NRC Dockets Terra Innovatum Topical Reports, Initiates Formal Review of SOLO MMR

The U.S. Nuclear Regulatory Commission has docketed several topical reports and regulatory submissions for Terra Innovatum Global N.V.’s SOLO micro‑modular reactor, putting the company’s licensing package into the NRC’s formal technical review and advancing the Construction Permit and Operating License pathway under NRC Docket 99902138, Terra Innovatum said March 5, 2026. The company framed the action as a procedural milestone that allows NRC staff to begin detailed safety and design evaluations.

Terra Innovatum’s pre‑application materials filed with the NRC list specific documents and ML accession numbers that remain in the agency’s review queue. The Dec 17, 2025 pre‑application table records Regulatory Engagement Plan Rev 0 (ML25017A401) and Rev 1 (ML25159A006) as no review requested, and shows white papers and a topical report under review: Design Considerations on Reactor Core (Fuel) at Nominal Conditions (ML25159A010), Proposed Preliminary Safety Analysis Report Content and Exceptions (ML25159A011), Transportation and Logistics for SOLO Research and Test Reactor Deployment (ML25159A008), and the SOLO Micro Modular Nuclear Reactor Principal Design Criteria topical report (ML25159A013). Terra Innovatum said, “Together, these reports outline the fundamental engineering, safety, and regulatory framework for the SOLO™ reactor and support the broader licensing pathway required for reactor construction and operation.”

Terra Innovatum’s engagement with the NRC stretches back to January 2025, when the company began pre‑application activities. The company submitted additional regulatory documents through late 2025 and early 2026, and World Nuclear News noted a prior submission on 29 September that was placed under legal review by the NRC for potential withholding of proprietary information. Company materials and third‑party summaries show some filings listed as under review and others flagged for legal review before public posting.

Technical details in the filings define SOLO as a roughly 1 MWe unit intended to form a scalable modular platform from MWe to GWe class. Design features cited in company white papers include a solid heterogeneous composite moderator, helium gas heat removal that removes the need for water in the reactor coolant system, accommodation for zircaloy‑clad LEU fuel and future LEU+ or HALEU fuels, autonomous operation, and on‑line safeguards‑by‑design. Terra Innovatum also submitted white papers on factory‑based manufacturing, transportation, and on‑site assembly and on transportation and logistics for deployment.

The company is pitching SOLO as a radioisotope production platform with dedicated irradiation channels, integrated hot cell connections, and simultaneous multi‑isotope capability for technetium‑99m, lutetium‑177, iodine‑131, actinium‑225, iridium‑192, and cobalt‑60. Terra Innovatum has also announced supply‑chain and partnership activity, including memorandums with Ameresco for U.S. siting and RAIT 88 for commercialisation acceleration, and has stated it has secured key nuclear and non‑nuclear components in preparation for deployment.

Terra Innovatum executives framed the next phase as an intensive NRC interaction. “Docketing initiates the NRC’s detailed evaluation of key design, safety, and regulatory elements. Our team is actively supporting the NRC audit process as we work toward safety evaluation of the Topical Reports and continued progress toward licensing,” said Cesare Frepoli, Co‑Founder, COO and Director of Regulatory Affairs. “We believe the docketing of these reports reflects the technical preparation and maturity of the SOLO program,” said Alessandro Petruzzi, Co‑Founder and CEO. “Entering the NRC’s formal technical review process represents one of the most significant regulatory milestones in the nuclear licensing pathway and supports our goal of first‑of‑a‑kind deployment.”