Multiple MSRs proposed for French industrial park

A major player in technology, artificial intelligence and digital infrastructure, Unitel Group co-founded the Laboratoire Fos-Berre with the French State in 2022. This think tank is dedicated to studying energy models capable of meeting the future needs of Europe's largest industrial basins. That work gave rise to the conviction that an integrated energy hub could be a priority response to the challenges facing the Fos-sur-Mer region. To carry this ambition forward, Unitel created the Energie Hub consortium, a platform dedicated to the development, financing, construction and operation of strategic energy infrastructure.

With the signing of the MoU, by combining their complementary expertise in nuclear technology, energy infrastructure and digital systems, the partners plan to deliver the progressive deployment of several Stellarium units, next-generation modular reactors developed by Stellaria. This phased approach will allow each stage of the project to be validated while ensuring safety and industrial control. These units will supply low-carbon electricity, industrial heat, and grid flexibility and support services for the Fos-sur-Mer area.

The partners will also develop an AI-powered digital energy management platform that will optimise energy production and consumption, manage networks in real time, oversee storage capacity, and anticipate industrial demand.

The partners will agree on the structuring of the project's financing, preparations for creating a dedicated entity for its development and operation, and the establishment of a strategic partnership between the three companies.

"The signing of this memorandum marks an important milestone for the future of European industry," said Nicolas Breyton, President of Stellaria. "We are proud to take part in a project of this scale, with the ambition of building a new generation of energy infrastructure. Through the self-sufficient Stellarium reactors, we will help industrial players in the Fos-sur-Mer area move toward sovereign, low-carbon production."

Kevin Polizzi, president of Unitel Group, added: "European industry is entering a new phase, one in which mastering energy has become a decisive factor for competitiveness, sovereignty and resilience. With this multi-energy hub project, we aim to offer an integrated model combining low-carbon energy production, digital intelligence and industrial capability. Fos-sur-Mer is a strategic location to demonstrate that a new generation of energy infrastructure can sustainably support the decarbonisation of our major industrial basins."

The Stellarium reactor proposed by Stellaria - a start-up spun out of the French Alternative Energies & Atomic Energy Commission and Schneider Electric - will be very compact (measuring 4 cubic metres) and will be able to use a diversified range of nuclear fuels (uranium, plutonium, mixed-oxide, minor actinides, even thorium). Stellaria says the reactor is "the world's first reactor to operate with a liquid fuel capable of destroying more waste than it produces".

In November 2025, Stellaria signed a pre-order agreement with California-headquartered data centre developer and operator Equinix. Under the agreement, Equinix has secured the first power capacity reservation on the Stellarium, the reactor that Stellaria plans to deploy starting in 2035.

Molten salt reactors (MSRs) use molten fluoride salts as primary coolant, at low pressure. They may operate with epithermal or fast neutron spectrums, and with a variety of fuels. Much of the interest today in reviving the MSR concept relates to using thorium (to breed fissile uranium-233), where an initial source of fissile material such as plutonium-239 needs to be provided. There are a number of different MSR design concepts, and a number of interesting challenges in the commercialisation of many, especially with thorium.

In December 2024, Unitel announced the design and deployment of a revolutionary AI/HPC (Artificial Intelligence for High-Performance Computing) cluster for Stellaria. This collaboration enabled Stellaria to compute all parameters of its reactor's digital twins in record time.