Following Clean Core Thorium Energy's (CCTE) successful testing at Idaho National Lab's Advanced Test Reactor, new data from the post-irradiation examination shows markedly less cracking, fuel restructuring and swelling than conventional uranium dioxide fuel, adding new evidence of the fuel's structural stability and fuel performance under demanding irradiation conditions as well as advancing the path toward commercialization.
CHICAGO, Oct. 14, 2026 (GLOBE NEWSWIRE) -- Clean Core Thorium Energy (CCTE) today announced new results from testing at Idaho National Laboratory (INL) showing that its thorium-based nuclear fuel remained structurally intact after irradiation beyond 45 GWd/MTU and exhibited markedly less radial cracking, fuel restructuring and swelling than conventional uranium dioxide fuel examined under comparable conditions.
Uranium dioxide (UO₂) is the standard fuel material used across much of today's nuclear reactor fleet. When researchers at INL examined CCTE's irradiated thorium fuel in comparison to UO2 pellets, CCTE's pellets remained intact, with no evidence of gross fragmentation. The results provide new physical evidence of the fuel's structural stability under irradiation and add to the growing body of experimental data supporting CCTE's thorium-based nuclear fuel platform (called ANEEL). The findings come from post-irradiation examination (PIE) of the medium-burnup batch of CCTE's thorium-based fuel pellets, following irradiation in INL's Advanced Test Reactor (ATR). Three of the four rodlets in the batch have now completed detailed examination at INL's Materials and Fuels Complex (MFC), providing a detailed view of the fuel's microstructural condition after irradiation.
The fuel exceeded 45 gigawatt-days per metric ton (GWd/MTU) of burnup, a measure of how much energy has been extracted from nuclear fuel. During irradiation, the annular fuel pellets experienced a volumetric power density of approximately 1,500 W/cm³ (around four times that of CANDU fuel) and a neutron flux of approximately 5 × 10¹⁴ n/cm²·s.
Following a cooling period in the water canal adjacent to the reactor, the rodlets were transferred to MFC's Hot Fuel Examination Facility (HFEF), where INL researchers conducted non-destructive and destructive examinations to characterize the condition of the fuel. Optical microscopy of the polished and sectioned fuel provides a side-by-side comparison between CCTE's thorium-based fuel pellets and a conventional UO₂ pellet. The UO₂ pellet, despite having accumulated less burnup, exhibits substantially more fuel fragmentation. CCTE's pellets remained intact across the examined cross-sections, with no evidence of gross fragmentation or adverse fuel-cladding or pellet-pellet interaction. The results also show limited fuel restructuring and swelling in CCTE's fuel. Together with the observed cracking behavior, these findings provide encouraging evidence of favorable thermal-mechanical behavior under irradiation and are consistent with the fission gas retention behavior observed in CCTE's earlier irradiation work.
Optical micrographs comparing polished cross-sections of medium-burnup ANEEL fuel pellets (left, >45 GWd/MTU) and a standard UO2 pellet (right, ~30 GWd/MTU) following irradiation. The ANEEL pellet shows markedly less fragmentation than the UO₂ pellet, despite having a higher burnup.
CCTE develops its thorium-based fuel products using its patented ANEEL advanced nuclear fuel platform. The platform combines CCTE's fuel technology, intellectual property, physical irradiation data, and advanced modelling to support the development of thorium-based nuclear fuel products and other applications for the global nuclear industry. These medium-burnup PIE results build on CCTE's growing body of physical irradiation data. CCTE's fuel first exceeded 20 GWd/MTU in 2024, followed by the medium-burnup batch exceeding 45 GWd/MTU in 2025. A separate high-burnup batch subsequently completed irradiation beyond 60 GWd/MTU in 2026.
Milan Shah, Chief Operating Officer of Clean Core Thorium Energy, said:
“These results represent an important step in the maturation of ANEEL, adding direct post-irradiation evidence to the growing body of physical performance data supporting the technology. Seeing the fuel retain its structural integrity beyond 45 GWd/MTU, with markedly less radial cracking than standard UO₂, gives us greater confidence in thorium, the ANEEL technology and its commercial potential. Our focus now is translating this growing scientific evidence into commercial reactor demonstration and deployment.”
Danial Wachs, National Technical Director for the DOE's Advanced Fuel Campaign said:
“Meeting the modern demand for nuclear energy is going to require utilities to simultaneously increase energy production and lower energy cost. The engagement of nuclear fuel technology innovators will be necessary to deliver the solutions necessary to achieve this challenging goal. INL is proud to make its unique experimental capabilities accessible to industrial partners, like CCTE, for testing their ideas and collecting important performance data.”
With the medium-burnup PIE now complete for three rodlets and data available from the completed high-burnup irradiation campaign, CCTE continues to build the technical evidence supporting its ANEEL platform and the development of commercial thorium-based nuclear fuel.
The work builds on CCTE's recent progress, including its supply agreement with BWXT Canada to fabricate full-scale demonstration fuel bundles at Canadian Nuclear Laboratories and its ongoing independent qualification review with Kinectrics. CCTE will continue working with INL and industry partners towards commercial reactor demonstration and deployment of its thorium-based fuel technology.
About ANEEL Fuel
ANEEL is CCTE's nuclear fuel platform which includes fuel designs and manufacturing, patents and intellectual property, the largest global dataset of physical high-burnup irradiation data, advanced modelling, and more. The fuel designs are flexible combining thorium and enriched uranium (LEU to HALEU), with potential applications across Pressurized Heavy Water Reactors (PHWRs), Advanced Reactors, and Light Water Reactors (LWRs). Across these reactor technologies, ANEEL is designed to improve fuel utilization and economics, with the potential to reduce long-lived spent fuel volumes per unit of energy generated and strengthen safety margins by improving inherent safety characteristics and proliferation resistance.
About Clean Core Thorium Energy
Clean Core Thorium Energy is a US-based nuclear fuel company leading thorium-driven nuclear innovations. The company is developing ANEEL, a thorium-based fuel platform designed to improve the economics, performance and sustainability of existing and next-generation nuclear reactors. CCTE's long-term vision is to establish ANEEL as a global nuclear fuel platform, develop scalable supply chains and creating new pathways for thorium across both the nuclear fuel cycle and non-nuclear applications.
Learn more at https://cleancore.energy/. Follow us on social media: LinkedIn and X.
About Idaho National Laboratory
Idaho National Laboratory is managed by Battelle Energy Alliance for the U.S. Department of Energy's Office of Nuclear Energy. INL serves as the nation's leading center for nuclear energy research and development, alongside research across DOE's energy, national security, science, and environmental mission areas. Learn more at www.inl.gov. Follow INL on Facebook, Instagram, LinkedIn, and X.
Media Contact:
Milan Shah
Chief Operating Officer
info@cleancore.energy
A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/02ac4c3a-c657-4158-8e01-f2cde3174ec8