Southern Co.'s head of nuclear development told an energy conference Thursday that negotiations on a Department of Energy loan guarantee for new reactors at Plant Vogtle have progressed, and that a deal could emerge by mid year.The guarantee received preliminary approval in 2010. Joseph "Buzz" Miller told the Platts conference the delay in finalizing the financing stems from the terms of the loan guarantee program that usually works with smaller companies. The Wall Street Journal also quoted him as saying negotiations have mostly centered on issues besides the size of the deal's credit subsidy – the capital plant owners would be required to give the government in exchange for the guarantee.Construction is underway on two Westinghouse AP1000 reactors at the plant near Augusta, Ga. The units are expected to cost $14 billion, which its owners maintain they can finance independently if the $8.3 billion loan guarantee does not meet their terms. Southern owns 45.7 percent of the project and will operate the plant, with Oglethorpe Power, the Municipal Electric Authority of Georgia and Dalton Utilities holding smaller stakes.