Continued work is needed by the nuclear industry to ensure sites remain resilient against the future effects of climate change in the medium and long-term, the Chief Nuclear Inspector’s Themed Inspection on climate change has revealed.
But progress made by the nuclear sector to ensure climate change effects are understood and mitigated against is noted, with no fundamental shortfalls identified that challenge their robustness against future external hazards.
The Chief Nuclear Inspector’s (CNI) Themed Inspection report on climate change, from the Office for Nuclear Regulation (ONR), has been published today which concludes a two year targeted regulatory focus on the topic.
The 52 page report examines how the nuclear sector is responding to recent climate change projections and implementing appropriate safeguards.
The themed inspection was conducted in three phases:
- Initial self-assessment questionnaires - completed by 14 dutyholders for 32 sites - providing information on their climate change resilience arrangements;
- Five targeted site-based inspections at representative facilities across the UK, including Heysham 2 in Lancashire, Sizewell B in Suffolk, Sellafield in Cumbria, Dounreay in Caithness, Scotland, and AWE Plc Aldermaston in Berkshire; and
- Development of a detailed summary report identifying key findings and future regulatory priorities.
The self-assessments revealed the majority of dutyholders incorporate climate change in safety case external hazards definitions, primarily focusing on high air temperature and external flooding.
While the majority of dutyholders use modelling software to understand potential future scenarios and are actively incorporating recent climate data, further work is needed to ensure all potentially affected external hazards include climate change considerations in safety case definitions.
The five site-based inspections assessed how nuclear sites are preparing for climate change impacts and building operational resilience.
The results showed that AWE Aldermaston met ONR's expectations for climate resilience, while Dounreay, Heysham 2, Sellafield and Sizewell B partially met expectations.
Following the self-assessment and site-based inspections, the themed inspection team identified seven key areas requiring attention.
The seven key themes are:
- Review and monitoring of data, risks and trends;
- Update and implementation of dutyholders’ guidance, external hazards analysis and safety cases, including periodicity;
- Periodic safety review frequency, scope and effectiveness;
- Ownership, responsibilities and arrangements in relation to climate change;
- Plant improvements and mitigation measures, including use of the managed adaptive approach;
- Risk informed approach to understanding the potential effects and consequences of climate change on plant; and
- Future regulatory activities in relation to climate change.
(Themes 1-6 are industry focused and Theme 7 is an internal theme for ONR to consider.)
ONR’s inspections also found there are inconsistencies in how nuclear site operators manage climate change risks. While some sites have adopted good practices – such as establishing operational temperature thresholds and designing adaptable infrastructure – these approaches aren't universal.
Implementation of safety modifications often faces delays despite identification in periodic reviews. The integration of climate change "trigger points" into safety cases remains limited, indicating underdeveloped long-term resilience strategies.
These gaps create uncertainty about risk management effectiveness across the industry, potentially affecting long-term safety and operational continuity.
During the next two years, ONR will conduct follow-up regulatory activities at Dounreay, Heysham 2, Sellafield and Sizewell B to monitor progress on these issues and ensure updated climate information is further incorporated into hazard definitions and safety cases.
Mark Foy, ONR’s outgoing Chief Executive and Chief Nuclear Inspector, said: “This themed inspection was commissioned in response to scientific evidence that the UK climate may be changing at a faster rate than anticipated.
“As regulators, we consider climate change challenges a vital area of focus for the entire sector. Therefore, the themed inspection was a key element of our wider strategy of influencing improvements against our regulatory priorities.
"We found that industry is making progress and we didn't identify fundamental shortfalls in current robustness against external hazards. However, there is still work required by dutyholders to implement adequate arrangements ensuring sites remain resilient against future climate change effects in the medium and long-term."
ONR has formally outlined these findings and its expectations to the nuclear industry and will continue targeted regulatory activities, working with industry to ensure this is done efficiently and effectively.
ONR has worked collaboratively with environment agencies, key industry stakeholders and international parties throughout the themed inspection process, maximising shared learning and identifying opportunities for enhanced cooperation.
Mike Finnerty, ONR’s new Chief Executive and Chief Nuclear Inspector added: "Working with a diverse range of national and international partners across the industry has been invaluable in sharing learning and good practices - a primary objective of this themed inspection.
"We are committed to regularly reviewing our regulation of external hazards to incorporate the latest understanding of climate change impacts.
"Our proactive engagement with the nuclear industry ensures operators remain aware of, and respond to, current climate change projections in both their safety cases and physical measures at nuclear licensed sites.
"We have also extensively consulted with new build sites about climate change effects during design assessment, licensing and construction phases. This forward-looking approach is essential, as these facilities will operate during periods when climate change impacts are likely to become more pronounced.
ONR is particularly grateful to the environment agencies who supported the inspection phase and whose valuable insights are incorporated into this summary report."
Andy Mayall, New and Operational Nuclear Sites Manager for the Environment Agency, said: “Adaptation and resilience to climate change is crucial for our energy security, achieving net zero and nuclear and environmental safety.
“We welcome the Chief Nuclear Inspector’s themed inspection and the opportunity to work jointly on this priority area. We gained greater insight into how nuclear operators are managing climate change effects and risks as well as identifying learning for industry and regulators alike.”
CNI themed inspections were introduced in 2017 and are designed to examine regulatory matters that are strategic or broader in nature than ONR’s more routine regulatory inspection activities.
They also raise awareness of important issues and highlight ONR’s regulatory activities and expectations to a wider audience, in addition to the nuclear industry.