THE managing director of Hunterston 'B' Power Station says tests have been carried out on the cracks in Reactor 3 showing it could withstand an earthquake.

The reactor has been on shutdown since May as more of the core has been investigated, while academic tests and modelling analysis has helped show how the reactor and its cracked bricks could cope with a major seismic event.

Hunterston supremo Colin Weir told the News that tests will continue but he is content the reactor will go back online on November 17.

Measurements have shown that over 70 bricks have cracks.

Mr Weir said: "We examined around a quarter of the core during the last inspection, more than 700 bricks, looking for evidence of a number of things.

"As well as identifying new keyway root cracks in the channels that hold the fuel, we wanted to see if there was evidence of distortion in the core and check the size of the previously identified cracks.

"As expected, we did identify new cracks.

"We found around 70 in this most recent campaign, which is where we expected to be in relation to the current safety case.

"We also found that previously identified cracks had opened less than we had conservatively modelled and there was no significant distortion.

"Importantly, there were no cracks or defects found in the 11 control rod channels we examined. These results support the work we are doing on the long-term safety case and underline our confidence that the operation of our primary control and shut-down systems is unaffected.”

The online date will see a trial run of operations for a period of time yet to be defined with the regulators, before a permanent power-up.

When reactors three and four are in full operation, they supply 1.7m people in Scotland with electricity.

The projected closure of Hunterston 'B' is 2023 but Mr Weir said that the date could change.

EDF Energy say it is important to put the size of the cracks into context.

A spokeswoman said that the bricks, see picture, were the size of large barrels, with small cracks the size of the head of a ballpoint pen amounting to between 1-2mm.

Mr Weir added: "Following these tests, which include an earthquake of 7.4 on the Richter scale, the projected cracks within the bricks are still well within our defined parameters of safety - that is for a 1 in 10,000 year seismic event."