Office for Nuclear Regulation

Hunterston A – Inspection ID: 52768

Executive summary

Date(s) of inspection:

  • September 2023

Aim of inspection

The aim of the inspection is to establish if Magnox Ltd arrangements are adequately implemented to detect the onset of equipment degradation, ensuring the organisational capability to adequately manage ageing management, the identification and management of obsolescence and the ongoing investment in asset management. The inspection will be targeted at the reactor civil structure and ventilation stacks.

Subject(s) of inspection

  • LC23 – Operating rules – Rating: Green
  • LC28 – Examination, inspection, maintenance and testing – Rating: Green

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

Hunterston A does have arrangements in place to provide for a maintenance schedule for the plant building structures. Evidence of appropriate structural repairs and maintenance was observed during the inspection. The main conclusion was that the process for structural maintenance needs to recognise the importance of maintaining the weather barrier to an appropriate standard, which the arrangements do not specifically define as yet. Accordingly, a level 4 regulatory issue has been raised on this matter.


Hunterston A has arrangements to provide for maintenance to the facility structures and good maintenance and repair work to the leaking reactor and SRU hall roofs was being undertaken at the time of the inspection. We spoke to a sample of the personnel involved in producing the maintenance schedule and those undertaking the work. Based on this we judged the Compliance with LC23 and LC28 to be Green (Adequate).