Stellaria
Updated: August 19, 2026
Founders: Guillaume Campioni, Lucas Tardieu, Nicolas Breyton
Country: France | Funding: €33M (+)
Founded: 2023
Website: https://www.stellaria-energy.com/
Stellaria is looking to develop an energy system based on the molten chloride fast reactor (MCFR) technology. It's a liquid-core 250 MWe reactor capable of renewing 100% of its fuel during operation, incinerating long-lived high-level waste and achieving revolutionary levels of intrinsic safety. Its low-pressure operation ensures maximum safety. Installing the reactor several metres underground provides failproof protection against earthquakes and overhead winds. Reactor power self-adapts to demand: under the effect of heat, the liquid fuel expands, slowing down the reaction. The reactor produces both electricity and heat. The startup says they developed one of the most efficient turbines on the market that reaches 45% efficiency.
Founded: 2023
Website: https://www.stellaria-energy.com/
Stellaria is looking to develop an energy system based on the molten chloride fast reactor (MCFR) technology. It's a liquid-core 250 MWe reactor capable of renewing 100% of its fuel during operation, incinerating long-lived high-level waste and achieving revolutionary levels of intrinsic safety. Its low-pressure operation ensures maximum safety. Installing the reactor several metres underground provides failproof protection against earthquakes and overhead winds. Reactor power self-adapts to demand: under the effect of heat, the liquid fuel expands, slowing down the reaction. The reactor produces both electricity and heat. The startup says they developed one of the most efficient turbines on the market that reaches 45% efficiency.
