A South Gloucestershire firm pioneering a novel approach to nuclear fusion has secured £23 million in Series A funding, a cash injection it will use to produce medical isotopes critical for cancer care, expand its modular reactor manufacturing and push forward fusion research.
Hallen-based Astral Systems said the round — led by Mercia Ventures and backed by Tees River, Daphni and Blast Club, alongside existing investors Speedinvest and Playfair Capital — brings total fundraising to more than £28 million. The company has already generated over £3 million in revenue from commercial and research contracts and currently operates three commercial fusion facilities with multiple reactors at Technology Readiness Level 9, indicating real-world deployment.
Chief executive and co-founder Talmon Firestone, a serial entrepreneur in the fusion space, said: “We are rewriting how we approach fusion and, in doing so, redefining what it means to be a fusion company. This is evident in our novel technology and its near-term applications in modern medicine, as well as facilitating the search for hybrid energy.”
Multi-state fusion: how the technology works
At the heart of Astral Systems’ offering is what it calls “multi-state fusion technology” (MSF). The firm says its modular reactors can operate with greater efficiency and at a lower cost than traditional fusion configurations. The technology is designed to harness fusion reactions in a way that produces high-flux neutrons, which can then be used for a range of applications beyond energy generation.
The most immediate use is the production of medical radioisotopes. Global demand for these isotopes — essential for more than 50 million nuclear medicine procedures every year — is rising, yet the supply chain remains fragile. Ageing reactors are being retired, and the UK currently has no reliable domestic source for the isotopes used in both diagnosis and therapy. Astral Systems aims to fill that gap by manufacturing isotopes at its new high-energy facility being developed at the former Berkeley Power Station in Gloucestershire.
The company is already working with partners including McMaster University in Canada and Brazil’s Institute for Energy and Nuclear Research to produce Actinium-225 and Lead-212, isotopes increasingly used in targeted cancer therapies. The firm intends to bring one or more medical isotopes to market by early 2027.
Co-founder Dr Tom Wallace-Smith, a nuclear physicist who previously worked on Rolls-Royce’s nuclear submarine programme, has built the technology with a team that now includes two high-profile new hires: Dr Theresa Benyo, a NASA Laureate, as chief research officer, and Dr Mahmoud Bakr as chief scientist.
Lee Lindley, who led the investment for Mercia Ventures, said: “Astral’s technology has the potential to transform the manufacturing and supply of medical isotopes, which are vitally important for diagnostic and therapeutic purposes. Astral Systems is a perfect example of the bold ideas that Mercia likes to back.”
Expansion plans and facility build-out
Astral Systems recently began work on its new high-energy facility at the decommissioned Berkeley Power Station, a Magnox plant that operated from 1962 to 1989 and is now being redeveloped as part of a planned Nuclear and Clean Energy Technology Park. The company says the site will host the world’s highest-flux, highest-intensity, continuously operable private fusion volumetric neutron source. It aims to have multiple reactors running at full capacity there by the end of 2026.
The firm currently employs 23 people and plans to increase that to more than 40 by the end of the year. Over the following years it intends to manufacture dozens more reactors and expand their use into other commercial sectors, while continuing to advance fusion research and explore hybrid energy applications.
The investment comes against a backdrop of significant UK government commitment to fusion energy. Ministers have pledged over £2.5 billion over five years to fusion research and development as part of the “Plan for Change”, with an ambition to support more than 10,000 fusion-related jobs by 2030. The government has also funded the Sunrise AI supercomputer dedicated to fusion energy, invested in tritium loop facilities, and pushed forward the STEP programme aimed at a prototype fusion power plant by 2040.
For Astral Systems, the funding provides the runway to move from a company that has already demonstrated revenue and commercial traction to one that can scale its reactor production and — critically — deliver a domestic supply of isotopes that the NHS and other healthcare systems currently rely on from overseas. The company has said it expects to become profitable within 2027.
