Office for Nuclear Regulation

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Dungeness B - LC22 planned inspection and unannounced LC26 inspection

Executive summary

Purpose of Intervention

The purpose of this intervention was to undertake a licence condition (LC) compliance inspection of NGL’s LC22 arrangements for Modification or Experiment on Existing Plant, and to undertake a planned unannounced LC26 inspection for Control and supervision of operations at EDF Energy Nuclear Generation Limited (NGL) Dungeness B Power Station. This is in line with the inspection programme contained in the Dungeness B integrated intervention strategy (IIS) for 2018/19.

The LC26 intervention was supported by an ONR internal hazards specialist inspector and was accompanied by the licensee’s internal safety regulator.

Interventions Carried Out by ONR

As part of this intervention, I inspected NGL’s LC22 arrangements for modification or experiment on existing plant, in accordance with ONR guide NS-INSP-GD-022 Revision 3. I also undertook a planned unannounced LC26 inspection for control and supervision of operations in accordance with ONR guide NS-INSP-GD-022 Revision 4.

For the LC22 inspection I sampled a selection of the licensee’s associated procedures, oversight and control of modifications, an examination of various open and closed category 1 and 2 engineering changes and the status of defeat of interlocks.

I conducted an LC26 inspection during the double reactor outage when there are a large number of activities being carried out by contractors during the outage. This unannounced inspection was undertaken during the night shift of the station’s operations,

The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.

During my station visit I also attended the site stake holder group meeting which was held at the DNB visitor centre and undertook follow up of reported events and routine engagements with station staff.

Explanation of Judgement if Safety System Not Judged to be Adequate

No safety system inspection was undertaken, hence this is not applicable.

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

From my sampled inspection of the licensee’s arrangements for LC22 I noted that the licensee was undertaking the correct level of oversight and control of modifications using its Asset Management System (AMS) enabling appropriate configuration control. I sampled engineering change (EC’s) modifications that were being implemented during the reactor 22 periodic shutdown including engineering change modifications that were implemented prior to the outage.

I also examined the status of interlock defeats which identified 14 that were currently in place, this has fallen from the original 28 active interlock defeats. Given that the station is managing the control of historic interlock defeats I consider that legal requirements are also being met.

I noted that post reactor 22 outage the station is to re-implement a check sheet for Responsible Engineer’s which has previously been rarely used. The implementation of this will be used to improve the quality of EC’s that are raised. Given that this is a new initiative regarding the implementation of an existing check sheet that has had little exposure, I have elected to raise a level 4 regulatory issue in order to follow the progress of this initiative. From my sampled inspection I was content that the arrangements and their implementation for LC22 met legal requirements therefore I have provided a regulatory rating of Green for the LC22 no further regulatory action required.

For the LC26 unannounced compliance inspection we interviewed several individuals ranging from the licensee senior management and operational staff to various contract partners undertaking work activities on behalf of the licensee. The interviews took place at different work faces within Dungeness B power station for various tasks being undertaken. I noted good control and supervision of the activities being undertaken and a willingness to stop work in areas where there was doubt and to seek advice.

Whilst some relatively minor deficiencies and anomalies were identified, I considered these deficiencies to be low in significance.  As such, an inspection rating of Green was awarded.  However, during the plant walk down I observed a number of housekeeping issues; in particular I noted that the fire hydrants in the Decontamination Yard were obstructed by scaffolding and other equipment.  In light of this observation I have raised a regulatory issue in order follow the station’s progress in rectifying this. 

Conclusion of Intervention

Overall I was content that the arrangements and their implementation for LC22 and LC26 for the sample undertaken met legal requirements therefore I have provided a regulatory rating of Green for the LC22 and LC26 compliance inspections.  However, two regulatory issues were raised during the course of this inspection which will be followed up by the site inspector; the inspection findings of this inspection were shared and accepted by NGL as part of normal inspection feedback.

There are no findings from this inspection that could significantly undermine nuclear safety nor require change to the planned interventions and inspections of Dungeness B.