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Issue #24: Culham's Journey From Air Station to Fusion Pioneer to Exascale AI Hub
From the frontiers of fusion research to the frontiers of artificial intelligence
Ben Baldieri
March 12, 2025 • Estimated Reading Time: 13 minutes
It’s been an eventful few months for the Culham Campus.
And by eventful, I mean the Joint European Torus (JET) powering down after four decades, the site’s designation as the UK’s first AI Growth Zone, and an open call for private-sector investment and public/private partnerships to build exascale infrastructure alongside fusion and other cutting-edge science like robotics, autonomous vehicles, and advanced materials science.
Like I said.
Eventful.
I’m Ben Baldieri, and each week I break down the moves shaping GPU compute, AI infrastructure, and the data centres that power it all.
And somehow, I ended up at this week’s AI & Data Centre Strategic Investment Event for the first AI Growth Zone at the UK Atomic Energy Authority’s Culham Campus.
Here’s what’s inside:
Let’s dive in.
The GPU Audio Companion Issue #24
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What Is An AI Growth Zone?
Before we dive in, let’s recap something important: What is an AI Growth Zone?
To answer that, we must cast our minds back into the annals of history and recall January 13th, 2025. This market moves fast, so I know it might be a challenge to remember that far back. If you’re struggling, let me jog your memory.
Prime Minister Sir Keir Starmer unveiled the UK AI Opportunities Action Plan.
Central to this plan is the concept of the AI Growth Zone (AIGZ). These zones have three main goals:
Expand UK AI Capability – By speeding up data centre construction and ensuring reliable power, AIGZs lower barriers for AI developers and HPC operators.
Establish Leading Net-Zero and AI Centres of Excellence – Each zone stands poised to merge deep scientific expertise with state-of-the-art AI, bolstering Britain’s global standing.
Build Stronger Links Between Government and Industry – The government wants to foster deeper strategic partnerships with investors, scaling AI infrastructure while strengthening the UK’s AI ecosystem.
The zones are designed to accelerate the build-out of AI infrastructure by streamlining planning processes, improving access to power, and attracting private investment. Each zone can have a different flavour depending on local strengths, but they all share one overarching ambition:
Positioning the UK to move fast, unlock investment, and become a leader in AI infrastructure.
The goals and vision are clearly of national importance, which begs the question:
Why Culham?
A Brief History of Culham
So, why is a sleepy village in Oxfordshire the site of the UK’s first AI Growth Zone?
Because Culham is, in fact, not just a sleepy village. It is a globally renowned hub of fusion research.
And its roots go deep.
From Air Station to Fusion Pioneer
Fusion research in the UK began in earnest in the late 1940s and 50s.
Early work took place at universities like Imperial and Oxford and sites like Harwell under experiments such as the Zero Energy Thermonuclear Assembly (ZETA). By the mid-1960s, the UK Atomic Energy Authority created a purpose-built laboratory at Culham, transforming a former Royal Naval Air Station into what would become a world-leading fusion powerhouse.
Early Tokamak Validation
In 1969, Culham researchers travelled to Moscow to verify plasma temperatures on the Russian T3 tokamak in the search for proof that tokamaks could hit tens of millions of degrees Celsius.
That discovery pushed Culham’s work toward refining tokamak designs.
JET Arrives
The European Economic Community selected Culham for its Joint European Torus (JET) in 1977, achieving the first plasma by 1983 and making headlines in 1991 for the world’s first controlled fusion.
A record 16 MW of fusion power followed in 1997.
Spherical Tokamak Innovation
From the 1990s onward, Culham pioneered more compact “spherical” tokamaks, notably START and later MAST, pushing the boundaries of how smaller, more efficient fusion devices might be built.
Renamed and Expanded
In 2009, the laboratory rebranded as the Culham Centre for Fusion Energy (CCFE), reflecting a renewed mission to bring low-carbon fusion power to the world.
Over time, CCFE was joined by the RACE robotics facility and the Materials Research Facility, broadening Culham’s technology scope.
Today, as JET decommissions after 40-plus years, Culham is once again at a turning point, leveraging its fusion pedigree for the next generation of high-performance computing and AI infrastructure solutions.
For more about the history of the Culham Campus, check out the history page on their website here:
Why JET’s Shutdown Sets the Stage for Exascale AI Compute
JET ran for decades, drawing 800 MW of power in 20-second pulses to test the boundaries of plasma physics before decommissioning.
But that doesn’t mean Culham is done with Fusion.
I mentioned each of the AIGZs will have a specific flavour. For Culham, that flavour centres on fusion research, sovereign AI infrastructure, and domestic energy production as catalysts for economic growth. Culham is unique - there’s a clear link between fusion and AI that the government finds exciting. Even the current CFO of OpenAI once consulted at Culham straight out of university. This history of collaboration underlines that it’s more than just a science park; it’s a place to test big ideas that merge large-scale AI projects with advanced engineering.
The government aims to build a world-leading asset here, tapping into the site’s power capacity and fusion pedigree.
In turn, the idea is to create a public/private partnership that serves as a “fantastic commercial asset,” aligning with net-zero and broader AI goals.
And given Culham’s newly minted AI Growth Zone status, the government sees it as a prime environment to help the UK “move fast” on AI, from attracting significant capital to developing critical infrastructure and forging real commercial returns.
Culham’s AI and Simulation Centre of Excellence will form the core of the AIGZ. The centre is envisioned as a dual-partition environment, split between:
Research Partition (20%)
Around 100 MW initially, with a target operational date of April 2028.
Aimed at net-zero research, fusion modelling, and wider government-led priorities.
