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Russian thistle is a dead menace here on the windswept desert of south-central Washington.
Each winter, the deep tap root on the plant decays, and the spiny brown skeleton above ground breaks off and rolls away. But that's about as likely as a Soviet reunion. While less than 1 percent of the tumbleweeds corralled and compacted at Hanford are radioactive, the cost of cleanup can run into millions of dollars. Hanford is the most contaminated nuclear site in the country, built in 1943 for the top-secret Manhattan Project. For 40 years, Hanford made plutonium for the nation's nuclear arsenal, including the atomic bomb that was dropped on Nagasaki, Japan.