Case study: Fusion energy & enabling supply chain — a city or utility pilot and the results so far

The UK Atomic Energy Authority's (UKAEA) Spherical Tokamak for Energy Production (STEP) program, sited at West Burton in Nottinghamshire, represents the most advanced national fusion energy pilot with a defined timeline to grid connection by the early 2040s. As of early 2026, the UK government has committed over £650 million in direct funding to STEP, with an additional £184 million allocated to the Fusion Futures Programme supporting the enabling supply chain across 14 UK regions (UKAEA, 2025). The West Burton site has completed initial geological surveys, secured planning consent for the prototype reactor, and enrolled over 260 companies in the fusion supply chain development program. This case study examines how the STEP pilot has evolved from a conceptual design exercise into a regional economic development anchor, and what it reveals about the practical challenges of building an industrial supply chain for a technology that does not yet produce commercial electricity.

Why It Matters

Fusion energy promises baseload, zero-carbon electricity without the long-lived radioactive waste associated with fission or the intermittency constraints of wind and solar. The global fusion industry attracted $6.2 billion in cumulative private investment through 2025, with $1.4 billion raised in 2024 alone (Fusion Industry Association, 2025). The International Energy Agency's 2024 World Energy Outlook models fusion as a potential contributor to global electricity supply by the 2050s, noting that achieving net zero targets becomes significantly more challenging without firm, clean baseload generation.

The UK has positioned itself as a global leader in fusion energy policy. In 2021, the UK became the first country to establish a dedicated regulatory framework for fusion energy, classifying it separately from fission under the Environment Agency rather than the Office for Nuclear Regulation. This regulatory distinction reduces licensing complexity and has been credited with accelerating private sector interest. The Fusion Strategy published by the Department for Energy Security and Net Zero in 2023 set an explicit goal: a prototype fusion power plant connected to the grid producing net electricity. For utilities, energy planners, and supply chain companies, STEP represents both a technology demonstration and a test case for whether public investment in pre-commercial energy technology can generate measurable industrial and economic returns before the first watt is generated.

Key Concepts

Several technical and programmatic concepts are essential to understanding the STEP pilot and its supply chain implications.

Spherical tokamak design: Unlike conventional tokamaks such as ITER, which use a doughnut-shaped plasma chamber, STEP employs a compact spherical configuration that reduces the volume of superconducting magnets required. The UKAEA's MAST Upgrade facility in Culham demonstrated that spherical tokamaks can achieve plasma temperatures exceeding 100 million degrees Celsius while operating in a significantly smaller footprint than conventional designs, potentially reducing capital costs by 30 to 40%.

Tritium breeding blanket: STEP's design requires on-site production of tritium, a hydrogen isotope that serves as fuel for the deuterium-tritium fusion reaction. The breeding blanket, a lithium-containing structure surrounding the plasma chamber, captures neutrons from fusion reactions to generate tritium. This component represents one of the highest-value and most technically demanding supply chain opportunities, requiring advanced materials capable of withstanding neutron fluxes of 10 to 20 displacements per atom over the reactor's lifetime.

High-temperature superconducting (HTS) magnets: STEP will use HTS magnets made from rare earth barium copper oxide (REBCO) tape to confine the plasma. These magnets operate at temperatures of 10 to 20 Kelvin and generate magnetic fields exceeding 10 Tesla, enabling a more compact reactor design. The global supply of REBCO tape is currently concentrated among a small number of manufacturers, making magnet supply chain development a critical path item.

Fusion Futures Programme: Launched in 2023 with £184 million in funding, this UKAEA-led initiative provides grants, technical partnerships, and capability-building support to UK companies seeking to enter the fusion supply chain. The program covers materials development, remote handling robotics, advanced manufacturing, and digital twin technology.

What's Working

The STEP pilot has generated concrete outcomes across industrial development, workforce creation, and technology maturation that extend well beyond the reactor itself.

