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 submission of a notice of intent letter. The NRC has assigned Project No. 99902174 and a dedicated project manager to facilitate the pre-application activities, as confirmed in an NRC letter dated July 24, 2026. This administrative step provides a formal tracking mechanism for future interactions, though it does not imply NRC approval or endorsement of the design.
The company submitted its notice of intent on June 23, 2026, outlining its planned interactions with NRC staff. The notice letter is publicly available in the NRC's Agencywide Documents Access and Management System (ADAMS) under Accession No. ML26189A392, accessible at this link. Thorium Atomics intends to engage under 10 CFR Part 53, the NRC's risk-informed, performance-based, and technology-inclusive licensing framework, which became available on April 29, 2026. The company is preparing a Regulatory Engagement Plan detailing the Tesseract technology, licensing strategy, and planned submissions.
Dr. Jack Vecchiarelli, Chief Scientific and Regulatory Officer, emphasized the significance of having a defined point of contact and trackable reference. "Part 53 is risk-informed and technology-inclusive, making it well suited to a high-temperature gas-cooled reactor. Commencing that engagement while the design is still being developed serves to ensure that regulatory expectations are clearly understood and addressed, thereby informing the design development process and helping to de-risk the future licensing pathway."
Young Hwang, Founder and CEO, added, "This is a clear external marker of where our program stands. It comes alongside our application to Idaho National Laboratory's Nuclear Energy Launch Pad program and our proposed pathway for independent, qualified-code reactor-physics verification at a U.S. national laboratory. We are deliberately building the regulatory, engineering, and technical-validation records in parallel."
The Tesseract TGR is a pebble-bed high-temperature gas-cooled reactor, using helium coolant and TRISO fuel, which relies on passive safety rather than active systems. It is designed for 250 MWth, delivering approximately 100 MWe of electricity or industrial process heat up to 750°C. The reactor is initially fueled with uranium enriched below 10% U-235 and includes a thorium-bearing fertile blanket to breed U-233, potentially reducing mined-uranium requirements by about half compared to a Generation II light-water reactor. This estimate is subject to further engineering and validation.
This milestone underscores Thorium Atomics' commitment to early regulatory engagement, which is critical for advanced reactor developers to identify and address potential licensing issues before formal application. The assignment of a project number and project manager by the NRC signals a collaborative process that could streamline future reviews. As the company advances its design and validation efforts, this proactive approach may serve as a model for other advanced reactor developers navigating the new Part 53 framework. The outcome of these pre-application activities will be pivotal in determining the viability and timeline for deploying the Tesseract TGR, potentially contributing to decarbonization of industrial heat and electricity generation.
