Our Annual Report and Accounts for 2025/26 reflects a year of continued strong regulatory delivery, organisational development, and commitment to our new mission of ensuring safe nuclear for a secure and sustainable future.
Some of our key highlights include:
- Overseeing sustained improvements at sites subject to enhanced and significantly enhanced regulatory attention.
- Continuing our work to influence timely hazard and risk reduction at Sellafield.
- Permissioning the transfer of Hunterston B to Nuclear Restoration Services following fuel-free verification, the first Advanced Gas-Cooled Reactor to achieve this status.
- Engaging with dutyholders and the Department for Energy Security and Net Zero to ensure clear regulatory expectations to support delivery of High-Assay Low-Enriched Uranium and Nuclear Fuel Programmes.
- Working with stakeholders, particularly on application of ‘As Low As Reasonably Practicable’ (ALARP) to improve proportionality and reduce unnecessary regulatory burden.
- Delivering a funded programme of AI pilot activity, using secure sandboxing to assess the regulatory benefits and risks.
- Ensuring the UK met all of its safeguards’ obligations and effectively facilitating International Atomic Energy Agency safeguards activities in the UK.
- Completing Step 2 of the Generic Design Assessment (GDA) for two Small Modular Reactor (SMR) designs, the GE Vernova Hitachi BWRX-300 and the Holtec International SMR-300. Assessment of the Rolls-Royce SMR Ltd design also advanced, with Step 3 of its GDA progressed during the year.
During the year, we worked closely with the Nuclear Regulatory Review team and have begun implementing its recommendations through a significant programme of activity. A key recommendation from the review is the establishment of a lead regulator model as the first step towards a UK Commission for Nuclear Regulation. Work has progressed well in this area and will continue at pace this year.
The year also saw the development of our new rolling strategy, ONR Together, which sets a clear direction for ONR to become a more modern, agile and productive regulator.
We were pleased that our commitment to fostering an inclusive workplace continued to be recognised externally, with the organisation receiving re-accreditation for both Disability Confident Leader status and the National Equality Standard for the third consecutive time, demonstrating sustained progress against national diversity and inclusion benchmarks.
Dr Nicki Crauford, ONR Chair, said:
“It has been a year of leadership transition, with Mike Finnerty succeeding Mark Foy as Chief Executive and Chief Nuclear Inspector from 1 July 2025. We also welcomed two new Non-Executive Directors to our board during the year.
“The organisation has navigated this period of change effectively, maintaining strong governance and regulatory stability.
“We have maintained a stable financial position and risk profile, and continued to promote openness and transparency. We made good progress against our 2025/26 Corporate Plan, delivering the majority of our commitments in full and demonstrating a disciplined and effective approach to operations and regulation.”
Mike Finnerty, ONR Chief Executive and Chief Nuclear Inspector, said:
“We have maintained effective oversight across the nuclear estate, providing assurance to government and the public that nuclear activities meet the high standards we expect.
“As we close a successful 2025/26, we look forward to launching and embedding our new Strategy and further progressing our work to deliver the recommendations of the Nuclear Regulatory Review – supporting safe, innovative growth across the sector and contributing to a thriving national economy. Working collaboratively with government, industry and international partners, I believe we are well placed to meet the opportunities and challenges ahead.”
The ONR Annual Report and Accounts was formally laid in Parliament by the Department for Work and Pensions, ONR's government sponsorship body throughout 2025-26. Following a Machinery of Government change announced on 2 July 2026, sponsorship of ONR will transfer to the Department for Energy Security and Net Zero from 1 August 2026.
Statement by the Secretary of State for Work and Pensions, Pat McFadden
The Office for Nuclear Regulation Annual Report and Accounts 2025/26 for the year ended 31 March 2026. Laid 14 July 2026.
The Statement is presented to Parliament pursuant to Paragraph 25(3) of Schedule 7 to the Energy Act 2013. The Office for Nuclear Regulation (ONR) Annual Report and Accounts 2025/26 is being laid today. This document will also be published on the ONR website. I can confirm, in accordance with Paragraph 25(3) of Schedule 7 to the Energy Act 2013, that there have been no exclusions to the published document on the grounds of national security.