MIT spinout Commonwealth Fusion Systems (CFS) has become the first international company to join the UK Atomic Energy Authority’s (UKAEA) flagship program to test tritium breeding technologies, a key step toward commercial fusion power.
The collaboration gives the U.S.-based fusion company access to UKAEA’s new Lithium Breeding Tritium Innovation (LIBRTI) facility at the Culham Campus in Oxfordshire, where companies will test and validate blanket technologies under fusion-relevant conditions.
The £220 million UK government-backed initiative is designed to demonstrate net tritium production, an important milestone for commercial fusion reactors. Future fusion power plants will need to produce enough tritium to sustain their own operations instead of relying on external supplies of the fuel.
As part of the agreement, UKAEA and CFS will jointly design experiments, develop testing protocols, and conduct blanket technology tests at the facility. CFS will also build the test articles for the first round of investigations.
Fuel production challenge
A fusion blanket surrounds the reactor and absorbs high-energy neutrons released during fusion reactions. When those neutrons strike lithium atoms inside the blanket, they produce tritium, one of the hydrogen isotopes needed to fuel a fusion power plant.
Proving that a reactor can breed more tritium than it consumes remains one of the biggest engineering hurdles to making fusion commercially viable. To support that work, UKAEA recently acquired a customized high-flux neutron source that will recreate the neutron environment expected inside future fusion reactors.
Tim Bestwick, CEO of UKAEA, said: “The UK Fusion Strategy emphasises the UK’s position as a leader in fusion research while recognising the value of continued global collaboration.”
Amanda Quadling, Senior Responsible Officer for LIBRTI, said: “Welcoming CFS is a defining moment for LIBRTI. Their participation adds momentum to our own efforts and accelerates the global pathway to demonstrated fusion powerplant scale technology.”
Commercial fusion ambitions
Founded in 2018, the MIT spinout has raised more than $3 billion in private funding, making it the world’s best-funded fusion energy company. The company is building its SPARC fusion demonstration machine and expects its first ARC fusion power plant in Virginia to begin generating electricity in the early 2030s.
CFS said the partnership will help validate the blanket system planned for its commercial reactors.
Brandon Sorbom, co-founder and chief science officer at CFS, said: “LIBRTI’s specialized testing capabilities will allow us to demonstrate net tritium production and increase confidence in our ARC blanket system design.”
He added: “Through this collaboration, CFS will gain hands-on experience engineering and building blanket systems directly representative of our commercial fusion power plant.”
Heena Mutha, director of fuel cycle and blanket technology at CFS, said: “It’s an incredible moment for the fusion industry that we’re building the capability to investigate the performance of blankets in a fusion-relevant environment.”
The collaboration marks the first international industry participation in LIBRTI and reflects growing cooperation between public research organizations and private fusion companies as they work to solve the remaining engineering challenges before commercial fusion power becomes a reality.