Office for Nuclear Regulation

Dounreay – Inspection ID: 52380

Executive summary

Date(s) of inspection:

August 2023

Aim of inspection

This inspection will sample Dounreay’s site wide arrangements for collecting information on incidents on site, categorising these incidents, investigating and reporting as appropriate to review progress in addressing Regulatory Issue 8984.

Subject(s) of inspection

  • LC 07 – Incidents on the site – Rating: AMBER

Key findings, inspector’s opinions and reasons for judgement made

I undertook an LC7 Inspection at Dounreay to review progress in addressing the findings of RI8984:

  • Ensuring that incidents were reported appropriately with regard to their potential significance.
  • Ensuring investigations were initiated at the appropriate level commensurate to the potential significance of the incident.
  • Monitoring the delay between the incident and commencement of the associated investigation.
  • Dissemination of learning from operational experience.
  • Effectiveness of learning from operational experience [repeat events]

I sampled three recent investigations, several events raised on the site UNOR system, and the management information around these systems as a whole. Overall I was satisfied that Dounreay is conducting adequate quality and timely investigations which are reaching the root causes and proposing suitable actions to prevent recurrence. However, the management information is indicating that fewer than expected events are reaching the threshold, as more site level investigations have been undertaken over the past year than local level, which is not in line with expectations for a site with effective reporting and learning culture. This was supported by the detail in the investigations and events sampled where all investigations and the majority of the events indicated missed opportunities that had been identified to prevent the event but were not followed up or failed for a variety of reasons.

On this basis, whilst I note the progress made in the timeliness and quality of investigations being undertaken, there remains shortfalls in how site is learning from its low levels events and sharing the learning across site, therefore I have rated this inspection as Amber – Seek Improvement. I have closed Regulatory Issue 8984 noting the improvements made in the investigation performance and have raised a new Regulatory Issue at Level 3 to focus on the reporting of lower level events and sharing of learning from these.


Based on the investigations sampled, I judge that Dounreay is undertaking adequate investigations in a timely manner and consider the actions in RI8984 around completing investigations are now completed. The site arrangements for LC7 are broadly adequate, but the implementation of it on site falls short of regulatory expectations as there are still significant reports of repeat incidents, the overall event reporting to the site UNOR system is low, and the number of local investigations is low in comparison to the higher significance site investigations. On this basis I rate this inspection as Amber – Seek Improvement.

Noting that this inspection was monitoring progress against an extant regulatory issue, and progress has been made in the quality of investigations, I have updated the existing Regulatory Issue (RI8984) to note the improvements and have recommended the issue for closure. However as some actions remain outstanding I have raised a new regulatory issue (11566) to refocus on these areas alongside the updated information from this inspection. The issue require improvements in the efficacy of the site event reporting arrangements with a focus on sharing of knowledge, and to review the metrics used at all management levels to track action closeout and monitor repeat events and site wide learning from operational experience.