Office for Nuclear Regulation

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EDF Energy Nuclear Generation Ltd (NGL) - Dungeness B (DNB) Planned Intervention

Executive summary

Purpose of intervention

This is a planned inspection at EDF Energy Nuclear Generation Ltd's (NGL's) Dungeness B (DNB) power station, undertaken as part of the planned intervention strategy for the Civil Nuclear Reactor Programme (CNRP) of the Office for Nuclear Regulation (ONR).

Interventions carried out by ONR

I inspected compliance with Licence Condition 10 (LC10) "Training". The theme of this inspection was "training for reactor faults".

At the time of this intervention, DNB Reactor 21 was on its periodic shutdown (also known as its statutory outage). Since this periodic shutdown was nearing completion, a start-up meeting with a superintending inspector, the Reactor 21 project inspector, a structural integrity inspector and myself was held. We undertook a plant inspection of Reactor 21 prior to this meeting. We have related this plant inspection to Licence Condition 28 "Examination, Inspection, Maintenance and Testing". We have related the start-up meeting itself to Licence Condition 30 "Periodic Shutdown".

I undertook a review of ONR's issues database with the licensee. We also held a routine meeting with the licensee internal regulator and undertook information gathering.

Explanation of judgement if safety system not judged to be adequate

Not applicable.

Key findings, Inspector's opinions and reasons for judgements made

In relation to the LC10 compliance inspection I was satisfied that a suitable process was in place to safety case inform the Central Control Room (CCR) simulator training plan for reactor faults. However, this plan did not consider faults on a shut down reactor. After this intervention I was provided with a guide that provides some training relating to such faults. However, this did not explicitly provide a link with the safety case. I placed an action to address this. A document linking the training for operators out on the plant to the full reactor safety case was also not available. I placed an action to address this. Based on DNB's good response to recent reactor faults and the extensive CCR simulator training programme in place I am of the opinion that the gaps identified relate mainly to establishing explicit links, rather than to significant gaps in competence. I also established that the process for safety case informing the CCR simulator training plan was part of DNB's LC10 compliance arrangements and satisfied myself that training for boiler tube leak faults was being undertaken in line with the CCR simulator training plan. Taking all these factors into account I assigned an Integrated Intervention Strategy (IIS) Rating of 3 (adequate) to LC10.

In relation to the plant inspection of Reactor 21 prior to the start-up meeting we observed that there was consistently good and positive challenge from the NGL staff and that this had been taken positively by those affected. We observed several instances of below standard work and laydown areas and an unlatched nuclear significant fire door. We considered there to be a common theme of situational awareness. Due to the good and positive challenge from the NGL staff and their raising of a condition report relating to the nuclear significant fire door, we raised no actions. Taking all these factors into account we assigned an IIS Rating of 4 (below standard) to LC28.

In relation to the Reactor 21 start-up meeting we considered that it was efficient and effective. We considered this to be due to: a) thorough preparation by both NGL and ONR; b) regular communication between NGL and ONR starting from the periodic shutdown planning phase; c) maintenance of an ONR Action Tracker and; d) the use of common agreed formats for meetings etc, which facilitated co-ordination of both NGL and ONR inputs. Taking all these factors into account we assigned an IIS Rating of 2 (good standard) to LC30.

In relation to the other activities undertaken in this intervention, no key findings arose.

The licence conditions were inspected against ONR's published guidance requirements (as described in our technical inspection guides).

Conclusion of intervention

From the evidence obtained during this intervention, no matters have been identified that are likely to have a significant impact on nuclear safety on the station at this time. Therefore, no additional regulatory action arising from this visit is considered necessary at this time.