**World's first factory dedicated to mass-producing portable nuclear reactors.** Announced October 2025; groundbreaking targeted early 2026. Located at a former Manhattan Project site in Oak Ridge, Tennessee — the symbolic birthplace of the US nuclear industry. Name: "R-50" — nods to the historical Oak Ridge site naming convention (K-25, X-10, Y-12, etc.) AND the ambitious 50 reactors/year production target. Strategy: deliver first mass-produced Kaleidos by 2028; scale to 50 reactors/year within a few years.
Two HALEU supply firsts: (1) Radiant became the **first reactor company to sign a contract with the DOE for HALEU fuel** for the 2026 INL DOME test. April 2025: one of five companies selected by DOE to receive HALEU near-term fuel allocation. (2) Radiant signed the **first binding commercial contract by a US advanced reactor developer for Western commercial HALEU enrichment services** with Urenco — at a ceremony at the US embassy in London. Anchors Radiant's HALEU supply chain across both DOE-allocated and Western commercial sources.
**First-ever deal for mass-manufactured nuclear microreactors on a US military base.** Initial contract signed August 2025 with DIU + Department of the Air Force for FOAK delivery in 2028. Subsequently selected April 2026 under the Advanced Nuclear Power for Installations (ANPI) initiative alongside Antares (Joint Base San Antonio) and Westinghouse — Radiant's ANPI base assignment + value not yet disclosed. Earlier DoD funding awards evaluated microreactor integration at Hill Air Force Base (Salt Lake City, Utah).
August 2025 — Radiant signed deal **with deposits** with Equinix to purchase 20 Kaleidos microreactors for data center power. Part of Equinix's broader nuclear portfolio strategy (parallel deals with ULC-Energy, Stellaria, and Oklo). **First major hyperscaler microreactor commitment with deposits attached** — Equinix put real money down rather than just an LOI.
Radiant's flagship reactor — 1 MWe / 1.9 MWth (some sources cite 1.2 MWe / 3 MWth post-design refinement). Helium-cooled HTGR with TRISO HALEU fuel in prismatic graphite blocks. Passive air-jacket natural convection cooling for decay heat removal. Containerized — fits in shipping container envelope, transportable by land, sea, or air. Installable in days. Designed for **mass production** rather than bespoke build — aerospace-style factory output. Core thesis: Kaleidos replaces diesel generators wherever continuous off-grid power is needed.
**First new US reactor design** to be tested at INL's new DOME (Demonstration of Microreactor Experiments) facility — DOME is the repurposed containment structure from the former Experimental Breeder Reactor II (EBR-II), converted by DOE/INL into a dedicated testbed for fueled microreactors. Radiant's testing structured as a yearlong campaign from initial criticality to sustained full-power operation. **Radiant claims to be the only nuclear energy company conducting a full power, commercial-scale, multi-megawatt-powered test at INL DOME in 2026** — distinct from low-power criticality demonstrations of other Pilot Program participants. December 2025 milestone: pressure vessel + first order of nuclear-grade American-made graphite (extruded for the first time in over a decade) delivered, reactor assembly began.
Portable 1 MWe helium-cooled microreactor for military forward operating bases and remote industrial sites. Truck-deployable, self-contained, containerized design.
Series A round. Specific amount not publicly disclosed at full detail. Established Radiant's engineering team and El Segundo operations.
October 2023 — Radiant selected as one of three advanced nuclear energy developers to receive funding totaling $3.9M from DOE for developing and testing microreactor designs using INL's DOME facility. Foundational federal R&D capital for the Kaleidos demonstration pathway.
Series B led by a16z American Dynamism. Establishes Radiant within the defense-tech / national-security venture ecosystem. Specific amount not fully disclosed publicly.
Series C funding announced November 14, 2024 with $100M led by DCVC. Extended to $165M total by June 2025 close with additional Giant Ventures, StepStone, ARK Venture Fund. Funded Kaleidos Development Unit (KDU) for INL DOME testing.
Series D announced December 17, 2025 — over $300M raised in just a few weeks, six months after Series C close. Led by Draper Associates and Boost VC (Tim Draper + Adam Draper publicly endorsed Radiant's execution discipline). Additional investment from Founders Fund, ARK Venture Fund, Chevron Technology Ventures (Chevron — first major energy company on the Radiant cap table). Funds R-50 Oak Ridge factory groundbreaking + commercialization scale-up. Cumulative funding $465M+.