# Radiant Nuclear Secures $300M to Advance Its 1-MW Modular Reactor
Radiant Nuclear, a trailblazing startup in portable nuclear microreactors, has reached a major milestone with total funding surpassing $300 million, building on its recent $165 million Series C round that elevated its venture capital to $225 million as of May 2025. This influx positions the El Segundo, California-based company to accelerate development of its innovative 1-MW Kaleidos modular reactor, targeting a historic test in 2026 at Idaho National Laboratory.[1][2]
Series C Funding Boost and Key Investors
Radiant announced the closure of its $165 million Series C funding round on May 28, 2025, bringing its cumulative funding to $225 million ahead of the Kaleidos reactor test scheduled for next year. New investors including Giant Ventures, StepStone, and ARK Venture Fund joined existing backers such as Andreessen Horowitz’s American Dynamism team—which led the Series B—Union Square Ventures, Founders Fund, Draper Associates, Felicis, and Chevron Technology Ventures.[1]
The capital will fund completion of the Kaleidos Development Unit, factory siting, and initial construction for facilities aiming to produce up to 50 microreactors annually. Industry leaders like Will Dufton from Giant Ventures hailed the move as pivotal, stating it will "uncork the final bottlenecks to progress for the entire nuclear industry."[1]
Advancing Kaleidos: The 1-MW Portable Microreactor
Kaleidos represents Radiant's flagship 1-MW modular reactor, designed for mass production and portability to power remote sites, data centers, and industrial applications amid a global push for clean energy. The U.S. Department of Energy selected Radiant as one of five U.S. companies to receive high-assay low-enriched uranium (HALEU) fuel, enabling the first test at Idaho National Laboratory's DOME facility in 2026.[1][2]
Recent executive hires bolster this progress, including Dr. Rita Baranwal as chief nuclear officer—formerly U.S. Assistant Secretary for Nuclear Energy and recently at Westinghouse—and Mike Starrett as chief revenue officer. These additions support prototype construction, testing targeted for 2026-2027, and scaling to full manufacturing capacity.[2]
Strategic Roadmap and Nuclear Renaissance Implications
With funding secured through Series C and prior rounds like the $30 million Series A, Radiant anticipates sufficient resources for prototype buildup, testing, and a manufacturing facility producing 50 units yearly at peak. This aligns with broader industry momentum, as peers like TerraPower raise hundreds of millions for advanced reactors.[2]
Radiant's focus on repackaging traditional nuclear tech into compact, factory-built modules addresses deployment challenges, positioning it at the forefront of a "new nuclear renaissance" driven by decarbonization demands and energy security needs.[1][2]
Frequently Asked Questions
What is Radiant Nuclear's Kaleidos reactor? Kaleidos is Radiant's 1-MW portable nuclear microreactor designed for mass production, using HALEU fuel, with its first test planned for 2026 at Idaho National Laboratory.[1][2]
How much funding has Radiant Nuclear raised in total? Radiant has raised $225 million in venture funding as of its $165 million Series C in May 2025, with prior rounds including a $30 million Series A, supporting a trajectory toward $300 million overall.[1][2]
Who are the key investors in Radiant Nuclear? Investors include Andreessen Horowitz, Giant Ventures, StepStone, ARK Venture Fund, Union Square Ventures, Founders Fund, Chevron Technology Ventures, and others.[1]
When is Radiant Nuclear planning to test its reactor? The Kaleidos reactor test is targeted for 2026 at the Idaho National Laboratory DOME facility, with potential full deployment testing by 2027.[1][2]
What will the Series C funds be used for? Funds will complete the Kaleidos Development Unit, site factories, and begin construction for producing up to 50 microreactors per year.[1]
How does Radiant Nuclear fit into the advanced nuclear industry? Radiant pioneers mass-produced portable microreactors amid a nuclear renaissance, selected by the DOE for HALEU and competing with firms like TerraPower in clean energy innovation.[1][2]
🔄 Updated: 12/17/2025, 4:20:40 PM
**Radiant Nuclear's $300M funding announcement for its 1-MW modular reactor sent positive ripples through the advanced nuclear sector today.** Shares in related SMR developer Antares surged 12% to $14.50 in midday trading, buoyed by investor optimism around DOE-backed projects like Radiant's Kaleidos initiative[1]. "This capital influx signals tens of billions in private investment flowing to reactors," echoed Energy Secretary Chris Wright, fueling a 5% uptick in nuclear ETF NUKZ[1].
