Office for Nuclear Regulation

This website uses non-intrusive cookies to improve your user experience. You can visit our cookie privacy page for more information.

Mechanical Inspection of Hunterston B R4 2014 Statutory Outage

Executive summary

Purpose of intervention

This report records the findings of my intervention visit to Hunterston B Power Station during the 2014 Reactor 4 Periodic Shutdown. The intervention was undertaken to confirm the adequacy of the work conducted by the Licensee to comply with the requirements of Licence Conditions 22 modification of existing plant and 28, examination, inspection, maintenance and testing.

Interventions Carried Out by ONR

I undertook on-site meetings and plant inspections with relevant staff from EDF Nuclear Generation (NGL) and its contractors to determine the adequacy of the work being undertaken on Reactor 4 in complying with the requirements of Licence Condition 22 and 28. The activities examined were selected due to their significance to nuclear safety, with due consideration being given to any fleet wide interventions and included:

The inspection was supported by visits to the following areas:

The licence conditions were inspected against ONR's published guidance requirements (as described in our technical inspection guides).

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

Based on the sampling of the above areas, undertaken as part of my inspection I am satisfied that from a mechanical engineering perspective, modifications carried out on existing plant under Licence Condition 22 arrangements appear adequate and inline with my expectations.

The arrangements for testing of the Emergency Boiler Feed Pump (EBFP) in line with Licence Condition 28 also appear to be adequate and whist I commented on the level of detail recorded on paperwork associated with the testing of the EBFP I do not consider this significant. Further more I am satisfied that my feedback back to the Steam and Rotating Plant Group Head (SRPGH) is sufficient to secure improvement in this area.

Conclusion of Intervention

Based on my intervention, I conclude that the licensee has performed the work to an adequate standard. I judge that the following Integrated Intervention Strategy (IIS) ratings are appropriate:

From a mechanical engineering perspective, I found no significant issues during my inspection and therefore support the return to operation of Hunterston Reactor 4.