Microreactor startup Antares raises $96M for land, sea, and space-based nuclear power

Antares, a pioneering nuclear startup, has successfully secured $96 million in Series B funding aimed at advancing its innovative small modular reactor design. This funding round, spearheaded by Shine Capital, saw contributions from a range of investors, including Alt Capital, Caffeinated, FiftyThree Stations, and Industrious. The capital infusion comprises $71 million in equity and $25 million in debt, underscoring the growing interest in nuclear technology. The company is focusing on its R1 microreactor, designed to generate between 100 kilowatts and 1 megawatt of electricity, with applications spanning commercial, defense, and even space. Antares’ reactor utilizes TRISO fuel, which consists of uranium spheres encased in carbon and ceramic coatings that are embedded in graphite, enhancing safety and efficiency. Antares is part of a larger trend, as several companies have recently attracted significant investments due to a resurgence in nuclear energy interest. Notably, Amazon-backed X-energy announced a remarkable $700 million in Series D funding, shortly after completing a similarly sized Series C round in February. Additionally, Deep Fission transitioned to public status through a $30 million reverse merger, while Aalo Atomics raised $100 million to establish a microreactor-powered demonstration data center. The renewables sector is also witnessing a renewed focus on traditional nuclear power. For instance, Constellation Energy, a partner of Microsoft, received a $1 billion loan from the Department of Energy to reactivate the Three Mile Island reactor by 2028, with refurbishment costs projected at $1.6 billion. Moreover, Google has partnered with NextEra Energy for the restoration of a nuclear facility in Iowa, and Amazon acquired nearly 2 gigawatts of capacity from a Talen Energy plant in Pennsylvania. The current administration is optimistic about the future of small modular reactors, viewing them as a vital component in revitalizing the nuclear industry over the next decade. In an encouraging development, Antares was recently selected as one of 11 participants in the Department of Energy’s reactor pilot program, which aims to have at least three operational by July 4, 2026 — a timeline that is notably ambitious for the sector. Antares plans to showcase its reactor to the DOE next year and intends to achieve full-power operation by 2027.