Office for Nuclear Regulation

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Assessment of Quality Investigations and Operational Experience Feedback Processes

Executive summary

Purpose of intervention

This intervention was part of a series of interventions across Magnox Limited on the topic of organisational learning.  The purpose of the intervention was to assess the quality of event investigations and operational experience feedback processes at Hunterston A.

Interventions Carried Out by ONR

The intervention comprised observation of aspects of Hunterston A’s operational experience processes (eg the monthly event review team meeting), a site walkdown, interviews with event investigators and those with key responsibilities in the operational experience system, and meetings with the independent site inspector and safety representatives.

The intervention was carried out by two organisational capability specialist inspectors and a non-nuclear health and safety inspector.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

We found that event investigations carried out at Hunterston A did not adequately identify the root causes of events, in particular human factors, and therefore that the actions may not be sufficient to prevent a recurrence.  This was indicated by an incidence of similar events at the site, eg relating to lifting operations and contamination of non-radiological waste streams, and the failure of the sampled investigations (including a root cause investigation) to pursue all reasonable lines of enquiry.  I have raised a regulatory issue with Hunterston A to elevate the standard of its investigations to that expected by ONR (Technical Inspection Guide 7), also reflected in Magnox corporate standards which the site is in the process of implementing.  I have also raised a regulatory issue with the Magnox corporate centre to consider how it can increase its support to ensure implementation of robust event investigation processes across the Magnox fleet.

In the course of our inspection we were told that Hunterston A (as part of a Magnox wide initiative) has implemented a reduction of 25% in its agency and contract supplied workforce.  We were advised that this affects some nuclear baseline positions and other personnel which support nuclear baseline positions.  Hunterston A has not implemented a management of change process for these changes but plans to do so if and when a vacancy in a baseline post arises.  The Hunterston A site inspector plans to follow up this matter as part of a forthcoming Licence Condition 36 (organisational capability) inspection. I have also drawn the matter to the attention of the ONR corporate inspector responsible for Magnox. 

Our intervention identified a number of good practices at Hunterston A in the area of operational experience feedback, including:

We also advised the site of a number of opportunities for improvement including:

Conclusion of Intervention

The Hunterston A site is in the process of aligning itself to Magnox corporate arrangements for operational experience feedback.  However there is currently a shortfall in the standard of its event investigations in terms of identification of root causes, in particular human factors, when viewed against ONR expectations.  To address this matter I have raised regulatory issues, firstly with the site (to improve the standard of its investigations to the expected level within 12 months), and secondly with the Magnox corporate centre (to consider the additional support it can provide to improve event investigations across the fleet).