US-based Clean Core Thorium Energy (CCTE) and Canadian Nuclear Laboratories (CNL) have announced an agreement to manufacture demonstration irradiation bundles of ANEEL fuel. 

These bundles are full-scale prototypes designed to match the physical specifications of fuel that are currently used in commercial reactors for the purpose of interface and irradiation testing.

ANEEL fuel is a technology that combines thorium with high-assay low-enriched uranium (HALEU). This uranium component is enriched to between 5% and 20% of the uranium-235 isotope. In comparison, standard fuel for pressurized heavy-water reactors generally contains less than 0.72% uranium-235. 

The fuel maintains the same external geometry as existing 19-element and 37-element fuel designs, which allows it to be integrated into current CANDU and pressurized heavy-water reactor systems without hardware or core design modifications. 

It is designed to achieve higher burnup and improved fuel utilization in a once-through fuel cycle. 

This design has the potential to reduce the total volume of long-lived spent fuel produced per unit of energy generated and to increase resistance to nuclear proliferation.

Supporting future commercial reactor fleet

The manufacturing process will be managed by CNL at the Chalk River Laboratories in Ontario. CNL will handle the development, qualification, and fabrication of the ANEEL fuel in accordance with Canadian Standard Association requirements. 

The resulting data from the irradiation of these bundles will provide in-reactor information to support the future qualification and deployment of the fuel in the commercial reactor fleet. 

This manufacturing stage follows the completion of a collaborative project under the Canadian Nuclear Research Initiative which validated the computer codes and analysis methods used for design and safety analysis. 

The demonstration irradiation is intended to provide data to the designer, the utility, the manufacturer, and the regulator regarding fuel performance.

Other components of the development program include irradiation testing at the Idaho National Laboratory. In 2025, results from the Advanced Test Reactor indicated that ANEEL fuel pellets maintained their structural integrity after several months of testing.

The program is targeting burnup levels that exceed 60 GWd/t/MTU. CCTE has also completed a Phase 1 pre-licensing vendor design review with the Canadian Nuclear Safety Commission.

To provide necessary performance data

Mehul Shah, CEO of Clean Core Thorium Energy, stated that the fabrication of reactor-representative bundles will provide the performance data necessary for regulatory review and fleet deployment. 

“This milestone advances ANEEL from validated models to an engineered, fleet-compatible fuel design,” said Shah.

Dr. Monica Regalbuto, Vice-President of Science and Technology at CNL, stated that the laboratories are using their fuel research and fabrication capabilities for the manufacturing of this fuel type. 

“We are pleased to be working with CCTE and to apply the deep expertise of the labs to this exciting advanced fuel project,” she concluded.  

These activities are intended to support the commercial readiness of the fuel for use in existing heavy-water reactor designs.