Friday, April 1, 2011

As Fukushima fallout circles the globe, nuclear sleuths sift it for clues

Fallout from the Fukushima Daiichi nuclear plant has landed on 30 exquisitely sensitive detectors on desolate Arctic islands, on the tops of tall buildings and in other windy locales across the Northern Hemisphere, according to the Comprehensive Test Ban Treaty Organization, which maintains those sensors. Sniffing the air like silent sentinels, the 63 shack-like stations (with 17 more planned) are capturing tiny radioactive particles in filters much like those on a home furnace. Analysis of that dust is a key step in an intricate process of nuclear sleuthing: The dust’s distinctive chemical signature can show scientists whether the particles blew into the air from a bomb, a damaged nuclear reactor or used uranium fuel. It can even point to the extent of damage suffered by a fission reactor. Tracing global wind patterns back then pinpoints where the emissions originated. “It’s nuclear forensics,” said Berkeley Lab's Kai Vetter, who built his own radiation detector atop a campus building after the Fukushima crisis began. More>