ORNL Prints Specimen Capsule for Reactor Tests

A research team from Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, has successfully designed, additively manufactured, and tested a specimen capsule for use in the High Flux Isotope Reactor (HFIR). The specimen capsules are essential for nuclear fuels and materials research as they hold experiments during irradiation in test reactors.

To validate the use of AM for creating a rabbit capsule, ORNL utilized a Laser Beam Powder Bed Fusion (PBF-LB) additive manufacturing machine to construct a stainless-steel capsule. The capsule was assembled, loaded, and sealed before being inserted into HFIR, where it endured nearly a month in a high neutron flux environment.

“This is a pivotal step in proving that Additive Manufacturing can produce specialized components that are difficult to create using conventional machining,” said Richard Howard, group lead for irradiation engineering. Ryan Dehoff, director of the Manufacturing Demonstration Facility, added that as the reliability of these printed components is confirmed, AM could become standard for producing other critical reactor parts.

ORNL will continue conducting post-irradiation evaluations of the capsule. Successful testing could open the door for broader use of additively manufactured components in safety-critical applications across the nuclear energy sector and other highly regulated industries. The team aims to leverage the geometric flexibility of AM to create complex designs that are challenging to fabricate conventionally. This work is supported by the US Department of Energy’s Advanced Materials and Manufacturing Technologies program.