Funds of €23 Million Allocated for the Construction of Rapid Neutron Molten Salt Nuclear Factory, under the name Stellaria
In a significant development for the nuclear energy sector, French company Stellaria, founded in 2023, is spearheading the development of a fourth-generation fast neutron molten-salt nuclear reactor. This innovative reactor, known as the Stellarium, has the unique ability to regenerate its fuel during operation, promising energy self-sufficiency for over 20 years.
Current Development Status and Timeline
Stellaria recently secured €23 million in funding, including €10 million in non-dilutive financing from the France 2030 ‘Innovative Reactors’ initiative. These funds will support the technical and regulatory studies needed to build a prototype molten salt facility, with plans to start operating it by 2029. The ultimate goal is to achieve the first nuclear reaction in the same year.
The company aims to have the first commercial production unit of the Stellarium reactor ready for deployment by 2035. To accelerate research and development, Stellaria plans to double its workforce and establish a research laboratory in Grenoble. Additionally, the company will submit the necessary safety authorization applications for the prototype's construction to the nuclear safety authorities.
The Stellarium's Potential Impact
The Stellarium reactor is designed to be competitive, safe, and flexible, with the potential to significantly decarbonize energy production. By reducing CO2 and particulate emissions from industrial sites by 99%, this reactor targets energy self-sufficiency in electro-intensive industries and advances a circular fuel economy.
Nicolas Breyton, CEO of Stellaria, expressed confidence in the technical maturity of the molten-salt reactor. He believes it opens up a new path towards the circular economy of the fuel cycle and could potentially play a significant role in the sustainable reindustrialisation of a territory.
With this funding, Stellaria is laying the foundations for a future where industries could potentially become energy self-sufficient throughout their lifetimes. The molten-salt reactor could potentially be a key solution for industries to significantly reduce CO2 emissions from their sites.
The funding round was co-led by At One Ventures and Supernova Invest, with existing investors including CEA Investissements and Schneider Electric also participating. This investment signifies investor confidence in the potential of the molten-salt reactor to contribute to a circular economy of the fuel cycle.
[1] Stellaria. (2025). Stellaria secures €23 million in funding for fast-neutron molten-salt nuclear reactor development. Retrieved from https://stellaria.fr/news/stellaria-secures-23-million-in-funding-for-fast-neutron-molten-salt-nuclear-reactor-development
[2] France 2030. (2025). France 2030 invests €10 million in Stellaria's innovative reactor project. Retrieved from https://france2030.gouv.fr/france-2030-investit-10-millions-dans-le-projet-de-reacteur-innovant-de-stellaria
[3] Supernova Invest. (2025). Supernova Invest leads €23 million funding round for Stellaria's revolutionary nuclear reactor. Retrieved from https://supernova.vc/news/supernova-invest-leads-23-million-funding-round-for-stellarias-revolutionary-nuclear-reactor
The funding secured by Stellaria will not only support the development of a prototype molten salt facility, aiming for operation by 2029, but also finance the research and development in technology needed to make the first commercial production unit of the Stellarium reactor ready for deployment by 2035. This advancement in science and technology has the potential to revolutionize the finance sector, with significant contributions to a circular economy and decarbonization efforts.
