In March 2018, Hunterston Reactor 3 was taken offline to carry out routine inspections of the graphite core. The inspections confirmed the expected presence of cracks and also identified these happening at a higher rate than modelled.
EDF has since completed an extensive inspection programme, one of the most detailed of its kind in the world and carried out further inspections on Reactor 4 so they know what condition both cores are in. In that time they improved the modelling of the reactor operation in normal conditions and in a highly unlikely earthquake situation, showing conclusively that reactors will operate and shutdown as designed, with absolutely no erosion of safety. In all circumstances all control rods will enter the core and there is no challenge to safe operation.
Following the core inspections and extensive modelling, the safety case providing the justification for return to service of Reactor 4 has been provided to Office for Nuclear Regulation (ONR) for their assessment. The ONR will, completely independently, review the case before deciding whether or not to approve for return to service. It is not possible know with certainty how long this process will take but it will be rigorously carried out. To provide for the ONR assessment, EDF has declared 30 April 2019 the date for returning Reactor 4 to service. The Reactor 3 safety case is currently going through EDF’s internal process of independent review. On completion it will be submitted to the ONR for their assessment. To allow sufficient time for this EDF has declared 30 June 2019 for returning Reactor 3 to service. Commenting, Kenneth Gibson said:
“I visited Hunterston B and spoke with members of their senior management team, following concerns raised by constituents.
“I am convinced that neither EDF Energy nor the ONR, the UK nuclear safety regulator, would ever allow the Hunterston reactors to restart unless completely satisfied that it is safe to do so. EDF’s own workforce and their families live near the plant and they would not put their lives or anyone else’s in danger.
“I look forward to the plant re-opening once the ONR has carried out its thorough checks.
“Hunterston B is scheduled to cease all operations in 2023.”