Clues to events at crippled plant found in traces of radiation reaching Pacific Northwest
Radioactive particles wafting eastward over the Pacific Ocean from Japan have been spotted in Seattle and used by a forensic team of physicists as a window into recent events inside the crippled Fukushima Daiichi nuclear plant 5,000 miles away. Working backward from these nuclear byproducts, the physicists have confirmed that contaminated steam is the source of this radiation, not spent fuel rods or material ejected directly from the reactor core.
“We haven’t seen any of the heavier stuff that would come right from the core, which people saw 30 years ago during the Chernobyl accident,” says Andreas Knecht, a nuclear and particle physicist at the University of Washington in Seattle who published the new data online March 24 at arXiv.org.
Starting March 16, Knecht and his colleagues saved and analyzed the air filters that clean 100 million liters of air every day in the ventilation system of the University of Washington’s physics and astronomy bu