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Global monitoring of Fukushima radiation fallout

Radioactive iodine-131 and cesium-137 are key to this process. They don’t exist in nature, so their appearance signals a nuclear event — either a bomb or a reactor in trouble…..Nuclear detectives can dive deeper still, sorting out whether radioactive emissions emanate from a dangerously active and still-fissioning reactor core, from burning fuel rods, or from used fuel sitting in pools.

As Fukushima fallout circles the globe, nuclear sleuths sift it for clues, The Washington Post, by Brian Vastag 1 April 11, 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 Kai Vetter, a professor of nuclear engineering at the University of California…
In the United States, another network of more than 100 stations maintained by the Environmental Protection Agency is also gathering radioactivity from Japan. State health departments maintain their own monitoring systems, which is how Maryland detected tiny traces in the air and water March 24…….
Radioactive iodine-131 and cesium-137 are key to this process. They don’t exist in nature, so their appearance signals a nuclear event — either a bomb or a reactor in trouble. Both can cause health problems in large amounts. But iodine-131 decays relatively rapidly: After eight days, half the original amount is gone. Its presence means that the event that created it occurred just weeks beforehand. Cesium-137 takes much longer to decay, with a half-life of 30 years. Traces of cesium-137 from Chernobyl still waft on Earth’s great jetstreams…….

Nuclear detectives can dive deeper still, sorting out whether radioactive emissions emanate from a dangerously active and still-fissioning reactor core, from burning fuel rods, or from used fuel sitting in pools.

When the active core of Chernobyl exploded, it sent dozens of different radioactive elements into the atmosphere, including isotopes of strontium, yttrium, and rhodium — all produced only by active reactor cores or burning fuel rods……

As Fukushima fallout circles the globe, nuclear sleuths sift it for clues – The Washington Post

April 2, 2011 - Posted by Christina Macpherson | - Fukushima 2011, technology