Stellaria raises €23mn to develop a molten salt nuclear reactor by 2035, led by At One Ventures and Supernova Invest.

Jul 21, 2025•28 days ago

Amount Raised

€23 Million

GrenobleEnergy

Investors

Technip EnergiesExergonSchneider ElectricCea InvestissementSupernova InvestAt One Ventures

Description

French start-up Stellaria secures €23mn ($25.2mn) in a funding round to develop a prototype fast neutron molten salt reactor, targeting first fission by 2029. The funding will support technical and regulatory studies for an INB installation. The round was led by US-based impact fund At One Ventures and French fund Supernova Invest, along with its historical investors. Stellaria plans to double its workforce and expand research capabilities in Grenoble.

Company Information

Company

Stellaria

Location

Grenoble, Auvergne Rhône Alpes, France

About

Stellaria is a French start-up developing a fourth-generation nuclear reactor called the Stellarium, capable of operating in a closed fuel cycle with molten salt technology. Founded in 2023, the reactor aims for self-sustainability over 20 years while significantly reducing long-lived nuclear waste. Its first nuclear reaction is targeted for 2029, with commercial deployment expected by 2035.

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