Apollo Atomics has announced a $31 million seed round to commercialize a pressurized water reactor platform designed for serial manufacturing rather than on-site construction. The MIT spin-off aims to deliver its first unit by 2028.
The oversubscribed round was led by FCVC and included participation from Y Combinator, Telesoft Partners, Alumni Ventures, Robinhood Ventures, Nucleation Capital, Pelion VC, and Duke Capital Partners. The capital will be used to expand long-duration reliability testing, build out manufacturing capacity, and advance the regulatory process with the U.S. Nuclear Regulatory Commission. Apollo has already submitted its engagement plan to the NRC in early 2026 and is targeting a construction permit application by 2028.
The core of Apollo Atomics‘ approach lies in a single redesign: the steam generator. Pressurized water reactors power roughly 80% of the world’s nuclear plants, but their size has historically been dictated by massive steam generators that must be hand-built on site. Drawing on more than 15 years of MIT research, Apollo has developed a Compact Steam Supply System with power density approximately an order of magnitude higher than conventional designs. The result: a reactor roughly 40 times smaller than its predecessors, while delivering the same output. Low-enriched uranium fuel, light water, existing supply chains. No exotic materials, no unproven cooling technology.
The company has already built a 40 kilowatt-electric demonstrator at MIT. Tests conducted in collaboration with MIT’s Department of Nuclear Science and Engineering are aimed at validating computational models under conditions identical to those of large-scale commercial plants. Three output sizes are planned: 10 MW, 50 MW, and 300 MWe, targeting data centers, industrial facilities, and utilities respectively. Internal estimates suggest a 300 MW plant could be completed in under 24 months from project launch, with reactor manufacturing costs four to five times lower than conventional projects. The stated target is $0.03 per kilowatt-hour — competitive with fossil fuels, natural gas included.
Demand is there. Data centers and large industrial facilities are seeking continuous, uninterrupted power, and the rise of artificial intelligence infrastructure is intensifying pressure on available generation capacity. Most SMRs currently in development require specialized fuels or supply chains that do not yet exist, with deployment timelines slipping well past 2035. Apollo positions itself as a concrete option for customers who need power before 2030, citing letters of intent already signed for a combined 20 GW.
If the MIT tests and the NRC process stay on schedule, Apollo Atomics could find itself delivering the first serial-production nuclear reactor in history: not a prototype, not a megaproject, but a repeatable industrial product. It is a promise the nuclear sector has made many times before. This time, however, the underlying technology is already proven — and the capital to pursue it is in place.
