Thorium Atomics Inc. has announced the commencement of pre-application regulatory engagement with the U.S. Nuclear Regulatory Commission (NRC) for its Tesseract TGR advanced reactor. The company submitted a notice of intent letter on June 23, 2026, and by July 24, 2026, the NRC assigned Project No. 99902174 and a dedicated project manager from its Office of Advanced Reactors to coordinate pre-application activities. This administrative step provides a formal channel for future correspondence and reviews, but it does not signify NRC approval of the design.
The engagement will proceed under 10 CFR Part 53, the NRC's new risk-informed, performance-based, and technology-inclusive licensing framework that became available on April 29, 2026. Thorium Atomics is preparing a Regulatory Engagement Plan detailing its technology, licensing strategy, and planned submissions. Dr. Jack Vecchiarelli, Chief Scientific and Regulatory Officer, emphasized that starting early with the NRC while the design is still being developed helps ensure regulatory expectations are integrated into the design process, thereby de-risking the future licensing pathway.
The Tesseract TGR is a pebble-bed high-temperature gas-cooled reactor using helium coolant and TRISO fuel. It is designed for a thermal output of 250 MWth, delivering about 100 MWe of electricity or industrial process heat up to 750°C. The reactor uses uranium TRISO fuel enriched below 10% U-235 and incorporates a thorium-bearing fertile blanket to breed uranium-233, aiming to diversify the fuel supply chain and improve uranium utilization. Current estimates suggest it could reduce mined-uranium requirements by approximately half per unit of energy compared to a Generation II light-water reactor, pending further validation.
Young Hwang, Founder and CEO, highlighted that this regulatory milestone parallels their application to Idaho National Laboratory's Nuclear Energy Launch Pad program and their proposed pathway for independent reactor-physics verification at a U.S. national laboratory. He noted that the company is deliberately building regulatory, engineering, and technical-validation records in parallel.
The NRC's assignment of a project number is an administrative action that does not constitute acceptance of a license application or any form of design approval. The notice letter is publicly accessible in the NRC's ADAMS system under Accession No. ML26189A392, with a direct link available at https://www.nrc.gov/docs/ML2618/ML26189A392.pdf.
Thorium Atomics, with offices in Toronto and Knoxville, is also maintaining a parallel regulatory pathway with the Canadian Nuclear Safety Commission. Further information about the company and its Tesseract TGR can be found at thoriumatomics.com.
