ORNL and Idaho Lab Use Wire Arc 3D Printing for Nuclear Pressure Vessels

Oak Ridge National Laboratory and Idaho National Laboratory have demonstrated a new way to make the large metal tanks that nuclear reactors need. Together, they used wire arc additive manufacturing, or WAAM, to build a pressure vessel at Oak Ridge's Manufacturing Demonstration Facility.

WAAM works by feeding metal wire through a robotic arm and melting it with an electric arc, depositing material layer by layer. The two labs used ORNL's MedUSA platform, which has three robotic arms working in concert. That setup let them print a nuclear-grade steel vessel faster and with less waste than conventional forging or machining.

The collaboration targets the pressure vessels used in nuclear energy and chemical processing. These parts are expensive, heavy, and hard to ship. Being able to print them near the point of use changes the economics for domestic manufacturing.

Idaho National Laboratory will help qualify the process for industrial use. The goal is a repeatable, certified workflow that other manufacturers can adopt. A demonstration vessel was already shown at the Materials and Manufacturing Innovation Days event in August.

The partnership reflects a broader push to rebuild U.S. heavy manufacturing with additive processes. Nuclear expansion plans under discussion in Washington will need thousands of these vessels over the next decade. If WAAM can cut lead times and cost, it becomes more than a research curiosity. It becomes infrastructure.