Office for Nuclear Regulation

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DRDL - Planned Inspection

Executive summary

Purpose of Intervention

This intervention at the Devonport Royal Dockyard licensed site was undertaken in order to conduct licence condition (LC) compliance inspections, as scheduled in the Devonport Royal Dockyard Limited (DRDL) integrated intervention strategy.

Interventions Carried Out by ONR

This inspection examined the adequacy of DRDL’s arrangements and subsequent implementation for LC23 operating rules (ORs) and LC24 operating instructions.  The inspections were focussed on DRDL’s 9 Dock and the Low Level Refuel Facility (LLRF).

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

The LC23 compliance inspection examined the implementation of DRDL’s LC23 arrangements to inform progress against an extant regulatory issue.  ONR found personnel did understand the importance of conditions and limits, however, lack of clarity in the wording / information in some of the ORs sampled does not adequately facilitate implementation and compliance.  The inspection identified a number of shortfalls against regulatory expectations.

There are currently no LLRF ORs / Identified Operating Instructions (IOIs) that impose formal conditions and limits on the configuration of fuel and its subsequent handling.  This represents a shortfall against regulatory expectations but DRDL had implemented appropriate administrative controls to manage criticality risk with linkage to LLRF ‘safety case assumptions’.

ONR identified that DRDL requires more robust validation and verification processes for modified ORs / IOIs because of the following findings.

During normal operations it would be difficult for DRDL to comply with a recently modified LLRF IOI.  DRDL committed to modify this IOI prior to the receipt of used fuel.  ONR noted the IOI had undergone local review and had not been progressed via the Nuclear Operations Improvement Programme (NOIP).

The wording of a recently modified 9 Dock IOI, which had also not progressed through NOIP, was considered to be ambiguous and it was not immediately clear whether there had been a shortfall in compliance.  It was subsequently confirmed that operations were in compliance with this IOI.

Whilst surveillances confirming OR / IOI compliance were being completed regularly, in some cases, it was not possible to establish clear linkages between surveillance periodicity and safety case requirements.

An example was identified where no written instructions, to define how a component of an IOI should be complied with, were available. The local arrangements appeared adequate and this was subsequently confirmed via discussion with safety case authors.  DRDL agreed to update operating instruction to capture these arrangements.

Conclusion of Intervention

LC23 was rated  ‘AMBER’ and a new Level 4 regulatory issue has been raised to monitor close out of DRDL’s specific commitments to review and update LLRF ORs / IOIs and associated operating instructions, prior to the receipt of used fuel into the facility.  The delivery of wider improvements to facilitate sustained LC23 compliance will continue to be monitored via the extant regulatory issue on this topic.

LC24 was rated as ‘GREEN’ as generally ONR found that DRDL broadly meets the regulatory expectations set out in technical inspection guidance (NS-INSP-GD-023) within the area sampled.  However, there are a number of extant regulatory issues associated with observed shortfalls in operating instructions in other areas and DRDL identifies LC24 an area where improvement is required within its Nuclear Safety Improvement Programme (NSIP).  ONR welcomed DRDL’s commitment to develop corporate LC24 guidance which seeks to improve the quality and consistency of operating instructions across the site.  Progress will again be monitored via the extant regulatory issues on this topic.

No findings from this intervention were found which were judged to be of such regulatory concern as to require immediate action.  The extant regulatory issues associated with LC23 and LC24 remain open to resolve shortfalls in compliance.