Office for Nuclear Regulation

Reactor 3 Return to Service inspection

Executive summary

Purpose of Intervention

This was a planned inspection of EDF Energy Nuclear Generation Ltd.’s (NGL’s) Hunterston B Power Station, 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 accordance with the planned inspection programme contained in the Hunterston B Integrated Intervention Strategy (IIS) for 20120/21.

Interventions Carried Out by ONR

As part of this intervention I, the nominated site inspector, carried out inspections against:

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

I also held a number of routine meetings and received updates on the progress being made to close out regulatory issues previously raised.

Explanation of Judgement if Safety System Not Judged to be Adequate

No system based inspection was undertaken, hence this is not applicable for this intervention.

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

The inspection was carried out as part of the ONR decision making process to determine whether Reactor 3 at Hunterston B should be granted Consent to return to power.  This inspection scope considered:

The inspection confirmed that the Reactor 3 plant is being thoroughly checked and re-commissioned to place it in the best state for return to service.  Confidence was gained in the OSRC process which ensures all required checks will be carried out prior to making a recommendation that Reactor 3 may return to service. 

The inspection identified that morale at station has been low and this has contributed to number of recent safety events.  This has been recognised and improvement plans are in place to correct this; evidence was provided which confirmed that safety improvement actions are having a positive effect.

Inspection of the Reactor 3 plant confirmed that the plant has been maintained to a high standard.  Learning from the Reactor 4 outage has been re-applied to Reactor 3, the Operations ‘Match fit’ improvement process has been extended to all departments and quality assurance audits are being carried out to independently confirm that re-commissioning quality plans are being adhered to.  Adequate Covid-19 control measures are in place and staffing levels are returning to normal to support return to service.

The inspection confirmed that all operations staff have been thoroughly trained and the Central Control Room team has demonstrated a robust response to a challenging exercise scenario.

Conclusion of Intervention

From the sample of the governance and oversight applied to the return to service of Reactor 3 at Hunterston B, I judged that station is robustly applying its Operational Safety Review Committee processes and that no issues were identified that could impact nuclear safety.  The inspections for LC 7, 10, 28 and 30 were rated Green, no formal action, and the results of this inspection would support an ONR decision to return Reactor 3 to service.