Office for Nuclear Regulation

Dungeness B – Inspection ID: 22-010

  • Site: Dungeness B
  • IR number: 22-010
  • Date: April 2022
  • LC numbers: 28

Executive summary

Purpose of Intervention

The purpose of this inspection was to undertake an electrical engineering licence condition (LC) 28 compliance inspection at EDF Energy Nuclear Generation Limited (NGL) Dungeness B power station, in line with the inspection programme contained in the Dungeness B integrated intervention strategy (IIS) for 2022/23.

The inspection was carried out by an electrical specialist inspector with support from a nuclear associate. For the purposes of this report, the term “we” refers to the judgements and opinions formed by the electrical specialist inspector and nuclear associate during this intervention.

Interventions Carried Out by ONR

We undertook a planned inspection of the implementation of the arrangements for LC 28 examination, inspection, maintenance and testing (EIMT) at Dungeness B power station.

The intervention sample targeted the work being undertaken by Dungeness B in delivering their defueling aspirations. This included:

  • An inspection of the planned electrical work being undertaken as part of the reactor 21 pre-defueling outage including the planned electrical maintenance activities and any reactive electrical work emergent from the outage;
  • Any maintenance schedule preface changes in support of any Dungeness B defueling aspirations;
  • Any electrical engineering SSC maintenance suspensions and future maintenance suspension planning in support of any Dungeness B maintenance interval extension reviews; and
  • The engineering change related to reactor control rod isolations, the arrangements for isolation and their implementation

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

Based on the discussions, explanations and the sample inspected, on this occasion, we were 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 Dungeness B reactor 21 pre-defueling outage. During the inspection we sampled a number of reactor 21 pre-defueling outage related electrical activities and we were advised that progress made against electrical activities during the pre-defueling outage was as planned and anticipated. We were satisfied that Dungeness B had acted in a timely manner to address any areas of specific interest.

All the Dungeness B staff spoken to throughout the course of this intervention presented a knowledgeable and professional approach and provided open and honest responses to our questions.

We considered that the implementation of the LC 28 arrangements for the Dungeness B reactor 21 pre-defueling outage related electrical activities were adequate. Therefore, a ‘Green’ inspection rating, no formal action, was awarded.

Conclusion of Intervention

From the sample inspected, it was judged that for the electrical work activities undertaken at Dungeness B during the reactor 21 pre-defueling outage, compliance against LC28 met the required standard, therefore a ‘Green’ rating, no formal action, was given.

From the evidence gathered during this intervention, there were no matters identified that have the potential to impact significantly on nuclear safety. The implementation of the arrangements sampled were adequate and aligned with relevant good practice based on this intervention.