Funds To Shut Nuclear Plants Fall Short

—Owners at 19 plants have won approval to mothball reactors for as long as 60 years. A method called Safestor has been approved for reactors including the three Palo Verde units in the Arizona desert and the Three Mile Island 1 reactor near Harrisburg, Pa.

Under this method, radioactive fuel is removed from the reactor and the spent fuel storage pool and is stored in dry casks on plant property. Plant systems are drained of water, and the remaining radioactivity in the plant is left to decay until the facility is dismantled.

But some analysts worry the utility companies that own nuclear plants might not even exist in six decades.

"Our concern is that they'll just walk away from it," said Jim Riccio, a Greenpeace nuclear policy analyst. "It's like a sitting time bomb. The notion that you can just walk away from these sites and everything will be hunky-dory is just not true."

—The operators of 54 nuclear plants, or more than half in the U.S., have already received 20-year license extensions. Sixteen more are being reviewed, and the commission expects to receive 21 more applications in the next several years. To date, the NRC hasn't turned down any license extensions.