Office for Nuclear Regulation

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Calder Hall on Sellafield Ltd.’s nuclear licensed site, in Cumbria to Conduct an LC17 Compliance Inspection

Executive summary

Purpose of intervention

This intervention was undertaken on 12 January 2016 on Sellafield Limited’s (SL) nuclear licensed site at Sellafield in Cumbria, and focussed on Calder Hall reactor 4 which has recently completed defueling.  Consistent with ONR’s regulation of Magnox reactors, Calder Hall reactor 4 was selected for this intervention in order to conduct fuel free verification inspections at defueled reactors following the licensee declaring the reactor(s) fuel free.  A quality verification process is an essential element in the licensee’s case to support this declaration.

Inspection of Licence Condition (LC) compliance at nuclear licensed sites forms a significant part of ONR’s activities.  ONR’s Sellafield Programme has defined a programme of safety system inspections and LC compliance inspections to be undertaken on the Sellafield site and this is a key aspect of ONR’s regulatory strategy for the Sellafield site.  Undertaking this planned intervention is consistent with this strategy and is identified on ONR’s PP4 inspection plan the scope of which covers SL’s defueling operations at Calder Hall. 

Interventions Carried Out by ONR

LC 17(2) requires the licensee to make and implement adequate quality management arrangements within its management systems in respect of all matters which may affect safety.  I carried out an inspection against LC 17(2) to determine the adequacy of the licensee's quality management arrangements for the verification of defueling.

I carried out the LC17 compliance inspection in accordance with the following ONR guidance:

This inspection was undertaken jointly by a Nuclear Safety Inspector and a Civil Nuclear Security inspector.  We undertook the inspection over one day, comprising a number of discussion sessions with the licensee’s employees, examination of relevant documents and a plant walk down.

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A.  This was not a safety system inspection.

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

I reviewed the verification process documentation and consider that it clearly describes a process that will provide confidence, on its completion, that the reactor buildings are free of fuel and significant fuel fragments.

I discussed the work activities involved with operational personnel and consider that they have a good understanding of the arrangements in place and their importance.

I saw evidence of completed verification activities both in-core and out-of-core.  I consider that the licensee is able to demonstrate that its arrangements are being adequately implemented.

Conclusion of Intervention

On balance, I judge an IIS rating of 3 (adequate) to be appropriate against LC17 in the areas inspected. 

Based on the evidence gathered, no significant matters have been identified that are likely to impact on nuclear safety on the Sellafield site at this time.