Clean Core Thorium Energy announced on July 15, 2026, the publication of a comprehensive technical assessment of its ANEEL fuel in Nuclear Engineering and Design, published by Elsevier and one of the leading peer-reviewed journals in nuclear engineering. The publication follows the completion of a multi-year irradiation campaign at Idaho National Laboratory, where the fuel physically achieved burnup exceeding 60 GWd/MTU in the Advanced Test Reactor.
That figure is far from trivial. Pressurized heavy water reactors (PHWRs) and CANDU reactors traditionally operate on natural uranium fuel, with typical discharge burnup around 7–8 GWd/MTU. ANEEL has exceeded that threshold by more than eight times. The fuel blends thorium with low-enriched high-assay uranium — so-called HALEU, with U-235 enrichment between 5% and 20% — while retaining the same external geometry as the 19- and 37-element bundles already used in CANDU and PHWR systems. This means it can replace existing fuel without any hardware modifications to the reactor or core design.
The scientific publication covers four technical areas: reactivity behavior and safety coefficients, compatibility with existing control and shutdown systems, thermal-hydraulic performance under postulated accident conditions, and structural integrity at high burnup. Each of these analyses is now available in open peer-reviewed literature. The irradiation campaign saw 12 rodlets loaded into the Advanced Test Reactor in May 2024, with staged burnup targets of 20, 40, and 60 GWd/MTU. The final four capsules are those that surpassed the maximum milestone. Irradiation conditions in the ATR are more demanding than those in a commercial reactor, making the data obtained particularly significant for qualification purposes.
The path to commercialization for CCTE is advancing on several parallel fronts. In 2024, the Canadian Nuclear Safety Commission completed Phase 1 of the Vendor Design Review without identifying any fundamental barriers to licensing the fuel in Canada. Canadian Nuclear Laboratories‘ Chalk River Laboratories are manufacturing full-scale demonstration bundles, intended for demonstrational irradiation in a commercial reactor. On the Indian front, CCTE has signed agreements with NTPC and Larsen & Toubro — two major industrial players — targeting the country’s substantial thorium reserves. The fuel reduces spent nuclear fuel volume by up to 87.5% compared to current standards and offers inherent proliferation resistance.
The transition from scientific validation to commercial demonstration is the step that truly matters. With ATR irradiation data now published and demonstration bundles in production at Chalk River, the regulatory qualification cycle for existing CANDU and PHWR reactors — a fleet of dozens of units across Canada, India, Romania, South Korea, and Argentina — can move forward on a documented basis. If the timeline holds, ANEEL could become the first thorium fuel to enter a commercial reactor in an open fuel cycle, with no requirement for new power infrastructure investment.
