As the global energy landscape shifts toward cleaner and more efficient power sources, nuclear energy is undergoing a renaissance. New and improved nuclear fuels are at the forefront of this revolution, promising to enhance power generation, safety, and economic viability. These developments are not only key to addressing energy needs but also pivotal in shaping nuclear geopolitics and ensuring national security. Several countries are leading this charge, investing heavily in advanced nuclear fuel technologies to secure their energy independence, assert geopolitical influence, and mitigate the risks of nuclear proliferation.
Types of Nuclear Fuel
Nuclear fuel comes in various forms, including metals, alloys, and oxides. The most common type of fuel used in reactors is uranium dioxide, Fuel fabrication plants convert enriched uranium into fuel, shaping it into pellets that are inserted into fuel assemblies for use in reactors. Once inside, the fuel undergoes nuclear fission, generating energy for electricity production. During fission, neutrons are released, initiating a chain reaction that sustains energy generation.
The most common form of fuel in reactors today is uranium dioxide, a solid oxide used for its high melting point and stability. Over time, after a significant portion of the uranium-235 or plutonium-239 undergoes fission, the fuel is removed. Once the fuel is spent, it is highly radioactive and must be cooled in water for several years before being repurposed or stored.
This “spent” or irradiated fuel is extremely hot and radioactive and must be cooled for several years before further handling. Spent fuel is typically stored in large, deep pools of water that act both as a coolant to remove decay heat and as a radiation shield to protect workers. Once adequately cooled, the fuel can either be reprocessed for reuse or stored depending on the prevailing regulations.
Uranium-235 being the most widely used Nuclear fuel, Reactors like Canada’s CANDU use natural uranium with low concentrations of uranium-235, while others require slightly enriched uranium (3% to 5%). Plutonium-239, produced from uranium-238, is used in fast breeder reactors and can also be recycled in thermal reactors. Ongoing research explores the use of thorium-232 as an alternative nuclear fuel.
Liquid nuclear fuels, though less common, are also being developed. These have significant safety advantages due to their self-regulating nature, reducing the risk of reactor meltdowns and providing enhanced operational flexibility.
Military and Weapons-Grade Nuclear Material
In military applications, highly enriched uranium (HEU) is the primary material, typically containing 20% to 90% uranium-235. This HEU can be blended with low-enriched uranium (LEU) to create fuel for power reactors. Similarly, weapons-grade plutonium can be blended to form mixed oxide (MOX) fuel, which could power reactors for over a year based on current uranium production.
Advancements in Nuclear Fuel Technology
Nuclear power, despite its low carbon footprint and high energy density, faces several challenges that have hindered its broader adoption. Safety concerns, waste management, and the risk of nuclear proliferation are intrinsic to the technology. While nuclear fuel generates less waste than fossil fuels, the waste produced is highly radioactive and requires meticulous handling. The complexity of extracting energy from nuclear fuels demands stringent regulation. Geopolitical factors further complicate the global landscape, as concerns over nuclear proliferation have already led to conflict and remain a potential source of tension. Competition among exporters of civil nuclear technology has lowered costs but raised questions about whether current international safeguards are robust enough to ensure the secure and responsible use of nuclear power.
In recent years, much attention has been paid to innovations in nuclear reactor technology, but the transformation of nuclear fuels is equally crucial. This focus is driven by the potential to enhance the safety, efficiency, and economics of power generation. Dr. Tatiana Ivanova, a nuclear engineer and head of the Nuclear Science division at the Paris-based Nuclear Energy Agency (NEA), emphasizes that nuclear fuel is the core component of nuclear power plants. Optimizing fuel design is a “cornerstone” for deploying modern fuel for light-water reactors (LWRs), advanced reactors, and small modular reactors (SMRs). It is also integral to the safe storage, recycling, and disposal of used nuclear fuel. The research and development of nuclear fuels remain a high priority for many nuclear nations.
Safety is the primary driver behind rapid fuel design optimization. The 2011 Fukushima disaster highlighted the risks associated with zirconium-steam reactions under low-frequency accidents, where cooling system failures can lead to dangerous core damage. In response, the NEA and its 33 member countries began exploring accident-tolerant fuels (ATF) for LWRs. This research aims to develop fuel that can better withstand extreme conditions and enhance reactor safety.
Advanced Nuclear Fuels: A New Frontier
Traditional nuclear reactors rely on uranium-based fuel, typically enriched to low levels of uranium-235, which generates heat through fission reactions. While effective, this method has certain limitations related to waste production, efficiency, and safety. New nuclear fuel types aim to address these challenges while offering enhanced performance, longer reactor lifetimes, and improved waste management.
