Oak Ridge National Laboratory and Idaho National Laboratory have announced they will collaborate to help industry develop a process for wire arc 3D printing of industrial pressure vessels used for nuclear energy and chemical processing.

"By working with industry to demonstrate, validate, and qualify advanced manufacturing technologies, we can reduce risk, accelerate deployment, and strengthen the domestic supply chains essential to America's energy future," said Robert Wagner, ORNL associate laboratory director for energy science and technology.

Manufacturing bottleneck: Pressure vessels are key nuclear reactor components that operate under extreme conditions and require extraordinary toughness and structural integrity. Traditionally, they are forged, but as the United States works to expand its nuclear energy production, limited forging capacity poses a supply challenge.

Wire arc additive manufacturing is a technique that uses a robotic welding arm and wire feedstock to 3D print components, building them up layer by layer. It can be used to print large parts and offers speed and flexibility that forging does not, providing an alternative manufacturing option that could expand the domestic supply chain.

The demonstration: In July, scientists at ORNL's Manufacturing Demonstration Facility used wire arc 3D printing to manufacture a small (3 feet by 5 feet) nuclear pressure vessel. According to a joint announcement from both national labs, the demonstration showcased the ability to print a large, closed vessel with a steel alloy relevant to nuclear applications, marking an early milestone in pressure vessel research.

The team used ORNL's MedUSA platform, which uses three coordinated robotic arms to build complex parts by melting wire with electric arcs.

The project combines INL's expertise in manufacturing technologies for nuclear reactors and digital engineering with ORNL's leadership in additive manufacturing and the characterization of printed parts.

"With this project, we're bringing together expertise from both labs to integrate AI and data science with advanced 3D printing so we can evaluate a part's performance in real time, while it's being printed, instead of waiting for post-production testing," said Jorgen Rufner, INL group lead for advanced manufacturing and a specialist in harsh environment materials.

According to the announcement, ORNL used the same MedUSA printer and material in the AI-accelerated production of neutron sensor brackets for Antares's Mark-0 microreactor, which achieved zero-power fueled criticality at INL in June.

Transformational Challenge Reactor: This is not ORNL's first project to make use of AI and additive manufacturing in the nuclear space. The lab led the Transformational Challenge Reactor project, launched by the DOE Office of Nuclear Energy in 2019, which set out to use advanced manufacturing to create an operating nuclear microreactor in 2023. This task was part of a larger objective to offset economic and deployment challenges facing commercial nuclear plants by demonstrating new technology for industrial adoption.

While the project did not ultimately complete a reactor demonstration, a special issue of Nuclear Science and Engineering documented some of the team's research highlights, including pioneering reactor design and materials testing work enabled by rapid prototyping using advanced manufacturing.