THE head of a Scottish nuclear power station yesterday insisted the site is not unsafe after cracks were found in bricks around the core of a reactor.

Inspectors discovered fissures in three graphite bricks during planned maintenance checks at Hunterston B near West Kilbride in North Ayrshire.

Operator EDF said the cracks were predicted due to the age of the reactor.

The station began operating in 1976 and was scheduled to close in 2011 before its working life was extended to 2023.

Yesterday, energy minister Fergus Ewing and WWF Scotland director Lang Banks raised concerns about the safety of the facility and the failure of the Westminster Government to develop the UK’s energy infrastructure.

However, Colin Weir, station director at Hunterston B, dismissed the fears, saying: “Nuclear safety drives everything we do. This means we work within very large safety margins. This applies to graphite bricks too.

“The level of cracking which is considered reasonable is far below anything which would affect the reactor’s safe operation.

“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.

“The observations were anticipated and are in line with our understanding, so our view of the best estimate lifetime planning date of 2023 has not changed.”

Two cracked bricks were also found during maintenance of the site’s other reactor in October last year.

Yesterday, EDF said it was making the latest information public as part of its “commitment to openness and transparency”.

Further inspections are now planned to examine more of the graphite core and EDF will issue a fresh statement if further cracks are found.

EDF said: “Three graphite bricks were found to be cracked. This is known as keyway root cracking and was predicted to start happening at this point in the station’s lifetime.

“It does not affect the operation of the reactor and the findings have no safety implications and are well within any limits for safe operation.”

Banks said: “Despite the assurances given by the nuclear industry, with cracks now found in both reactors it’s clear the problem is spreading and that we can expect this facility to become even more unreliable in the future.

“News of more cracks in the country’s ageing fleet of nuclear power stations underscores why we’re right to be taking steps to harness cleaner, safer forms of energy.”

Meanwhile, Ewing said: “The reactor operator has provided assurances that there are no immediate safety implications affecting Hunterston B, and that it is safe to continue generating electricity.

“At the same time, this development does illustrate that Scotland’s nuclear facilities have a limited lifespan and we need to put in place longer term energy alternatives.

“Just yesterday, 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.”