(Reuters) - Southern Co, one of the biggest U.S. power companies, said it hopes to announce plans by the end of the year to build more nuclear reactors, a spokesman said late Wednesday.

That makes Southern the first company to pursue new reactors since the U.S. Environmental Protection Agency announced plans earlier this year to reduce carbon emissions from existing power plants to 30 percent below 2005 levels by 2030. Nuclear reactors produce almost no carbon emissions.

The company is already building two new 1,117-megawatt reactors at its Vogtle nuclear site in Georgia and Southern Chief Executive Tom Fanning said any new reactors would be of the same Westinghouse AP1000 design.

Westinghouse is majority owned by Toshiba Corp, a Japanese conglomerate.

Fanning made his comments on Wednesday on the sidelines of a conference in Washington held by the Bipartisan Policy Center, according to a report from Platts.

The company is evaluating six possible sites for additional reactors, including existing plants and greenfield locations, Fanning said at the conference.

The Vogtle units under construction cost about $14 billion but delays related to licensing have added about $381 million, Southern said.

In the past it has taken years to gain the federal and state approvals needed to build a new reactors. Southern applied with the U.S. Nuclear Regulatory Commission to build the Vogtle units now under construction in 2008 and finally gained NRC approval in 2012.

Southern expects the first new Vogtle reactor to enter service in late 2017 or early 2018, with the second unit on about a year later.

More than a dozen companies have considered construction of new reactors since the so-called nuclear renaissance in the early 2000s when the U.S. government was expected to adopt rules to limit carbon emissions and the cost of fossil fuels like natural gas were high.

But until now the government has failed to adopt carbon regulations and gas prices have plunged as the increased use of hydraulic fracturing, horizontal drilling and other new technologies has opened up the nation's shale fields for economic development.

Only Southern and Scana Corp, which is building two AP1000 reactors in South Carolina, are actually building new nuclear units.

For a list of other proposed nuclear projects, see

(Reporting by Scott DiSavino; Editing by Meredith Mazzilli)