Among the most promising advancements are Accident-Tolerant Fuels (ATFs), High-Assay Low-Enriched Uranium (HALEU), and molten salt fuels. These fuels offer a combination of higher efficiency, reduced waste, and enhanced safety in extreme conditions, such as those experienced during reactor malfunctions.
Accident-Tolerant Fuels (ATFs):
ATFs are engineered to endure higher temperatures and significantly lower the risk of reactor meltdown during cooling system failures. These advanced fuels incorporate materials like silicon carbide and innovative cladding that limit hydrogen production—a critical factor in preventing explosive scenarios during reactor malfunctions. Countries such as the United States, France, and Japan are leading efforts to develop and implement ATFs, aiming to enhance the safety and reliability of their nuclear reactors.
High-Assay Low-Enriched Uranium (HALEU):
HALEU fuels contain a higher concentration of uranium-235—ranging from 5% to 20%—compared to conventional reactor fuels, enabling longer operational cycles and higher energy output. The U.S. Department of Energy (DOE), along with private companies like TerraPower, is pushing forward the development of HALEU-based fuels. These fuels are crucial for powering next-generation reactors, such as small modular reactors (SMRs) and advanced fast reactors, while also helping reduce nuclear waste and supporting global non-proliferation objectives.
Molten Salt Fuels:
Unlike traditional solid fuel rods, molten salt reactors (MSRs) use liquid fuels, where uranium or thorium is dissolved in molten salt. This innovative design offers major safety benefits, as the liquid fuel can naturally dissipate heat during an emergency, reducing the risk of meltdown. China and the United States are leading the development of MSR technology, with China on track to commission its first experimental MSR in the near future. MSRs represent a significant leap forward in nuclear safety and efficiency.
TRISO Particles: The Future of Nuclear Fuel
One of the most promising advancements in nuclear fuel is TRISO (TRi-structural ISOtropic) particles. These small, robust fuel particles are encapsulated by layers of carbon and ceramic materials that prevent the release of radioactive fission products. TRISO fuel offers unparalleled resistance to high temperatures, neutron irradiation, and oxidation, making it one of the safest nuclear fuels available. This fuel is currently being developed for high-temperature gas and molten salt reactors, and its ability to withstand extreme conditions could revolutionize the nuclear industry.
TRISO (TRi-structural ISOtropic) particle fuel is a cutting-edge nuclear fuel composed of a uranium, carbon, and oxygen core encapsulated by three layers of carbon- and ceramic-based materials. Each particle is incredibly small, roughly the size of a poppy seed, yet extremely robust. These TRISO particles can be formed into cylindrical pellets or spherical “pebbles” for use in high-temperature gas or molten salt reactors.
What sets TRISO apart from traditional nuclear fuels is its superior resistance to neutron irradiation, corrosion, oxidation, and high temperatures, factors that typically degrade fuel performance. Each TRISO particle has its own containment system, ensuring the retention of radioactive fission products under all reactor conditions. Remarkably, TRISO particles cannot melt in a reactor and can withstand temperatures far beyond the limits of current nuclear fuels.
First developed in the U.S. and the U.K. in the 1960s using uranium dioxide, TRISO fuel has since undergone significant improvements. In 2002, the U.S. Department of Energy (DOE) enhanced TRISO by using uranium oxycarbide fuel kernels, improving irradiation performance and manufacturing techniques for advanced high-temperature gas reactors. In 2009, TRISO fuel set an international record, achieving a 19% maximum burnup during a three-year test at Idaho National Laboratory (INL), far surpassing the performance of traditional light-water fuels.
The irradiated TRISO fuel was subjected to over 300 hours of testing at temperatures exceeding 1800°C (more than 3,000°F)—conditions beyond the worst-case scenarios for high-temperature gas reactors. These tests showed no significant damage to the particles, demonstrating complete retention of fission products.
Currently, the DOE is collaborating with industry stakeholders and the Electric Power Research Institute to advance the licensing of TRISO fuel. This fuel is attracting interest from advanced reactor developers like X-energy and Kairos Power, and even the Department of Defense, for use in small modular and micro-reactor designs. Additionally, DOE is supporting X-energy’s efforts to establish a TRISO fuel fabrication facility that will produce fuel using high-assay low-enriched uranium for future high-temperature gas and molten salt reactors.
TRISO particles are the most robust nuclear fuel available, offering unmatched safety, durability, and performance for next-generation reactors. Their ability to withstand extreme conditions positions TRISO as a key technology for future nuclear energy innovations.
