Nuclear power plant developers have told NCE they hope to build more than 20 small modular reactors (SMRs), including advanced modular reactors (AMRs), in the UK by the mid-2030s.
This follows the announcement yesterday on Monday that the US and UK have agreed to work together to deploy SMRs, AMRs and at least one micro-modular reactor (MMR). This was revealed ahead of president Trump’s state visit to the UK scheduled from today to Thursday, 18 September.
The term SMR refers to both a specific type of nuclear reactor design, as well as the full range of other smaller nuclear reactors covered by the AMR and MMR descriptions.
An example of an SMR is Rolls-Royce SMR’s 470MW reactor, which has been selected by Great British Energy – Nuclear to receive financial support from the public purse.
X-energy and Centrica aiming to deploy 20 AMRs by mid-2030s
Amazon-backed AMR developer X-energy has joined forces with British energy giant Centrica with ambitions to build “up to 12 advanced modular reactors in Hartlepool, with a follow-on UK-wide programme targeting a fleet of 6GW of nuclear power”.
X-energy’s Xe-100 (pictured) is an “80MWe reactor that can be scaled into a ‘four-pack’ 320MWe power plant”, according to the company. It also describes the Xe-100 as “the safest, most economic and most advanced design for a small modular nuclear reactor”.
Sharing more details with NCE about its plans to deploy its AMR reactors in the UK with Centrica, an X-energy spokesperson said: “Following the signing of the Joint Development Agreement, we will now begin the process towards full mobilisation and finalisation of all activities and schedules, including on submission of the DCO (development consent order) and wider permits and licenses.”
The spokesperson said the total value of the investment the companies are looking to make is “commercially confidential”, but did say that the companies are “confident from testing the market, and the evidence of Sizewell C, that there is a strong appetite to invest in nuclear, provided the risk profile is right”.
The £38bn Sizewell C nuclear power plant, which is a government project, was only able to secure the final investment decision (FID) with private investors by having the Treasury recapitalise the National Wealth Fund so it could provide a £36.6bn debt financing guarantee for the project.
The spokesperson continued: “X-energy already has over $1.5bn [£1.1bn] in private funding committed to the company from investors, including Amazon, and we believe that with the right supporting policies from [the UK government] we can unlock further private funding for our programme of new build here.”
Different nuclear power plant developers say they have different requirements for public financial support, with some requiring none at all, and others hinting they would need some support.
“We’re not looking for public procurement, but visible support for the first project to unlock private investment,” the X-energy spokesperson told NCE. “[The UK government] has said publicly that they are willing to negotiate some equity and debt and a financing framework to attract investors for privately led projects, and that’s what we’re looking for.
“Partial US government support for X-energy’s first project unlocked $1.5bn of private investment from Dow and Amazon and others, and we can replicate that here, only at a smaller cost to the taxpayer or billpayer because of the work that has already been done in the US.”
A critical question for nuclear power proponents is the speed of deployment, because a key argument in favour of nuclear energy is its role in avoiding greenhouse gas emissions as part of the response to climate breakdown, especially given that it is much faster to deploy renewable energy solutions like wind and solar farms.
In addition, countries and companies are racing to be the first to deploy new nuclear capacity, to show how capable they are and how friendly their regulatory frameworks are to the industry.
“We will start to mobilise fully in 2026 with a view to having first power online in the mid-2030s. Establishing the precise schedule within that timeframe will be one of the first development activities we will look at as part of our joint work,” the X-energy spokesperson told NCE.
“We are encouraged by the moves the UK government and regulators are taking to accelerate approval times and are confident the positive progress made in advancing the Xe-100 through both the US and Canadian regulatory processes will support the timely delivery of our plans here.”
X-energy and Centrica are hoping to build 12 AMRs at Hartlepool, which is the site of one of the UK’s operating gigawatt-scale nuclear power plants.
The existing reactors at Hartlepool are some of the closest in the UK to residential neighbourhoods. It would not be possible to build a nuclear plant today in this location, given the current status of a regulation called the Semi-Urban Population Density Criterion (SUPDC).
