One of the nuclear power reactors at Torness in East Lothian has been shut down following a problem with a valve, prompting increased concerns about its future.
EDF Energy, the French company that runs Torness, has said that reactor two went offline on 23 June because a key valve in the steam turbine closed. It is investigating what went wrong, and hoping to restart the reactor on 30 June.
Reactor one at Torness, which is still running, is now the only one of four reactors in Scotland currently generating electricity. The other two reactors at Hunterston in North Ayrshire have been closed for most of the last two years because of spreading cracks in their graphite cores.
Torness station director, Robert Gunn, emailed local stakeholders on 25 June with news of the closure. “The shutdown was due to the closure of a governor valve in the conventional non-nuclear part of the power station,” he said.
“Our systems are designed to ‘fail safe’ and as our operators worked to resolve the issue, the unit automatically shut down. As a result, steam was released from the vents which made a loud noise.”
Gunn added: “This was perfectly normal and expected in a safe shut down like this. The reactor shut down and cooled safely, which is our overriding priority when a reactor goes offline, and there were no health or environmental impacts.
“The unit will be returned to service once an investigation has been carried out.”
Gunn pointed out that Torness reactor two had been operating uninterrupted for 552 days before it shut down on 23 June. The station, which started up in 1988, has the capacity to generate electricity for more than two million homes.
Gavin Corbett, a green councillor for Edinburgh and a member of the Torness local liaison committee, was informed of the closure. “The plant manager was at pains to emphasise that the shut down did not pose any safety concerns although that is for the investigation to determine rather than being prejudged,” he told The Ferret.
“Clearly, a nuclear reactor isn’t closed down for a week for no reason. Torness is 31 years old now and should have been approaching its closure very soon.”
Corbett pointed out that the plant’s “shelf life” had been extended until 2030. “I’d expect very close scrutiny of the operation and plans developed to ensure the staff and suppliers have a long term future in a thriving Lothian and Forth renewables industry,” he said.
Thanks to the staff at Torness this morning for a Zoom liaison meeting. I asked about this week’s unplanned outage in Unit 2 (note to come today) and about the risks from cracking in the graphite reactor core as the plant ages. pic.twitter.com/7XDMCWvNp1
— Gavin Corbett (@gavincorbett) June 25, 2020
The Ferret reported on 6 May 2020 that the UK’s nuclear safety watchdog was predicting that cracks would start appearing in graphite cores at Torness six years sooner that previously thought. The Office for Nuclear Regulation said that cracking – which could increase the risk of a nuclear accident – was now expected to begin in 2022.
Friends of the Earth Scotland warned that nuclear power isn’t helping the country’s energy mix. “With cracks in reactor cores nuclear power is clearly on a shoogly peg in Scotland,” said the environmental group’s director, Dr Richard Dixon.
“The sooner we phase out nuclear power and rely on a broad mix of renewables and storage systems the better.”
“But the lights haven’t gone out. It’s time to phase out nuclear and go 100 per cent renewable.”
A spokesperson for EDF Energy said: “Unit two at Torness power station came offline due to the closure of a valve associated with the boilers in the conventional, or non-nuclear, side of the plant. Shutdown took place as expected and we expect to re-start in a few days.”
EDF Energy’s email about Torness to local stakeholders
Photo thanks to EDF Energy.