In conclusion, advancements in nuclear fuel technology are critical to ensuring the future of nuclear energy. From ATF initiatives to the development of TRISO fuels, the industry is moving toward safer, more efficient, and economically viable solutions. The ongoing research and international collaboration underscore the importance of fuel innovation in driving the next generation of nuclear power.
Geopolitical Implications: Dominating the Global Nuclear Arena
Countries that succeed in developing and deploying advanced nuclear fuels will not only boost their own energy security but also enhance their geopolitical standing. Nuclear energy is increasingly seen as a strategic asset, with control over nuclear technology giving nations leverage in global affairs. The race to develop new nuclear fuels has intensified as nations seek to export their technologies, secure supply chains for critical materials, and shape international nuclear norms.
Ongoing research focuses on optimizing nuclear fuel performance to enhance reactor safety and efficiency. For example, the Nuclear Energy Agency (NEA) is pushing forward enhanced accident-tolerant fuels (ATFs) that can better withstand the high-temperature, hydrogen-producing conditions that contributed to the Fukushima disaster. Countries like the U.S. and Russia are actively developing new nuclear fuels for next-generation reactors, with efforts to extend reactor lifespans and improve economic viability. Russia, through its state corporation Rosatom, has made significant strides in developing fuel for VVER and fast reactors, showcasing its ambition to lead in nuclear fuel innovation.
The United States:
Long a leader in nuclear technology, the U.S. is focused on maintaining its competitive edge through the development of advanced reactors and fuels like HALEU and ATFs. The U.S. government’s investments in nuclear innovation are driven by a desire to reduce dependence on fossil fuels, strengthen energy security, and maintain leadership in nuclear non-proliferation efforts. U.S. companies are also exploring export opportunities, particularly in emerging markets that are looking to transition to low-carbon energy sources.
In the U.S., the Department of Energy (DOE) has taken an aggressive approach to ATF development through its Enhanced Accident Tolerant Fuel program. This program, prompted by several reactor retirements due to economic challenges, seeks to improve reactor performance and extend their operational licenses. The U.S. nuclear fleet, many of which will see their 60-year operating licenses expire in the 2030s, stands to benefit significantly from this effort.
The U.S. Department of Energy (DOE) is leading a broad program to develop advanced nuclear fuels, collaborating with U.S. utilities, universities, and the Electric Power Research Institute (EPRI). The program focuses on supporting Accident Tolerant Fuel (ATF) concepts that enhance fuel safety and performance. These initiatives involve several key industry players, including Global Nuclear Fuel (GNF, a GE-Hitachi joint venture), Westinghouse, General Atomics, and Framatome. As part of this program, vendors are required to install lead test assemblies in U.S. commercial power plants and prototypic pin segments in the Idaho National Laboratory’s (INL) Advanced Test Reactor by 2023, with full fuel cores licensed for higher burnups by 2026.
Among the notable projects, GNF is testing two fuel cladding materials—iron-chromium-aluminum “IronClad” and coated zirconium “ARMOR”—at Southern Nuclear’s Edwin I. Hatch Nuclear Plant in Georgia. Additional installations of IronClad and ARMOR materials have been made at Exelon’s Clinton plant in Illinois. Westinghouse has also made significant strides, installing its EnCore Fuel at Exelon’s Byron Unit 2 in Illinois. EnCore Fuel features chromium-coated zirconium cladding for enhanced oxidation and corrosion resistance, high-density ADOPT pellets for improved fuel economics, and uranium silicide pellets for greater efficiency.
Several industry-led ATF fuel concepts are under development, backed by the DOE and various U.S. utilities and universities. GE-Hitachi, Westinghouse, and Framatome are among the companies leading the charge, each developing new materials for fuel pellets and cladding. For example, GE-Hitachi has developed the IronClad and ARMOR cladding materials, while Westinghouse has introduced chromium-coated zirconium cladding for enhanced corrosion resistance.
U.S. Government Develops Advanced Nuclear Fuel: ANEEL
The U.S. Department of Energy (DOE) Idaho National Laboratory (INL), in partnership with Texas A&M’s Nuclear Engineering & Science Center and Clean Core Thorium Energy (CCTE), has developed a groundbreaking nuclear fuel known as “Advanced Nuclear Energy for Enriched Life” (ANEEL). This new fuel combines thorium (Th) and High Assay Low Enriched Uranium (HALEU) in a proprietary mix that addresses key challenges in nuclear energy: cost, waste management, and nuclear proliferation. The fact that it is domestically produced positions ANEEL as an ideal candidate for export to emerging nuclear markets.
