Office for Nuclear Regulation

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ONR readiness inspection for Sellafield Ltd to commence modification, active commissioning and operation of the Plutonium Management Facility - North Fan 6 and 7 Contingency Project

Executive summary

Purpose of Intervention

On the 10 May 2017 the Office for Nuclear Regulation (ONR) undertook an intervention on the Sellafield site to inspect Sellafield Ltd’s (SL) readiness to commence modification, active commissioning and operation of the Plutonium Management Facility – North (PMF(N)) Fan 6 and 7 Contingency Project.

The PMF(N) complex includes legacy plant areas that have high levels of loose contamination in some of the radiologically designated zones. The building duty and standby ventilation extract system (i.e. Fans 6 and 7) perform a principal role in preventing the spread of contamination from these areas to normal access and external areas. The extract system infrastructure is suffering from degradation and obsolescence issues, so SL intends to replace and upgrade key components of the system.  

The purpose of the intervention was to inspect SL’s implementation of its Licence Condition (LC) 22 arrangements for this project and gain assurance that for the proposed modification, SL is in a state of readiness to safely commence its implementation. The findings of the intervention will be used to inform the regulatory decision on SL’s request for ONR’s agreement to commence the modification.     

Interventions Carried Out by ONR

The scope of this intervention was to inspect PMF(N) from a plant, processes and people perspective and assess the licensee’s readiness to safely commence the proposed modification. The readiness inspection was undertaken against LC 22 ‘Modification or experiment on existing plant’, which requires the licensee to make and implement adequate arrangements to control any modification or experiment carried out on any part of the existing plant or processes which may affect safety.   

The inspection comprised desktop-based discussions and facility inspection. It was undertaken against LC 22 in accordance with ONR guidance Technical Inspection Guide (TIG) NS-INSP-GD-022, LC22: Modification or experiment on existing plant, Revision 3, December 2014.

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 22 arrangements as Green. With respect to ONR’s TIG NS-INSP-GD-022, SL adequately demonstrated:

In relation to SL’s overall state of readiness to commence the proposed modification, it needs to complete its specified programme of work, which SL acknowledged. As a result, sufficient evidence was unavailable at the time of this intervention on certain aspects that we judge relevant to the permissioning decision. These including confirmation of SL’s quality control of critical spares, implementation of all emergency instructions, adequate assessment of training requirements and competency assurance.

Conclusion of Intervention

Based on our findings from the available evidence, we judge that SL’s implementation of its LC22 arrangements related to the Plant Modification Proposal process is adequate in this instance. From the evidence sampled, no shortfalls were identified that would prevent permission being granted for SL to commence the modification. However, we identified a number of actions that SL still has to provide evidence against to inform ONR’s permissioning decision. These relate to the provision of operational safety documentation and evidence supporting SL’s proposal as identified in the section above.