3D Printed Capsules Withstand Nuclear Reactor Testing

Can 3D printed components meet the strict standards required for nuclear energy applications? That’s the question being explored by the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL). The lab has just reached a significant milestone by successfully testing two experimental capsules 3D printed in stainless steel in their High Flux Isotope Reactor (HFIR). These capsules contain materials that researchers aim to evaluate for their performance in nuclear environments.

Additive manufacturing was chosen to create these capsules because it significantly reduced both production costs and time multiple capsules can be printed on a single build plate, optimizing the fabrication process. A laser powder bed fusion machine was used, with 316H stainless steel. This material offers good resistance to high temperatures, radiation, and corrosion. Once the capsule is printed, the team inserts the material they want to test. In fact, the capsule serves as both a pressure boundary and containment vessel two key features for ensuring the safety of the experiment.

Several capsules can be 3D printed at the same time.

These 3D printed capsules were then inserted into ORNL’s High Flux Isotope Reactor (HFIR) after an assembly and qualification phase. This reactor produces one of the highest neutron fluxes in the world, allowing researchers to replicate the environment of a nuclear reactor and thus test and qualify materials. The capsules remained in the reactor for one month, and according to the researchers, their structure remained unchanged.