One of ANEEL’s main advantages is its high fuel burn-up rate of 55,000 MWd/T (megawatt-days per ton of fuel), significantly higher than the 7,000 MWd/T typical of natural uranium fuels in today’s reactors like PHWRs and CANDUs. Higher burn-up means the fuel stays in reactors longer, producing more energy from the same quantity of fuel. This not only improves energy output but also leads to the generation of neutron poisons, such as Pu-240,241,242, which make the spent fuel unsuitable for weapons use.
Additionally, ANEEL reduces nuclear waste by over 80% and results in significantly lower plutonium production. More plutonium is burned as energy, rendering the spent fuel proliferation-resistant. The reduced waste also means less frequent refueling, lower operational costs, and a smaller amount of radioactive material to handle and store. Moreover, reactors like the PHWR and CANDU can be refueled without being shut down, enhancing operational efficiency. For instance, the Kaiga Unit-1 in India and Canada’s Darlington Unit-1 set records for continuous operation at 962 and 963 days, respectively.
In conventional CANDU reactors, each natural uranium fuel bundle weighs 15 kg and requires frequent replacements. ANEEL fuel bundles weigh 10.65 kg, and after an initial 1,400 days of operation, only one bundle needs to be replaced daily, significantly reducing waste and fuel-handling requirements over a reactor’s 60-year lifespan.
Dr. Sean McDeavitt, Director of the Nuclear Engineering & Science Center at Texas A&M, emphasizes the value of ANEEL’s design, noting that its integration with CANDU and PHWR technology leverages thorium’s superior properties and abundance to generate cleaner electricity with a reduced environmental impact. Texas A&M will produce the ANEEL fuel pellets, while INL will perform high burn-up irradiation testing, with the aim of qualifying the fuel under DOE and Nuclear Regulatory Commission (NRC) standards.
Mehul Shah, CEO and Founder of CCTE, highlights the critical need for clean, reliable base-load power, particularly in emerging countries. He stresses the urgency of deploying solutions like ANEEL to address key barriers of cost, efficiency, and sustainability in the face of an escalating climate crisis.
Russia:
Russia has positioned itself as a dominant force in the global nuclear energy market, with its state-owned nuclear giant, Rosatom, supplying fuel, reactors, and services to over 30 countries. Russia’s strategy includes the development of advanced nuclear fuel cycles that can recycle spent fuel, thus reducing waste and ensuring a steady supply of materials for reactors.
Russia’s TVEL, the nuclear fuel fabrication and supply arm of state-owned Rosatom, has also made significant progress. In October 2019, TVEL loaded two experimental ATF fuel assemblies into its MIR research reactor, containing VVER and pressurized water reactor (PWR) fuel rods. This global push for ATF innovations highlights the nuclear industry’s commitment to enhancing safety and efficiency in future reactor designs.
Russia has also been at the forefront of nuclear fuel development, particularly for its VVER and fast reactor units. In 2016, over 250 experts gathered at a conference in Russia to discuss new-generation nuclear fuel for nuclear power plants. Organized by the fuel company Tvel, a subsidiary of Rosatom, the conference explored advancements in zirconium materials and fast reactor fuel development. Key projects include the development of Remix fuel (regenerated mixture), MOX (mixed uranium-plutonium oxide), and MNUP (mixed nitride uranium-plutonium) fuels, which promise enhanced efficiency and safety.
Russia’s global nuclear exports are part of a broader geopolitical strategy to strengthen alliances, gain influence, and secure long-term contracts for fuel supply and reactor servicing.
China:
China is aggressively pursuing advanced nuclear fuel technologies, including molten salt reactors and fast breeder reactors, to meet its growing energy needs and reduce reliance on coal. China’s commitment to becoming a global leader in nuclear technology is evident in its heavy investments in research and development, with the goal of exporting its nuclear reactors and fuels to countries across Asia, Africa, and Europe. By doing so, China seeks to challenge the dominance of Western and Russian nuclear firms and secure a foothold in key strategic regions.
France:
As a nation that relies heavily on nuclear power for its electricity, France is focusing on improving the safety and efficiency of its reactors through ATF and next-generation fuel development. France’s nuclear industry, led by EDF and Framatome, is working on deploying new fuels that will extend the life of its existing reactor fleet while reducing costs and enhancing safety. France also plays a key role in shaping European nuclear policy, advocating for the inclusion of nuclear energy in the EU’s green taxonomy for sustainable finance.
