FILE - This Nov. 3, 2008 file photo shows aboveground casks designed to store radioactive waste from a nuclear reactor at Pacific Gas and Electric's Diablo Canyon Power Plant in Avila Beach, Calif. A senior federal nuclear expert who was stationed at the plant is urging regulators to shut down the facility until they can determine whether it can withstand powerful shaking from any one of several earthquake faults that have been discovered near the complex in recent years. (AP Photo/Michael A. Mariant, File)