Nuclear power startup Antares Nuclear has raised $470 million to build small reactors for U.S. military bases, underscoring investors' growing interest in advanced nuclear startups.

Unlike traditional reactors, Antares’ SMR uses TRISO fuel, which is touted as a safer alternative and can be cooled by gases like helium or molten salts. The company’s Mark-0 reactor reached criticality on June 4 at the Idaho National Laboratory.

Antares hopes to bring its first electricity-producing reactor online next year with deployments planned for 2028. However, these reactors are unlikely to be cost competitive in the near future, with Lazard estimating costs of $214 per megawatt hour.

Despite this, Antares is one of three finalists in the Pentagon's Advanced Nuclear Power for Installations program, testing SMRs on Air Force bases in Colorado and Montana. Investors are flocking to nuclear power as electricity demand surges in response to data center construction and the broader electrification of the economy.

However, while advanced nuclear startups face hurdles like an immature supply chain and challenges with scaling production, mass manufacturing could eventually reduce costs significantly — if they can survive long enough to see that day.