The construction of new reactors in the United States has stalled since the Three Mile Island accident in 1979.
Two new projects, from Southern Co's Georgia Power unit and SCANA Corp's South Carolina Electric & Gas Co unit, however, are on track to receive the combined construction permit and operating licenses COL from the U.S. Nuclear Regulatory Commission NRC, possibly before the end of 2011, S&P said.
Both companies want to add two of Westinghouse Electric's 1,154-megawatt AP1000 reactors at existing nuclear power sites: Southern's Vogtle plant in Georgia and SCANA's Summer plant in South Carolina.
Westinghouse is majority owned by Japan's Toshiba Corp and the U.S. construction firm Shaw Group Inc.
The S&P analysts said improvements in the regulatory process should help the U.S. projects to proceed with few material delays.
"In light of the cost and complexity of the new nuclear plants' designs and the four- to five-year construction period, the current licensing process can help companies avoid committing significant capital to a project until they have received all necessary licenses," Standard & Poor's credit analyst Dimitri Nikas, said in a statement before the call.
The new plants benefit from the NRC's revamped licensing framework established in 1989, which addresses all safety, design, construction, and operational aspects of a plant up front, before construction begins. In the past, nuclear operators had to apply for a license to build the plant and later apply another license to operate it.
The combined operating license includes a certified nuclear plant design that is likely to be more than 90 percent complete when construction begins, as well as an early site permit, which is effectively an environmental review.
Once the NRC approves the combined operating license, the company can begin full construction of the new plant.