The Nuclear Regulatory Commission has received applications to build 15 new reactors in eight states. Later this year, plants in seven other states plan to seek permits for a dozen more reactors.
The first could be built and operating by 2016.
While 104 commercial nuclear reactors remain in operation in the U.S., the NRC has not approved a construction license for a new reactor since 1978.
The nuclear revival is far from a done deal, however. Companies still must arrange financing, and will need federal loan guarantees and states' approval to hike rates to pay for construction if those loans are to be affordable.
The current push is being driven by soaring demand for electricity nationwide - about 25 percent more electric-generating capacity will be needed by 2030, according to industry experts. And utility companies say environmental and regulatory hurdles have stalled their efforts to build more coal-fired plants.
Economic incentives included in a 2005 energy bill passed by Congress are another factor, encouraging utilities to build new, advanced nuclear reactors that produce no greenhouse gases but cost billions to build.
"We're talking about a trillion-dollar investment in the nation's power infrastructure," said Steve Kerekes, a spokesman for the Nuclear Energy Institute, the industry's policy organization. "That's a very substantial undertaking in providing the electricity that we all depend on.
"We have to have nuclear power as part of that," he said. "We need renewables, but by themselves, that's not going to get us where we need to be."
But critics say solar, wind and other "greener" electricity-producing alternatives can play a bigger role, and that nuclear reactors are expensive and dangerous. Some residents near the proposed sites have protested, saying nuclear plants could become terrorist targets. Opponents also are concerned that while the updated reactors called for in the plans are used in Europe, they are untried in the U.S.
And in arid states such as Texas, where two companies are looking to build new reactors, there are concerns about the vast amounts of water such plants require. Most of the new plants would be built in the South, which has faced severe drought recently.
"Investing in a very expensive nuclear plant with technology that's never been used in this country is a risky and costly option," said Cyrus Reed, conservation director of the Sierra Club's Lone Star Chapter. "And there's no power source that uses more water, which is especially a problem in parts of Texas."
The last time the NRC approved a construction license for a nuclear reactor was in 1978 near Raleigh, N.C.; it started operating in 1987. The last reactor to go online in the U.S. was in 1996 - Watts Bar near Spring City, Tenn. - although its construction license was approved in 1973.
Dozens of permits were issued in the 1960s and '70s and nuclear reactors were built in the '70s and '80s, although some projects were scrapped because of high costs and new regulations, said Sam Walker, an NRC historian.
In 1979, an accident at the Three Mile Island nuclear power plant near Middletown, Penn., caused radioactive materials to be released. It was the most serious commercial nuclear plant disaster in the nation's history.
Although no one died, the NRC didn't issue licenses for a year and a half and the disaster prompted significant changes to safety, regulations and oversight, Walker said.
Since then, existing nuclear reactors have increased output by 25 percent, Kerekes said. But many are reaching their limits and some must eventually be decommissioned due to age.
The NRC received its first application in about 30 years in November, when Houston-based NRG Texas applied for a license to build two reactors at its South Texas Project near Bay City.
Dallas-based Luminant Power is expected to apply in September to build two reactors at its Comanche Peak plant in Glen Rose, about 50 miles south of Fort Worth. Luminant spokesman Tom Kleckner said the reactors are used in Japan, based on proven technology and have a good operating record.
Utilities looking to build new nuclear plants may have to wait in line for the huge steel containers that house the reactors. Most of the vessels - about the size of a 6-story building - are supplied by a single Japanese company.
They will also face the still-unresolved issue of long-term nuclear waste disposal.
The Bush administration is trying to get approval for a national 77,000-ton nuclear waste dump at Yucca Mountain outside Las Vegas. Federal law requires the government to take spent reactor fuel piling up at commercial power plants and defense sites.
But Nevada's attorney general has recently challenged that plan.
"We feel it's very important to go ahead with the project because we need to stop greenhouse gas emissions," said David Knox, an NRG Texas spokesman. "We're confident the government will meet its obligation."