The Nuclear Energy Renaissance: Alternative Uranium Fuels

In the era of nuclear energy renaissance, many countries are strategically planning to significantly increase nuclear energy capacity in the coming decades as part of efforts to diversify energy sources and enhance long-term energy security. However, ensuring fuel supply for operations has become increasingly complex, particularly after sanctions on Russian energy products were implemented. Currently, alternative uranium fuels are promising for the nuclear energy industry.

Current Nuclear Technology and Future Fuel Requirements

Nuclear fission, used in all existing nuclear power plants, is the process by which the nucleus of an atom splits into two or more smaller nuclei and other particles. Fission can release large amounts of heat and radiation. Today's nuclear power plants use this heat to boil water and drive steam turbines to generate electricity. Operators typically use uranium fuel enriched to 5% uranium-235 (U-235) to power nuclear reactors.

Comparison of Nuclear Fuel Types

In the future, operators will increasingly need to use high-assay low-enriched uranium (HALEU), enriched from over 5% and below 20%, to power advanced nuclear reactors and small modular reactors (SMRs) currently being developed. However, HALEU is not currently produced commercially on a large scale, with only Russia and China currently producing this fuel at scale.

Efforts to Develop HALEU Production

Following the ban on Russian uranium imports in 2024, the United States government has focused efforts on developing domestic HALEU production capabilities. Consequently, Centrus Energy produced over 920 kg of HALEU from an experiment at Piketon, Ohio, between October 2023 and mid-2025.

In January 2026, the US Department of Energy (DoE) allocated $2.7 billion to expand domestic uranium enrichment capacity over the next decade. Meanwhile, in the United Kingdom, the government announced in January 2024 that it would allocate £300 million to support HALEU production.

TRISO: Advanced Fuel for SMRs

An increasing number of operators are using TRISO (TRi-structural ISOtropic particle) fuel in SMRs, which is produced from HALEU. It is safer and more efficient than conventional enriched uranium, with the same amount of fuel being compressed into a smaller package, while being able to consume more U-235 before the small fuel particles are depleted.

Each TRISO particle is coated with three specialized ceramic layers and other materials to contain fission gases and provide the particle with high-temperature resistance, thereby preventing TRISO fuel from melting. Additionally, TRISO fuel reactors use helium or molten salt as a heat transfer medium instead of water, which has lower reactivity or higher boiling points. Each TRISO particle operates as a separate containment vessel, meaning there is no need to build massive facilities to contain meltdowns.

Although TRISO is more expensive than conventional nuclear fuels, it can power lighter, less expensive reactors.

Challenges and Alternative Solutions

However, accessing HALEU and TRISO at scale remains a challenge, as the China National Nuclear Corporation is the only TRISO producer at commercial scale, and Russia's TENEX is the only HALEU supplier at commercial scale. This has driven many companies in the US and across Europe to explore alternative fuels to power SMRs, reducing dependence on Russia and China.

Companies like GE Hitachi, Westinghouse, and Aalo Atomics have chosen Low-Enriched Uranium (LEU) instead of HALEU to power operations, as it can be purchased from existing US facilities. Holtec's SMR-300 has been developed to operate on conventional LEU or LEU with U-235 concentrations from 5 to 10%.

Comparison of TRISO and LEU Fuels

Companies Choosing LEU to Accelerate Deployment

"We know we want to get to market fast, and we know we need to scale to build hundreds of reactors, and we can't do that with HALEU for many years, because America is still pumping money into that HALEU machine, trying to figure out the code," explained Yasir Arafat, Chief Technology Officer at Aalo Atomics, on why Aalo chose LEU as its primary fuel.

He believes that LEU-powered SMRs will develop faster than HALEU-powered SMRs because "We actually have a company starting to produce LEU right here in America."

Urenco USA was granted permission by the US Nuclear Regulatory Commission to produce LEU at its facility in Eunice, New Mexico, in September last year, and has since produced small amounts of fuel. The company expects to achieve commercial production by mid-2026.

Aalo has signed a supply chain agreement with Urenco for the fuel needed to operate the Aalo-X experimental reactor, currently being developed as part of the Department of Energy's Experimental Reactor Program. The company plans to launch the commercial Aalo Pod reactor, powered by LEU, in 2029.

The Future of Nuclear Energy

While some companies continue to depend on Russia for uranium supply, some countries are seeking to develop domestic HALEU production capabilities, while many companies are exploring the potential of using more accessible alternative uranium fuels to power operations.

The development of alternative fuel options like LEU and new technologies like TRISO is reshaping the global nuclear energy landscape, particularly in the context of geopolitical sanctions and the growing demand for clean, reliable energy.

Countries and companies are weighing whether to invest in advanced technologies like HALEU and TRISO for optimal efficiency and safety, or to use more readily available solutions like LEU to accelerate deployment and reduce dependence on specific countries.

The future of nuclear energy will likely see the coexistence of multiple fuel types and technologies, each suited to the specific goals and conditions of different countries and developers.