Executive summary
Date(s) of inspection: April 2024
Aim of inspection
We intend to conduct a series of interventions focusing on Dounreay’s ability to maintain its assets in a safe manner. These interventions will be conducted over 2024-2025 and consider a number of elements of Dounreay’s asset management arrangements. The inspections will utilise the same format as previous chief nuclear inspectors themed inspections on the management of ageing assets. The purpose of the inspection is to seek assurance of sustainable programmes for management of ageing assets against:
- Effective strategies for the characterisation, monitoring, trending and analysis of ageing, at facility, system and component level are present.
- Commitment to ensure that the right level of organisational capability to sustain specialist safety case and other technical capability to substantiate on-going safe operation.
- Methods to identify and manage obsolescence in facilities for their operation design life and any potential lifetime extensions.
- Sustained focus and commitment to ongoing investment in plant, people and processes concerned with ageing management.
The first of these interventions will focus on asset management of civil structures and will consider the above points in that context.
Subject(s) of inspection
- Health & Safety at Work Act - Rating: Amber
- LC28 - Examination, inspection, maintenance and testing - Rating: Amber
Key findings, inspector's opinions and reasons for judgement made
We undertook a planned themed inspection focusing on the asset management of civil structures at Dounreay covering LC28 (Examination, Inspection, Maintenance, and Testing) and compliance with the Health and Safety at Work etc. Act 1974. The inspection was informed by previous ONR walkdowns where significant deterioration of the PFR turbine hall building structure had been observed, which resulted in RI-11283 being raised.
During the inspection we sampled Dounreay’s updated asset management strategy and value stream lifetime plans. We were content that these met the regulatory expectations detailed in the ONR Civil Engineering and Asset Management Technical Assessment Guides.
We undertook a walkdown of the PFR, DMTR, and D1208 Facilities, as well as a general walkdown of the FCA secure area. The ONR Civil Engineering specialist inspector was content that the buildings in the FCA, DMTR, and D1208 were in good condition for their age with only minor defects noted which had suitable rectification plans to address. However, we noted that the conditions in PFR SG Hall and Turbine Hall were poor with significant corrosion of the steel structure. On this basis we awarded an Inspection rating of AMBER and will issue formal Regulatory Advice to Dounreay on its regulatory duties to maintain the PFR buildings in suitable conditions.
Conclusion
The ONR civil engineering specialist judged that Dounreay’s approach to developing asset management plans for buildings and structures met expectations of RGP as the risk scores were based on a fundamentally qualitative (not quantitative) assessment.
The ONR civil specialist judged that the DMTR and D1208 buildings’ condition meets ONR expectations and that Dounreay have adequate proposals and arrangements in place to ensure future asset care.
The inspection identified significant corrosion and metal loss of structural steelwork in the PFR Turbine Hall. I consider that these matters represent a departure from relevant good practice and corrective action is required. To determine the appropriate enforcement decision, I have used the ONR enforcement management model, which for these circumstances has resulted in regulatory advice.
The ONR civil engineering specialist noted that Dounreay’s agency supplied civil engineering specialist had proposed a series of works to prevent further degradation. These were described during the inspection, and the ONR civil specialist concluded these proposals would likely meet regulatory expectations subject to their being sufficient margin left in the civil engineering structure to substantiate the building through to its ultimate demolition in line with the site Lifetime Plan.
Due to the poor condition of the steel structure of the PFR SG Hall and Turbine Hall we awarded an Inspection rating of amber and will issue formal Regulatory Advice to Dounreay on its regulatory duties to maintain the PFR buildings in suitable conditions.