Redefining nuclear for a sustainable future
Designed to meet the needs of industries, urban heating networks, and regions in transition, Otrera reactors offer a concrete solution to the challenges of decarbonization, energy sovereignty, and reshoring production.

50 years of French research and industrial expertise in fast neutron reactors to redefine nuclear energy
OTRERA is a French deeptech company that develops sodium-cooled fast modular reactors (SFRs), capable of co-generating competitive electricity and heat.
Founded in 2024 in Aix-en-Provence, the company now brings together over 30 employees. A laureate of the France 2030 program and certified Greentech Innovation, OTRERA is shaping the future of sustainable nuclear energy — both in France and internationally.
Together, we are building the energy of tomorrow















At Otrera, we believe that tomorrow’s nuclear energy must not only produce clean energy, but also multiply its potential and make it accessible at a reliable and controlled cost. From almost nothing, everything becomes possible: this is our promise of abundant, competitive, and sustainable energy for generations to come.
Frédéric VaraineFounder – CEO, Otrera

At the heart of Otrera’s next-generation reactor
Compact and modular architecture
A simplified architecture with six 50 MWth modules, a vessel less than 3 meters, and standardized components, ready for large-scale industrial manufacturing. All deployable on an area of less than 5 ha.
Flexible, sustainable, and closed-cycle oriented
A high-performance, long-operating-cycle, next-generation core, compatible with both MOX fuels from currently unreprocessed and stored spent fuel assemblies, as well as with UO₂ HALEU, which is simpler to manufacture and intended for export.
Integrated safety and sustainable performance
Operating unpressurized, in an inert atmosphere, the reactor benefits from four containment barriers and passive safety systems. Designed to offer lasting resilience, it incorporates the requirements necessary for enhanced public acceptance, particularly when located in urban or industrial areas.


A compact solution, where it is needed.
Reactors designed to meet the needs of regions and energy-intensive industries
The reactors developed by Otrera are aimed at public and private stakeholders committed to decarbonizing their energy production, securing their supply, or reindustrializing their regions. Thanks to their modular format, cogeneration capacity, and economic competitiveness, they meet the needs of multiple sectors.

Urban heating networks
decarbonize the heat distributed to public buildings, residential areas, and collective facilities.

provide local, reliable, and low-carbon electricity.

supply heat and electricity to decarbonized production units.

provide the necessary energy for the operation of intensive technologies.

ensure a heat supply for facilities located in coastal areas.

guarantee competitive and sovereign energy for manufacturing activities.

revitalize local activity thanks to available, sustainable, and non-intermittent energy.

contribute to grid stability by providing a dispatchable load.
French excellence in nuclear engineering and innovation

News
& Media

OTRERA accelerates: €17M secured to advance its 4th-generation fast neutron reactor
OTRERA announces €17 million in funding, consisting of equity and grants from the France 2030 program. This fundraising brings together a consortium of leading strategic shareholders: Groupe ADF, Groupe EDF, Isospin Exergon, Ingerop, Fortil Group, Normandie Participations, Onet Technologies, Groupe REEL, and SNEF / Ekium.

OTRERA announces the establishment of its plant in Cherbourg-en-Cotentin and accelerates its industrial development
OTRERA officially announces the establishment of an industrial plant and technology hub in Cherbourg-en-Cotentin. A decisive step toward the industrialization of the next-generation fast reactor.

OTRERA on the Ici Normandie news: a look back at the announcement of the Les Pieux site
OTRERA makes the headlines on Ici Normandie following the announcement of its plant’s establishment in the municipality of Les Pieux, within the Le Cotentin urban community.