US authorities say six underground storage tanks at the Hanford nuclear site in the western Washington state have been leaking radioactive waste. Earlier they had said only one was leaking, but insist there is “no immediate” risk to public health.
However Governor Jay Inslee said “nonetheless this is disturbing news for all Washingtonians”.
The tanks, a few kilometres from the Columbia River, a major source of drinking water, are more than six decades old.
The site, which closed in the late 1980s, produced plutonium for one of the atomic bombs dropped on Japan at the end of World War II.