The Office for Nuclear Regulation (ONR) explains how it is responding to government recommendations to reform the UK nuclear regulatory framework, and what this means in practice
This is a significant moment for nuclear regulation in the UK. The independent Nuclear Regulatory Taskforce, commissioned by the Prime Minister, published its final report in November 2025, setting out 47 recommendations for reform of the nuclear regulatory framework. The government accepted all 47 in its implementation plan, Building Our Nuclear Nation, published in March 2026. At the Office for Nuclear Regulation, we have been part of this process from the start – contributing evidence, shaping thinking, and now working to implement the changes that fall to us.
Our starting point
We are the United Kingdom’s independent nuclear regulator. Our mission is to provide efficient and effective regulation of the nuclear industry, holding it to account on behalf of the public. The Energy Act 2013 established our purposes for the regulation of nuclear safety, nuclear site conventional health and safety, civil nuclear security, safeguards, and the transport of radioactive materials. Our dutyholders include 36 nuclear licensed sites and hundreds of service providers, transport operators, and non-nuclear sites. We employ more than 600 staff, including more than 400 specialist nuclear inspectors who bring world-leading expertise to their work.
We have always been an enabling regulator, working with industry constructively, providing early clarity on what is needed. We focus on risk and avoid unnecessary burden where it does not serve safety or security. The Nuclear Regulatory Review has now provided the impetus, and in some areas the mandate, to go further and faster in applying those principles consistently across everything we do.
The Taskforce’s central finding was that the UK’s nuclear regulatory framework had become more process-heavy than the actual risks warranted. Safety cases had grown in volume and complexity, regulatory interactions across multiple bodies were sometimes duplicated rather than coordinated. A tendency towards caution had taken hold.
We recognise those observations. We submitted detailed evidence to the Taskforce throughout its review, and we were candid about where we believed improvements were needed. The Taskforce itself acknowledged that the UK’s nuclear sector has an excellent safety record, delivered by expert and credible regulators. Our task now is to maintain that record while removing the friction that has built up around it.
What we are doing
Taking the lead on regulatory coordination
One of the most practically significant changes we have delivered is the establishment of a lead regulator model. On any major nuclear project, multiple regulatory bodies have a role to play – ourselves, the Environment Agency, the Health and Safety Executive, the Defence Nuclear Safety Regulator, Natural Resources Wales, the Planning Inspectorate, among others. Without coordination, each body engaging separately can create duplication, inconsistency, and delay.
The Taskforce’s recommendation to establish a commission is the long-term solution to this issue. Until legislation can enact the commission, ONR has been designated as the interim lead regulator for the nuclear fission sector, with formal arrangements in place across what we have described as the ’super six’ regulatory bodies. We convened the inaugural Lead Nuclear Regulator Group meeting in early 2026, agreeing terms of reference and identifying priority projects for coordinated action. We are now focused on demonstrating the practical benefits of this approach through delivery on real projects.
The model draws on experience we already have. Our collaborative approach at Sellafield showed what is possible when regulators come together with a shared purpose – a group of regulatory bodies working effectively under coordinated arrangements.
For developers and operators, this means a clearer, more joined-up experience of the regulatory process. It means less time spent managing parallel engagements with multiple bodies, and more predictable timelines. We are committed to making the lead regulator model work well in practice, not just on paper.
Resetting how safety cases are developed
We have begun work to reset the approach to safety case development. Safety cases are the foundational documents through which operators demonstrate how their facilities will be operated safely. Over time, they have grown substantially – not always because the safety content required it, but because a culture developed in which more documentation was equated with better demonstration of safety.
We want to change that. Safety cases should be clear, proportionate documents that are genuinely useful to the people who operate nuclear facilities – working tools, not paper exercises. We are engaging with industry and fellow regulators to identify where the accumulated complexity can be reduced – creating conditions in which operators feel confident proposing proportionate approaches rather than defaulting to over-documentation.
Our principle here is straightforward: we require good practice, not gold-plating. Where a dutyholder proposes a solution that exceeds what is necessary for safety, we will say so. Where guidance has accumulated beyond what serves its original purpose, we should simplify it. We are working through our regulatory guidance documents with exactly this in mind. Consultation is now ongoing for our updated Safety Assessment Principles, with a revised version to follow by December 2026.
Cultural change across the nuclear sector
We are taking a deliberate and evidence-based approach to culture change, both within our own organisation and across the wider nuclear industry. Recognising that effective regulation depends as much on behaviours and mindsets as on rules and processes, ONR commissioned an independent assessment of its own culture from the Alliance Manchester Business School.
That assessment provided a clear-eyed understanding of the cultural factors – including risk aversion, consensus-driven pace, and process dependency – that can enable or constrain regulatory effectiveness.
ONR has used the findings directly to shape leadership expectations and ways of working under its ‘ONR Together’ strategy, shifting towards more proportionate, outcome-focused regulation.
That new strategy, laid in Parliament in early July, sets our clear and ambitious direction, amid a sector changing and evolving at pace. With nuclear playing a central role in the UK’s economic growth, energy security and national defence, the demands on us as a regulator have never been greater.
ONR Together will transform how we work, outlining the modernisation of processes, leveraging modern technology, and empowering us to make timely and proportionate decisions. It highlights how we will set out clearly what acceptable compliance looks like, so industry has the certainty it needs to invest and deliver.
