EDF Energy has said the restart of one of the reactors at Hunterston B nuclear power station in Scotland where cracks were found is being delayed.
In an open letter, Station Director Colin Weir confirmed Reactor 3 – which has been offline since March 2018 after routine inspections found cracks in its graphite core – is now expected to restart on 15th January 2020.
It comes after the Big Six company revealed earlier this year that around 370 hairline fractures were found in the graphite bricks at the core of the nuclear reactor in Ayrshire.
The Office for Nuclear Regulation (ONR) must approve the safety case before allowing the energy giant to restart the reactor.
Mr Weir said: “After discussions with ONR, we have agreed that some additional technical analysis will be completed to support the Reactor 3 safety case assessment; it is estimated that this additional work will be completed over the next six weeks.
“Through our interactions with ONR, the steps required to complete the assessment of the Reactor 3 case have become much clearer, this has allowed the additional work and assessment timescales to be better estimated.”
The ONR has, however, given the go ahead for EDF Energy to bring Reactor 4 back to service for around four months of operation.
At full capacity, the two reactors can generate enough electricity to power around 1.7 million homes in the UK.