The UK government has been clear: nuclear power and the nuclear deterrent are both strategic priorities. One is central to energy security and net zero; the other is national security.
But there is a fundamental challenge. The UK has one nuclear sector, but in many ways, it operates as if it were two.
Civil and defence programmes are largely planned and delivered separately, despite relying on the same skills, supply chains, infrastructure and technical expertise.
The John Fingleton Nuclear Regulatory Review, published in late 2025, diagnosed this as a systemic problem, identifying fragmented oversight, duplicated regulation and weak incentives as barriers to delivery across both civil and defence programmes. The review recommended structural reform, including a single Commission on Nuclear Regulation and the merger of the Defence Nuclear Safety Regulator into the Office for Nuclear Regulation. More recently, the Chancellor’s letter to regulators and industry reinforced the call for accelerated delivery while streamlining the system around it and creating the conditions for sustained nuclear investment.
The UK has deep capability across both missions, and there is ample potential to expand and streamline delivery. The challenge is whether this can be organised and deployed in a coordinated way. At its core, this is a system design challenge. Civil and defence nuclear must be recognised as a single national capability, not parallel efforts. Coordinating workforce, supply chains, infrastructure and innovation at this level is what enables each mission to deliver at scale and meet the ambition set out by government.
Jason Dreisbach
Different missions, similar pressures
Civil and defence nuclear have evolved separately for good reason. They operate under different funding models, political pressures and definitions of success. Civil programmes must attract investment and demonstrate economic value. Defence programmes prioritise security, continuity and long-term assurance, often under constraints that limit openness and flexibility.
Yet the two are more intertwined than their current structures suggest. Sellafield is a case in point. The site was originally built in the late 1940s to produce plutonium for nuclear weapons. From those defence origins, it became central to the UK's civil nuclear fuel cycle and is now one of the largest decommissioning programmes in Europe. Today, the UK is exploring options to re-establish a nuclear fuel cycle for defence reactor fuel – a programme that will depend on civil nuclear knowledge and expertise. Decommissioning, too, is an area where the defence programme has much to draw from civil experience, where the discipline is more mature.
The same workforce underpins both sectors. Many of the most in-demand skills are not inherently “civil” or “defence”, yet they are treated as such in practice. The result is predictable churn: people move between programmes to fill gaps, driving up costs without increasing overall capacity and weakening delivery continuity.
The supply chain faces similar pressures. Companies are expected to invest without clear, consistent signals of long-term demand, often in emerging markets facing strong international competition. That uncertainty slows investment, extends lead times and reduces resilience.
Infrastructure tells the same story. In areas such as fuels, testing and long-term waste management, programmes are often solving closely-related problems in parallel. The result is duplication in some places and underused capability in others, at a time when capital is tight. Innovation also suffers, as learning travels more slowly and solutions are less likely to scale.
Left unaddressed, these constraints will limit how far and how fast the UK can scale nuclear capability across both missions.
Alignment without uniformity
Richard McMeekin
Civil and defence nuclear operate under different incentives, constraints and expectations. The challenge is to manage them as parts of a single national capability, while delivering them through distinct models.
What is needed is a clearer capability model: one that improves visibility, aligns incentives, and allows resources to move more fluidly across programmes.
Better visibility of demand, strategic requirements and constraints would allow skills, supply chains and infrastructure to be planned with greater intent. It would also allow expertise to move more easily across organisational and sector boundaries, rather than remaining locked within them.
Regulatory reform is central to this. The Fingleton review identified fragmented oversight as a primary source of delay and cost, with a single project sometimes facing as many as eight regulators in defence, and no designated lead. The report’s recommendation to consolidate regulatory authority under a lead regulator model – and ultimately to merge the DNSR into the ONR – would reduce duplication, improve resource allocation and create clearer interfaces between civil and defence assurance. The government's acceptance of this direction is a welcome step; the priority now is pace and consistency of implementation.
Together, these changes would improve the government's ability to act as an intelligent client, coordinating delivery across programmes, supply chains and infrastructure, rather than relying on fragmented procurement to do so indirectly.
Alignment would also strengthen delivery and, more importantly, sovereign agility. In practice, that means the ability to reallocate skills, redirect supply chains and respond to changing national priorities. In a more uncertain geopolitical environment, this is essential. It allows the UK to move from reacting to pressure towards absorbing it as part of long-term capability building.
There is a strategic upside as well. Countries developing nuclear capacity are not only seeking technology, but partners who can deliver at scale, across the lifecycle. A more coordinated and capable domestic ecosystem strengthens the UK’s credibility and competitiveness in that role.
For organisations such as AtkinsRéalis, working across both civil and defence programmes, the case for a more integrated model is increasingly clear.
Two missions, one national capability
The UK has deep expertise across both domains, supported by a strong base of engineering, scientific and industrial expertise. What it lacks is a consistent way of bringing everything together across both missions at the scale required.
The Chancellor’s call to prioritise outcomes over process is welcome. But delivering that ambition depends less on individual programmes and more on how well the system is coordinated. Alignment is not the end goal. The prize is a step change in sovereign capability, energy security and national security. Recognising and managing civil and defence nuclear as a single national capability is essential to achieving that ambition.