VVER Fuel Innovations: Advancing Nuclear Technology
Framatome, the French nuclear technology leader, has made significant strides in developing innovative fuel solutions for nuclear reactors, including VVER (Water-Water Energetic Reactor) technologies. The company attributes much of its progress to support from the U.S. Department of Energy (DOE) and favorable market conditions in the U.S., particularly its competitive electricity markets, which drive demand for more cost-effective and efficient designs. These factors have been key in pushing Framatome’s innovation forward, especially with solutions like GAIA for pressurized water reactors (PWRs). The U.S. nuclear fleet, committed to extending the operational lifetimes of its reactors, has been particularly receptive to these new technologies.
Framatome is advancing its ATF efforts with the installation of four GAIA lead fuel assemblies at Southern Nuclear’s Vogtle 2 in Georgia. These assemblies incorporate advanced chromium-coated M5 zirconium-alloy cladding and enhanced ATF (EATF) pellets. The chromium coating improves high-temperature oxidation resistance, reduces hydrogen generation, and provides better mechanical performance, giving operators more time to respond in emergencies. Framatome is also in the early stages of manufacturing complete fuel assemblies, including full-length chromia-coated rods and chromium-enhanced pellets, for Exelon’s Calvert Cliffs reactor in Maryland, scheduled for delivery in 2021.
Framatome’s notable achievements in the U.S. market include the introduction of the ATRIUM 11 fuel, an 11 x 11 fuel rod array for boiling water reactors (BWRs). This design offers improved safety, enhanced fuel cycle efficiency, and increased operational flexibility for plants. Since its U.S. launch in 2015, two reactors have successfully begun producing power using ATRIUM 11. Framatome has also secured contracts to supply this advanced fuel to Talen Energy’s Susquehanna plant in Pennsylvania by 2021 and to the Tennessee Valley Authority’s Browns Ferry plant in 2023.
Framatome emphasizes that developing advanced fuel designs is a complex process that involves a global supply chain. Contrary to the misconception that fuel assemblies are simply produced in a single plant, these assemblies are highly engineered, built to exacting quality standards, and designed to operate flawlessly in harsh reactor environments for many years. While advancements in digital and additive manufacturing have improved fuel system designs, the industry still faces significant risks related to funding, regulatory compliance, and supply chain challenges.
Framatome’s innovations in nuclear fuel technology, especially for VVER and other reactors, demonstrate the importance of global collaboration, regulatory support, and technological advancements in pushing the boundaries of nuclear power. These innovations are critical to the future of nuclear energy, offering safer, more efficient, and cost-effective solutions for both current and next-generation reactors.
National Security and Non-Proliferation
The development of advanced nuclear fuels is closely linked to national security concerns. Ensuring the safe and secure use of nuclear technology is paramount for preventing the proliferation of nuclear weapons and minimizing the risk of nuclear terrorism. Countries that can develop and control new nuclear fuel cycles are better positioned to enforce non-proliferation agreements and prevent the diversion of nuclear materials for military purposes.
- Nuclear Waste Management: Advanced nuclear fuels, such as those used in fast breeder reactors, have the potential to reduce the long-term challenges associated with nuclear waste. By recycling spent fuel, these technologies can reduce the volume and radiotoxicity of nuclear waste, making storage and disposal easier and more secure. This has significant implications for countries looking to develop a closed nuclear fuel cycle, which enhances energy security and reduces the risk of waste proliferation.
- Non-Proliferation: The development of fuels like HALEU, which are unsuitable for weapons production, contributes to global non-proliferation efforts. Countries that adopt these advanced fuels can reduce the risk of nuclear materials being diverted for illicit purposes, thereby strengthening international security. Nations with advanced nuclear capabilities are also better positioned to assist other countries in securing their nuclear materials and preventing the spread of nuclear weapons technology.
Conclusion: A New Era of Nuclear Energy
The race to develop new and improved nuclear fuels marks the dawn of a new era in nuclear energy. By enhancing safety, improving economic efficiency, and reducing environmental impacts, these advanced fuels are poised to transform the global energy landscape. The countries leading this charge—such as the United States, Russia, China, and France—are not only shaping the future of nuclear power but also positioning themselves as key players in the geopolitical arena. As the world grapples with the dual challenges of climate change and energy security, advanced nuclear fuels offer a promising solution that can boost national security, drive economic growth, and ensure a more stable and secure global energy system.
References and Resources also include:
https://www.powermag.com/a-new-frontier-for-nuclear-fuels/
https://www.forbes.com/sites/jamesconca/2020/09/22/aneel-a-game-changing-nuclear-fuel/#55536fc014ea