Stellaria is developing the Stellarium — a fourth-generation fast-neutron molten salt reactor that regenerates its fuel during operation making it self-sufficient for over 20 years while reducing long-lived nuclear waste. Co-founded by CEA and Schneider Electric, Stellaria raised €23 million in 2025 led by At One Ventures and Supernova Invest alongside CEA Investissements and Schneider Electric. The company received €10 million in France 2030 programme funding. In February 2026 Stellaria submitted a prototype application (Alvin) to French authorities. The company signed a power pre-order agreement with data centre operator Equinix. An earlier record noted that the French regulator had begun formal scrutiny of the design alongside Jimmy Energy and Newcleo, and that Stellaria targets industrial heat and electricity applications in French industrial clusters. Regulatory status (ASNR, August 2026): on December 19, 2025 the ASNR received a copy of the licence application file for an experimental reactor at the CEA's Cadarache site, and on December 22, 2025 was asked to carry out the technical examination (Step 4), which is suspended pending additional information; a separate application for the ALPHA molten salt fuel synthesis plant was submitted on December 19, 2025. The ASNR dates the application December 2025, earlier than the February 2026 mentioned above.