“We are in constructive discussions with the UK Government about EN-7 and questions of the future application of the Semi-Urban Population Density Criterion, where we believe full recognition needs to be given to the inherent safety features of certain advanced nuclear technologies, which require a much smaller ‘Emergency Planning Zone’ around a site than traditional technologies,” X-energy told NCE.
EN-7 refers to the National Policy Statement for nuclear energy generation (EN-7), which is currently in draft form and expected to be finalised and launched by the end of 2025. It would open up more of England and Wales to new nuclear developments including SMRs.
The government said in its announcement this week that X-energy planned to deploy 12 AMRs at Hartlepool and had ambitions to deploy 6GW more widely in England and Wales.
“With the Xe-100 able to provide both clean electricity and process heat to support energy-intensive industries, we see potential for around 20 four-reactor power plants across the UK (including Hartlepool), and maybe even more,” X-energy told NCE.
“This was underpinned by a study conducted as part of the work under the joint X-energy and UK Government-funded Future Nuclear Enabling Fund, which looked at potential sites and end user demand, including existing EN-6 sites, Industrial Clusters, potential AI growth zones and wider sites.”
EN-6 is the previous national policy statement for the siting of nuclear power plants which largely covered the sites with operating and decommissioning gigawatt-scale nuclear reactors by name.
SMR construction could take just over 3 years – Holtec
Holtec, which was one of the companies that missed out on Great British Energy – Nuclear’s £2.5bn publicly-funded SMR programme, is working with EDF and Tritax on plans to develop advanced data centres powered by small modular reactors at the former Cottam coal-fired power station in Nottinghamshire.
Tritax is a real estate fund manager with plans to deploy data centres.
A Holtec spokesperson told NCE: “We are currently assessing the scope and feasibility of the DCO and will aim to submit the application in 2026.
“Overall, the SMRs expected to be deployed on the site are valued at £11bn. We are currently engaging with several potential investors on project financing.”
Holtec was more tight-lipped about the level of public money it was hoping to access.
“We are currently engaging with potential investors on project financing. Potential Investors include export credit agencies, investment funds, and corporate bodies,” the spokesperson told NCE.
“After commencing nuclear [construction], we expect power to be produced from the first reactor after three and a quarter years. We expect to have all regulatory approvals to commence nuclear construction in 2029.”
NCE also spoke with Tritax to get more information about its plans to deploy the data centre which would be powered by SMRs.
“We will be working on the master plan in the coming months, with a view to submitting for planning during 2026,” the Tritax spokesperson told NCE.
“Financing options for the data centre element of the project remain open and will be considered in due course.
“Holtec/EDF are engaging with relevant parties within UK and US governments, including Great British Energy – Nuclear and The National Wealth Fund.
“On the data centres side, we will consider our options, but we do not need public money to deliver this.”
Civils leader says SMRs must provide ‘visible economic results for communities’
Stantec UK and Ireland divisional director, nuclear Peter Sibley told NCE: “This promise of a national nuclear renaissance is extremely encouraging and these new deals send a positive signal to the industry both here and in the United States, building upon the announcement in the summer regarding Sizewell C and Rolls-Royce in SMRs.
“While these actions provide a strong indication of intent, they need to be quickly translated into ultra-efficient delivery, clear regulatory pathways and visible economic results for communities, there are some priority areas to focus on.
“Creating a truly ‘golden age’ of nuclear in Britain will mean both harnessing existing and creating new expertise in almost every sector in the built environment, from planning and consenting, digital innovation and advisory services, to engineering, technical design, and sustainable development across the whole nuclear lifecycle.
“The rise of AI and the immense demand for associated energy infrastructure brings national challenges and opportunities for skills and job creation, as well as aligned development objectives. By cultivating a sustainable and future-ready workforce, while taking full advantage of existing global expertise, we can move faster in unlocking the value of the nuclear economy.”
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