Office for Nuclear Regulation

Hunterston B Power Station - Reactor 3 Periodic Shutdown - Inspection of Electrical Related Aspects

Executive summary

Purpose of intervention

This report covers the nuclear safety related inspection of Hunterston B power station, undertaken as part of a series of planned interventions of the Reactor 3 (R3) periodic shutdown.

Interventions Carried Out by ONR

The inspection considered the electrical work being undertaken as part of the R3 periodic shutdown, including the planned work from the outage intentions document (OID) and any emergent work in this area.

This intervention was an information exchange inspection assessing the licensee’s progress in the implementation of Licence Conditions (LCs) 28 arrangements for R3 electrical outage activities. 

Explanation of Judgement if Safety System Not Judged to be Adequate

The current inspection was not a safety system inspection, and therefore this section is not applicable.

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

An inspection of R3 outage related electrical activities was carried out as part of the programme of outage related safety inspections included on the Hunterston B site intervention plan for 2015/16 to confirm that the planned examination, maintenance, inspection, test  and modification activities, are undertaken during the outage period.

During the course of the inspection it was found that station is maintaining its electrical plant and equipment in accordance with its arrangements, on the basis of the areas sampled by the inspection. 

In summary, the overall outcome from the safety inspection of the outage related electrical activities of R3 are that the implementation of the LC 28 arrangements for the electrical equipment is deemed to be adequate and an inspection rating of 3 was awarded to these activities. 

Conclusion of Intervention

From the information gathered and evidence obtained during this intervention, no matters have been identified that are likely to have a significant impact on nuclear safety on the station at this time.  Therefore, I consider that no additional regulatory action arising from this visit is necessary currently. The outcome from the inspection has been captured within the station event and action tracking arrangements as necessary, and in the ONR issues database as appropriate.

The overall outcome from the inspection is that no electrical issues have been identified from this work that should affect the return to service of Reactor 3, on completion of the planned and emergent work.


I recommend that actions resulting from this intervention and listed in this report should be monitored during future electrical inspections, with their resolution recorded in subsequent intervention reports for Hunterston B power station.