Cambridge Atomworks has opened a new laboratory at Granta Park, Cambridge, and has already begun physical testing on the ODIN microreactor. This is not desktop simulation work: engineers are building large-scale non-nuclear test rigs to study the reactor’s primary engineering systems, with experiments already underway on coolant fluids and heat transfer.
The facility includes a dedicated high-bay workspace and chemical laboratories. The team is using these spaces to characterise the properties of the molten salt coolant — the core of the ODIN concept — through a state-of-the-art STA-MS system capable of simultaneously performing thermogravimetric analysis, heat flow measurement and mass spectrometry. A prototype passive air cooling system has already been installed, and early results are yielding new quantitative data on the design’s effectiveness. This is concrete technical work, not a statement of ambition.
ODIN is a low-pressure fission reactor, cooled by molten salt and fuelled by solid fuel, designed to deliver autonomous electricity without external grid connections. The system is compact and transportable: it requires no proximity to a water source, relying instead on natural circulation of the molten salt and an auxiliary air cooling system for thermal management. This makes it well suited to remote and off-grid settings where the only alternatives are diesel generators — or nothing at all. The International Atomic Energy Agency classifies microreactors as units up to 10 MWe. ODIN falls within that category.
The project’s history is layered. Cambridge Atomworks was founded in 2023 as a consultancy partnership to develop ODIN on behalf of Nasdaq-listed American company NANO Nuclear Energy. In August of that year, the design passed a pre-conceptual review at the Idaho National Laboratory under the US Department of Energy. NANO Nuclear subsequently chose to focus on its gas-cooled reactors for data centres and put ODIN up for sale. Cambridge Atomworks acquired the design and all associated intellectual property for $6.2 million, with a non-refundable deposit of $250,000 and the balance due in 2026. The project is now firmly back in British hands.
Since then, expansion has been swift. In March 2026, Cambridge Atomworks signed a memorandum of understanding with Mott MacDonald, the major British engineering firm, to secure technical support in nuclear engineering, safety and the regulatory licensing process. In June, it signed a letter of intent with Chiltern Vital Group to establish a research and development facility at Berkeley Green Science and Technology Park in Gloucestershire — built on the site of the former Berkeley nuclear power station — with potential space for 1,000 jobs. Now come the physical tests at Granta Park. Each step has been measured and documented.
The stated goal is an operational prototype by 2030. Data gathered at Granta Park will be used to secure regulatory approval, which demands precise answers on reactor physics and thermal-hydraulics. If the licensing pathway proceeds as planned, Cambridge Atomworks aims to become a global supplier of clean energy to off-grid customers by the mid-2030s. The fact that the UK currently lacks a nuclear operator training facility makes Berkeley all the more significant: CEO Ian Farnan has already indicated that the prototype, once it has served its research purpose, could become exactly that.
