ORNL and INL Use Wire Arc 3D Printing to Fix Nuclear Supply Chain

What they built

Oak Ridge National Laboratory and Idaho National Laboratory have started a joint project to 3D print the large metal pressure vessels that nuclear reactors need. The two labs announced the collaboration on August 19 during an Oak Ridge manufacturing showcase. The goal is to create a domestic supply chain for these parts, which are currently forged in limited quantities overseas.

The process uses wire arc additive manufacturing. Molten metal wire is deposited layer by layer using robotic welding arms. ORNL's MedUSA platform, which coordinates three robotic arms, already printed a small nuclear pressure vessel measuring about 3 feet by 5 feet in July. That demonstration used a steel alloy relevant to nuclear applications and proved the technology can scale to large, closed vessels.

AI checks while printing

What makes this project different from standard metal 3D printing is the AI layer. The labs want to verify the shape and material properties of the vessel during printing, not after. ORNL lead researcher Patxi Fernandez-Zelaia calls these "born-qualified" components: parts whose worthiness for extreme environments is confirmed by data gathered in real time.

INL will bring its Prometheus AI tools, digital engineering expertise, and decades of nuclear reactor experience to the quality control side. The idea is to replace slow post-production testing with continuous in-process verification.

Why it matters

Pressure vessels are a bottleneck for nuclear energy expansion. Forging capacity in the U.S. is limited, and reactors cannot wait for overseas suppliers to catch up. Wire arc printing offers speed and flexibility that forging does not. If the labs can prove the printed vessels meet nuclear standards, the same methods could later apply to chemical refining, oil and gas, defense, and aerospace parts.

The collaboration also produced a working prototype earlier than the main project timeline. ORNL used the same MedUSA printer and material to make neutron sensor brackets for Antares Nuclear's R1 Mark-0 microreactor, which reached criticality at INL in June.