A Memorandum of Cooperation (MOC) signed between the UK Atomic Energy Authority (UKAEA) and Japan’s National Institutes for Quantum Science and Technology (QST) establishes a formal framework to solve critical scientific and engineering barriers to commercial fusion power. The MOC, signed during the visit to the UK by Japanese Prime Minister Sanae Takaichi, builds on an initial bilateral fusion agreement reached by both governments in June 2025. It coordinates concrete, practical collaboration between the primary fusion laboratories of the UK and Japan.
The agreement establishes a framework for joint research, engineering development and knowledge exchange, strengthening international collaboration to address key scientific and engineering challenges on the pathway to commercially deployable fusion energy.
Areas of collaboration may include:
- Fusion core and plant technologies, including breeding blanket systems, plasma science and materials;
- Fusion plant systems engineering and integration, covering whole-plant design, operation and maintenance, including robotics and autonomous systems;
- Fuel cycle and safety, including tritium technologies;
- Regulation, standards and skills development, supporting clear deployment pathways and a skilled fusion workforce;
- Affordability and commercial viability, supporting the delivery of economically attractive fusion energy.
To implement these strategic goals, UKAEA and QST are deploying active operational mechanisms. These include:
- Shared Facilities: Opening up localised research infrastructure to international counterparts to run joint tests.
- Staff Exchanges: Exchanging researchers and engineering specialists between UK and Japanese campuses to cross-pollinate specialised knowledge.
- Targeted Joint Projects: Launching specific, outcome-driven engineering initiatives to build out the global fusion supply chain.
The MOC aligns with the UK’s broader national fusion strategy, backed by over £2.5bn ($3.3bn) in funding. This domestic investment includes the Spherical Tokamak for Energy Production (STEP) prototype facility planned in Nottinghamshire. The partnership expands a growing web of UK commercial agreements, mirroring existing strategic fusion frameworks with the US and Canada.
Yasuyoshi Kakita, Vice-Minister for Policy Coordination at Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT), commented: “This institutional cooperation further concretizes the partnership between the two countries, and we look forward to the creation of outcomes that will be of value to both nations. In Japan’s new growth strategy, fusion energy has been designated as one of 17 key strategic areas, and efforts are underway to explore initiatives toward societal implementation, including research and development.”
UKAEA CEO Tim Bestwick said fusion energy is a global challenge that requires international collaboration. “This cooperation with QST strengthens our long-standing partnership with Japan in fusion-related technologies and creates new opportunities to combine our expertise to tackle key challenges in delivering fusion power. By working together, we can accelerate progress towards commercially deployable fusion and its long-term economic and energy benefits.”
Similar sentiments were expressed by QST President Shigeo Koyasu. “Fusion energy research and development is essential to addressing global challenges. This collaboration with UKAEA provides a new opportunity to further strengthen the long-standing partnership between Japan and the United Kingdom in fusion energy development, while bringing together the expertise of both sides to tackle key challenges toward the demonstration of fusion power generation.”
The UKAEA-QST agreement feeds directly into STEP. Rather than duplicating fundamental plasma physics experiments, the partnership relies on Japan’s hardware capabilities to optimise the UK’s reactor design. QST has decades of operational experience with large-scale superconducting magnets and traditional tokamaks. STEP relies on a tightly bound, “crunched” spherical tokamak configuration. Japan’s magnetic containment data assists UK engineers in stabilising high-pressure plasmas within this compact geometry.
For STEP to successfully produce continuous electricity, it must achieve tritium fuel self-sufficiency. Japan provides mature technical insight into breeding blanket technologies and tritium processing. This expertise acts as a physical validation loop for the UK’s primary tritium research initiative, the Lithium Breeding Tritium Innovation (LIBRTI) programme.
The bilateral roadmap leverages government-backed research to spur immediate industrial growth, linking the UK Fusion Cluster with the Japan Fusion Energy Council (J-Fusion). Major commercial ventures accelerating this supply chain include:
- Tokamak Energy & Furukawa Electric: A prominent private-sector joint venture focused on industrialising magnet production. This partnership manufactures High-Temperature Superconducting (HTS) magnet technology, creating the strong magnetic fields needed to confine commercial fusion plasmas.
- Kyoto Fusioneering Expansion: This Japanese fusion engineering spinoff relocated its international headquarters to the UKAEA’s Culham Campus in Oxfordshire. The company specialise in commercialising the complex plant subsystems, heat exchangers, and tritium recovery pumps needed to turn raw fusion heat into electricity.
