US lab heats up advanced nuclear reactor fuel testing for critical performance
Lightbridge Corporation has officially commenced the irradiation testing of its enriched uranium-zirconium alloy fuel material samples.
The testing is currently underway at the Advanced Test Reactor (ATR), located within the Idaho National Laboratory (INL).
“This milestone represents a significant step forward in the Company’s fuel development and testing program conducted under its Cooperative Research and Development Agreement (CRADA) with INL,” said the company in a press release.
The start of this campaign represents a transition from the manufacturing phase to active performance testing. Earlier in the year, the company successfully fabricated and loaded the enriched uranium-zirconium coupon samples into an experiment assembly.
These samples have now been inserted into the ATR to begin the irradiation testing campaign. The primary objective of this phase is to collect essential material performance data regarding the specific fuel design developed by Lightbridge.
Critical data generation
Engineers and scientists involved in the project expect the campaign to generate critical data points. Specifically, the testing will monitor the fuel alloy’s microstructural evolution and its thermal conductivity properties.
The team will analyze how these properties change as a function of burnup. This data is a technical requirement for the qualification and eventual licensing of Lightbridge Fuel for commercial use.
Dr. Jess Gehin, the Associate Laboratory Director for Nuclear Science & Technology at INL, commented on the collaboration. He noted that the commencement of irradiation testing represents a major achievement for both the laboratory and the company.
According to Gehin, the ATR provides a platform for evaluating advanced nuclear materials under realistic conditions, allowing for a detailed analysis of the experiment’s results.
Post-irradiation examination
Throughout the irradiation testing campaign, specific irradiated samples will be removed from the reactor at various burnup levels. These samples will then undergo a post-irradiation examination at INL facilities.
The purpose of this examination is to assess the fuel alloy’s performance over time, which will support further design qualification for future licensing report submissions.
Dr. Scott Holcombe, Vice President of Engineering at Lightbridge, described the start of capsule irradiation testing as a pivotal step. He stated that the data generated during this phase will assist in validating key thermo-mechanical properties of the fuel alloy.
Holcombe added that understanding how these properties vary with irradiation will move the company closer toward the commercial deployment of the fuel in both existing and new water-cooled reactors.
Prior technical preparations
This specific testing phase follows a series of technical preparations. Last month, the US-based company reported that its advanced fuel samples were fully contained within an experiment assembly, indicating readiness for this critical testing phase.
Prior to the current testing, Lightbridge achieved a technical milestone regarding the manufacturing of the fuel. Earlier this year, the company successfully co-extruded a coupon sample of the fuel at the Idaho National Laboratory.
This co-extrusion process involved encasing a metallic billet, composed of depleted uranium and zirconium, within a zirconium alloy cladding. This manufacturing success paved the way for the current irradiation experiments now active in the ATR.