The joint venture – named RH3OVA and incorporated in the UK – offers end-to-end services across the fuel lifecycle, from early-stage feasibility studies to deployment and operational support.
Deuterium and tritium are fuels commonly used in fusion energy. Deuterium is abundant in nature and extractable from seawater. In contrast, tritium is extremely rare. It is therefore essential to ensure careful and efficient management throughout the entire fuel cycle, from tritium’s production and use in energy generation to its recovery from exhaust gases and refinement for re-use.
“Having operated the Joint European Torus, which was the world’s most powerful deuterium-tritium fusion machine for more than 40 years, and with 30 years’ experience of tritium operations, the UK is a leader in tritium fuel cycle technology,” said Stephen Wheeler, Executive Director of Tritium Fuel Cycle at UKAEA. “For fusion to be realised as a commercially viable source of energy, however, this expertise must be scaled beyond the lab.
“RH3OVA offers best in class digital process models validated with real-world, fusion relevant data sets. RH3OVA will combine UKAEA’s scientific and operational know-how, with Eni’s large-scale industrial capability, and leverage this joint expertise to increase knowledge and understanding across the fusion sector.”
Lorenzo Fiorillo, Director Technology, R&D & Digital of Eni, added: “Fusion energy has the potential to redefine the global energy landscape, and at Eni we are committed on multiple fronts to turning this potential into tangible industrial progress. Our partnership with UKAEA is of great strategic value to us and represents a further step in scaling up innovation and translating scientific excellence into real-world solutions.
“Today, with UKAEA, we are continuing our joint commitment for further progress in the fusion energy field, with a particular focus on the fuel cycle for fusion. This builds on our collaboration developing the UKAEA-Eni H3AT Tritium Loop Facility started last year which will be a world-class facility of its kind. At the same time, RH3OVA will respond to the growing demand for specialised technical expertise and integrated engineering services dedicated to the fuel cycle, which will be essential enabling factors for the operation of fusion power plants using deuterium and tritium as fuels.”
UKAEA said RH3OVA “strengthens the strategic collaboration between Eni and UKAEA and their joint effort to commercialise fusion energy”.
In March 2025, UKAEA and Eni entered into a collaboration agreement to jointly conduct research and development activities in the field of fusion energy. The collaboration primarily starts with the construction of the world’s largest and most advanced tritium fuel cycle facility. The UKAEA-Eni H3AT Tritium Loop Facility, located at Culham Campus in Oxfordshire, England, will be complete in 2028. It is designed to serve as a world-class facility providing industry and academia with the opportunity to study how to process, store and recycle tritium.













