The UK Atomic Energy Authority (UKAEA) has officially unveiled its updated Fusion Materials Roadmap for 2025/26 outlining a strategic framework to accelerate the development and qualification of materials essential for commercial fusion energy. This comprehensive plan, shaped with insights from over a hundred experts from the UK research community, industry and national laboratories, identifies five major research areas and four cross-cutting themes that are crucial for achieving the commercialisation of fusion energy.
A key contributor to the roadmap is Oxford Sigma’s CEO, Professor Thomas Davis, who served as the Research Area Lead for Qualification, guiding the roadmap’s approach to materials assurance, standards, and regulatory alignment.
The roadmap highlights the development and assurance of fusion materials, emphasising the necessary infrastructure, capabilities, and skills to achieve commercial fusion. At the heart of the roadmap is the theme of powerplant readiness, which encompasses synergistic testing requirements, fuel breeder maturity, and the resolution of supply chain gaps. The challenges identified include developing materials for fusion construction and tritium production, particularly lithium-containing materials. The roadmap highlights the urgent need to develop materials capable of withstanding the extreme conditions inside fusion reactors such as high neutron flux, intense thermal cycling, and strong magnetic fields while also addressing tritium production, corrosion resistance, and regulatory qualification.
In addition to these research areas, the roadmap outlines four cross-cutting themes: establishing a UK supply chain, enhancing simulation capabilities for the fusion environment, creating new irradiation facilities, and developing standards and processes for qualifying new materials.
These themes are essential for building the necessary infrastructure and cultivating the skills required to support the development and deployment of fusion technologies.
Oxford Sigma is playing a pivotal role in delivering the roadmap’s objectives through a series of high-impact initiatives that span experimental validation, supply chain resilience, regulatory engagement, and advanced modelling:
Project VICE (Validation in Ceramics Experiments), which supports the Lithium Breeding Tritium Innovation (LIBRTI) This facility, expected to be operational by 2028, will simulate fusion-relevant conditions to experimentally demonstrate tritium breeding in engineering-scale breeder prototypes. Oxford Sigma is leveraging its expertise in fusion materials and manufacturing to optimise lithium ceramic production and reduce uncertainties in tritium recovery, directly addressing roadmap challenges around breeder blanket qualification, ceramic stability, and tritium extraction efficiency.
In parallel, Oxford Sigma is actively supporting UKAEA in establishing domestic supply chains for critical fusion materials. These include lithium ceramics, high-temperature superconducting (HTS) magnets, magnet insulators, tritium recovery materials, tungsten tile designs, and fusion-grade steels. In response to roadmap concerns about tungsten availability, Oxford Sigma is leveraging the UK’s significant tungsten ore deposits to mitigate supply risks and enable scalable production of fusion-grade components.
Oxford Sigma is also contributing to the design of synergistic testing facilities that simulate irradiation, thermal, magnetic, and chemical loads concurrently. These facilities will be critical for validating material performance under fusion-relevant conditions and informing qualification pathways—addressing a key infrastructure gap identified in the roadmap.
Oxford Sigma’s CEO, Professor Thomas Davis, chairs the American Society for Mechanical Engineers (ASME) Boiler Pressure Vessel Code (BPVC) Section III Division 4 committee ‘Fusion Energy Devices’. This group is shaping the development of pressure system codes and standards for fusion environments, ensuring materials exposed to high radiation, extreme temperatures, and neutron irradiation meet rigorous safety and performance criteria. These efforts directly support the roadmap’s cross-cutting theme on regulation, assurance, and qualification.
To further support materials qualification, Oxford Sigma is advancing predictive modelling frameworks that integrate experimental and computational approaches. This includes designing modelling/experimental matrices for small specimen testing and validating results against large-scale tests. Oxford Sigma is also developing multi-scale models to extrapolate data from irradiated samples to full engineering components, addressing the roadmap’s call for digital twins, uncertainty quantification, and simulation-informed qualification strategies.
Computational models to extrapolate data from small-scale tests. The testing of irradiated materials necessarily takes place on limited sample volumes and small specimen geometries. There are currently no detailed computer models that can reliably and mechanistically extrapolate between engineering components and small-scale tests that often demonstrate higher strengths and reduced occurrence of fracture. Such models are essential to qualify components. It is necessary to reduce the gap within multi-scale materials modelling hierarchy by establishing a strong link between engineering scale with mesoscopic and atomistic modelling to address the microstructure evolution of engineering materials. We are engaging with the modelling community in the design of integrated modelling/ experimental matrices and in development of small specimen testing protocols.
Strategically timed to support the roadmap’s intermediate-term goals, Oxford Sigma’s initiatives including Project VICE and LIBRTI are expected to deliver experimental data by 2028. This aligns with the STEP programme’s targets for tritium breeding validation and fuel self-sufficiency, reinforcing the UK’s leadership in fusion energy development.
The UKAEA Fusion Materials Roadmap 2025/26 represents a transformative step toward commercial fusion energy. With Oxford Sigma’s leadership in materials innovation, supply chain development, and qualification strategy, the UK is well-positioned to become a global leader in fusion energy technology. These collaborative efforts promise a sustainable, low-carbon future powered by the same principles that fuel the sun.
About Oxford Sigma
Oxford Sigma is a Fusion Technology company with a vision to tackle energy security and climate change by accelerating the commercialisation of fusion energy. Our mission is to deliver materials technology, materials solutions, and fusion design services. Oxford Sigma aims to produce advanced materials technologies, agnostic to fusion approach, for the materials ecosystem. Our fusion core materials are engineered to enable longer term operations for fusion pilot plants, with the aim of roll out to the first-of-a-kind commercial power stations. Oxford Sigma is internationally recognised as a key fusion materials and technological leader.
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About the UKAEA
UKAEA is the national organisation responsible for the research and delivery of sustainable fusion energy. It is an executive non-departmental public body, sponsored by the Department for Energy Security and Net Zero.
UKAEA runs the fusion machine MAST-Upgrade (Mega Amp Spherical Tokamak) and is delivering the transition of JET from plasma operations to repurposing and decommissioning. The insights gained from this process will contribute to the advancement of sustainable future fusion power plants.
STEP (Spherical Tokamak for Energy Production) is a major technology and infrastructure programme that will demonstrate net energy from fusion, fuel self-sufficiency and a route to plant maintenance. UKAEA is STEP’s fusion partner and will work alongside STEP’s industry partners – one in engineering and one in construction – with the following short-list announced here.
The STEP programme is being delivered by UK Industrial Fusion Solutions Ltd (UKIFS) a wholly owned subsidiary of UKAEA Group. UKIFS will lead STEP’s integrated delivery team to design and build the prototype plant at West Burton site in Nottinghamshire, targeting first operations in 2040.
UKAEA is now engaging in Fusion Futures, a programme that aims to foster world-leading innovation whilst stimulating general industry capacity through international collaboration and the development of future fusion power plants.
UKAEA also undertakes cutting edge work with research organisations and the industrial supply chain in a wide spectrum of areas, including robotics and materials.
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.