Office for Nuclear Regulation

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Dungeness B - Unplanned LC7 compliance inspection

Executive summary

Purpose of Intervention

This intervention undertook a reactive unplanned Licence Condition (LC) compliance inspection at EDF Energy Nuclear Generation Limited (NGL) Dungeness B (DNB) Power Station which supports the planned inspection programme contained in the DNB Integrated Intervention Strategy (IIS) for 2018/19.

Interventions Carried Out by ONR

I, the Nominated Site Inspector carried out a reactive compliance inspection against LC7 (Incidents on the site) and an LC24 (Operating instructions).  This inspection comprised enquiries into a routine incident report I had received that had highlighted a non-compliance with a station operating instruction (SOI), which appeared to me to be a shortfall in compliance with the Station’s arrangements for LC 24.

In addition to these unplanned compliance inspections, I also attended the DNB emergency preparedness consultative committee (EPCC) meeting and undertook Intelligence gathering activities during my station visit.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable: No safety system inspection was undertaken during this intervention.

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

The normal daily station operating instruction (SOI) required to meet the steam release safety case claims for this station (leak before break claims) had been relaxed to weekly during reactor shutdown. The routine report I received stated that this had not in fact been undertaken at all since October 2018. The duty emergency controller correctly identified that under the licensee’s reporting arrangements under LC7, this event required the licensee to consider formally reporting the event to ONR.   In this instance, the incident was not formally reported to ONR and was instead reported to me on the 18th January 2019 by the Station’s Corrective Action Program Coordinator via the routine incident reports I receive.

In my opinion, given that a required SOI had not been undertaken for a significant period of time over a number of shifts I consider this was a compliance failure against LC24. In addition, given that a reasoned explanation for the judgement made in not formally reporting the event to ONR, and the less than adequate quality of the investigation report in response to the event I consider there was also a compliance failure against LC7.

In light of the above findings this represents a shortfall of the arrangements for compliance against LC7 (incidents on site) and LC24 (operating instructions). I have therefore rated LC7 and LC24 as Amber (seek improvement), and agreed improvement actions with the Station that have been recorded as an ONR regulatory issue which will be used to monitor the station’s improvements in this area.

During my visit, I undertook intelligence gathering by undertaking a plant walkdown with a DNB team leader for the various work areas he was responsible for. The plant areas visited were the reactor charge hall, gas circulators, the decontamination and the laundry yards.

The decontamination and laundry yards had poor housekeeping standards I have therefore raise a regulatory issue to track the station’s progress in finding a long term solution in order to ensure sustained oversight of both areas.

 I held meetings with two newly qualified duly authorised (DAP’s) persons, the technical safety and support manager (TSSM) and the Station Director.

During my visit I attended the DNB emergency preparedness consultative committee (EPCC) meeting. This was a well-attended meeting with open discussions covering several areas of interest.

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 LC7 and 24, I judged that an IIS rating of ‘Amber’ is warranted on the following basis ;

In light of the above findings this represents a shortfall of the arrangements for compliance against LC7 (incidents on site) and LC24 (operating instructions).  An ONR regulatory issue has been raised to monitor the station’s improvements in this area. I will also apply the ONR enforcement management model (EMM) to determine the most appropriate enforcement action; the decision will be captured in a separate report.

For the poor housekeeping standards within the decontamination and the laundry yards, I have raise a regulatory issue to track the station’s progress in finding a long term solution in order to ensure sustained oversight of both areas.