Tiny fuel particles could power advanced nuclear reactors on Earth and in space

Antares Nuclear, a US company developing compact nuclear reactors for defense and space applications, has signed a multi-year agreement with Standard Nuclear to secure up to eight metric tons of TRISO fuel through 2035. The fuel will be used to power Antares’ microreactors, which are designed to provide reliable electricity in places where conventional power sources are difficult to deploy. The company is targeting applications ranging from US military installations to remote infrastructure and space missions. The agreement gives Antares a long-term supply of specialized nuclear fuel as it moves from reactor demonstrations toward planned deployments. Standard Nuclear will manufacture and deliver the TRISO fuel under the binding agreement. The two companies have been working together since 2025 on fuel specifications, manufacturability and production planning. The new deal formalizes that work and gives Antares greater certainty over fuel availability as it scales its reactor program. Tiny fuel for demanding missions TRISO, or tristructural isotropic particle fuel, consists of small fuel particles enclosed in multiple protective layers. The design is intended to retain radioactive material under extreme conditions and is being developed for several advanced nuclear reactor applications. For Antares, securing fuel is an important part of getting its microreactors from testing to deployment. The company says its Mark-0 microreactor achieved initial criticality in 2026 under the US Department of Energy’s Reactor Pilot Program. Antares is targeting electricity production from an advanced reactor in 2027, with initial production deployments to US military installations planned for 2028. “Antares exists to deliver nuclear power exactly where and when it is needed most, whether supporting stateside military installations, enabling persistent space operations, or powering mission-critical infrastructure far from the grid,” said Jordan Bramble, CEO and Co-founder of Antares. “Securing a long-term, industrial-scale supply of TRISO fuel from Standard Nuclear is a foundational step in moving our microreactors from demonstration to deployments.” The agreement also illustrates a challenge facing advanced nuclear developers. Building a reactor is only part of the task. Developers also need reliable supplies of specialized fuel, manufacturing capacity and supporting infrastructure before reactors can be deployed at scale. Building the advanced fuel pipeline Standard Nuclear says it is currently the only US company with industrial-scale TRISO fuel fabrication facilities. The company is working to expand its production capacity through additional facilities as demand for advanced nuclear fuel grows. “Antares is building reactors for some of the most demanding environments on earth and in space, and Standard Nuclear is proud to support Antares for their strategic energy applications,” said Kurt Terrani, CEO of Standard Nuclear. “We are working to scale our TRISO production capacity across identical facilities and continue to adhere to our customers’ needs.” The companies’ agreement is therefore more than a fuel purchase. It connects a microreactor developer with a domestic fuel manufacturer at a time when the US is trying to build a larger advanced nuclear supply chain. Antares was founded in 2023 and says it has raised more than $600 million. Its compact reactors are being developed for applications where grid power or conventional generators may not provide the required combination of reliability, mobility and resilience. The fuel agreement does not guarantee that Antares’ planned reactor deployments will meet their target dates. However, it addresses one of the practical requirements for moving its technology toward commercial and government customers. Get the latest in engineering, tech, space & science - delivered daily to your inbox.With over a decade-long career in journalism, Neetika Walter has worked with The Economic Times, ANI, and Hindustan Times, covering politics, business, technology, and the clean energy sector. Passionate about contemporary culture, books, poetry, and storytelling, she brings depth and insight to her writing. When she isn’t chasing stories, she’s likely lost in a book or enjoying the company of her dogs.