FILE - This Nov. 3, 2008, file photo, shows people on an overlook above Pacific Gas and Electric's Diablo Canyon Power Plant's nuclear reactors in Avila Beach, Calif. A senior federal nuclear expert is urging regulators to shut down California's last operating nuclear plant until they can determine whether the facility's twin reactors can withstand powerful shaking from any one of several nearby earthquake faults. (AP Photo/Michael A. Mariant,File)