Valar Atomics, the three-year-old nuclear startup, raised $1 billion in Series B funding led by Sequoia Capital at a $6 billion valuation, plus a $200 million credit facility from Erebor and other lenders. The funding will support the company's shift from proving its small modular reactor (SMR) technology to manufacturing fleets for production—a challenge the nuclear industry has struggled with for decades.
Valar's Ward 250 reactor achieved self-sustaining criticality on June 18, making it the first startup-built advanced reactor to reach that milestone outside a national laboratory. Days later, it successfully powered an NVIDIA Blackwell system, and Valar announced a partnership with NVIDIA to develop a waterless 30-megawatt AI factory in Utah. The startup plans to vertically integrate production, including manufacturing nuclear fuel itself at facilities co-located with reactors.
The funding reflects surging investor appetite for nuclear power as AI data center energy demands spiral. AI racks consume 50–100 kilowatts per unit versus 5–10 kilowatts for traditional servers, creating a grid interconnection crisis: the U.S. queue for power projects now spans 4–5 year wait times. The International Energy Agency reports SMR pipelines for data centers grew 80% in 18 months (25–45 gigawatts). Microsoft, Amazon, Google and Meta have all signed direct nuclear purchase agreements.
For architects, this matters because nuclear becomes a material lever on capex—eliminating multi-year grid waits by siting behind-the-meter reactors can compress a hyperscaler's data center timeline and cost structure. Valar's ambition to produce "tens, then hundreds, then thousands of reactors per year" signals a bet that manufacturing discipline will solve what megaproject finance has not.