Supply Chain Mobilization Is Ahead of Schedule

The UKAEA's Supply Chain Development Programme had a target of engaging 200 companies by the end of 2025. Actual enrollment reached 263 companies as of December 2025, spanning advanced materials, precision engineering, robotics, instrumentation, and construction services (UKAEA, 2025). Of these, 142 companies are based outside the traditional Oxford-Culham fusion research corridor, indicating geographic diversification of the industrial base. Sheffield Forgemasters, which produces large-scale steel forgings for defense and nuclear applications, secured a £28 million contract to develop prototype vacuum vessel components for STEP, adapting existing heavy forging capabilities to fusion-specific geometries and tolerances. Assystem, a French-origin engineering firm with a growing UK presence, won a £15 million systems integration contract for STEP's balance of plant design.

Regional Economic Impact Is Materializing Early

The West Burton site selection triggered a measurable economic response in the East Midlands region before any construction activity began. Bassetlaw District Council reported 14 new business registrations in the energy engineering sector within 12 months of the site announcement. The University of Nottingham launched a dedicated Fusion Engineering MSc program in 2024, enrolling 45 students in its first cohort, with 80% of graduates expected to enter fusion-related roles. The Humber Freeport designation, 40 miles from West Burton, has attracted three advanced manufacturing firms specifically citing proximity to STEP as a location factor. UKAEA estimates that the STEP project will create 3,500 direct jobs during peak construction and sustain 1,000 permanent operational roles, with a further 6,000 indirect supply chain jobs across the region (UKAEA, 2025).

Materials Qualification Is Producing Transferable Results

The Fusion Futures Programme funded 48 materials development projects in its first 18 months. Several have produced results with applications beyond fusion. Rolls-Royce's work on reduced-activation ferritic-martensitic (RAFM) steels for the STEP breeding blanket has yielded manufacturing process improvements applicable to advanced fission reactor pressure vessels. Tokamak Energy, a private fusion company based in Milton Keynes, developed a novel REBCO magnet winding technique under a Fusion Futures grant that reduced manufacturing time per coil from 14 days to 6 days, a result now being commercialized for MRI magnet production. These cross-sector technology transfers demonstrate that fusion supply chain investment can generate returns even before a fusion reactor produces electricity.

What's Not Working

The STEP pilot faces structural challenges that constrain the pace and breadth of supply chain development.

Tritium Supply Uncertainty Clouds Long-Term Planning

Global tritium reserves are estimated at approximately 25 kilograms, primarily produced as a byproduct of CANDU heavy-water fission reactors in Canada and South Korea. STEP requires an initial tritium inventory of 1 to 2 kilograms for startup, with the breeding blanket expected to produce replacement tritium during operation. However, Canadian Nuclear Laboratories has signaled that tritium extraction capacity from Ontario Power Generation's CANDU fleet may decline as reactors approach end-of-life in the 2030s. No commercial-scale alternative tritium production pathway exists today, creating supply chain risk for both STEP and the broader fusion industry. UKAEA has initiated a tritium supply security study, but results are not expected before 2027.

REBCO Tape Manufacturing Remains a Bottleneck

The global production capacity for REBCO superconducting tape was approximately 4,000 kilometers per year in 2025, split primarily among SuperOx (Russia), THEVA (Germany), Fujikura (Japan), and SuperPower (US). STEP's HTS magnets alone will require an estimated 1,500 to 2,000 kilometers of REBCO tape, representing 40 to 50% of current global annual capacity. The UK has no domestic REBCO manufacturer at scale. While Tokamak Energy is developing a pilot REBCO production line, it is not expected to reach meaningful volumes before 2029. This concentration risk leaves a critical component of the STEP supply chain dependent on imports from geopolitically complex sources.

