"Eighty percent of the world's nuclear power plants are more than 20 years old, raising safety concerns, a draft U.N. report says a year after Japan's Fukushima disaster. Many operators have begun programs, or expressed their intention, to run reactors beyond their planned design lifetimes, said the International Atomic Energy Agency (IAEA) document which has not yet been made public."

"'There are growing expectations that older nuclear reactors should meet enhanced safety objectives, closer to that of recent or future reactor designs,' the Vienna-based U.N. agency's annual Nuclear Safety Review said.

'There is a concern about the ability of the ageing nuclear fleet to fulfill these expectations.'"

Fredrik Dahl reports for Reuters March 13, 2012. [2]