Office for Nuclear Regulation

Heysham 1 - C & I Inspection

Executive summary

Purpose of Intervention

This intervention report describes our control and instrumentation (C&I) inspection that was performed as part of an ONR Operational Facilities Division (OFD) intervention applicable to EDF Energy Nuclear Generation Ltd (NGL) during the 2018 statutory outage of Reactor 2 (R2) at Heysham 1 (HYA) Power Station. The main focus of our inspection was to verify that relevant work activities have been carried out in relation to Control & Instrumentation (C&I) equipment and systems important to safety in order to confirm that they remain fit for their intended purpose at HYA.

Interventions Carried Out by ONR

Our inspection was in support of ONR’s 2018/19 statutory outage inspection programme. The outcome of our inspection, which included a review of progress made regarding various work items and projects associated with C&I equipment and systems important to safety at HYA, covered NGL’s arrangements under Licence Conditions LC22 (Modification or experiment on existing plant) and LC28 (Examination, inspection, maintenance and testing). Our inspection was 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 R2 at HYA to return to normal operating service.

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

This inspection has found that the commitments made in the HYA R2 Outage Intentions Document (OID) (TRIM 2017/446582) 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).

In general, this inspection has found the arrangements for the examination, inspection, maintenance and testing of the sampled reactor safety circuit instrumentation (Laddic modules), thermocouples (safety), Inlet Guide Vane (IGV) position calibration, Post Trip Logic (PTL) and secondary shutdown system were satisfactory. Actions raised included; NGL to review their arrangements for implementing the requirements of BEG/SPEC/ENG/027 in maintenance and test instructions for thermocouples and provide further details of PTL relay test equipment.

The OID identified that NGL was proposing to implement an Engineering Change (EC) associated with the replacement of reactor top dome differential pressure indication equipment during the outage. Prior to the inspection, NGL clarified the EC was no longer proceeding during the Outage due to plant constraints identified during the design phase. Discussions with NGL raised concerns regarding the availability and maintainability of the existing equipment due for replacement under the EC and an action was raised for NGL to inform ONR when the EC will be implemented.

During the plant walk-down we found poor house-keeping associated with the Gaseous Activity Monitor (GAM) and Make-Up Water Treatment Plant (MUWTP). It was noted that similar findings regarding the status of the GAM system and MUTWP control room equipment cubicles had been identified during previous interventions.

It was noted that the MUWTP control room appeared to be used as storage for office chairs, one of which was positioned impeding access to emergency Breathing Apparatus (BA). We requested the removal of the obstruction to allow access to the BA in an emergency.

A total of six actions were raised during the inspection, none of these actions are required to be addressed prior to return to service. All actions raised have been captured within the ONR Issues Database and will be monitored to closure as part of normal regulatory business.

Based on the findings of our inspection we have assigned an Integrated Intervention Strategy (IIS) rating of Green to LC28.

Conclusion of Intervention

From the evidence gathered during this intervention, we judge that there are no significant matters that may impact on nuclear safety. We have not identified any significant issues in relation to the C&I equipment and systems that should prevent ONR from issuing a Consent to allow R2 at HYA to restart.

On the basis of our inspection of the C&I aspects of the HYA R2 outage, we recommend that support be given for a consent to allow R2 at HYA to return to normal operating service.