The US Oak Ridge National Laboratory (ORNL) has designed, printed, and successfully tested a specimen capsule for use in its High Flux Isotope Reactor (HFIR). The achievement is a first for additive manufacturing which can be used to create, customize, and qualify complex shapes more quickly and at a lower cost than traditional fabrication methods.
The research team that created the 3D printed capsule plans to utilise the geometric flexibility that additive manufacturing enables to create more complex designs with unique features that are difficult to fabricate conventionally.
Specimen capsules, commonly referred to as rabbit capsules, are used in nuclear fuels and materials research to hold experiments undergoing irradiation in a test reactor. To demonstrate that additive manufacturing could produce and qualify a rabbit capsule for use in a reactor, ORNL used a laser powder bed printer to print a stainless-steel capsule that was then assembled, loaded, and sealed.
The capsule was later inserted into HFIR for nearly a month, where it successfully weathered the effects of the reactor’s high neutron flux environment. “This is a significant step toward demonstrating that additive manufacturing can be used to develop and qualify specialised components that cannot be conventionally machined,” said Richard Howard, group lead for irradiation engineering at ORNL.
Manufacturing Demonstration Facility Director Ryan Dehoff noted: “As we demonstrate the reliability of these printed components, we’re looking at a future where additive manufacturing might become standard practice in producing other critical reactor parts.,”
The successful testing of the capsule is anticipated to help pave the way for the use of other additively manufactured components in safety critical applications both within the nuclear energy community and other highly regulated industries that have stringent material composition, design, and qualification standards. ORNL will conduct post-irradiation evaluation of the additively manufactured rabbit capsule later this year.
Work was supported by the US Department of Energy’s Advanced Materials & Manufacturing Technologies programme, which aims to accelerate commercialisation of new materials and manufacturing technologies through demonstration and deployment.