Regulatory Pathway Gaps Persist for Novel Components

The UK's decision to regulate fusion under the Environment Agency rather than the Office for Nuclear Regulation was widely praised as reducing bureaucratic barriers. However, this approach creates gaps for components without regulatory precedent. The tritium breeding blanket, remote handling systems, and activated materials waste streams have no established licensing pathway. Companies developing these components report uncertainty about qualification standards, testing requirements, and liability frameworks, making it difficult to price contracts and secure investment. The Environment Agency published draft fusion-specific guidance in late 2025 but acknowledged that final regulations may not be in place until 2028.

SME Participation Faces Cash Flow Constraints

While 263 companies are enrolled in the supply chain program, many small and medium-sized enterprises (SMEs) report that the gap between program enrollment and contracted revenue is financially unsustainable. Fusion Futures grants cover research and development costs but do not fund production capacity buildout. SMEs must invest in facilities, certifications, and workforce training on the assumption that procurement contracts will materialize on a timeline that remains inherently uncertain. A 2025 survey by the Nuclear Industry Association found that 35% of enrolled SMEs had paused or reduced their fusion-related investment due to cash flow constraints (Nuclear Industry Association, 2025).

Key Players

Established Companies

• Rolls-Royce: Leads STEP balance of plant design and develops RAFM steels for breeding blanket structures under Fusion Futures contracts.
• Sheffield Forgemasters: Provides heavy forgings for STEP vacuum vessel prototyping, leveraging existing nuclear-grade manufacturing capabilities.
• Assystem: Delivers systems integration engineering for STEP plant design, drawing on nuclear and defense project experience.
• Jacobs Engineering: Supports UKAEA with site preparation, environmental assessment, and construction management for the West Burton facility.
• Cavendish Nuclear: Provides remote handling and decommissioning technology development relevant to STEP's maintenance systems.

Startups

• Tokamak Energy: Develops compact spherical tokamak designs and HTS magnet technology, operating the ST40 prototype in Milton Keynes and pursuing a pilot REBCO tape manufacturing line.
• First Light Fusion: Pursues a projectile-based inertial confinement fusion approach from its Oxford facility, with demonstrated fusion neutron production in 2022 and a partnership with the UKAEA on target manufacturing.
• Kyoto Fusioneering: A Japan-based company with a UK subsidiary developing breeding blanket and heat exchange technologies for fusion reactors, supplying prototype components to the STEP design effort.

Investors and Funders

• UK Department for Energy Security and Net Zero: Provides primary government funding for STEP and the Fusion Futures Programme, with committed funding exceeding £650 million.
• UK Research and Innovation (UKRI): Funds academic fusion research and industrial partnerships through the Engineering and Physical Sciences Research Council.
• Breakthrough Energy Ventures: Invested in multiple private fusion companies within the UK supply chain ecosystem, including Tokamak Energy.

KPI Summary

KPI	Baseline (2022)	Current (2025)	Target (2030)
Supply chain companies enrolled	0	263	500
Direct jobs created (construction phase)	0	180	3,500
Fusion Futures grants awarded	0	48	120
REBCO tape domestic production (km/year)	0	0	200
Regional business registrations (energy engineering)	Baseline	+14	+60
MSc fusion graduates (annual)	0	45	150
SME active investment rate	N/A	65%	85%

Action Checklist

• Map existing manufacturing capabilities against the STEP component breakdown structure to identify where current skills align with fusion supply chain requirements
• Engage with the UKAEA Supply Chain Development Programme to register interest and access technical briefings on upcoming procurement packages
• Evaluate Fusion Futures Programme grant opportunities for materials development, remote handling, or digital twin projects with near-term cross-sector applications
• Assess workforce development needs against the fusion technician and engineering skill profiles published by UKAEA, including high-voltage systems, vacuum technology, and cryogenics
• Monitor Environment Agency regulatory consultations on fusion-specific licensing to understand compliance requirements for novel components
• Develop partnerships with UK universities offering fusion-related degree programs to secure early access to specialist graduates
• Establish tritium handling capability assessments if your organization operates in the nuclear or radiopharmaceutical sectors, as tritium supply chain roles may emerge