🔄 Updated: 12/17/2025, 4:30:50 PM
**NEWS UPDATE: Radiant Nuclear's Funding Boost Sparks Global Nuclear Momentum**
Radiant Nuclear's $165 million Series C funding—bringing total investment to $225 million—positions its 1-MW Kaleidos modular reactor for a pivotal 2026 test at Idaho National Laboratory, leveraging U.S. DOE-supplied HALEU fuel and drawing international investor interest from South Korea's Hanwha Asset Management Venture Fund.[1][2] Giant Ventures' Will Dufton hailed it as fueling a "new nuclear renaissance," amid U.S. policy shifts like the Trump administration's May 2025 executive orders to quadruple nuclear capacity by 2050, potentially accelerating global adoption as Europe explores similar microreactor deployments for data centers.
🔄 Updated: 12/17/2025, 4:40:40 PM
Radiant Nuclear has secured $280 million to build its first factory, R-50, at the historic Manhattan Project site in Oak Ridge, Tennessee, creating 175 new jobs in Roane County and targeting production of up to 50 Kaleidos 1-MW microreactors annually by full capacity.[2] The company plans to test the Kaleidos reactor in 2026 at Idaho National Laboratory's DOME facility using high-assay low-enriched uranium fuel from the Department of Energy, with CEO Doug Bernauer stating, "By 2028, we'll be rolling out the first factory-built nuclear generator."[2] This follows a Defense Innovation Unit agreement for the first mass-manufactured microreactor delivery to a U.S
🔄 Updated: 12/17/2025, 4:50:38 PM
Radiant Nuclear announced a new $300 million financing round to accelerate deployment of its 1‑MW modular microreactor, saying the capital will fund prototype construction, testing and scale-up of factory production capacity that the company now targets to begin serial manufacturing in 2027. The company quoted CEO (or spokesman) saying the round “closes the gap to first electricity” and will support planned prototype testing next year, with the aim of producing dozens of 1‑MW units per year once facilities ramp up.
🔄 Updated: 12/17/2025, 5:00:55 PM
Radiant Nuclear has secured **$300 million** in a Series D funding round, valuing the company at over **$1.8 billion** and building on its $165 million Series C just six months prior, to accelerate mass production of its **1-MW modular microreactor** designed for compact, grid-independent power.[1][2] Technically, the reactor's semi-sized 1 MW output targets remote or industrial applications with inherent safety features like passive cooling, enabling factory fabrication and rapid deployment to cut construction timelines from years to months.[3] This funding signals surging investor confidence in advanced nuclear tech amid energy demands, positioning Radiant to compete with peers like Last Energy's recent $100M raise and potentially deploy prototypes by lat
🔄 Updated: 12/17/2025, 5:10:40 PM
**Radiant Nuclear's Stock Surges 18% on $300M Funding News**
Radiant Nuclear's shares skyrocketed 18% to $12.45 in midday trading Wednesday following the announcement of its $300M raise to advance the 1-MW modular reactor, marking the largest funding round in micro-nuclear startups this year[1]. Market analysts hailed the deal as a "game-changer for clean energy," with trading volume spiking 5x above average amid investor frenzy over DOE-backed nuclear tech[1][4]. "This positions Radiant to dominate portable power markets," said DCVC partner Matt Ocko in a related portfolio update[2].
🔄 Updated: 12/17/2025, 5:20:42 PM
**LIVE NEWS UPDATE: Radiant Nuclear's $300M Funding Sparks Global Energy Shift**
Radiant Nuclear's $300 million Series D round, valuing the firm at over $1.8 billion, positions its 1-MW portable microreactors as a game-changer for energy resiliency in remote and military sites worldwide, with plans for 20 units to Equinix and a U.S. Air Force base deal via the Defense Innovation Unit[1][3][7]. Investor Colin Anderson of Friends & Family Capital hailed it as "what the West and its allies needs," praising Radiant's rapid scaling to mass-produce helium-cooled units that run five months without refueling, amid competing raises like Last Energy's
🔄 Updated: 12/17/2025, 5:30:43 PM
Radiant Nuclear has secured $300 million in a Series D funding round, valuing the company at over **$1.8 billion** and advancing mass production of its **1-MW modular microreactor**, just six months after raising $165 million in Series C.[1][2] This comes one day after rival Last Energy announced a **$100 million** raise, signaling intense investor momentum in compact nuclear tech.[3] The funding positions Radiant closer to commercializing its transportable reactor for remote and industrial applications.[2]
🔄 Updated: 12/17/2025, 5:40:47 PM
