Stellaria raises €23 million for its molten-salt nuclear reactor

Stellaria, a French start-up originating from CEA and Schneider Electric, has announced that it has raised a total of €23 million to develop its fast neutron molten salt nuclear reactor by 2035. This new round of funding comes two years after a successful first round in 2023.

The round was co-led by US impact fund At One Ventures and Supernova Invest alongside Stellaria’s historical investors, including CEA Investissements, Schneider Electric, Exergon, and Technip Energies.

In addition to the €10 million in non-dilutive financing obtained by Stellaria through its success in the France 2030 Innovative Reactors call for projects, this funding will be used to finance all the technical and regulatory studies necessary to establish the world’s first molten-salt facility capable of sustaining a fission reaction, scheduled for 2029.

Thanks to this funding, Stellaria aims to to double its workforce to accelerate R&D around its reactor and finalise the development of its world's first liquid-core fast-neutron reactor demonstrator.

This step will allow it to develop its research laboratory in Grenoble by several million euros, to continue its scientific and and industrial collaborations, et de submit an Application for Authorisation to Create (DAC) a Basic Nuclear Installation (INB) to the safety authorities for the construction of its prototype.

Nicolas Breyton, CEO of Stellaria, said : “This funding round demonstrates the confidence of investors in the technical maturity of our molten-salt reactor, which opens up a new path towards the circular economy of the fuel cycle. We are laying the foundations for a model in which electro-intensive industries become self-sufficient in energy throughout the lifetime of their facilities. This is a key step towards the sustainable reindustrialisation of our territory.”

“We invested because Stellaria is solving the core technical and economic barriers holding back nuclear, cost, complexity, and waste“, explained lead investor Laurie Menoud, Partner at At One Ventures.

“The reactor offers low CAPEX and LCOE, passive safety with 72-hour cooldown, fuel flexibility, and fast power ramping. Add to that a favorable regulatory environment in France and early strategic engagement, and Stellaria stands out. This is the kind of planetary impact we’re here for, clean, dispatchable power that can be built faster, sited closer, and operated more safely. Stellaria isn’t just building a reactor, it’s building the future of nuclear energy.“

Francois Breniaux, General Partner chez Supernova Invest, explains : “Based on a unique development approach, Stellaria offers the only viable solution for many industries requiring a high-power energy supply, long-term price stability, and the operational flexibility of gas-fired power plants. This capability is essential both for sustaining traditional strategic electro-intensive sectors (such as steel and chemicals) and for enabling the growth of emerging industries, including CO₂-free hydrogen production and data centres driven by the rise of artificial intelligence. The teams' expertise enables rapid solutions to the known challenges in this high-potential technological field.”

Frédéric Godemel, Executive Vice President Energy Management at Schneider Electric said: "Stellaria is on track to develop the world's first fast neutron molten-salt nuclear reactor by 2035. This project will offer affordable and impactful solutions for industrial decarbonization, a tangible sign of the progress being made in the industry. Innovations like these show what can be achieved with bold ideas and strong partnerships”.

Benjamin Lechuga, Chief Strategy and Sustainability Officer at Technip Energies,added: “Technip Energies is pleased to continue its commitment alongside Stellaria as a strategic investor and partner in the development of Europe’s first fast neutron molten-salt nuclear reactor. We will support Stellaria in the industrial scale-up of this controllable, low-carbon energy production technology through concrete projects. This support reflects our commitment to long-term innovation and our belief in the complementary nature of energy solutions serving decarbonization“.

Giuseppe Sangiovanni, Co-founder and Managing Partner at Isospin Exergon commented: "Our fund is proud to support Stellaria as an investor since the first financing round. We are delighted with the company's continuing progress, the milestones that have already been validated and the growing business prospects at both European and international level. We invested in and supported Stellaria from the very first round, and we are delighted with the progress the company has made since then, as well as the growing business prospects. The quality of Stellaria’s team and partners, the innovative design of the reactor, and the major advantages of molten salt technology all combine to create a project that will be a real game changer for the industry".

For this operation, Stellaria was advised by the law firm Yards and by Optiva Capital for the fundraising, while the investors were advised by the law firms Chammas & Marcheteau and Goodwin.

*Via the nuclear isogeneration process (conversion of Uranium 238 into Plutonium 239).