Office for Nuclear Regulation

Dungeness B - LC11 inspection

Executive summary

Purpose of Intervention

This was a planned compliance inspection of licence condition 11 (Emergency arrangements) at EDF Energy Nuclear Generation Limited’s (NGL’s) Dungeness B power station. It was undertaken as part of the planned intervention strategy for the Operating Facilities Division (OFD) of the Office for Nuclear Regulation (ONR).

The work was carried out in-line with the planned inspection programme contained in the Dungeness B Integrated Intervention Strategy (IIS).

Interventions Carried out by ONR

During this intervention, the following activities were undertaken:

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

No system based inspection undertaken, hence not applicable.

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

An ONR team observed the emergency exercise demonstration “Vanguard”. This exercise was to demonstrate the implementation of the Beyond Design Basis Equipment (BDBE).  The scenario was a nuclear emergency which was initiated by a seismic event and included casualty recovery.  The scenario was challenging which required a range of different problems for the site staff to deal with.  Whilst the site demonstrated some improvements e.g. site mustering, overall, it was clear that many of the lessons from other sites’ in the deployment of the BDBE had not been learned. This resulted in significant failings in the timely deployment of the equipment and challenged its subsequent operation. There were also significant improvements needed to the operation of the Alternative Access Control Point.

In light of ONR’s observations, and those given by your independent assessment team at the exercise debrief, whose views very much aligned with those of our team. ONR require  re-demonstrated of the Alternative Access Control Point (AACP) and BDBE deployment during one of the shift exercises later this year after the station has reviewed and improved training, familiarisation, procedures and instilled a sense of urgency into its deployment.

ONR has rated this LC 11 compliance inspection as ‘Amber – seek improvement’; a single regulatory action has been raised to monitor the station’s progress in preparing and undertaking the re-demonstrated of the areas mentioned above.

Full feedback will be provided to the licensee by letter for incorporation to its improvement plan. Progress in addressing ONR’s observations will be monitored through the emergency arrangements review meetings (EARM).

ONR held an engagement meeting with IGSNR who were undertaking an annual independent assessment of the organisational structure of nuclear safety and radiation protection within the EDF Group. The report that they produce is destined for the President of EDF. It is also intended for all who, in any way, play a role at EDF in improving nuclear safety. The meeting was open and informative, it was clear that the IGSNR team shared many of our perspectives.

Routine engagement was undertaken with the station’s independent nuclear assurance team to discuss operational performance including recent events. ONR also attended the DNB site stake holder group meeting.

ONR also undertook a plant visit around the main steam lines and discussed the practicalities of the inspections, repairs and replacements with two of the team members who have been doing the work.  The individuals were very knowledgeable and it was useful to understand the layout of the work areas involved. No significant nuclear safety concerns were raised during this visit.

During the plant visit several housekeeping observations were made. In light of these the nominated site inspector has raised a regulatory issue to track the station’s progress in addressing them.

Conclusion of Intervention

In relation to LC11, I judge that an inspection rating of Amber is warranted based on ONR’s observations made at the AACP and the deployment of the BDBE. A single regulatory issue has been raised to follow the station’s progress in preparing and undertaking the re-demonstrated of the areas mentioned.

The two regulatory issues raised will be tracked through routine engagement; there were no findings from the intervention that would significantly undermine nuclear safety at the Station or that give ONR reason to change inspection plans.