Questions raised about flaws in Hanford storage tanks

Questions raised about flaws in Hanford storage tanks
In this April 3, 2008 file photo, a sign warns of radiation on the Hanford nuclear reservation near Richland, Wash. (AP Photo/Ted S. Warren, File)
SPOKANE, Wash. (AP) -- New documents show there are "significant construction flaws" in some newer, double-walled nuclear waste storage tanks that could lead to additional leaks at the Hanford nuclear complex in Washington state.

Those tanks hold some of the worst radioactive waste at the nation's most contaminated nuclear site.

One of the 28 giant underground tanks was found to be leaking in 2012. But documents obtained by The Associated Press show subsequent surveys of other double-walled tanks performed by a contractor for the U.S. Department of Energy found at least six shared defects with the leaking tank that could lead to future leaks.

The documents say 13 additional tanks also might be compromised.

Questions about the storage tanks jeopardize efforts to clean up radioactive waste at the southeastern Washington site. Those efforts already cost taxpayers about $2 billion a year.