Office for Nuclear Regulation

Sizewell B - RO16 Statutory Outage - Control and Instrumentation (C&I) inspection

Executive summary

Purpose of Intervention

This Intervention Record covers a Control and Instrumentation (C&I) inspection performed as part of an ONR Operating Facilities Programme (OFP) intervention applicable to EDF Nuclear Generation Ltd (EDF NGL) during the Refuelling Outage 16 (RO16) at Sizewell B (SZB) 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 in order to confirm that it remains fit for its intended purpose at SZB.

Interventions Carried Out by ONR

This inspection was undertaken in support of ONR’s 2019/20 statutory outage inspection programme. The outcome of this inspection, which included a review of progress made in various work items and projects associated with C&I equipment and systems important to safety at SZB, covered EDF NGL’s arrangements under Licence Conditions LC 22 (modification or experiment on existing plant), LC 27 (safety mechanisms, devices and circuits) and LC 28 (examination, inspection, maintenance and testing).

The intervention is intended to provide a contribution towards ONR’s regulatory decision as to whether a Consent, in accordance with LC 30 (periodic shutdown), should be issued to allow SZB to return to normal operating service.

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 Sizewell B RO16 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).

I raised two actions related to the Polar Crane, which put a hold on its use for any nuclear significant lifts. The two actions were related to the calibration of the load monitoring and protection system and the radial drive inverter. These actions are captured in the ONR regulatory issues database. In addition, I requested further information in relation to ongoing activities; this has been communicated to EDFNGL with appropriate timescales, which are not required for return to service.

Conclusion of Intervention

From the evidence gathered during this C&I-based intervention, I consider that following closure of the two actions related to the calibration of the load monitoring and protection system and the radial drive inverter on the Polar Crane, there are no significant matters that may impact on nuclear safety. I have not identified any other significant issues in relation to the C&I equipment and systems that should prevent ONR from issuing a Consent to allow SZB to restart  

On the basis of my inspection of C&I aspects of the SZB RO16 statutory outage it is recommended that, on closure of the two Polar Crane actions, support be given for a Consent to allow SZB to return to normal operating service following successful completion of the planned maintenance activities in accordance with LC30.