Investigators said officials could have prevented the poor management and lapses in safety that led to radiation contamination inside the federal government's only underground nuclear waste repository.
The shortcomings in New Mexico were outlined in a final report released Thursday by the United States Department of Energy's Accident Investigation Board.
Investigators spent more than a year looking into the cause of the radiation release at the waste isolation pilot plant.
Like a separate team of experts, they also found that the release was caused by a chemical reaction inside a drum of waste that had been packaged at Los Alamos National Laboratory.
Federal officials said it could take years and cost more than half a billion dollars to reopen the repository.
The Energy Department and its contractors are facing $54 million in fines from the state of New Mexico for the failures that led to the mishap.
