Office for Nuclear Regulation

LC 28 Inspection of Electrical related aspects

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake a Licence Condition (LC) 28 compliance inspection at EdF Energy Nuclear Generation Limited (NGL) Dungeness B, in line with the inspection programme contained in the Dungeness B Integrated Intervention Strategy (IIS) for 2018/19. The main focus of this inspection was to sample work activities carried out in relation to electrical engineering aspects of the 2018 statutory outage of Reactor 22 at Dungeness B power station in order to confirm that they are appropriate and remain fit for their intended purpose.

Interventions Carried Out by ONR

ONR undertook a planned inspection and assessment of the implementation of the arrangements for LC 28 Examination, Inspection, Maintenance and Testing (EIMT) at Dungeness B Power Station.

The inspection sample targeted the planned electrical work being undertaken as part of the Reactor 22 2018 periodic shutdown, including the planned electrical EIMT activities from the station’s outage intentions document, the implementation of the detailed modifications and any reactive electrical work emergent from the shutdown. Our inspection contributes towards ONR’s regulatory decision to grant Consent, to the return of Reactor 22 at Dungeness B to normal operating service, in accordance with LC30 (Periodic shutdown).

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

Based on the discussions, explanations and the sample inspected, on this occasion, I was satisfied that there were no significant shortfalls identified with the implementation of the established arrangements for LC 28 EIMT in relation to the planned electrical work undertaken as part of the Reactor 22 2018 periodic shutdown. The targeted inspection undertaken confirmed that the planned EIMT and modification activities during this shutdown were appropriate and that electrical plant and equipment that was being maintained and modified was in accordance with the established arrangements.

The inspection, however, identified an area for potential improvement in the area of conventional safety, and although the risk of personal injury was considered to be minor, station has agreed to take action to address it. Notwithstanding the finding, overall, the outcome from the safety inspection of the shutdown related electrical activities for the Reactor 22 2018 periodic shutdown was that the implementation of the LC 28 arrangements for the electrical equipment was found to be adequate; therefore a green inspection rating, no formal action, was awarded.

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

Conclusion of Intervention

From the sample inspected, it is judged that for the electrical work activities undertaken at Dungeness B during the Reactor 22 2018 periodic shutdown, compliance against LC28 met the required standard, therefore a ‘Green’ rating was given.

Based on these targeted interventions there were no issues identified from the electrical work activities which would prevent ONR granting Consent for Reactor 22 to return to service. This is subject to the completion of the planned EIMT activities, the implementation of the detailed modifications and the completion of emergent electrical work.

From the evidence gathered during these interventions, there were no matters identified that have the potential to impact significantly on nuclear safety.