Office for Nuclear Regulation

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ONR Readiness Inspection for Sellafield Ltd Commence Active Commissioning of the Dounreay Exotic Storage Facility

Executive summary

Purpose of intervention

On the 21 July 2016 the Office for Nuclear Regulation (ONR) undertook an intervention on the Sellafield site to inspect Sellafield Ltd's (SL) readiness to commence active commissioning and operation of the Dounreay Exotics Storage Facility (DESF). The purpose of the intervention was to inspect SL's implementation of its Licence Condition (LC) 21 arrangements for commissioning and gain assurance that DESF is in a state of readiness to safely commence active commissioning and operation.

The findings of the intervention will be used to inform the regulatory hold point on introducing active material into the DESF and will facilitate the export of Dounreay Sites Restoration Limited (DSRL) special nuclear material to Sellafield for safe interim storage, pending the development and availability of a future conditioning capability.

Interventions Carried Out by ONR

The primary focus of this intervention was to inspect the DESF's plant, processes and people to assess its readiness to safely commence active commissioning and operation. The readiness inspection was undertaken against LC 21 'Commissioning', which requires the licensee to make and implement adequate arrangements for the commissioning of any plant or process which may affect safety.

The inspection comprised desktop-based discussions and facility inspection and was undertaken against LC 21 in accordance with ONR guidance Technical Inspection Guide (TIG) NS-INSP-GD-021, LC21: Commissioning, Revision 4, March 2016.

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

Based on the evidence sampled during this intervention, we have judged SL's implementation of its LC 21 arrangements as Green. With respect to ONR's TIG NS-INSP-GD-021, SL demonstrated that:

Conclusion of Intervention

Based on our findings, we judge that SL's implementation of its LC21 commissioning arrangements is adequate. Based on the evidence sampled, no shortfalls were identified that would prevent permission being granted for SL to commence active commissioning and operation of the DESF.

In relation to SL's state of readiness for the proposed activity, SL needs to complete its specified programme of work, which SL acknowledged. As a result of the intervention, we identified a number of actions that SL will have to provide evidence of completion to inform ONR's permissioning decision and this relates to validation of safety case assumptions, handling out-of-specification material and the non-delivery of maintenance.