Twelve nuclear organisations and ONR send joint reply to Chancellor's call for culture reform

Twelve nuclear organisations, from Sizewell C Limited to Sellafield Limited and BAE Systems Submarines, have joined the Office for Nuclear Regulation (ONR) in a single reply to the Chancellor's call for a sector-wide change in culture.

The joint letter was sent on 12 November 2026 on behalf of the newly formed Nuclear Industry CEO Forum, the Nuclear Industry Association (NIA) said. According to the NIA, it is the first time industry and regulators have responded collectively to the Chancellor's call for reform.

The Chancellor's letter, issued in response to the Nuclear Regulatory Review 2025, asked regulators and industry leaders to treat organisational culture as a strategic priority. It asked them to report back on how they were dealing with excessive risk aversion, proceduralism and a reluctance to challenge established ways of working, the NIA said.

Mike Finnerty, ONR's Chief Executive and Chief Nuclear Inspector, said: "This forum gives us a shared platform to learn from each other, build confidence in new ways of working, and hold ourselves collectively accountable for the pace and scale of change, while maintaining a safe and secure industry."

Who signed

ONR's own page names the co-signatories as AWE Nuclear Security Technologies, Babcock International Group including Cavendish Nuclear, BAE Systems Submarines, Great British Energy - Nuclear, NNB Genco (HPC), the Nuclear Decommissioning Authority and Nuclear Restoration Services.

The remaining co-signatories are Rolls Royce SMR, Rolls Royce Submarines, Sellafield Limited, Sizewell C Limited and UK National Nuclear Laboratory, making 12 organisations in total alongside ONR.

ONR said the letter is addressed to John Healey MP as Chancellor of the Exchequer and signed by Michael Finnerty on behalf of the UK Nuclear Industry CEO Forum.

What the forum says

In its reply, the forum warned that without urgent, system-wide reform "the UK risks an energy security gap, diminished defence capability, escalating costs and the loss of a once-in-a-generation economic opportunity", according to the NIA.

The forum listed changes it said were already under way. These include moving from resource-intensive periodic reviews to continuous assurance, applying digital technologies and artificial intelligence to decision-making, streamlining engineering and safety processes to remove duplication, and strengthening early collaboration between industry and regulators.

The forum, led by ONR, will develop and share case studies of culture change, capture lessons learned and build confidence in new ways of working, the NIA said. Leaders said they would hold themselves personally accountable for the transformation.

How the sector got here

The Nuclear Regulatory Taskforce, an independent expert group commissioned by the Prime Minister, published its final report on 24 November 2025 with 47 recommendations. Its summary said the UK had become the most expensive place in the world to build nuclear projects and found "a deeply ingrained culture of complacency and extreme risk aversion across the sector".

The taskforce said a single project could face multiple regulators, as many as eight in defence, with no designated lead. It estimated savings of tens of billions of pounds from the £150bn projected cost of decommissioning legacy nuclear activities.

The government's response, Building Our Nuclear Nation, said the Chancellor accepted the principle of all 47 recommendations and committed to implementing everything by the end of 2027, subject to legislative timelines. It noted that Britain built 21 nuclear reactors in just under a decade in the late 1950s and 1960s but has not completed a commercial nuclear reactor since Sizewell B in 1995.

The Chancellor's open letter on culture was published on GOV.UK on 13 March 2026 and signed by Rachel Reeves as Chancellor of the Exchequer. It asked recipients to respond within six months and to name their organisation's Senior Responsible Owner for the change programme.

The letter cited the taskforce's finding that risk aversion, process over outcome and misaligned incentives drive high cost and delay. It said regulators can overreach, leading to gold plating, and that companies do not challenge that overreach often enough. "Delay is not a neutral outcome; it carries its own risks," the Chancellor wrote. The letter also confirmed the government is merging the Defence Nuclear Safety Regulator with ONR.

ONR's own reforms

ONR's individual reply, published in September 2026, set out an Industry CEO Forum bringing together senior leaders from government, industry and regulation, and the creation of a Lead Nuclear Regulator Group to improve coordination between regulators.

ONR said resource deployment on the two most recent two-step Generic Design Assessments, for the GE Vernova Hitachi BWRX-300 and Holtec SMR-300, was cut by more than 35% while keeping the same scope and level of regulatory rigour. Its new rolling strategy is called ONR Together.

The government has committed to implementing the taskforce's measures by December 2027.