Thorium Atomics Inc. has officially 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 responded by assigning Project No. 99902174 and a dedicated project manager in the Office of Advanced Reactors to coordinate pre-application activities. This administrative step provides a formal tracking mechanism for future interactions, though it does not constitute approval or certification of the reactor design.
The notice of intent, filed on June 23, 2026, outlines the company's planned engagement under 10 CFR Part 53, the NRC's new risk-informed, performance-based licensing framework that became available on April 29, 2026. Thorium Atomics is preparing a Regulatory Engagement Plan detailing the Tesseract technology, its licensing strategy, and the sequence of planned submissions. Dr. Jack Vecchiarelli, Chief Scientific and Regulatory Officer, emphasized that Part 53's technology-inclusive approach is well-suited for a high-temperature gas-cooled reactor, allowing regulatory expectations to be addressed early in the design process, thereby de-risking the future licensing pathway.
The Tesseract TGR is a pebble-bed high-temperature reactor cooled by helium and fueled with TRISO particles. It is designed for a thermal output of 250 MWth, delivering approximately 100 MWe of firm electricity or industrial process heat at temperatures up to 750°C. The reactor uses uranium enriched below 10% U-235 as an initial driver and incorporates a thorium-bearing fertile blanket to breed uranium-233, potentially reducing mined-uranium requirements by about half compared to conventional light-water reactors. This estimate is subject to further engineering and independent validation.
Young Hwang, Founder and CEO, noted that this milestone coincides with the company's application to Idaho National Laboratory's Nuclear Energy Launch Pad program and its proposed pathway for independent code verification at a U.S. national laboratory, reflecting a deliberate strategy to build regulatory, engineering, and technical-validation records in parallel.
The assignment of a project number is purely administrative and does not imply NRC approval. The notice letter is publicly available in the NRC's ADAMS system under Accession No. ML26189A392, accessible at https://www.nrc.gov/docs/ML2618/ML26189A392.pdf. This engagement marks a significant step toward potentially licensing an advanced reactor that could provide high-temperature heat for industrial processes currently reliant on combustion, contributing to decarbonization efforts beyond electricity generation.
