The United Kingdom and the United States have established a strategic partnership to develop advanced nuclear energy sources specifically to meet the burgeoning power demands of the artificial intelligence industry. This collaboration, part of a broader economic and technology agreement, aims to position both nations at the forefront of AI development by solving one of its most significant emerging constraints: a reliable and massive supply of clean energy.
As AI models grow in complexity and data centers expand to support them, their electricity consumption is projected to skyrocket, posing a major challenge to grid stability and climate goals. In response, government and industry leaders are increasingly turning to next-generation nuclear technologies, including small modular reactors and nuclear fusion, as a carbon-free power source capable of operating 24/7. This transatlantic initiative seeks to accelerate the research, development, and deployment of these systems to create a secure energy foundation for the future of computation.
An Alliance for Technological Prosperity
The foundation for this joint effort is the Atlantic Declaration, a wide-ranging economic partnership signed by UK Prime Minister Rishi Sunak and US President Joe Biden. The agreement is designed to deepen economic ties and address shared challenges, with a strong focus on critical and emerging technologies. UK Secretary of State for Science, Innovation and Technology, Michelle Donelan, has emphasized that a key pillar of this plan is ensuring the immense computational power required for AI leadership is sustained by a new generation of secure, clean energy.
The declaration outlines a joint action plan to promote cooperation across several key areas, including AI safety, quantum computing, and biotechnology. By explicitly linking AI’s future to nuclear energy, the two nations aim to create a resilient supply chain for both the hardware and the power that underpins the digital economy. The initiative frames the build-out of this infrastructure not just as an energy or technology issue, but as a matter of national security and long-term economic competitiveness, ensuring that critical AI capabilities are not dependent on unstable energy markets or geopolitical rivals.
The Exponential Power Drain of AI
The push for a new energy paradigm is driven by startling projections about AI’s electricity usage. Training a single large language model, such as those that power advanced chatbots, can consume gigawatt-hours of electricity, equivalent to the annual energy use of hundreds of homes. This initial training, however, is only a fraction of the total energy footprint. The subsequent phase, known as inference, where the model is actively used to generate text, analyze data, or create images, requires a constant and substantial power supply from vast data centers.
According to the International Energy Agency, data centers, which house the servers for AI and other digital services, already account for 1–1.5% of global electricity consumption. Some forecasts suggest that without significant efficiency gains, the electricity demand from data centers, AI, and cryptocurrencies could double by 2026, reaching a level of consumption comparable to that of Japan. This rapid growth puts immense pressure on existing power grids and threatens to undermine progress on decarbonization if it is met by burning more fossil fuels. The predictable, constant power output of nuclear energy is seen as an ideal match for the relentless, round-the-clock operational needs of these facilities.
Harnessing the Atom for Computation
The partnership focuses on two distinct but related streams of nuclear technology to power the AI revolution. The more immediate solution involves advanced fission reactors, while the long-term vision looks toward the transformative potential of fusion.
Small Modular Reactors (SMRs)
The primary near-term technology is the small modular reactor, or SMR. Unlike traditional, large-scale nuclear plants that are custom-built on-site and can take over a decade to construct, SMRs are designed to be manufactured in a factory setting and assembled on-location. This approach promises to reduce costs, shorten construction timelines, and improve safety through standardized, passive cooling systems. An SMR can typically generate up to 300 megawatts of electric power, sufficient to run a large data center complex or a small city. Their smaller footprint also allows for greater siting flexibility, including the potential for co-location directly with the industrial facilities or data centers they are intended to power, which would drastically reduce energy losses from long-distance transmission.
The Long-Term Bet on Fusion
The collaboration also supports research into nuclear fusion, the process that powers the sun. Fusion involves forcing atomic nuclei together to release massive amounts of energy. If commercialized, it could offer a virtually limitless source of clean power with no long-lived radioactive waste. While significant scientific breakthroughs have occurred, including achieving net energy gain in laboratory experiments, commercially viable fusion power is still believed to be decades away. The inclusion of fusion in the strategic plan signals a long-term vision, acknowledging that today’s investments are necessary to unlock the energy sources required for the even more advanced artificial intelligence of the future.
Industry Moves to Secure Nuclear Power
Beyond government agreements, the tech industry is already taking concrete steps to link its future to nuclear energy. In a landmark deal, Microsoft has partnered with energy provider Constellation to power one of its Virginia data centers with a direct supply of nuclear energy. The agreement aims to provide the facility with a constant stream of carbon-free electricity to help Microsoft meet its goal of running on 100% zero-emission energy by 2030. This move is seen as a blueprint for how tech companies can secure the reliable baseload power their operations demand without contributing to carbon emissions.
Meanwhile, prominent figures in the AI world are investing heavily in the next generation of nuclear technology. Sam Altman, the CEO of OpenAI, has personally invested hundreds of millions of dollars into Helion, a private company pursuing a unique approach to nuclear fusion. These private-sector actions demonstrate a growing consensus that the future of computing is inextricably linked to the future of nuclear energy, validating the strategic direction of the US-UK partnership.
Obstacles on the Path Forward
Despite the strong momentum, the path to a nuclear-powered AI future is laden with challenges. The deployment of SMRs faces significant regulatory hurdles in both the US and the UK, as safety and licensing frameworks designed for large, conventional reactors must be adapted for these new designs. Public perception and the unresolved political issue of permanent storage for high-level nuclear waste also remain significant obstacles.
Furthermore, the economics of SMRs are not yet fully proven. While the modular construction approach is designed to lower costs, the first-of-a-kind projects are expected to be expensive, and it remains to be seen if they can compete on price with other clean energy sources like solar and wind, especially when paired with battery storage. For fusion, the challenges are even more fundamental, centered on solving immense scientific and engineering problems to achieve a sustained and controllable reaction that can be harnessed for practical power generation. This transatlantic alliance aims to pool resources and expertise to systematically address these technical, regulatory, and financial barriers.