IF it wasn't so frightening, it would be like a scene from The Simpsons: the sea near the Hunterston nuclear power station in Ayrshire is glowing spookily green.

Don't be afraid, however, because it has nothing to do with radioactive leaks spawning three-eyed fish – or so we are told.

A local resident raised the alarm after spotting a patch of luminous green on the satellite photographs of the site published online by Google Earth. There is an equally vivid area visible just inside the site boundary.

Given the nature of the site, first thoughts were of plutonium or some other nuclear nasties contaminating the water and endangering locals' health.

But not so, says EDF Energy, the French company that generates electricity from the Hunterston B reactors. The green glow has a more mundane explanation: bubbling water.

The nuclear plant takes in large amounts of seawater to cool its reactors, and then discharges it back into the sea. The greenish area at sea is where the warmed water bubbles up from a pipeline, and the greenish area on the site is a shaft through which the water surges.

"The Google shot taken offshore is where our cooling water exits a pipe and enters the sea, producing a bubbling effect," a spokeswoman for EDF Energy told the Sunday Herald. "The other photograph is of our surge shaft, which the cooling water passes though."

Critics agreed that the green effect was probably not caused by radioactivity, but argued that nuclear power had other drawbacks.

Pete Roche, a nuclear consultant and former Government radiation adviser, said: "No matter how green the glow from Hunterston it cannot make nuclear power an environmentally sound energy source.

"We still have nowhere to put the highly dangerous waste and there are continuous reports of health problems associated with radiation emissions even without any accidents like Fukushima, Chernobyl and Three Mile Island."