Office for Nuclear Regulation

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Dungeness B - Inspection Week

Executive summary

Purpose of Intervention

This was a planned inspection at EDF Energy Nuclear Generation Ltd'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 key activities were undertaken:

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

I undertook a reactive unplanned intervention against LC22, focusing on the implementation, during which I:

Sampled two engineering changes which were being conducted during the outage. The licensee's asset management system provides the capability to record, control and track engineering changes through to implementation and close-out.

Found evidence to demonstrate that the asset management system is being used appropriately and the implementation of the modification with respect to documentation and training is being adequately considered and tracked.

No significant shortfalls were identified; one observation was made relating to issuance of affected plant operating instructions. This was rectified quickly, no regulatory action was required.

I undertook a planned intervention against LC26, focusing on licensee oversight, during which I:

Sampled the planned gas circulator 21 return to service activity and judged that appropriate level of control and supervision was evident at the workplace and suitable oversight was being provided by the licensee.

Confirmed nuclear safety oversight was being carried out by a duly authorised person appointed by the licensee, as required by LC26. The individual was appointed under LC12, this was confirmed but not examined further therefore LC12 was not rated.

No significant shortfalls were identified; an observation was made relating to the return to service flow-sheet. The licensee has raised a condition report and an associated ONR regulatory issue will be updated accordingly to tracked resolution and cover extent of condition.

Prior to the start-up meeting a plant walk-down was conducted and feedback given. I found evidence that the station has taken the opportunity to make safety improvements where possible and improve the identification of components whose failure alone will result in an immediate reactor trip or power reduction. I did note standards of housekeeping and use of personal protective equipment requires further improvement. This was discussed at the start-up meeting.

The start-up meeting was well attended and the discussions held were open and constructive. There was clear evidence that the examination, inspection, maintenance or testing required by the plant maintenance schedule has been conducted. There was one ONR query shared with the station which needs to be resolved prior to ONR issuing consent to re-start.

I undertook routine engagement with the station and the independent nuclear assurance team to discuss outage and station performance including recent events. I judge that the station is taking the appropriate action to management performance and investigate events. No significant nuclear safety concerns were raised during these discussions.

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

In relation to LC 22, I judged that the IIS rating of 'Green' is warranted on the basis that the station could demonstrate that asset management system is being appropriately used to control modifications and the implementation of the engineering changes sampled are being considered and tracked.

In relation to LC 26, I judged that the IIS rating of 'Green' is warranted on the basis that the station could demonstrate adequate control and supervision of operations which may affect safety.

In relation to LC 30, I judged that the IIS rating of 'Green' is warranted on the basis that the examination, inspection, maintenance or testing required by the plant maintenance schedule has been completed.

There are no findings from this inspection that could significantly undermine nuclear safety.