Thorium Atomics Inc. has commenced pre-application regulatory engagement with the U.S. Nuclear Regulatory Commission (NRC) for its Tesseract TGR advanced reactor, following the company's submission of a notice of intent letter. The NRC has assigned Project No. 99902174 and a project manager to coordinate pre-application activities, providing a defined point of contact and a trackable reference for future submissions and meetings.
The notice of intent letter was submitted on June 23, 2026, and the NRC responded on July 24, 2026, designating a project manager in the Office of Advanced Reactors. This administrative step does not constitute approval or endorsement of the Tesseract design but establishes a formal channel for regulatory discussions. The notice letter is publicly available in the NRC's Agencywide Documents Access and Management System under Accession No. ML26189A392, with a direct link at https://www.nrc.gov/docs/ML2618/ML26189A392.pdf.
Thorium Atomics plans to engage under 10 CFR Part 53, the NRC's risk-informed, performance-based, and technology-inclusive licensing framework that became available on April 29, 2026. The company is preparing a Regulatory Engagement Plan detailing the Tesseract technology, its licensing strategy, and the sequence of pre-application submissions. Dr. Jack Vecchiarelli, Chief Scientific and Regulatory Officer, noted that Part 53 is well suited for a high-temperature gas-cooled reactor and that early engagement helps ensure regulatory expectations are understood and addressed, 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 250 MWth thermal output, delivering approximately 100 MWe of electricity or industrial process heat up to 750 degrees Celsius. The reactor uses uranium TRISO fuel enriched below 10% U-235 and incorporates a thorium-bearing fertile blanket to convert thorium-232 into fissile uranium-233 during operation. This architecture aims to diversify the nuclear fuel supply chain and improve uranium utilization, with current estimates suggesting a reduction of mined-uranium requirements by about half compared to a Generation II light-water reactor, subject to further validation.
Young Hwang, Founder and CEO, emphasized that this milestone comes alongside the company's application to Idaho National Laboratory's Nuclear Energy Launch Pad program and its proposed pathway for independent reactor-physics verification at a U.S. national laboratory. He stated that Thorium Atomics is deliberately building the regulatory, engineering, and technical-validation records in parallel.
The company is also maintaining a parallel regulatory pathway with the Canadian Nuclear Safety Commission. With offices in Toronto and Knoxville, Thorium Atomics is advancing the Tesseract TGR through pre-application activities, aiming to establish a clear licensing path for its advanced reactor design.
