Building the first in a new generation of nuclear power plants could take at least a year longer than expected and involve hundreds of millions of dollars in extra costs.

Atlanta-based Southern Co. planned to have the first of its new reactors at Plant Vogtle built by April 1, 2016. A second reactor in eastern Georgia was supposed to start operating the following year.

A nuclear engineer hired by Georgia's Public Service Commission, William Jacobs Jr., says he believes the first plant will not be completed earlier than June 2017. He says longer delays are possible.

Building the new power plant costs an estimated $14 billion. Jacobs says delaying construction by a single year adds hundreds of millions of dollars in construction and financing costs

Tags: Plant Vogtle, delays, nuclear power, construction cost