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 one percent of the tumbleweeds corralled and compacted at Hanford are radioactive, the cost of the clean-up 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.