Oak Ridge 3D Prints Steel Nuclear Vessel With Three-Armed Robot

A three-armed robot builds a nuclear pressure vessel

Inside an advanced Tennessee facility, a giant three-armed robot named MedUSA guided molten steel into place, building a three-by-five-foot pressure vessel for nuclear reactors. This vessel, produced using multirobot wire-arc additive manufacturing, went on display at the recent Materials and Manufacturing Innovation Days event at Oak Ridge National Laboratory.

Nearby sat a 12-foot impact limiter printed from strong plastic, replacing traditional wood designs used to protect spent nuclear fuel during transport. Both parts served as live demonstrations of how additive manufacturing could rewrite the rulebook for heavy industrial components.

Why forging is not keeping up

Standard reactor pressure vessels rely on large-scale forging and welding. Domestic capacity for those processes has become severely constrained. Lead times for major custom components in sectors like hydropower can stretch past ten years. That timeline is not acceptable for energy infrastructure that needs to come online sooner.

The 3D-printed vessel at ORNL was a direct response to those delays. By depositing material only where it is needed and using robots to reach complex geometry, wire-arc additive manufacturing can produce large metal parts without the tooling and capacity limits that hold forging back.

Supply chains, certification, and the road ahead

Over 350 industry and government leaders gathered at ORNL to discuss how to remove the administrative and technical obstacles slowing advanced manufacturing adoption. The message was consistent: printing a part is only half the battle. Getting that part certified for real-world nuclear use is where momentum usually stalls.

ORNL announced a joint research effort with Idaho National Laboratory to standardize digital qualification methods across facilities. The goal is to give regulators the data needed to certify 3D-printed nuclear and energy components in months rather than years. Real-time sensors, machine learning, and defect-tracking algorithms during the build process are central to that plan.

New partnerships with energy companies like SLB and Kairos Power add commercial weight to the research. If the qualification bottleneck breaks, large metal 3D printing could move from laboratory demonstrations to factory-floor reality within the next few years.