Apollo Atomics Secures $26 Million to Challenge Conventional Nuclear Power Designs

The nuclear power industry is experiencing a resurgence with increased funding flowing to startups aiming to develop advanced reactors that promise to reduce costs. However, recent forecasts suggest that these new reactors may not achieve cost-competitiveness in the near future. Apollo Atomics, founded by Assil Halimi and Drew Walker, is approaching the challenge differently by focusing on enhancing thermal energy conversion rather than creating new reactor designs.

Halimi, the CEO of Apollo, emphasized the company’s focus on the steam generator, the largest component of a nuclear power system. “We focus on the largest component, the steam generator,” Halimi stated. “We have been able to shrink that component and make the whole system way more compact than any other reactor in the market.” Traditional steam generators are often several stories tall and require intensive manual construction, whereas Apollo claims its generator can be mass-produced and is roughly the size of a person. This innovation has enabled Apollo to construct a reactor that is 40 times smaller than those utilizing conventional steam generators.

In a recent funding round aimed at developing a demonstration reactor for anticipated commercial deployment in 2028, Apollo closed a $26 million seed round, which included $5 million in debt. The company has based its designs on research conducted at MIT.

Halimi predicts that an Apollo power plant could generate electricity at a cost of 3 cents per kilowatt hour. He expressed the company’s ambition, stating, “We don’t want to be incremental in nuclear and just improve a small thing. Our target is to beat natural gas.”

Halimi noted that existing steam generators are based on outdated designs which primarily draw from those used in coal and natural gas plants—fuels with much lower energy densities than nuclear fuel sources like uranium. He pointed out that the potential of nuclear fuel is underutilized, saying, “You have this high-potential fuel, but you’re converting just a small piece of it.”

Apollo’s innovative generator design includes a compact block of metal threaded with needle-thin channels that efficiently transfer heat between the coolant and steam-generating fluids. This design allows for a more efficient thermal exchange, significantly reducing the size of the generator.

Further leveraging this compact design, Apollo intends to assemble both the reactor and steam generator in a factory setting rather than on site, which is the current industry standard for nuclear plants. Halimi anticipates that this approach, combined with the generator’s size, will enable Apollo to complete a 300-megawatt power plant in less than 24 months, potentially lowering production costs by four to five times compared to existing designs.

Apollo Atomics has already built a small-scale 40-kilowatt reactor at MIT to validate its technology and plans to produce reactors in three sizes, ranging from 10 megawatts-electric to 300 megawatts.

FCVC led the recent funding round, with participation from Telesoft Partners, Y Combinator, Alumni Ventures, Robinhood Ventures, Nucleation Capital, Pelion VC, Duke Capital Partners, New Era Ventures, Orange Collective, Stanford University, E14 Fund, and Neutron Power Ventures. Apollo is also a participant in Y Combinator’s Spring 2026 batch.