites innovation at ORNL, explained that the challenge extended beyond geometric precision. The moulds needed to maintain their structural integrity under high stress. This required both mechanical resilience and innovative design and printing strategies, pushing the limits of what additive manufacturing can achieve for structural applications.

The project exemplifies how advanced manufacturing is being used to modernise one of the most traditional construction sectors in American infrastructure. “We’re leveraging the best aspects of additive manufacturing – modularity, flexibility, rapid iteration – and applying them to nuclear energy,” he said. “This project demonstrates that we can overcome outdated methods with new technologies that lower barriers, reduce risk, and accelerate construction timelines.”

The SM2ART Moonshot Project

The collaboration with Kairos Power was facilitated by a broader, multi-year initiative called the SM2ART Moonshot Project, led by the MDF and the University of Maine and funded by the Department of Energy’s Advanced Materials and Manufacturing Technologies Office. The project leverages ORNL’s unique combination of world-class materials science expertise, supercomputing and artificial intelligence resources, and large-format additive manufacturing capabilities. The University of Maine contributes complementary strengths in large-scale 3D printing, structural infrastructure development, and digital manufacturing platforms. Together with Kairos Power, the partners aim to de-risk and modernise nuclear construction through rapid, flexible, and cost-effective solutions.

National Significance and Future Developments

This project holds national significance. The Knoxville-Oak Ridge region is the world’s largest hub of nuclear-focused companies, and Hermes is the first advanced reactor to receive a construction permit from the U.S. Nuclear Regulatory Commission. It lays the foundation for Kairos Power’s future commercial plants and a new generation of reactors that will play a pivotal role in meeting surging U.S. energy demands in the coming decades.

Over the next 18 months, the SM2ART Moonshot Project will continue to support Kairos Power construction initiatives, expanding to include full-scale production of forms for radiation shielding and reactor building enclosures, and integrating smart manufacturing techniques, digital twins, and data-driven quality control. The partners aim to use printable biocomposite feedstocks derived from timber residuals, targeting a 75% reduction in material cost using domestic forest products.

By demonstrating that nuclear construction can adopt manufacturing practices – from design agility to rapid deployment – the project offers a compelling vision for lowering the cost and timeline of future reactors.