Japan

UK, Japan Sign £18 Billion Tech and Nuclear Pact

Is the UK-Japan tech pact a landmark strategic alliance or an ambitious deal built on unproven foundations?

JUN 16·Updated JUN 17

UK, Japan Sign £18 Billion Tech and Nuclear Pact

Story

Above: British Prime Minister Keir Starmer with his Japanese counterpart Sanae Takaichi at 10 Downing Street in London on June 14. Image credit: Andy Rain/EPA/Bloomberg/Getty Images

The Facts

Rolls-Royce, the U.K. National Nuclear Laboratory and the Japan Atomic Energy Agency (JAEA) signed two Memorandums of Cooperation on Sunday at 10 Downing Street, during Japanese Prime Minister Sanae Takaichi's visit to the U.K.
Japan Atomic Energy Agency
Rolls-Royce
The agreements cover High-Temperature Gas-Cooled Advanced Modular Reactor (AMR) technology and next-generation Coated Particle Fuel. Rolls-Royce aims to build a demonstrator AMR in the U.K. by the mid-2030s using safety data shared by the JAEA.
Rolls-Royce
Japan Atomic Energy Agency
The AMRs are designed to run at temperatures of 700 degrees or more, producing between 15 and 35 megawatts of electricity, and could supply heat and power for energy-intensive industries such as steel-making and green hydrogen production.
Tomorrow's World Today
The Telegraph
The reactors will use TRISO fuel, made from poppy seed-sized uranium pieces wrapped in ceramic layers. The U.K. has announced a £300 million program with Urenco to build a domestic enrichment facility to produce the uranium required.
Agenzia Nova
No2NuclearPower
The Telegraph
Takaichi and Prime Minister Keir Starmer also announced the Japan-U.K. Frontier Technology Partnership, a bilateral framework covering AI, quantum technologies, space, and cybersecurity, alongside investments totaling £18 billion.
Japan Wire by Kyodo News
The Asahi Shimbun
The two leaders agreed to accelerate development of the Global Combat Air Programme, a next-generation fighter jet being developed jointly by the U.K., Japan and Italy, with an international contract due to be signed by the end of June.
Japan Wire by Kyodo News
Daily Mirror

Sources Split

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The Spin

Narrative A

This is a serious strategic win, locking in collaboration on AI, quantum computing, semiconductors and cyber defense at a moment when geopolitical instability demands exactly this kind of coordinated action. Combining U.K. software leadership with Japan's manufacturing power creates a genuinely competitive edge neither country could build alone. This is the kind of high-value alliance that drives growth and hardens national security simultaneously.

GOV.UK

John Hemmings on X

Narrative B

The nuclear piece of this £18 billion deal rests on technology that remains commercially unproven after decades of Japanese testing, and Japan's own public trust problems around nuclear power make smooth implementation far from guaranteed. Rolls-Royce building a demonstrator AMR by the mid-2030s sounds promising, but without a credible waste strategy and public buy-in, engineering ambition alone won't carry this across the finish line.