Office for Nuclear Regulation

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Safety system based inspection on ventilation systems and package handling equipment in PMF (N) Store 9 and Store 9 Extension on Sellafield Ltd.’s nuclear licensed site at Sellafield, Cumbria

Executive summary

Purpose of intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with the Sellafield site licensee (Sellafield Limited, SL) against a strategy defined by the ONR Sellafield Programme.

In accordance with that strategy, a Licence Condition (LC) compliance inspection of the Highly Active Liquor, Evaporation and Storage Operating Unit (HALES OU) was carried out as planned in December 2015. 

The purpose of this inspection was for the ONR to confirm the adequacy of implementation of the licensee’s formal arrangements for compliance with LC 28 (Examination, maintenance, inspection and testing). This facility was identified for this inspection due to the hazardous nature of the highly active liquors that the facility stores and processes.

Interventions Carried Out by ONR

On 10 December 2015, I carried out a one-day, on-site LC28 compliance inspection of the HALES OU.  The inspection comprised discussions with SL staff and reviews of plant records and other documentation.

LC28 requires SL to make and implement adequate arrangements for the regular systematic examination, inspection, maintenance and testing of all plant that may affect safety.

As part of the preparation for delivery of this intervention, the following formal ONR guidance documentation was used:

The inspection was used to inform a parallel inspection on the adequacy of the wider site arrangements for LC28.  This parallel inspection is reported separately in report ONR-SEL-IR-15-067.

Explanation of Judgement if Safety System Not Judged to be Adequate

This was not a system based inspection, and therefore no judgement has been made of the adequacy of implementation of any part of the safety case.

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

During my inspection, I sampled recent improvements to the maintenance capability and capacity of HALES OU, where historical shortfalls had resulted in a significant increase in maintenance backlog.  I also sampled implementation of the relevant processes for the delivery of asset condition assessment and management.

I judged that, on the evidence sampled, the licensee has adequately implemented those processes that ensure that the system health is monitored effectively.  Furthermore, I also consider that the licensee has established changes in the organisation and management of maintenance teams within the OU that have begun to address their historical issues in maintenance delivery; they will however, need to sustain this initial performance improvement for some time before ONR can be confident that the changes have fully addressed the shortfalls.

From the evidence gathered, I judged that the licensee has re-established a flexible maintenance capability that can both deliver the planned maintenance burden, as well as responding adequately to the demand of emergent defects on the plant.  Therefore, it is my opinion that an IIS rating of 3 (Adequate) is merited for the implementation of the licensee’s arrangements for compliance with Licence Condition 28.

Within this inspection, I have made a small number of regulatory observations, all of which have been accepted by the licensee, and which are summarised within this Intervention Record.  Additionally, I have identified what improvements could attract a higher IIS rating at a future LC28 compliance inspection, or equivalent related intervention.

Conclusion of Intervention

From the evidence sampled during these inspections, I judge that there was sufficient evidence that the formal arrangements for Licence Conditions 28 are being implemented adequately.