Report: Radioactive Waste Leaking At Washington Nuclear Site YAKIMA, Wash. – Six underground tanks holding a mix of radioactive and toxic waste are leaking at America’s most contaminated nuclear site in Washington, federal and state officials say, posing an eventual risk to groundwater and rivers. The leaking materials at Hanford Nuclear Reservation are no immediate threat to public safety or the environment because it would take perhaps years for the chemicals to reach groundwater, Washington Gov. Jay Inslee said Friday. So far, nearby monitoring wells haven't detected higher radioactivity levels. But the leaks have renewed discussion over delays for emptying the tanks, which were installed decades ago and are long past their intended 20-year life span. "None of these tanks would be acceptable for use today. They are all beyond their design life. None of them should be in service," said Tom Carpenter of Hanford Challenge, a Hanford watchdog group. "And yet, they're holding two-thirds of the nation's high-level nuclear waste."