• Commonwealth Fusion Systems (CFS), the world's largest fusion energy company, is the first international company to join the UK national fusion laboratory's flagship programme to test new tritium blanket technologies.
• CFS to gain early access to world-leading infrastructure for blanket testing, which includes a customised large-scale neutron source.
• The agreement builds on momentum from the King's Address to the U.S. Congress in April.

OXFORD, United Kingdom, July 1, 2026 /PRNewswire/ -- The UK Atomic Energy Authority (UKAEA) today announced that Commonwealth Fusion Systems (CFS), the largest fusion energy company, will be the first international company to participate in UKAEA's flagship Lithium Breeding Tritium Innovation programme (LIBRTI).

LIBRTI is a £220 million UK government initiative that aims to demonstrate net tritium production – a vital capability for commercializing fusion energy that means fusion power plants can produce enough of this fuel component to cover their own use.

The programme is creating a first-of-a-kind technology facility at UKAEA's Culham Campus following the recent acquisition of a high-flux neutron source.

In a fusion power plant, a blanket is the region where neutrons from the fusion process strike lithium atoms that then turn into tritium, a form of hydrogen used as fusion fuel. The production technique is called breeding, and the new LIBRTI facility will enable industry partners to develop and verify their blanket technologies in fusion environments representative of full-scale machines.

CFS is a private company based in Devens, Massachusetts, that spun out of the Massachusetts Institute of Technology (MIT) in 2018. The company has raised more than US$3 billion in private capital, making it the best-funded fusion energy company globally. CFS is currently building its SPARC fusion demonstration machine and expects to generate electricity from its first ARC fusion power plant in Virginia in the United States in the early 2030s.

CFS and UKAEA will work together, designing the experimental setup, developing testing protocols, and conducting experiments at the LIBRTI facility. CFS will build the test articles to be used in the first investigations.

Tim Bestwick, CEO, 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, 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."

Brandon Sorbom, Co-founder and Chief Science Officer, CFS, said:

"LIBRTI's specialized testing capabilities will allow us to demonstrate net tritium production and increase confidence in our ARC blanket system design. Through this collaboration, CFS will gain hands-on experience engineering and building blanket systems directly representative of our commercial fusion power plant. We're thrilled to partner with UKAEA and the LIBRTI team as an early user."

Heena Mutha, Director of Fuel Cycle and Blanket Technology, 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. We look forward to this collaboration with the UKAEA and LIBRTI."

For more information, please contact:

• Mike Bridge, Media & Communications Manager, via email: mediaenquiry@ukaea.uk
• Christine Dunn, Head of External Communications at CFS, via email: press@cfs.energy

About the United Kingdom Atomic Energy Authority 

Who we are 

The United Kingdom Atomic Energy Authority (UKAEA) is the UK's national fusion energy research organisation. We are an executive non-departmental public body of the Department for Energy Security and Net Zero (DESNZ). 

The work we do 

UKAEA's mission is to lead the delivery of sustainable fusion energy to maximise scientific and UK economic benefit. We do this by being technical experts, partnering with companies and the international research community. 

At the core of UKAEA's efforts is the operation of world-leading facilities that build a comprehensive knowledge base for fusion energy. By addressing and solving the challenges across the full lifecycle of fusion, and integrating solutions from various disciplines, we establish technical centres of excellence that serve as the foundation for future fusion power plant programmes. 

UKAEA collaborates with its partners to develop fusion power plants by providing access to our skills, facilities and expertise. UKAEA owns UK Fusion Energy (UKFE) on behalf of the UK government. Through UKFE, we're spearheading the Spherical Tokamak for Energy Production (STEP) programme to design and build the UK's first prototype fusion energy power plant in Nottinghamshire. 

To grow the fusion ecosystem, UKAEA focuses on cultivating skilled talent, growing the fusion industry and creating 'innovation clusters'. We actively seek opportunities to advance fusion technologies and communicate its vast potential to stakeholders and the public alike to accelerate fusion energy's future – the energy of tomorrow we need today. 

More information: https://www.gov.uk/ukaea. Social Media: @UKAEAofficial 

About fusion energy 

When a mix of two forms of hydrogen (deuterium and tritium) is heated to form a controlled plasma at extreme temperatures – 10 times hotter than the core of the Sun – they fuse together to create helium and release energy which can be harnessed to produce electricity. There is more than one way of achieving this. UKAEA's approach is to hold this hot plasma using strong magnets in a ring-shaped machine called a 'tokamak', and then to harness this heat to produce electricity in a similar way to existing power stations.  

About Commonwealth Fusion Systems

Commonwealth Fusion Systems is the world's largest and leading private fusion company. The company's marquee fusion project, SPARC, will generate net energy, paving the way for limitless carbon-free energy. The company has raised more than $3 billion in capital since it was founded in 2018.

SPARC® and ARC™ are trademarks of Commonwealth Fusion Systems®.

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