Office for Nuclear Regulation

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Heysham 1 - Pre-Outage Inspection

Executive summary

Purpose of Intervention

Site License Condition 30 requires EDF Energy Nuclear Generation Ltd (NGL) to periodically shutdown each reactor at its nuclear power stations for the purpose of undertaking the examination, inspection, maintenance and testing of items important to safety in accordance with the requirements of the plant maintenance schedule (Site License Condition 28).

The purpose of this inspection was to provide regulatory confidence in the implementation of mechanical engineering aspects related to the overhaul of gas circulators in readiness for their exchange during the forthcoming statutory outage. The purpose was also to inform the ONR decision relating to the issue of a Licence Instrument for Consent for return to service, post outage at Heysham Reactor 2 [TRIM 2018/123449].

Interventions Carried Out by ONR

I selected the following as my sample for inspection:

Arrangements for the overhaul of three (3) gas circulators in preparation for exchange during the planned outage

My proposed inspection is described in a pre-outage inspection plan [TRIM 2017/461935].

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

I inspected the plant maintenance schedule and obtained evidence of how NGL’s arrangements are derived from its safety case requirements. I sampled the written instructions used by its operators to undertake examination, inspection, maintenance or testing and confirmed that suitably qualified and experienced personnel were undertaking those tasks. I also identified that duly authorised persons were providing appropriate supervision and control.

I observed appropriate use of foreign material exclusion covers on penetrations and openings to the gas circulators and confirmed that independent inspections were carried out during tasks to provide appropriate assurance that procedures in place to exclude foreign material were followed.

As part of my walk-down of the gas circulator maintenance facility, I observed on-going maintenance tasks and a lifting operation. I also witnessed the facility’s housekeeping arrangements, together with its arrangements to ensure that radiation and contamination were appropriately monitored and kept as low as reasonably practicable.

In my opinion, the facility’s arrangements were adequate and showed evidence of improvement.

Conclusion of Intervention

After examining the evidence sampled during my inspection, I judge that the gas circulators are appropriately refurbished and are ready for installation during the statutory outage to commence in June 2018.

It is my judgement therefore that a rating of Green was appropriate for this inspection.