The Scottish Government has received assurances over the safety of Hunterston B nuclear power station after cracks were found in bricks making up the core of one of its two reactors.

Energy minister Fergus Ewing said he had spoken to a senior representative of the Office for Nuclear Regulation (ONR) to confirm the discovery posed no threat to public safety.

EDF Energy, which operates the North Ayrshire plant, said that two cracked bricks were found during a planned maintenance inspection of the 6,000 that make up the reactor's graphite core.

The company said that the cracks, found during planned maintenance checks, were predicted and did not pose any safety risks.

Mr Ewing told MSPs at Holyrood: "The Office for Nuclear Regulation, to whom I spoke this morning, have confirmed what they have made absolutely clear, and they have provided as the regulator an assurance that there are no immediate safety implications affecting Hunterston B and that it is safe to continue generating electricity."

The nuclear power station began operating in 1976 and was originally scheduled to be shut down in 2011, but this has been extended until 2023.

Green MSP Alison Johnstone called for full environmental impact assessments to be carried out before any decision to extend the lifetime of a nuclear power station is taken.

Mr Ewing said: "The consideration of the environmental case was made when the life was extended to 2023, an extension which was made two years ago and which has been fully discussed and reported in this parliament already."

The energy minister said he had received further assurance from the ONR that periodic safety assessments were also carried out, with the next due around 2016.

He added: "I can also assure Ms Johnstone that the defect which has been found is not unexpected.

"It is something which, on the contrary, was expected and to be expected and known about both by EDF, the operator, and by the ONR.

"I'm sure that we would all agree that no-one in this chamber would wish to be unduly alarmist about highly-technical matters where the regulator has been very closely involved working with the company.

"We expect Hunterston to continue to generate to 2023 and of course Torness...provided they can do so efficiently and safely."