US-UK deal nuclear signed to speed up reactor approval, as companies announce cross-border partnerships

SIR KEIR STARMER and Donald Trump have signed a bilateral agreement to advance nuclear technology, alongside a series of commercial partnerships between US and UK companies.

The Atlantic Partnership for Advanced Nuclear Energy, signed between the two leaders during the US president’s second state visit to the UK, aims to speed up regulatory approval in both countries for nuclear power projects by allowing assessment results to be shared. The deal is focused on next generation nuclear technology as well as small modular reactors (SMRs).

The deal has been welcomed by industry and is viewed as a step toward deeper transatlantic collaboration on nuclear development between the US and UK.

The bilateral agreement allows regulatory tests approved in one country to support reactor assessments in the other. The UK government expects the agreement to cut the time required to secure a nuclear project licence from three to four years down to two.  

Among the commercial partnerships announced ahead of the state visit was a deal between US nuclear reactor designer X-Energy and Centrica, owner of the UK’s second largest electricity supplier British Gas. Under the deal, the two companies will build up to 12 advanced modular reactors in Hartlepool in northeast England, generating a combined 960 MW of electricity – enough to power around 1.5m homes.

They aim to follow this with a UK-wide programme delivering up to 6 GW of nuclear power generation.

The agreement promises to create 2,500 jobs and guarantees a nuclear future for Hartlepool beyond 2028 when the ageing nuclear power station in the town is scheduled to enter decommissioning. X-Energy CEO J Clay Sell praised Hartlepool’s “base of professionals and services who can help drive the next generation of nuclear forward”. 

Advanced modular reactors (AMRs) are compact units that use fourth-generation reactor designs, typically cooled by novel substances such as molten salts or gas, rather than conventional water-based systems. The technology has only been operational at scale since 2023 when China’s helium-cooled HTR-PM reactor entered commercial operation.

The coolants used in AMRs can transfer heat at higher temperatures than water, making the technology a promising option for producing low-carbon process heat. The helium coolant used in X-Energy’s Xe-100 reactors – set to be delivered to Hartlepool under the Centrica deal – can reach temperatures of up to 750°C. Each reactor can generate 80 MW of electricity or 200 MW of process heat and has an operational lifetime of 60 years.

Transatlantic business

Business ties between American and British companies have strengthened since UK aerospace and defence contractor Rolls-Royce partnered with US nuclear components supplier BWXT last year to develop nuclear fission systems for UK and US space missions. Already selected to build the UK’s first three commercial small modular reactors, Rolls-Royce SMR has now submitted its reactor designs to the US regulatory process.

Other partnerships announced last week between US-based modular reactor designers and UK-based companies include:

• Holtec’s deal with the UK’s sole commercial nuclear power operator EDF and property developer Tritax to develop SMR-powered data centres on the site of the former Cottam coal-fired power station in Nottinghamshire
• A partnership between Last Energy and UK port operator DP World to launch a micro nuclear power station to supply the expansion of the London Gateway port and business park
• A deal under which Urenco, a uranium enricher majority owned by the UK and Dutch governments, will supply high-assay low-enriched uranium (HALEU) fuel to US nuclear microreactor builder Radiant
• Plans from TerraPower and tech commercialisation investor KBR, both US-based, to evaluate UK sites for sodium-cooled Natrium reactors

Nuclear power has fallen in the UK from contributing 25% of grid supply in the 1990s to around 15% today, with many of the country’s ageing power stations scheduled to enter decommissioning over the next decade. Keir Starmer and UK energy secretary Ed Miliband have said the partnership will usher in a “golden age” of nuclear power in the country. The bilateral agreement follows recent UK government commitments of £11.5bn (US$15.5bn) for the Sizewell C nuclear power station and £2.5bn for Rolls-Royce SMR. Meanwhile, US energy secretary Chris Wright and interior secretary Doug Burgum said the deal will strengthen the country’s “energy dominance”.

‘Indispensable technology’

The US-UK nuclear agreement follows the International Atomic Energy Agency’s (IAEA) fifth consecutive upward revision of global nuclear power forecasts, projecting capacity to grow from 377 GW in 2024 to between 561 and 992 GW by 2050. The agency expects SMRs to play a significant role, accounting for up to 24% of new capacity.

The IAEA’s projections have increased each year since 2021, having stagnated for ten years following the Fukushima disaster in 2011. Japan has also made moves to return to nuclear, launching feasibility studies into building the country’s first reactor since the Fukushima meltdown.

Rafael Mariano Grossi, director general of the IAEA, said the rising projections “underscore a growing global consensus: nuclear power is indispensable for achieving clean, reliable and sustainable energy for all”.