Seven hours after the Aug. 19, 2009 automatic shutdown of the Wolf Creek nuclear plant, due to an electric problem related to a lightning strike, an NRC inspector found water leaking from the system that cools the emergency diesel generators and virtually all other emergency equipment.
An internal study in 2007 had forecast such leakage, showing that a vital cooling system was prone to rust damage that would result in leaks. Management did nothing, the UCS report says. In 2008, the same piping developed the leaks, just as predicted. Management only patched the leaks, doing little about the rusting causing the problem. In 2009, the piping developed more leaks. This time, workers failed to notice the water puddling on the floor until an NRC inspector found it 7 hours later.
(While the event occurred in 2009, the NRC report appeared in 2010.)