Advanced TRISO Fuel Could Support Expansion of Next-Generation Nuclear Power

A new generation of nuclear fuels designed to tolerate extreme temperatures could help address one of the safety and supply-chain challenges facing advanced nuclear power as developers prepare smaller reactors for commercial, defense, and remote-energy applications.

Standard Nuclear, an Oak Ridge, Tennessee-based nuclear fuel manufacturer, is expanding production of TRISO, or tri-structural isotropic particle fuel. Unlike the fuel assemblies used in most conventional light-water reactors, TRISO contains uranium inside multiple layers of carbon and ceramic materials designed to retain radioactive fission products even at very high temperatures.

The technology is attracting increased attention as companies develop small modular reactors and microreactors that could provide low-carbon electricity in locations ranging from industrial facilities and data centers to military installations and remote communities.

Standard Nuclear CEO and nuclear engineer Kurt Terrani told Forbes that improving the inherent safety characteristics of nuclear fuel could reduce reliance on some of the engineering systems historically needed to prevent or contain severe reactor accidents. The company went public in July 2026 and is positioning TRISO manufacturing as part of an emerging supply chain for advanced reactors.

How TRISO Fuel Works

TRISO fuel particles are approximately the size of a poppy seed. According to the U.S. Department of Energy, each contains a uranium-based fuel kernel surrounded by several layers of carbon and ceramic material.

These coatings function as containment barriers, helping prevent the release of radioactive fission products. The Department of Energy describes TRISO as structurally more resistant than traditional reactor fuel to neutron irradiation, corrosion, oxidation, and high temperatures.

The characteristics are particularly relevant for advanced reactor designs that operate differently from conventional water-cooled nuclear plants. TRISO particles can be incorporated into cylindrical fuel compacts or larger spherical fuel elements known as pebbles, including for high-temperature gas-cooled reactor designs.

However, the technology should not be interpreted as eliminating nuclear safety requirements. Reactor safety depends on the interaction between fuel, reactor physics, cooling systems, containment strategy, operating procedures, and regulatory oversight. Advanced fuel can reduce particular failure mechanisms, but it does not remove the need for engineered safety systems or comprehensive licensing.

Commercial Agreements Begin to Emerge

The business case for expanding TRISO production increasingly depends on whether advanced reactor developers move from demonstration projects into repeat deployments.

Standard Nuclear recently signed a binding fuel supply agreement with Antares Nuclear, which is developing microreactors for defense and space applications. Under the agreement, Standard Nuclear will provide at least one metric ton of uranium in TRISO fuel, with Antares holding options for up to seven additional metric tons.

The agreement could therefore cover as much as eight metric tons. The company has said deliveries are associated with Antares' planned microreactor program through the end of the decade.

Standard Nuclear has also entered a binding agreement with Radiant Industries for multiple metric tons of TRISO fuel through 2031. Radiant is developing Kaleidos, a transportable 1 MW microreactor intended to provide power directly at customer sites.

Together, the agreements illustrate how the nuclear fuel market could change if microreactors and other advanced designs reach commercial deployment. Instead of fuel production being concentrated primarily around large gigawatt-scale power stations, manufacturers could eventually serve a wider range of smaller reactors with different operating profiles and customers.

Standard Nuclear reported a total contract backlog of $576.9 million after accounting for its August agreement with Antares, including $119.3 million of funded backlog and $443.5 million of purchase options under executed contracts. Those figures indicate substantial prospective demand, although optional purchases should not be treated as guaranteed future revenue or fuel deliveries.

Fuel Availability Remains a Critical Constraint

Producing TRISO particles is only one element of the advanced nuclear fuel chain.

Many emerging reactor designs require high-assay low-enriched uranium, commonly known as HALEU. This fuel contains uranium enriched above the levels typically used by the existing commercial reactor fleet but below 20% uranium-235.

Building a reliable domestic supply of enriched material, converting it into suitable chemical forms, and fabricating reactor-specific fuels are therefore becoming strategic issues for advanced nuclear deployment.

The U.S. Department of Energy has been supporting domestic HALEU availability for research, demonstration, and commercial advanced reactor projects. Its nuclear fuel programs include production, recovery, and down-blending of uranium inventories while private-sector enrichment and fabrication capacity develops.

For reactor developers, the issue is increasingly one of synchronization. Manufacturing plants, enrichment capacity, reactor licensing, construction schedules and fuel qualification programs must progress at compatible rates. A delay in one part of the supply chain can postpone an entire reactor project.

Regulators Prepare for New Fuels

Advanced fuels must also pass extensive regulatory review before they can be deployed commercially.

The U.S. Nuclear Regulatory Commission is preparing for increasing numbers of applications involving accident-tolerant fuels, advanced reactor fuels, and higher uranium enrichment levels. Its current licensing activities include projects involving TRISO fuel and enrichment levels between 5% and 20% uranium-235.

The NRC has concluded that its existing regulatory framework can support licensing of near-term accident-tolerant fuels and higher-enrichment technologies, although it has identified areas where procedures can be improved to make reviews more effective and efficient.

The regulator is also engaging developers earlier in the research and development process, reflecting the technical differences between established light-water reactor fuels and the materials proposed for advanced reactors.

What it Means for the Net-Zero Transition

Advanced nuclear technologies are increasingly being considered as a potential source of firm, low-carbon electricity alongside rapidly growing wind, solar and energy-storage capacity.

Microreactors could be particularly relevant where customers require continuous power but have limited access to large transmission networks, including industrial facilities, remote sites and defense installations. Larger advanced reactors could potentially support electricity grids requiring additional low-carbon capacity that can operate independently of weather conditions.

But safer fuel alone will not determine whether a new nuclear construction cycle emerges.

Projects must still demonstrate competitive costs, secure financing, complete regulatory reviews, establish reliable fuel supplies, and prove that reactors can be manufactured and deployed repeatedly rather than as expensive one-off projects. Long-term radioactive waste management also remains part of the nuclear lifecycle regardless of reactor or fuel design.

TRISO nevertheless addresses an important technical component of that equation. If fuel capable of retaining radioactive material under extreme conditions can be manufactured at commercial scale, reactor designers may have greater flexibility to develop systems with stronger passive safety characteristics.

The growing number of fuel supply agreements now provides an early indication that the advanced reactor industry is moving beyond conceptual design toward procurement and manufacturing.

Whether that translates into a wider nuclear energy expansion will depend on what happens next across the entire value chain, from uranium enrichment and fuel qualification to reactor licensing, construction, and commercial operation.

Source: www.forbes.com