Office for Nuclear Regulation

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LC22 Inspection of Modifications in SR&DP Demolitions team

Executive summary

Purpose of intervention

This inspection was undertaken on 3 December 2014 at the Sellafield Limited (SL) nuclear licensed site in Cumbria.

This inspection was added to my inspection programme to follow up on an event reported on site where a safety mechanism had been taken out of service during a demolition project for a period which exceeded the Operating Rule. My inspection focussed on the Demolitions team within the Decommissioning Division, as the initial event follow up had indicated potential issues with the categorisation of modifications authored by that team.

Interventions Carried Out by ONR

I carried out an inspection of the Licensee’s arrangements for compliance with Licence Condition 22 in the Decommissioning Division. LC22 requires the licensee to make and implement adequate arrangements to control any modifications or experiment carried out on any part of the existing plant or process which may affect safety.

This inspection was carried out against the requirements of LC22 and ONR’s inspection guidance as defined in NS-INSP-GD-022. The inspection was carried out through office-based examination of procedures and records and interviews with staff. The intervention was undertaken by the Site Inspector supported by an ONR Human Factors specialist inspector.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A – This was not a Systems Based Inspection.

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

SL presented an overview of the two processes it uses to control modifications to plants; these are the:

Both of these procedures use the same categorisation criteria, which ranges from Cat. D (lowest safety significance) to Cat. A (highest safety significance). The DWCP is a less onerous process than the PMP process, and is only used for lesser safety significant decommissioning/demolition work.

The modification related to the reported event was carried out using the PMP process. Following an internal review, the Demolitions team concluded that they had complied with the process sequence, but that the scope of the PMP was beyond the normal work scope for demolition tasks. The Demolitions team is taking steps to clarify scopes and responsibilities for the drafting of PMPs and isolation of plants prior to demolition works. This will ensure that only suitable persons with appropriate knowledge plan and carry out these tasks in future, and that sufficient time is available to ensure that substitution arrangements are fully in place before works commence. I was satisfied that these actions proposed will be adequate to address the issues which were identified as contributory factors to the event.  

I was satisfied that the arrangements shown for both modification routes broadly meet the requirements of LC22 and ONR’s expectations defined in the inspection guidance. However a number of shortfalls were identified in the DWCP process.  The most significant of these was the absence of a requirement for the modification originators to have been trained in categorisation of modifications. The licensee agreed to address this by making it a requirement of the process.

Conclusion of Intervention

Due to the gaps identified in SL’s arrangements I judged the licensee’s compliance with LC22 to be Below Standard (i.e. an IIS Rating of 4). Although the fundamental requirements were met, some specific procedural weaknesses were identified. I am satisfied that the actions agreed by the licensee will be adequate to address these shortfalls and these do not represent an immediate safety concern. These actions will be followed up the ONR site inspector as part of routine regulatory interactions using the ONR Regulatory Issues management arrangements. No further follow up inspection is considered necessary as a result of this inspection.