Likely a silicon agnostic GPU/CPU mix aiming for exascale performance, aspiring to rank among the top 10 supercomputers globally.
Plans to co-locate with UK-based AI startups, fostering an open, competitive ecosystem driven by silicon diversity and accessible APIs.
Commercial Partition (80%)
Designed to create a world-class AI facility serving the rapidly expanding UK AI sector.
Specific hardware details are to be confirmed, but the focus is on high-performance, flexible tech that enables “bursting” of capacity between research and commercial tasks.
Leveraging up to 525 MW peak (200 MW guaranteed, with the potential to reach 500 MW by the decade’s end), Culham aims to become the country’s most power-rich AI campus. Plasma modelling alone demands exascale computing, so the centre’s capacity for HPC dovetails neatly with the site’s fusion heritage.
A New Vision for Culham Campus
Considering the scale of the follow-on plans from JET above, the UKAEA and government understand they can’t go it alone. As such, two distinct partnership paths are on offer for Culham’s transformation:
The Strategic Investment Partnership
The AI Data Centre Partnership
For both tracks, the UKAEA and the government want collaborators who share the campus’s aspirations: weaving fusion research, AI-driven breakthroughs, and advanced engineering under one secure, high-performance roof.
If you’re envisioning standard colocation racks or cookie-cutter retail parks, you may want to look elsewhere.
The Strategic Investment Partnership
This first opportunity is about co-developing the campus’s real estate in phased stages, ensuring each plot aligns with Culham’s future-forward vision.
That might include specialised R&D labs for autonomous vehicles, pilot-scale manufacturing for advanced materials, or collaborative robotics test spaces.
Key Points
Aligned Vision: UKAEA wants a partner who sees the value in sustaining (and enhancing) Culham’s fusion heritage, net-zero objectives, and HPC ambitions. A typical retail development or basic office park wouldn’t cut it.
Phased Rollout: Plots become available based on a joint business plan. Every build must bolster the campus’s role as a technology epicentre, not detract from it.
Security & Infrastructure: With high-level security protocols already in place, long leasehold terms up for negotiation, and the AI Growth Zone eliminating planning bottlenecks, this is prime ground for specialised high-tech tenants who can thrive in a secure, well-powered environment.
Why It Matters
For the right investor, these 50+ acres are a chance to launch or expand a next-generation R&D cluster in direct proximity to world-leading fusion experts.
You won’t just be throwing up buildings; you’ll be curating a campus that complements advanced robotics, HPC, and net-zero research.
The AI Data Centre Partnership
The second partnership focuses on establishing a specialised data centre that caters to exascale ambitions.
Culham’s leftover grid capacity from JET means operators can stand up a massive HPC footprint without the usual multi-year grid negotiations.
200MW is guaranteed with a very soft target of 2028, and 500MW could become available by the end of the decade.
In other words, plug in and power up, with the campus’s global renown as a bonus.
Key Points
20%/80% Partition: As mentioned above, part of the compute (around 20%) is earmarked for government-led fusion and net-zero research. The other 80% will be for commercial AI or HPC workloads, especially those that demand reliable, large-scale power.
No Standard “Colo”: UKAEA wants a partner that will integrate with Culham’s broader scientific goals. Think top-tier GPU clusters, open APIs, maybe even on-site collaborations with robotics teams. Anything less wouldn’t make use of Culham’s full potential.
Power & Security: It’s hard to find data centre sites with nuclear-grade security and ample power in waiting. Culham checks both boxes, plus the government’s AI Growth Zone status helps cut through typical red tape.
Why It Matters
Sitting on an exascale-ready HPC environment next to advanced robotics labs and net-zero experiments puts HPC operators in the thick of major R&D breakthroughs.
It’s a chance to be the engine that drives real scientific and commercial value on the highest-powered AI campus in the UK.
Not just another server farm in an industrial estate.
Tying It All Together
Both the Strategic Investment Partnership and the AI Data Centre Partnership hinge on a single principle: alignment.
Culham’s metamorphosis is about building an integrated, high-tech campus rather than a patchwork of unrelated developments.
The UKAEA and the government are eager for both market feedback and partners who genuinely support the site’s fusion-to-net-zero mission and can add meaningful capabilities, be it HPC capacity or labs for advanced engineering.
Official Support, Industry-Led Innovation: UKAEA has set the stage from AI Growth Zone incentives to phased land releases. But they want real input from specialised investors, HPC operators, and AI innovators on how best to structure these projects.
No “One Size Fits All”: If your proposal doesn’t mesh with Culham’s focus on net-zero, HPC synergy, and advanced science, the campus probably isn’t the right home.
For interested parties, whether you’re an investment group eyeing high-tech real estate, a data centre operator seeking a location with truly massive power on tap, or a bigger player with the vision needed to integrate both tracks, this might just be the perfect moment to step onto a campus that’s rewriting the rules of how advanced science, AI, and industry converge.
Conclusion: Waiting for the RFI
Right now, the UKAEA is keeping its cards close to its chest, and the formal Request for Information (RFI) for Culham’s transformation has yet to land.
Until then, UKAEA and government officials are in genuine listening mode, gathering thoughts on how best to align net-zero goals, HPC performance, and commercial viability.
To put it another way, they want feedback from the market, and lots of it.
For investors, data centre operators, or AI innovators, that’s an open invitation to influence Culham’s next step before timelines and requirements become set in stone.
If you have a vision for exascale computing, advanced research, or large-scale robotics, this is the moment to speak up because once the RFI drops, milestones and partnership parameters will quickly fall into place.
After all, playing a role in shaping the UK’s most ambitious national project in decades is not a chance you want slipping away.
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