BWXT set for production of advanced form of TRISO fuel

Wednesday, 23 July 2025

The company's Advanced Technologies subsidiary recently completed the installation and testing of a chemical vapor infiltration (CVI) furnace which solidifies the pre-forms that are filled with tri-structural isotropic (TRISO) particles. The CVI furnace, it said, completes the equipment necessary to execute BWXT's Advanced Reactor Demonstration Program (ARDP) project with the US Department of Energy.

In December 2020, BWXT was awarded an 80/20 cost share for the BWXT Advanced Nuclear Reactor (BANR) - a transportable microreactor using TRISO fuel for use in off-grid applications and remote areas - under an ARDP sub-programme intended to address technical, operational, and regulatory challenges to enable advanced nuclear reactor designs.  

TRISO fuel comprises spherical kernels of enriched uranium oxycarbide (or uranium dioxide) surrounded by layers of carbon and silicon carbide, giving a containment for fission products which is stable up to very high temperatures. High-assay low-enriched uranium (HALEU) TRISO fuels are being considered as the preferred fuel in several advanced reactor designs currently under development.

With the existing TRISO manufacturing line, a previously commissioned binder jet for additive manufacturing and a computed tomography scanner for non-destructive testing, BWXT can now load Uranium Nitride (UN) TRISO into additively manufactured fuel forms. The result is a nuclear fuel product comprising a higher mass of uranium per unit volume than traditional TRISO compacts. The new fuel is designed to be more cost-effective with a longer reactor lifespan, potentially reducing overall reactor system costs.

BWXT's established TRISO manufacturing line currently produces Uranium Oxy Carbide (UCO) TRISO for Project Pele - the Department of Defense Strategic Capabilities Office demonstration microreactor programme - as well as UN TRISO for the ARDP scope.

BWXT said it is planning to ramp up TRISO manufacturing to support the BANR programme and meet the market demand of other TRISO users. The existing fuel manufacturing line, combined with these new capabilities, allows BWXT to manufacture diverse forms of TRISO particles (UN or UCO with varying layer thickness), traditional compacts, or chemically densified complex geometries filled with TRISO particles and the resulting digital twins to support fuel qualification efforts.

"Our advanced capability to manufacture TRISO fuel in multiple forms and shapes at scale will play an important role in enabling the small modular reactor and advanced microreactor market to flourish," said Kate Kelly, president of BWXT Advanced Technologies. "We're proud to be working with DOE to diversify and optimise our TRISO fuel manufacturing capabilities as part of our ARDP scope and, more broadly, ensure the success of America's growing advanced nuclear industry."

Acting Assistant Secretary for Nuclear Energy Mike Goff added: "DOE's support of BWXT's microreactor design and TRISO fuel manufacturing capabilities is a great example of how we are working hand-in-hand with industry to re-establish the United States as a global leader in nuclear energy. I'm excited to see this work progress and look forward to BWXT's future accomplishments."