A reactor at a nuclear power station has reopened after an upsurge in seaweed forced bosses to shut it down.
Managers at Torness plant in East Lothian closed its two reactors last week amid fears that seaweed in the Forth Estuary could clog the station's cooling water intake system.
Stormy seas have been blamed for an increase in seaweed in the water.
The reactor was taken out of service on Thursday and resumed activity on Monday morning, operators EDF energy said.
Another which was shut on Friday will reopen in due course, the company said.
"Unit 2 at Torness power station was resynchronised to the grid at 6.33am on Monday. The unit came offline on Thursday due to increased seaweed levels as a result of the severe weather and sea conditions in the area," a spokesman said.
"We are aware that at certain times of the year with particular weather conditions in this part of the Forth Estuary, seaweed volumes can increase and enter the station's cooling water intake system. The operational staff are 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 in-built mechanisms will take the unit offline automatically should levels rise beyond prescribed settings, ensuring optimum safety at all times."
WWF Scotland said that nuclear power had "once again proven itself unreliable".
Director Lang Banks said: "We should all be thankful that Scotland has grown its renewable energy capacity enough to be able to deal with Torness nuclear power station going offline without warning. As we tap into ever more of our huge renewable resource, we look forward to the day Scotland can switch off nuclear power for good."