Decades of Science, Refined for Industry
From research to readiness, TRISO-X represents decades of proven science made practical — reliable fuel for reactors that will shape the future of clean, reliable energy.
TRISO-X is the keystone of our safety case, replacing massive external containment structures with microscopic engineering to simplify reactor design and maximize operational safety. TRISO-X is reshaping the industry with proven material science and fundamental physics.
Coated Particle Fuel
18,000 uranium kernels in each pebble
Precision Fabrication
Produced using patented processes
Multi Layered Safety
Ceramic layers trap fission products
Extreme Heat Tolerance
Remains stable above 1450C
HALEU Fuel
Enables higher efficiency and burnup
Graphite Matrix
Embedded in durable graphite pebbles
Proliferation Resistant
High burnup reduces usable isotopes
Safe Storage
Simplified spent fuel handling and storage
Microscopic Containment for Next-Generation Safety
By embedding multi-layered containment at the particle level, TRISO-X delivers a level of thermal stability and energy density that enables decades of continuous, clean operation. This microscopic approach fundamentally reimagines nuclear safety by building containment directly into the fuel itself—four ceramic and carbon barrier layers that remain stable at 600°C above light water reactor temperatures.
The Kernel
The heart of the particle is a high-assay uranium kernel that harnesses the power of fission more efficiently than conventional fuels.
Carbon Buffer Layer
The first layer, which consists of approximately 50% dense pyrocarbon and serves two primary functions: it provides void space to accommodate fission gases released from the kernel and creates distance between the kernel and the other coating layers to prevent concentrated damage in those layers from high-energy fission product recoils.
Pyrolytic Carbon (PyC) Layer
The PyC layer functions as an effective barrier to gasses and diffusion of many of the actinides and fission products. The IPyC layer is responsible for contributing to retention of fission gasses during irradiation and protecting the kernel from HCl vapor, which is a byproduct of the silicon carbide (SiC) layer deposition process. The OPyC layer also contributes to the retention of fission products and acts as a substrate to bond the graphite matrix.
Silicon Carbide (SiC)
The SiC layer critically serves as both the primary source of structural strength for the particle and the primary barrier to the release of fission products which are not retained within the kernel.
Zirconium Carbide (ZrC)
The ZrC layer provides fission product retention at higher temperatures and in extreme reducing environments. This refractory ceramic is often referred to as Nuclear Thermal Propulsion applications.
01/03
Built on 60 Years of Science
TRISO-X is the commercial evolution of decades of Department of Energy research. By refining the proven science of the Advanced Gas Reactor program, we created a proprietary fuel that is historically validated and industrially scalable. This microscopic containment vault is engineered to withstand extreme temperatures.
02/03
The Engine of the XE-100
Our fuel is the foundation of the XE-100 reactor’s performance, enabling the continuous online refueling that eliminates costly downtime. This integration allows for a significantly smaller safety perimeter, bringing power closer to the point of need.
03/03
Unlocking a Vast Breadth of Applications
The robustness of TRISO-X allows nuclear technology to move into non-traditional markets. From powering heavy industry with high-temperature steam to propelling the next era of deep space exploration, our fuel is designed for the future of human progress.
FAQs
TRISO-X fuel is a proprietary version of tri-structural isotropic (TRISO) particle fuel developed by X-energy. It is a robust fuel designed to withstand high temperatures without melting and offers enhanced safety features for advanced nuclear reactors.
TRISO-X fuel is crucial in ensuring the safety and reliability of advanced nuclear reactors. Its ability to withstand high temperatures without melting provides safety benefits and contributes to the overall performance of the reactor.
X-energy manufactures TRISO-X fuel using a patent-protected manufacturing process. TRISO-X has assembled a team of fuel development and production experts who have refined the TRISO fuel fabrication process, resulting in higher yields, improved quality, and the generation of multiple patents.
TRISO-X fuel offers several advantages, including enhanced safety, improved economics, and flexibility in reactor design and operation. It eliminates the need for large and costly physical pressure-retaining containment structures since the TRISO-X particle itself acts as the containment vessel. The fuel’s ability to operate at high temperatures and utilize HALEU enables longer periods of reactor operation and reduces fuel costs.
TRISO-X fuel is safer and more advanced than any nuclear reactor fuel on the planet. It is designed to withstand high temperatures without melting, making it highly resistant to fuel failure and release of radioactive materials. The multiple barrier layers surrounding the uranium kernel provide stability and containment, enhancing safety and reducing the risk of accidents or meltdowns.
TRISO-X fuel utilizes high assay low enriched uranium (HALEU), which allows for longer periods of reactor operation compared to conventional fuel. We expect this to contribute to increased energy output and reduced fuel costs. X-energy’s proprietary TRISO manufacturing process also contributes to cost reduction.
The use of TRISO-X fuel enables the incorporation of passive safety systems and reduces the required footprint for the reactor. This flexibility allows for greater options in site selection and extends the applicability of advanced nuclear reactors to non-traditional nuclear markets.
TRISO-X fuel offers superior safety characteristics compared to conventional fuel. Safety is built directly inside these reactors, with its robust design and ability to withstand high temperatures without melting. These features provide a higher level of safety and reduce the risk of fuel failure. The containment properties of TRISO-X fuel eliminate the need for large and costly physical pressure-retaining containment structures associated with conventional fuel.
TRISO-X fuel represents a significant step forward in nuclear fuel technology. Its enhanced safety, economic benefits, and flexibility in reactor design make it a promising solution for the advancement of advanced nuclear reactors. TRISO-X fuel contributes to the development of cleaner, more efficient, and safer nuclear energy options.
X-energy, IHI Corporation Partner to Advance U.S.-Japan SMR Supply Chain Development
