The Nuclear Regulation Bill: a New(clear) Era (Part 2 – Government Objective 1)

On 13 May 2026, it was announced that a Nuclear Regulation Bill would be introduced for discussion in the upcoming parliamentary session.¹ With Parliament returning from its conference recess, this article forms the second part of a three-part exploration of the Nuclear Regulation Bill (the “Bill”) and three key changes that are expected to be enacted by the Government as part of its ‘Objective 1’ (although at the time of writing, the detailed provisions of the Bill have not yet been published).²

1. Broadened Powers for the Office for Nuclear Regulation

The Bill is expected to expand the remit of the Office for Nuclear Regulation (“ONR”), allowing it to take account of, amongst other things, national security, climate objectives and economic growth when exercising its regulatory responsibilities.³

The “Nuclear Regulatory Review 2025” (the “Fingleton Review”) also proposed that ONR should hold concurrent statutory powers for the regulation of radioactive substances alongside the Environment Agency.⁴ The intended result is that a single regulator would oversee radioactive substances on any particular nuclear site, rather than requiring operators to manage overlapping regulatory interfaces.

What’s the difference?

At present, ONR is established under Part 3 of the Energy Act 2013 and has five statutory purposes: nuclear safety, nuclear site health and safety, nuclear security, nuclear safeguards, and the transport of radioactive materials. Critically, ONR’s current statutory framework confines its regulatory decisions to safety and security considerations and does not allow it to weigh the broader societal value of nuclear power, including for example energy security, progress towards net zero, and economic development. This has meant that regulatory assessments have been conducted through a narrow lens focused exclusively on safety and security, without reference to the strategic importance of the projects under consideration.

Why does it matter?

The broadening of the ONR’s mandate should result in more balanced regulatory decision-making. In practice, this could mean faster approvals for developers, and a more proportionate approach to regulatory requirements where projects deliver significant strategic benefits. However, stakeholders should also be alert to the possibility that an expanded ONR remit could bring new regulatory requirements or processes. Developers will need to monitor closely which regulatory functions are expanded and how the transition is managed in practice.

2. Establishment of a Commission for Nuclear Regulation

The Fingleton Review found that up to six separate regulators may be engaged on a single project, with no established process for resolving conflicts among regulators or securing consistent decisions within a reasonable timeframe.⁵ This fragmentation has been a significant driver of delay and increased costs, as developers have been required to satisfy multiple, sometimes overlapping or conflicting, regulatory requirements.

The Bill is expected to establish a new statutory body, the Commission for Nuclear Regulation (the “Commission”).⁶ The Commission will be presided over by the Chief Nuclear Inspector and will include two Deputy Chief Nuclear Inspectors, one for civil and one for defence matters. The Commission will be empowered to set regulatory guidance, resolve disputes between regulators, and act as the final sign-off authority for substantial regulatory decisions.

What’s the difference?

Under the current regulatory framework, decision-making authority is dispersed across multiple regulatory bodies, including ONR, the Environment Agency, Defence Nuclear Safety Regulation (“DNSR”) and several other agencies. The Government has indicated that the Commission is expected to be fully functioning by Summer 2028. In the interim, the lead regulator model (with ONR as the default lead regulator) is already operational and is intended to provide a bridge to the new statutory framework.⁷

Why does it matter?

The establishment of the Commission means the creation of a single point of authority within the regulatory system. Clearer dispute resolution mechanisms should reduce the risk of projects being delayed by regulatory misunderstanding and misalignment, and provide greater certainty and consistency. However, stakeholders should be prepared for a transitional period during which the existing multi-regulator model and the emerging Commission framework may operate in parallel. Early engagement with both ONR in its lead regulator capacity and the emerging Commission will be important to avoid things slipping through the cracks.

3. Reform of the Tolerability of Risk Framework

The Bill is expected to transfer responsibility for defining the tolerability of risk for the nuclear sector from individual regulators to the Government, and will include clarifying language regarding the legal definition of proportionality as it applies to nuclear safety regulation.⁸

What’s the difference?

Currently, individual regulators define and apply tolerability of risk through the “as low as reasonably practicable” (ALARP) principle. In practice, the Fingleton Review concluded that this arrangement had produced cautious and uneven outcomes, with regulators applying differing thresholds for acceptable risk even when addressing comparable or identical issues. The Fingleton Review noted that this was a key factor in the high costs of nuclear energy projects, and the absence of a clear, centrally defined standard of acceptable risk has meant that regulators have adopted cautious positions to avoid accusations of inadequate safety oversight.⁹

Why does it matter?

This reform has the potential to significantly reduce the cost and time currently associated with safety case preparation for nuclear projects. Revised Safety Assessment Principles from the ONR are anticipated by the end of 2026, after which developers should begin considering how their current safety case methodologies may need to be adapted. The transitional period will require careful navigation, as the existing standards will likely remain in force until the new framework is formally adopted.

Conclusion

The scale of the reform programme is ambitious, however, it is encouraging that the Government has already moved to implement interim measures, including the lead regulator model and the establishment of NRIP, whilst the detailed legislative framework is developed. It will be important for stakeholders to watch as the Bill progresses through Parliament this session.

¹https://www.gov.uk/government/speeches/the-kings-speech-2026.

²In its “Building Our Nuclear Nation” publication, in response to the Fingleton Review, the Government consolidated Fingleton’s recommendations into two core ‘objectives’. Objective 1 is concerned with ‘reinvigorating Britain’s nuclear sector’ through reform to the regulatory bodies and structures currently in place, across both civil and defence projects. Objective 2 is concerned with reform to the existing planning and environmental assessments.

³https://www.gov.uk/government/publications/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025-accessible-webpage, Objective 1, ‘Streamlining nuclear regulatory structures’.

⁴assets.publishing.service.gov.uk/media/692080f75c394e481336ab89/nuclear-regulatory-review-2025.pdf, paragraph 178 and Recommendation 4; https://nuclear.britishprogress.org/recommendation/4.

⁵assets.publishing.service.gov.uk/media/692080f75c394e481336ab89/nuclear-regulatory-review-2025.pdf, page 6.

⁶https://www.gov.uk/government/publications/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025-accessible-webpage, Objective 1, ‘Streamlining nuclear regulatory structures’.

⁷https://www.gov.uk/government/publications/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025-accessible-webpage, Commentary on Recommendation 2.

⁸https://www.gov.uk/government/publications/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025/building-our-nuclear-nation-government-response-to-the-nuclear-regulatory-review-2025-accessible-webpage, Objective 1, ‘Defining Risk’; Commentary on Recommendations 6 and 7.

⁹assets.publishing.service.gov.uk/media/692080f75c394e481336ab89/nuclear-regulatory-review-2025.pdf, page 20.

This information is provided by Vinson & Elkins LLP for educational and informational purposes only and is not intended, nor should it be construed, as legal advice.