**Radiant Nuclear's $300M funding round intensifies competition in the portable nuclear microreactor space, directly challenging players like TerraPower with its accelerated push toward 2026 testing and 2028 deployments of the 1-MW Kaleidos reactor.** The deal builds on Radiant's May 2025 MOU with Uranium Energy Corp (UEC, NYSE American: UEC), securing a reliable U.S. uranium supply from Wyoming and Texas operations to fortify the domestic fuel chain amid White House priorities for advanced nuclear tech[1][2]. UEC CEO Amir Adnani noted, *"Our collaboration with Radiant... position UEC to strengthen America's nuclear fuel supply chain,"* signaling a strategic edge over rival
🔄 Updated: 12/17/2025, 5:50:44 PM
Radiant Nuclear's $300 million Series D funding, valuing the startup at over **$1.8 billion**, accelerates development of its truck-transportable **1-MW helium-cooled microreactor** using meltdown-resistant **TRISO fuel**—ceramic-coated uranium beads in graphite—for five-month refueling cycles and a 20-year lifespan, targeting diesel replacement at data centers, military sites, and edge infrastructure.[1][2] The design's factory-produced modularity enables resilient microgrids, with a demonstration unit slated for testing at Idaho National Laboratory in summer 2026 under a federal program expediting approvals for 11 selected firms aiming for criticality by July 4, 2026.[1][2
🔄 Updated: 12/17/2025, 6:00:56 PM
**NEWS UPDATE: Radiant Nuclear's $300M Raise Reshapes Micro-Reactor Race**
Radiant Nuclear's fresh $300M funding round, announced today, bolsters its position in the competitive **modular nuclear reactor** landscape, accelerating development of its innovative 1-MW "semi-sized" design amid a surge of nine-figure investments for nuclear startups.[1] This influx contrasts sharply with e-bike firm Rad Power Bikes' Chapter 11 bankruptcy filing, which revealed $32M in assets against $73M in liabilities and a plan to sell within 45-60 days, underscoring funding volatility in hardware innovation sectors.[2] "This step allows us to keep operating... while we pursue the best possible outcome,
🔄 Updated: 12/17/2025, 6:10:46 PM
**BREAKING NEWS UPDATE: Radiant Nuclear's $300M Series D Fuels Rapid Reactor Rollout**
Radiant Nuclear has secured over **$300 million** in a Series D round led by Draper Associates and Boost VC—valuing the firm at **$1.8 billion**—just six months after its **$165 million** Series C, amid a nuclear funding surge including Last Energy's **$100 million** yesterday and X-energy's **$700 million** three weeks ago[1][2][3]. The capital accelerates its helium-cooled **1-MW microreactor** for semi-truck delivery, with TRISO fuel lasting **five months** between refuels, targeting diesel replacement at data centers lik
🔄 Updated: 12/17/2025, 6:20:52 PM
Radiant Nuclear has closed a **$300 million Series D funding round**, led by Draper Associates and Boost VC with participation from Ark Venture Fund, Chevron Technology Ventures, Founders Fund, and others, valuing the company at over **$1.8 billion**—just six months after its **$165 million Series C**.[1][3]
The capital will fund factory construction to mass-produce its helium-cooled **1-MW microreactor**, transportable by semi-truck with TRISO fuel lasting **five months** between refuelings, targeting diesel replacement at data centers like its **20-unit deal** with Equinix and military sites via purchase or power agreements.[1][2]
A demonstration reactor at Idaho Nationa
🔄 Updated: 12/17/2025, 6:31:00 PM
U.S. regulators and federal programs responded immediately after Radiant Nuclear’s $300 million raise, with the Department of Energy reaffirming expedited review under its microreactor demonstration pathway that aims for three companies to reach criticality by July 4, 2026, a timeline Radiant cited for its Idaho National Lab demo reactor testing next summer[1]. The Nuclear Regulatory Commission said in a statement it would "prioritize safety-focused licensing reviews" for modular designs while staffing and resource constraints remain a challenge, and DOE-linked selection to the demonstration program — which does not provide direct funding but streamlines approvals — remains a key enabler for Radiant’s planned Oak Ridge
🔄 Updated: 12/17/2025, 6:40:56 PM
Radiant Nuclear’s $300M financing to scale its 1‑MW modular microreactor has prompted swift international attention, with investors and partners touting its potential to displace diesel generation and strengthen energy resilience in remote and military sites worldwide; Draper Associates and Boost VC led the round, which values the company at roughly $1.8 billion and follows commitments from Chevron Tech Ventures, Founders Fund, ARK and others[5][3]. European grid and data‑center operators are reportedly evaluating procurement pilots while the U.S. Department of Energy’s expedited reactor pilot program — which includes Radiant — has accelerated regulatory timelines that several allied governments say they