FILE - In this April 2007 file photo provided by the Tennessee Valley Authority, steam rises from the cooling tower of the single operating reactor at the Watts Bar Nuclear Plant in Spring City, Tenn. The Tennessee Valley Authority has concluded that construction of the power plant, initially budgeted for $2.5 billion, is about three years behind schedule and will cost up to $2 billion more. Licensing delay charges, soaring construction expenses and installation glitches have also driven up the costs of nuclear plants in Georgia and South Carolina, according to an Associated Press analysis of public records and regulatory filings. (AP Photo/Tennessee Valley Authority, File)