Cracks have been found in three bricks at the core of a nuclear reactor in Ayrshire, Scotland.
Operator EDF Energy stated they were found during planned maintenance of the Hunterston B power station.
The finding doesn’t affect operations of the reactor and has no safety implications, it added.
Station Director Colin Weir said the level of cracking is considered “reasonable” and is far below anything which would affect the reactor’s safe operation.
He added: “It is accepted by our regulators and materials experts that cracks will occur in some of the bricks and that the core will lose some of its mass as part of the normal ageing process.”
Scottish Energy Minister Fergus Ewing said the finding proves the country’s nuclear facilities have a “limited lifespan” and long term energy alternatives such as renewables are needed.
He added: “The UK Government recognised belatedly that its policies have weakened energy security and pushed up bills but they continue to miss opportunities to put in place new plans to address the gaps in UK energy policy, with few if any new actual incentives to drive energy generation. Their policy is inconsistent in terms of getting the best deal for bill payers, incoherent in terms of reducing carbon emissions and is proving ineffectual in terms of ensuring security of supply.”
Mr Ewing said the Scottish Government is opposed to new nuclear build in Scotland “as it would divert billions of pounds away from renewable alternatives”.
The UK Government is investing £2 billion in Hinkley Point C nuclear station.
Earlier this week, it also announced coal-fired plants will be closed by 2025 and will be replaced by gas.