Office for Nuclear Regulation

Planned intervention - Hinkley Point B

Executive summary

Purpose of intervention

This was a planned inspection of EDF Energy Nuclear Generation Ltd’s (NGL’s) Hinkley Point B power station, undertaken as part of the planned intervention strategy for the Civil Nuclear Reactor Programme (CNRP) of the Office for Nuclear Regulation (ONR).

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

Interventions Carried Out by ONR

I (the nominated site inspector for Hinkley Point B) with support from ONR and HSE inspectors:

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

Not applicable – no system inspections were carried out on this visit.

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

Licence condition 11 (emergency arrangements): Emergency Exercise ‘Blackbird” took place at Hinkley Point B power station on 9th June 2015 and was a combined level 1 and 3 exercise.  The exercise scenario was designed to test the station response to a nuclear safety event and to provide a suitable scenario for the level 3 exercise which continued for most of the day.  The ONR team noted several areas of good performance alongside some learning opportunities and these will be communicated to the station via letter.  ONR concluded that this was an adequate demonstration of the station’s emergency arrangements.  We therefore assigned an IIS rating of 3, (adequate) to this inspection.

I met with an Independent Nuclear Assurance (INA) Inspector on site to review recent events using the standard INA/ONR agenda.  The recent incident at the buffer store, field supervision, fuel route improvements and quality improvement initiatives on site were discussed.

A significant near miss event occurred on the pile cap when an outage closure plug was ejected from a buffer storage tube. There were no nuclear safety implications or damage to the plant, no fuel was involved and nobody was injured (although operators were in the immediate vicinity).  ONR carried out initial enquiries to determine what happened and what action had been/is being taken by the licensee and on this visit the outcome of the licensees internal investigation was discussed. 

I was satisfied with the information exchanged during meetings with station staff on a range of topics including the development of an inspection strategy to be implemented following the discovery of keyway root cracks in the graphite core, progress with the new Nitrogen plant, a recent request to suspend a Nuclear Safety Requirement on the gas turbine fuel oil tanks and preparations for the next annual review of safety meeting.

Conclusion of Intervention

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