Office for Nuclear Regulation

Hunterston B Power Station – Reactor 3 Statutory Outage 2015 – Control and Instrumentation Inspection

Executive summary

Purpose of intervention

This Intervention Report covers a Control and Instrumentation (C&I) inspection performed as a part of an ONR Civil Nuclear Reactor Programme (CNRP) intervention applicable to EDF Energy Nuclear Generation Ltd (EDFNGL) during the Reactor 34 (R3) 2015 Statutory Outage (LC30) at Hunterston B (HNB) Power Station. The main focus of this inspection was to verify that relevant work activities have been carried out in relation to C&I equipment and systems important to safety at R3 in order to confirm that it remains fit for its intended purpose at HNB. This is intended to provide a contribution towards ONR’s regulatory decision as to whether a Consent in accordance with LC30 (Periodic Shutdown) should be issued to allow R3 to return to normal operating service.

Interventions Carried Out by ONR

This inspection was made in support of ONR’s R3 2015 Statutory Outage inspection programme. The subject of this inspection included a review of progress made in various work items and projects associated with C&I equipment and systems important to safety at R3. It covered EDFNGL’s arrangements under Licence Conditions 22 (Modification or experiment on existing plant), 27 (Safety mechanisms, devices and circuits) and 28 (Examination, inspection, maintenance and testing).

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

 My inspection found that the commitments made in the Hunterston B R3 Outage Intentions Document for C&I equipment and systems important to nuclear safety have been satisfied for those elements of work complete at the time of the inspection. My inspection of the work activities covered during this intervention has generally found that the workmanship applied was adequate and consistent with the standards expected from C&I suitably qualified and experienced persons (SQEP).

Two actions have been raised during the inspection, as identified within this record, to provide further information from tests that have yet to be conducted. Neither of these actions will have an impact on return to service as the significance of this information is mainly associated with trends in respect of equipment reliability.

Conclusion of Intervention

From the evidence gathered during this intervention, I judge there are no significant matters that may impact on nuclear safety. The assessment covered by this report has not identified any significant issues in relation to the C&I equipment and systems that should prevent ONR from issuing a Consent to allow R3 to restart.

On the basis of my inspections of C&I aspects of the HNB R3 2015 statutory outage it is recommended that support be given for a Consent to allow R3 to return to normal operating service.