Clean Core Thorium Energy (CCTE) has announced a major breakthrough in advanced nuclear fuel technology. Its patented ANEEL fuel successfully completed a high burnup irradiation test at the Advanced Test Reactor (ATR) located at Idaho National Laboratory (INL). The final set of irradiation capsules achieved more than 60 GWd/MTU of burnup, marking a significant milestone for the thorium-HALEU fuel cycle.
Significance of the Achievement
This burnup level is more than eight times the typical discharge burnup of traditional pressurized heavy water reactors (PHWRs) and Canada Deuterium Uranium (CANDU) reactors. The achievement demonstrates the potential of ANEEL fuel to dramatically improve fuel utilization in existing reactor fleets and paves the way for near-term commercialization.
Higher burnups from ANEEL fuel translate into several operational benefits when integrated with existing reactor designs. These include reduced nuclear spent fuel volumes, improved reactor economics, enhanced safety performance, and increased proliferation resistance. The irradiation results build on decades of global research into thorium fuel cycles aimed at improving fuel utilization and resource efficiency in heavy-water reactors without requiring reactor modifications.
Irradiation Campaign Details
The ATR irradiation campaign involved twelve ANEEL fuel rodlets loaded into the reactor in May 2024. They were designed to reach three burnup targets: 20, 40, and 60 GWd/MTU. Eight rodlets exceeded the first two targets last year and are currently undergoing post-irradiation examination (PIE) at INL's Materials and Fuels Complex (MFC). Less than two years after irradiation began, the remaining four rodlets reached the highest target of over 60 GWd/MTU and will be transferred to MFC after a short cooling period.
This campaign represents a crucial step in generating real-world performance data for ANEEL fuel under reactor conditions. The PIE results will provide detailed insights into fuel behavior, microstructure, and performance at high burnup levels.
Performance Under Aggressive Conditions
Due to its compact, high-flux nature, irradiation conditions in the ATR are typically more aggressive than in a PHWR. This allows fuel behavior to be evaluated under accelerated conditions that simulate extended reactor operation. PIE results to date are consistent with findings reported in the literature and suggest that ANEEL fuel performs well, with some test rodlets exhibiting superior fission gas retention compared to traditional UO2 fuel. Initial observations also show that ANEEL fuel maintains structural integrity and favorable fission gas retention behavior throughout irradiation.
CEO Statement
Mehul Shah, CEO of Clean Core Thorium Energy, commented: "Surpassing 60 GWd/MTU of burnup in the Advanced Test Reactor marks an important milestone for the ANEEL fuel program. This irradiation campaign provides meaningful performance data and demonstrates that thorium-HALEU fuel can achieve burnup levels comparable to those seen in PWR fuels while offering improved fuel utilization, enhanced safety characteristics, inherent proliferation resistance, and meaningful reductions in long-lived nuclear spent fuel radioisotopes. Our objective has been to introduce thorium into the nuclear fuel cycle in a practical way using existing reactors, and this milestone represents a significant step toward that goal."
