Nuclear experts have warned against re-opening a 43-year-old Scottish nuclear reactor riddled with cracks over fears of a meltdown.
Hunterston B nuclear power plant was shut down last year after it was found that Reactor 3 had almost 400 cracks in it – exceeding the operational limit.
EDF, which own the plant in Ardrossan, Ayrshire, are pushing to return the reactor to service at the end of June and July and want to extend the operational limit of crack allowed from 350 to 700.
However, the plans to reopen the plant have sparked fears it could lead to a nuclear meltdown similar to the 1986 Chernoybl disaster .
Experts have warned that in the very worst case the hot graphite core could become exposed to air and ignite leading to radioactive contamination and evacuation of a large area of Scotland’s central belt – including Glasgow and Edinburgh.
According to Dr Ian Fairlie, an independent consultant on radioactivity in the environment, and Dr David Toke, Reader in Energy Policy at the University of Aberdeen, the two reactors definitely should not be restarted.
Speaking about the cracks in the barrels, they warned: “This is a serious matter because if an untoward incident were to occur – for example an earth tremor, gas excursion, steam surge, sudden outage, or sudden depressurisation, the barrels could become dislodged and/or misaligned.
“These events could in turn lead to large emissions of radioactive gases.
“Further, if hot spots were to occur and if nuclear fuel were to react with the graphite moderator they could lead to explosions inside the reactor core.
“In the very worst case the hot graphite core could become exposed to air and ignite leading to radioactive contamination of large areas of central Scotland, including the metropolitan areas of Glasgow and Edinburgh.”
A planned inspection of the graphite bricks that make up the core of reactor three in March last year uncovered new “keyway root cracks”.
Around 370 hairline fractures were found, which the BBC reports equates to about one in every 10 bricks in the reactor core.
EDF Energy said these have now grown to an average of 2mm wide.
The operational limit was 350 cracks but the inspection found this had been exceeded.
Cracks to the graphite blocks is known to occur but legislation is in place to ensure they do not threaten the structural integrity of the reactor.
EDF is now hoping to prove it is safe to use and would stand up to the most stringent tests and wants the ONR to increase the upper operational limit to 700 cracks.
The reactors have been closed since October 2018, but EDF Energy said yesterday it was confident its Hunterston B nuclear plant would eventually reopen.
Station Director Colin Weir said: “Nuclear safety is our overriding priority and reactor three has been off for the year so that we can do further inspections.