IDAHO FALLS - Federal officials say the first known rupture of a barrel containing radioactive sludge at an eastern Idaho nuclear site might not be the last.
That's because secretive record keeping during the Cold War makes it hard for officials to now know the exact contents of similar barrels.
The U.S. Department of Energy said Thursday that the 55-gallon barrel ruptured late Wednesday at the 890-square-mile site that includes the Idaho National Laboratory.
Officials say crews responded to a containment structure at the Idaho Cleanup Project's Radioactive Waste Management Complex.
Officials say no one was injured and there's no threat to the public.
Experts say more barrels might contain a rupture-inducing mix of radioactive and other materials.
The barrels are from nuclear weapons production at the Rocky Flats Plant near Denver, Colorado.
