Hunterston nuclear reactor offline due to seaweed level
A reactor at the Hunterston B nuclear power station in Ayrshire has been taken offline due to high levels of seaweed in the waters around the plant.
The plant relies on water taken from the sea for cooling.
Operator EDF Energy said the shut down at 18:40 on Monday was a "precautionary measure" with "no health, safety or environmental impacts".
It said the station's second reactor was continuing to operate, but at a reduced load.
In a letter to stakeholders, station director Colin Weir said: "Hunterston B power station's reactor 3 was manually shut down at 18.40 on Monday 1 June due to severe seaweed ingress, accompanied by strong winds and storm surges.
"This was done as a precautionary measure when it was clear that the seaweed levels weren't reducing.
"Reactor 4 was also reduced in power and remains operating at a reduced power."
Mr Weir said staff at the station were monitoring the weather and seaweed levels would begin the return to normal service when it was determined conditions were "in a stable state".
"We are aware that at certain times of year with particular weather conditions in this part of the Firth of Clyde seaweed volumes can increase and enter the station's cooling water intake system," he said.
"Our operational staff are well trained to respond in this situation and to take the plant offline if necessary.
"In addition, the many-layered safety systems monitor conditions like this and the plant's inbuilt mechanisms will take the unit offline automatically, should levels rise beyond prescribed settings, ensuring optimum safety at all times."
Mr Weir added: "Cooling to the reactor was maintained at all times and there are no health, safety or environmental impacts."
Hunterston B has two advanced gas-cooled reactors, similar to those found at nuclear plants around the UK.
Hunterston began operating in 1976 and its working life has already been extended to 2023 - well beyond its planned closure date.