FAQ

Q: When will the STEP reactor actually produce electricity? A: UKAEA's current program timeline targets first plasma in the late 2030s and grid-connected electricity production in the early 2040s. However, this timeline is contingent on resolving several technology challenges, particularly tritium breeding blanket performance and HTS magnet qualification. Independent assessments by the National Audit Office and the Institution of Mechanical Engineers have both flagged the timeline as ambitious given the number of first-of-a-kind engineering challenges remaining. Supply chain companies should plan against a range of scenarios spanning 2040 to 2045 for initial operations.

Q: Is there a credible market for fusion energy given falling costs of renewables and storage? A: Fusion targets a specific gap in the future electricity system: firm, dispatchable, zero-carbon baseload generation that does not depend on weather, geographic siting, or seasonal energy storage. The UK's National Grid ESO 2024 Future Energy Scenarios model shows that even with aggressive renewable deployment, the UK requires 15 to 25 GW of firm low-carbon capacity by 2050 to meet net zero targets. Fusion would compete not against wind and solar but against advanced fission, hydrogen-fired turbines, and carbon capture-equipped gas plants for this role. The economic case depends heavily on capital cost: UKAEA targets a levelized cost of electricity below £60 per MWh, which would be competitive with new nuclear fission but requires achieving construction costs of £5,000 to £7,000 per kW of installed capacity.

Q: What are the most valuable supply chain opportunities for UK manufacturers in the near term? A: The highest-value near-term opportunities are concentrated in four areas. First, advanced materials, particularly RAFM steels and tungsten alloys for plasma-facing components, where Sheffield Forgemasters and specialty metals firms have existing capabilities. Second, remote handling robotics, because STEP's activated internal components will require fully robotic maintenance, creating demand for radiation-hardened manipulators and autonomous systems. Third, cryogenic systems for HTS magnet cooling, where UK firms like Oxford Cryosystems have relevant expertise. Fourth, digital twin and simulation software, as STEP's integrated plant model will require real-time performance monitoring and predictive maintenance platforms.

Q: How does the UK regulatory approach to fusion differ from other countries? A: The UK is unique in regulating fusion energy under environmental legislation rather than nuclear safety legislation. The Environment Agency oversees fusion facilities, applying permitting requirements focused on tritium handling, radioactive waste management, and environmental impact rather than the full nuclear safety case regime used for fission reactors. This approach reduces the licensing timeline from an estimated 10 to 15 years under fission regulation to a target of 3 to 5 years. The US Nuclear Regulatory Commission adopted a similar approach in 2023, classifying fusion devices under 10 CFR Part 30 byproduct material regulations. Canada and the EU have not yet established fusion-specific regulatory frameworks, creating uncertainty for international supply chain companies seeking to serve multiple markets.

Sources

• UK Atomic Energy Authority. (2025). STEP Programme: Annual Progress Report 2024-25. Culham, UK: UKAEA.
• Fusion Industry Association. (2025). The Global Fusion Industry in 2025: Annual Report. Washington, DC: FIA.
• Nuclear Industry Association. (2025). Fusion Supply Chain Readiness Survey: UK Company Perspectives. London, UK: NIA.
• UK Department for Energy Security and Net Zero. (2023). Towards Fusion Energy: The UK Fusion Strategy. London, UK: DESNZ.
• National Grid ESO. (2024). Future Energy Scenarios 2024. Warwick, UK: National Grid ESO.
• Environment Agency. (2025). Regulatory Guidance for Fusion Energy Facilities: Draft Consultation Document. Bristol, UK: EA.
• Tokamak Energy. (2025). HTS Magnet Manufacturing: Progress Report on REBCO Coil Production. Milton Keynes, UK: Tokamak Energy Ltd.
• International Energy Agency. (2024). World Energy Outlook 2024. Paris, France: IEA.