Small reactor startup Antares raises $96 million for land, sea and space nuclear power

Nuclear energy startup Antares said Tuesday it has raised $96 million in Series B funding as it seeks to design its own small modular reactor.

The round, led by Shine Capital with participation from Alt Capital, Caffeinated, FiftyThree Station, Industrious and others, consists of $71 million in equity and $25 million in debt.

Antares says it is targeting commercial, defense and space applications with its R1 small reactor, which will produce between 100 kilowatts and 1 megawatt of electricity. The design uses TRISO fuel, which in the case of the Antares is carbon-ceramic-coated uranium balls embedded in graphite.

The startup is one of several companies that have recently benefited from renewed interest in nuclear energy over the past six months.

Last week, Amazon-backed X-energy said it had raised a $700 million Series D round, which came on the heels of a $700 million Series C round it closed in February. The company is also designing a reactor based on Triso fuel. Deep Fission, which struggled to raise money until April, went public in a $30 million reverse merger in September.

Aalo Atomics raised $100 million in August to build an experimental data center powered by a small reactor, and in June, Nvidia contributed to a $650 million round for TerraPower, a small modular reactor startup also backed by Bill Gates.

Major nuclear plants have also been given a second chance.

Earlier this month, Microsoft partner Constellation Energy received a $1 billion loan from the Department of Energy to restart a reactor at Three Mile Island by 2028. That project is expected to cost $1.6 billion to renovate the reactor that was decommissioned in 2019. In October, Google said it would work with NextEra Energy to reopen a nuclear power plant in Iowa that was damaged during heavy rains in 2020.

Earlier this summer, Amazon purchased 1.92 gigawatts of generating capacity from the Talen Energy nuclear plant in Pennsylvania. Meta also said in June that it would buy clean energy properties from the Constellation Energy nuclear power plant in Illinois.

While big nuclear has been the main beneficiary, the Trump administration is optimistic about small nuclear’s ability to revive the industry’s fortunes in the next decade.

In August, Antares was selected as one of 11 participants in the Energy Department’s reactor pilot program, which aims to have at least three of them up and running by July 4, 2026, a much faster timeline than the nuclear industry is accustomed to.

Antares said it aims to demonstrate its reactor to the Department of Energy next year, and plans to operate its reactor at full power sometime in 2027.