Lightbridge Advances Nuclear Fuel Technology with New Patent

Lightbridge Corporation, a US-based company specializing in advanced nuclear fuel technology, has announced it has received a Notice of Allowance from the United States Patent and Trademark Office. The patent application, titled “Fuel Assembly,” covers key aspects of their innovative fuel design.

Patent Details: Multi-Lobed Fuel Elements

The allowance encompasses 16 claims related to Lightbridge’s spirally twisted, multi-lobed fuel element technology. This technology is specifically designed for pressurized heavy-water reactors, including CANDU-type designs. The patent focuses on the mechanical and structural benefits of the fuel in heavy-water environments.

Strategic Importance of the Patent

Seth Grae, President and CEO of Lightbridge, highlighted the significance of this development. “This Notice of Allowance further strengthens our US intellectual property portfolio, particularly for our multi-lobed fuel element design optimized for pressurized heavy water reactors,” he stated. He also noted the substantial market opportunity presented by the existing CANDU reactor fleet.

Improving Reactor Performance and Safety

The patented fuel assembly architecture is designed to enhance both reactor performance and safety. It features elongated fuel elements with a spirally twisted geometry, incorporating structural spiral ribs and a fuel kernel. This kernel contains fissile material dispersed within a metal non-fuel matrix, all protected by cladding.

Key Design Specifications

According to Lightbridge, each fuel element includes a fuel kernel with fissile material in a metal matrix, surrounded by cladding, and maintains a moderator-to-fuel ratio of 2.4 or less. The patent covers both the fuel assembly itself and its integration into a pressurized heavy water reactor.

Progress in Performance Testing

This patent allowance coincides with Lightbridge’s ongoing validation of its technology. In November 2025, the company began irradiation testing of enriched uranium-zirconium alloy fuel material samples at the Advanced Test Reactor at the Idaho National Laboratory.

Monitoring Fuel Evolution

Scientists are currently monitoring the fuel alloy’s microstructural evolution at a molecular level during operation. The testing also tracks thermal conductivity properties to assess heat transfer efficiency as the fuel is depleted (“burnup”).

Path to Commercialization and Future Applications

The data from the Idaho National Laboratory campaign is crucial for the qualification and licensing of Lightbridge Fuel for commercial use. Beyond traditional reactors, Lightbridge is also adapting its fuel for use in Small Modular Reactors (SMRs).

The company aims to provide a zero-carbon energy solution with enhanced proliferation resistance and the ability to integrate with intermittent renewable energy sources like wind and solar.