UK, USA enhance cooperation on fusion energy

Firstly, the United Kingdom Atomic Energy Authority (UKAEA) and the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) have signed a joint declaration of intent to explore linking their advanced fusion supercomputing platforms, using artificial intelligence to accelerate fusion energy's development.

Under the joint declaration - signed at the Global Fusion Policy Summit in London on Monday - UKAEA's SUNRISE mission-focused AI supercomputer would be linked with PPPL's Simulation, Technology and Experiment Leveraging Learning-Accelerated Research (STELLAR-AI) platform through a partnership known as the SUNRISE–STELLAR-AI Federation. SUNRISE is the UK's first AI supercomputer dedicated to fusion energy, backed by GBP45 million (USD60.6 million) from the UK government. STELLAR-AI is PPPL's USD13 million AI and high-performance computing platform to be operated with support from Princeton University. STELLAR-AI is designed to host AI tools and workflows as they mature.

The collaboration - which builds on a memorandum of understanding signed between UKAEA and PPPL in June - would draw on experiments completed using UKAEA's MAST Upgrade facility in Oxfordshire and PPPL's NSTX-U facility in New Jersey. The federation will mean both advanced computers will be used to train the same AI models, which need large volumes of high-quality data to make accurate predictions.

Linking the two computer systems will let researchers on both sides of the Atlantic share experimental data, train AI on the results of two different experimental fusion facilities and run their models on the machine best suited to the task, PPPL noted. Both MAST Upgrade and NSTX-U are compact spherical tokamaks with similar designs, making them well suited for joint AI training.

"When different facilities are combined, researchers can develop more powerful machine-learning models that better capture the underlying physics and help accelerate future fusion projects, including the UK's Spherical Tokamak for Energy Production (STEP Fusion) and US concepts such as PPPL's Spherical Tokamak Advanced Reactor (STAR)," UKAEA said.

"Fusion is one of the great scientific and engineering challenges of our time," said Joe Milnes, Executive Director for Engineering and Computing at UKAEA. "To solve these challenges, fusion needs partnerships. The US and UK are two global leaders in fusion research, and the federation of SUNRISE and STELLAR-AI would build on a long history of transatlantic cooperation to further advance fusion development."

"UKAEA and PPPL would draw on experimental data from two world-leading fusion machines, using simulation to fill the gaps and extend those datasets into regimes we have yet to explore," added Rob Akers, Director of Computing Programmes and Senior Fellow at UKAEA. "Together, we can develop digital twins of both machines to support the design of future fusion power plants, creating models of spherical tokamaks that are more predictive, more actionable and ultimately more useful to fusion engineers. The real power will come from working as one team. Together, we can learn faster and learn more, extracting maximum insight. The computing and international collaboration will help us accelerate the journey from today's experiments to tomorrow's fusion power plants."

Jonathan Menard, Chief Scientist at PPPL, said: "A fusion power plant is one of the most complex machines humanity has ever tried to build and no single laboratory or nation will design it alone. By federating the SUNRISE and STELLAR-AI computer platforms, we can train AI on data from two leading fusion facilities, test ideas across two of the most capable computing systems in the world that are designed for fusion research, and accelerate the path to a compact fusion power plant."

"Our goal is to let models and experiments move freely between the two systems," said Shantenu Jha, Head of Computational Sciences at PPPL. "We will turn a collection of supercomputers into a single engine for fusion discovery."

The partners plan to expand the federation over time, with the long-term goal of a shared foundation model for spherical tokamaks and, eventually, a wider range of tokamak configurations.

Shielding materials

The UK's University of Birmingham and US independent, nonprofit energy research and development organisation EPRI have announced a major collaboration to advance the development of fusion energy technologies through the FURESHMA (Fusion Reactor Shielding Materials) programme.

FURESHMA aims to test advanced boride and carbide shielding materials capable of protecting critical components from the extreme conditions inside future fusion power plants. The project addresses a key barrier to commercial fusion energy by improving the durability, reliability and long-term performance of shielding materials exposed to intense neutron irradiation.

The GBP2.63 million collaboration has been funded by the UKRI Engineering & Physical Sciences Research Council and EPRI, with additional participation of Element Six, building on the partnership initially set up with Tokamak Energy.

The collaboration brings together the university's internationally recognised expertise in fusion materials with EPRI's extensive experience in energy research, nuclear materials and technology deployment.

Building on existing EPRI-Birmingham research and development, this collaboration connects innovative research with the practical requirements of future commercial fusion facilities. It will also support technology transfer and accelerate the path from laboratory discoveries to real-world energy applications. The University of Birmingham and EPRI have agreed that data generated through the project will be made openly available, helping the UK industry and the wider global fusion community benefit from the findings.

"Fusion energy has the potential to provide a secure, low-carbon source of power for future generations, but commercial deployment depends on developing materials capable of withstanding fusion's extreme conditions in terms of temperatures, irradiation doses and thermo-mechanical stresses," said Professor Arunodaya Bhattacharya, Chair in Fusion Energy at the University of Birmingham and Deputy Head of Research in the School of Metallurgy and Materials. "By combining the University of Birmingham's world-leading expertise in fusion materials with EPRI's deep understanding of the energy sector, we can accelerate the solutions that will bring fusion power to grid."

Steve Chengelis, EPRI Vice President, Nuclear Development and Fusion, added: "Developing fusion power plants that are buildable, reliable and maintainable will require a deeper understanding of how key materials perform under fusion conditions. Through FURESHMA, EPRI and the University of Birmingham can connect advanced materials research with the needs of future plant developers and operators, strengthen international knowledge exchange, and help establish a sound technical foundation for fusion deployment."

Tennessee, UKAEA enhance cooperation

Meanwhile, the State of Tennessee, the Tennessee Valley Authority (TVA), and the UK have announced a strengthened partnership to accelerate the commercial deployment of fusion energy, focusing on supply chains, workforce development, and enabling regulatory pathways that support safe and rapid commercial scale-up.

The collaboration builds on momentum from fusion projects underway in both Tennessee and the UK, including Project Infinity in Tennessee and the UK Infinity Fusion Consortium, which link expertise from Type One Energy, TVA, Tokamak Energy, Oak Ridge National Laboratory (ORNL), the UKAEA, and partners across the fusion supply chain. Tennessee's fusion-specific licensing framework - enacted in June 2026 - similarly mirrors the UK's proportionate approach under the UK Energy Act 2023, ensuring regulatory pathways that support safe and rapid commercial scale-up.

The partners will explore cooperation in areas including: strengthening fusion supply chains and advanced manufacturing in both jurisdictions; development of the fusion fuel cycle, including tritium handling, lithium enrichment, and breeding blanket materials; scientific and technical exchange between ORNL, the UKAEA, universities, national laboratories, and research institutions; engagement among utilities, developers, investors, and industrial partners on siting, interconnection, and offtake planning; workforce development, apprenticeships, and talent exchange; coordination on fusion regulation, licensing, and safety frameworks; and joint conferences, forums, and activities that support global fusion sector growth.