U.S. Apollo Atomics Secures $31 Million in Funding to Advance Commercialization of Compact Pressurized Water Reactor

U.S.-based Apollo Atomics recently announced the completion of a $31 million seed funding round to advance the commercialization of its next-generation compact pressurized water reactor. Incubated by the Massachusetts Institute of Technology (MIT) and backed by Y Combinator, the company plans to shift the reactor from the traditional “one-off large-scale construction” model to a factory-manufactured, scalable product.

The round was led by FCVC, with participation from Y Combinator, Telesoft Partners, Alumni Ventures, Robinhood Ventures, Nucleation Capital, Pelion VC, and Duke Capital Partners. The company stated that the proceeds will be used to expand demonstration and long-term reliability testing, build manufacturing capabilities, and advance regulatory engagement with the U.S. Nuclear Regulatory Commission (NRC).

Apollo Atomics' technical approach does not alter the mature foundations of pressurized water reactors, including light water reactor technology, commercial low-enriched uranium fuel, and the existing supply chain. Instead, the company focuses on redesigning one of the largest and most structurally complex components of the nuclear steam supply system—the steam generator. The company claims that its proprietary compact steam system achieves a power density approximately an order of magnitude higher than conventional designs, enabling the reactor's overall footprint to be reduced by roughly 40 times. This supports factory manufacturing of high-power-output equipment, transportation by truck, and deployment within 24 months.

The company has built and tested a reactor system demonstration unit at MIT's Department of Nuclear Science and Engineering to validate the relevant hardware under conditions approaching those of commercial reactors. Apollo Atomics is also advancing its commercial regulatory pathway, having submitted a regulatory engagement plan to the NRC earlier this year and seeking NRC authorization for commercial use of its selected fuel configuration by the end of 2026. This fuel configuration has previously achieved criticality at full power conditions.

Apollo Atomics is currently developing three reactor systems: the A-10 (10 MWe), the A-50 (50 MWe), and the A-300 (300 MWe), targeting applications including data centers, industrial facilities, utilities, and other large energy consumers. The company states that its commercial pipeline includes signed letters of intent totaling more than 20 GW of project capacity.

The funding will also support the company in building its next demonstration facility, the A-1, a 1 MW-class commercial demonstration unit, as well as advancing vertical integration of key manufacturing processes, expanding engineering and operations teams, and maintaining ongoing engagement with the NRC.