A reactor at Torness nuclear power station has been shut down due to a fault.
Operator EDF Energy said there was no health or environmental impact as a result of the automatic shutdown at the facility in East Lothian.
A spokeswoman said: "Reactor 2 was automatically shut down at around 1.15am due to a fault within the protection equipment on one of our reactor plant electrical systems.
"This equipment is designed to 'fail safe'; in other words a fault with protection will result in the reactor shutting down safely."
Reactor 1 at the plant was temporarily shut down in July due to an issue with the electrical system.
WWF Scotland director Lang Banks said: "With yet another unplanned shutdown this year at a Scottish facility, nuclear power has once again shown itself to be a totally unreliable source of energy. Thankfully Scotland has plenty of cleaner, safer energy alternatives it can call on to be able to deal with unplanned shutdowns at atomic facilities like this.
"Last month, wind turbines in Scotland alone generated enough electricity to supply three millions homes in the UK - equivalent to 126% of the electricity needs of every house north of the border."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article