Within the industry, we identified a significant gap in how safety culture was being assessed and understood. Approaches were inconsistent, making it difficult for organisations to benchmark their performance or learn from one another in any structured way.
In response, we led the development of the Nuclear Industry Safety Culture Inventory – NISCI – a standardised software tool launched in June 2025 that enables dutyholders to measure safety culture performance, benchmark against peers, and identify priorities for improvement, while providing a more consistent evidence base for regulatory conversations across the sector.
Early signs of impact are encouraging. More than half of licensed nuclear sites have adopted the tool, the Safety Directors’ Forum has aligned its culture sub-group meetings to the NISCI framework, and we have extended our reach beyond licensed sites by piloting it at the Henry Royce Institute.
Alongside NISCI, we have developed a practical framework of organisational culture flags to support inspectors in day-to-day regulatory interactions. Using nine indicators, inspectors can consistently observe and record weak signals that reveal meaningful patterns in how an organisation is functioning.
Bringing defence and civil nuclear regulation closer together
The government has committed to merging the Defence Nuclear Safety Regulator into ONR. Currently, on some sites regulated by both bodies, operators must comply with two overlapping nuclear regulatory regimes for the same assets. That creates duplication and complicates regulatory engagement.
We are working with the Ministry of Defence and the Department for Energy Security and Net Zero on the approach to consolidation.
The merger, when complete, will mean operators on defence sites deal with a single nuclear regulator rather than two. It will also allow us to deploy technical expertise more efficiently across civil and defence programmes – a practical benefit at a time when the demands on specialist nuclear expertise across the sector are significant and growing.
International harmonisation
We are investing significantly in further strengthening our international collaboration – one of the areas with the greatest potential for practical benefit to the UK’s nuclear programme.
We are already working with the US Nuclear Regulatory Commission and the Canadian Nuclear Safety Commission on collaborative design assessments, including for the BWRX-300 reactor. A group of European regulators is also observing our Generic Design Assessment of the Rolls-Royce Small Modular Reactor – the first time such collaboration has been undertaken at this scale, and something that could meaningfully accelerate the deployment of UK reactor technology internationally.
Our approach to mutual recognition of regulatory assessments is underpinned by rigorous due diligence. Benchmarking of regulatory standards, reciprocal assessments and clear governance arrangements. International harmonisation does not mean lowering our standards or accepting another country’s assessments uncritically. It means focusing our regulatory effort where it adds the most value, rather than duplicating work that has already been carried out to an equivalent standard by a trusted partner.
We welcome the government’s commitment to fund dedicated resources for international collaboration work. Meaningful engagement of this kind requires sustained investment, and we are working with government to secure the necessary funding on an ongoing basis.
Embracing digital tools and AI
We are embracing digital innovation in how we regulate. This is about being a modern, credible regulator that keeps pace with the technological environment in which the industry operates.
We have trialled generative AI to assist with assessment work, to explore opportunities and limitations. We have undertaken the world’s first regulatory sandboxing on AI within the nuclear industry. This has enabled Sellafield to develop an AI-based computer vision system with potential cost efficiencies exceeding £100m, and accelerate the deployment of mobile robotics that reduce worker radiation exposure.
We have developed a position paper with peer regulators on principles for safe AI deployment in nuclear applications and established an international agreement with six other regulators to promote harmonisation through regulatory sandboxing. We have completed and published research to be ready for the future regulation of AI in the civil and defence sector.
We are reviewing our regulatory guidance to simplify and streamline it, removing unnecessary complexity and volume so that it is clearer and more useful, both for our own inspectors and for the industry we regulate. Our approach to regulating AI adoption by industry is deliberately non-prescriptive, designed to accommodate innovation rather than constrain it.
Building capacity for what lies ahead
All this reform work sits alongside a very significant expansion in the UK’s nuclear programme – Sizewell C, the Wylfa SMR project, Hinkley Point C, The Dreadnought submarine programme, the ongoing decommissioning of legacy nuclear sites. These are substantial, long-duration programmes, and they require us to have the regulatory capacity to match.
We have introduced a fast-track inspector development programme that compresses the time for new recruits to become fully effective inspectors from 2-3 years to 12 months, through an intensive structured programme. We are running graduate and degree apprenticeship schemes to develop the next generation of nuclear inspectors. And we are actively engaged in the Nuclear Skills Delivery Board, supporting the broader sector effort to build the workforce that these programmes require.
Attracting and retaining technically skilled specialists in a sector where demand significantly exceeds supply is a persistent challenge. We are addressing it directly, but we are also realistic that it requires sustained effort and continued investment.
The principles that guide us
Through all of this, the principles that underpin our work do not change. We are here to protect workers and the public. We hold the nuclear industry to account through independent, evidence-based regulation. We provide the assurance – to government, to industry, to local communities, and to the public – that nuclear activities are conducted safely and securely.
The Taskforce process has challenged us to examine whether our delivery of that purpose is as efficient and proportionate as it could be. And we are now acting to address excessive processes, reducing guidance where appropriate and where the regulatory encounter could be clearer and more predictable without any compromise to safety or security.
This is the right thing to do – for the industry we regulate, for the country’s agreed energy projects, and for our own credibility as a regulator that takes its responsibilities seriously.
Please note, this article will also appear in the 27th edition of our quarterly publication.
