Hunterston B nuclear power station finally went offline at 12pm on Friday (7 January) after almost five decades of operation.
The EDF-run power station is closing at least a year earlier than previously planned after the Office for Nuclear Regulation (ONR) cleared the first of its two reactors to resume operations for a period of only six months.
Both reactors were taken offline in May 2018 after inspections found fresh cracks in the graphite bricks that make up the core of the first reactor. Although cracks were expected to form as it reached the end of its working life, they were found to be emerging faster than expected.
Over its lifetime the Scottish plant, located in Ayrshire, has produced 297.4 TWh of electricity which is enough to power every home in Scotland for 31 years.
It was originally due to run for 25 years to 2001 but its life was extended by a further two decades.
According to the Nuclear Industry Association (NIA), Hunterston B has saved 224 million tonnes of carbon dioxide emissions, based on the historical grid mix, since it began generation in 1976 – more than any other Scottish power source. It said these savings are worth £16.8 billion at current carbon prices.
The NIA warned that, with no replacement lined up for the site, the gap will have to be filled in part with imported gas sourced from volatile global markets, driving up costs and preventing more ambitious carbon reduction.
Tom Greatrex, the trade body’s chief executive, said: “Hunterston B has shown the best of what nuclear can provide for Scotland – clean, reliable power to keep the lights on and save our planet, and long-term, skilled jobs, on which people can build a life and a family.
“The dedicated staff who have helped keep Scottish homes warm and light for 46 years, deserve our gratitude.
“As the current energy crisis demonstrates, without nuclear the cost of the electricity we rely on is higher, causes pollution and leaves us reliant on burning imported fossil fuels.
“That’s why we need new nuclear – to get to net zero and provide the reliable, secure and clean power to live our lives.”
The closures of multiple nuclear plants in the UK have been brought forward in recent years. Hinkley Point B will begin the first stage of defueling in July – eight months earlier than previously scheduled. As with Hunterston, the advanced closure of the plant in Somerset was put down to a deterioration in the graphite blocks that make up the cores of its two reactors.
In July last year, EDF announced it had begun decommissioning Dungeness B in Kent seven years earlier than previously scheduled after faults were found at the plant. The advanced gas cooled reactor has been offline since 2018 after problems were discovered during maintenance.