Antares, a nuclear energy startup focused on resilient microreactors, has raised $30 million in a Series A funding round led by Alt Capital and Caffeinated Capital. This funding will accelerate the development of Antares’ first microreactor, with the goal of proving a new vision for small-scale, portable nuclear energy.
Unlike traditional nuclear projects focused on grid-scale power, Antares is developing kilowatt-scale reactors that can fit in a standard shipping container. These smaller reactors are designed to power critical infrastructure in remote locations, from military installations to space missions.
We are now seeing a surge of interest in nuclear startups. This has been largely driven by the increasing energy demands of AI which has prompted several tech giants to invest heavily in nuclear power as a sustainable and reliable solution.
Microsoft, for instance, has partnered with Constellation Energy to revive the Three Mile Island nuclear plant in Pennsylvania, securing 100% of its output to support its data centers. Google has signed a long-term agreement with Kairos Power to purchase energy from upcoming small modular reactors (SMRs), anticipated to be operational by 2030. Similarly, Amazon has invested in X-energy to develop SMRs and partnered with Energy Northwest to explore new nuclear facilities. These strategic moves underscore the tech sector’s recognition of nuclear energy’s potential to provide the consistent, carbon-free power needed to support the exponential growth in AI workloads.
“America needs to return to iterative development of nuclear reactors through a design, build, and learn approach,” says Jordan Bramble, Antares CEO. “This is mission-critical technology, and Antares wants to become America’s industrial base partner for special-purpose microreactors.”
The 23-person company has already made significant progress. They’ve demonstrated their first heat pipe, machined core components, and secured $4.3 million in Department of Defense and Department of Energy funding. The new capital will support their expansion, including opening an R&D facility in early 2025 where you’ll see development of high-temperature heat pipes and other critical components.
Antares’ first 240-kilowatt thermal demonstration unit is scheduled to power up by mid-2025. The reactor design emphasizes reliability and modularity, incorporating features like built-in shielding and automated controls that allow for three years of autonomous operation.
The company has established partnerships with major national laboratories, including Idaho National Laboratory and Sandia National Laboratories, to support independent verification and development of key systems. Jack Altman of Alt Capital will join the board of directors as part of the investment, which brings Antares’ total funding to $38 million.