Advanced nuclear reactor firm TerraPower has closed a $650 million fundraising round, with backing from Nvidia’s venture capital arm, NVentures.

The company, which is developing an advanced nuclear reactor paired with a gigawatt-scale energy storage system, known as the Natrium reactor, also received backing from founder Bill Gates and HD Hyundai.

“TerraPower was founded on the idea that innovation in nuclear science could make positive, global impacts. This round further establishes that our technologies are the solutions that industry is looking for,” said Chris Levesque, TerraPower president and CEO.

The Natrium reactor is a 345MWe sodium-cooled fast reactor with a molten salt-based energy storage system. According to the company, through its unique storage system, the technology’s capacity can be boosted to up to 500MWe for more than five and a half hours when required.

The company broke ground on its first plant in 2024 and expects to receive regulatory approval from the Nuclear Regulatory Commission next year. If it acquires approval, it will become the first commercial advanced nuclear technology to do so in the US market.

In April, the company submitted a letter to the UK Department for Energy Security and Net Zero declaring its intention to enter the UK Generic Design Assessment process. This is TerraPower’s first foray into an international market.

The backing from Nvidia represents a growing trend of data center firms and chip producers targeting the advanced nuclear and small modular reactor market as a potential crucial future energy source.

Commenting on the investment, Mohamed Siddeek, corporate vice president and head of NVentures, stated: “As AI continues to transform industries, nuclear energy is going to become a more vital energy source to help power these capabilities.”

TerraPower’s nuclear reactor technologies offer innovative, carbon-free solutions to meet global energy needs while minimizing environmental impact.”

In January, TerraPower signed a Memorandum of Understanding with Sabey Data Centers (SDC) to explore the use of the Natrium reactors in SDC’s current and future data center operations.

Several major data center developers have already made firm commitments to SMR firms, including Edged, Amazon, Google, Oracle, Sabey, Prometheus Hyperscale, Equinix, Switch, and others.

Most recently, in March, Data4 signed a deal with Westinghouse to explore the use of its AP300 SMR to power future data centers in the European market.