Beneath the surface of a giant pool at Calvert Cliffs Nuclear Power Plant in Southern Maryland, hundreds of bundles of spent fuel rods sit, throwing off radioactivity. It takes 10 years for the rods to "cool" enough to be shifted from the pool to nearby dry storage.
Just where the bundles and thousands of others like them from nuclear plants across the nation will eventually be stored is the topic of fierce national debate and a major question mark over the future of the industry.
Storing nuclear waste is not the only aspect of the plants that is worrying these days. Nuclear plants are seen as attractive terrorist targets and have been ever more tightly guarded since the Sept. 11 attacks.
Armed guards patrol the Calvert Cliffs plant in Lusby, which supplies a half-million customers with electricity. Airport-style monitors are used to scan employees and visitors, while the Coast Guard keeps boats on the Chesapeake Bay at safe distances.
Despite all of this, the long-ailing nuclear industry appears poised for revival.
Oil producers are struggling to meet soaring demand from China and other fast-growing Third World nations. That combined with limited refining capacity and other supply problems is driving global oil prices sharply higher.
Natural gas prices are moving higher too. There is growing concern about environmental effects of carbon dioxide emissions from coal-fired generators, and the potential of other energy alternatives seems limited.
So nuclear power - which already supplies electricity to one of five U.S. homes and businesses - is gaining renewed appeal, especially since the Bush administration favors it.
Without nuclear as a key contributor in a diversified U.S. energy portfolio, proponents say, the United States will never be able to meet a demand for electricity that is expected to grow 40 percent to 50 percent over the next two decades.
Since March, three separate groups of energy companies have formed consortiums hoping to join with the U.S. Department of Energy in testing a new licensing process for building and operating nuclear reactors.
One coalition includes Calvert Cliff's owner Constellation Energy Group Inc. of Baltimore, eight other power companies and two reactor vendors.
The coalition, known as Nu- Start Energy Development, plans to commit some $400 million to jointly apply for what would be the first new nuclear power plant license in decades.
"There's a growing recognition that nuclear is here; it's not in the future, like developing better solar panels or windmills," said Gilbert Brown, a professor of the nuclear engineering program at the University of Massachusetts at Lowell. "It's not like we need to develop it. We have it."
Michael J. Wallace, president of Constellation Generating Group, the power production arm of Constellation, says that for all its challenges the appeal of nuclear cannot be denied in an increasingly unstable world.
"When we look at nuclear, we are taking a long-term view of the energy needs for the country and what are the best sources, all things considered, to meet those energy needs," said Wallace. "Nuclear moves to the very top of the list. The world uranium supply is very significant, and much of it is in markets we'd expect to be open to us for along time."
Such enthusiasm represents a significant turn.
No company has applied to build a nuclear plant since 1973, when conservation efforts helped slow growth in electricity demand. Capital investments in new power plants declined, and utilities began favoring less costly natural gas-fired plants.
After the nuclear accident at Three Mile Island in Pennsylvania in 1979, some projects were canceled, though 51 nuclear reactors with prior approvals were completed throughout the 1980s and one as recently as 1996.
Since then, gaining regulatory approval of untested new plant designs has proven to be an insurmountable barrier to building new nuclear plants.
Still, energy experts and utility executives tout the industry's strides in safety and efficiency.
They say advanced plant designs offer promising potential - improved safety, stable fuel prices and lower production costs, and less environmental impact than other fuels, including coal and natural gas.
Nuclear energy, they say, is close to being cost effective. Though capital costs are much higher than other forms of power generation, operational costs are much lower than either gas or coal fired plants.
As a measure of the increased efficiency, the existing 103 U.S. plants have been able to generate electricity at what would have been the equivalent of adding about 26 1,000 megawatt plants, thanks to equipment upgrades and shorter outage times in the past decade, according to the Nuclear Energy Institute, the industry's policy organization.
"Nuclear is clean, safe and reliable," said Thelma Wiggins, of the Nuclear Energy Institute. "When you're looking at environmental issues this country and the world are now facing, you cannot meet the goals we're trying to meet as a nation and as a world without nuclear generation."
"The world is having to look at how they're generating electricity and realizing nuclear is a very important component to include if you're serious about combating global climate change," she said. "It's something our industry has known, but since the environmental awareness is growing in the U.S. and in the world, the benefits of nuclear are being recognized more."
South Korea, Japan, China and Taiwan have nuclear plants under construction, and Finland has announced plans to build a reactor.
Leaders in environmental movement have long objected to the use of nuclear energy, saying the uncalculated costs of fuel disposal combined with the extraordinary dangers of operating nuclear plants more than overcome claims of efficiency.
But some say the risks have been exaggerated.
"Opposition to nuclear energy is based on irrational fear fed by Hollywood-style fiction, the Green lobbies and the media," James Lovelock, an environmental scientist who was among the first researchers to warn of global climate change, wrote in commentary published in London's Independent in May. "These fears are unjustified, and nuclear energy from its start in 1952 has proved to be the safest of all energy sources."
David Lochbaum, a nuclear safety engineer for the Union of Concerned Scientists, an environmental watchdog organization in Cambridge, Mass., agrees that nuclear plant safety has improved over the past two decades.
But, "they're not inherently safe. It's a very inherently dangerous technology, and we have to be constantly vigilant to make sure the genie doesn't get out of the bottle. One bad day can wipe out a thousand good days."
The group argues that future energy needs can and should be met without building either new fossil-fuel fired plants or more nuclear generating plants. Rather, it says, the challenge can be met with a mix of renewable energy - wind power, solar power, bio-mass, fuel cells, geothermal - as well as increased power plant efficiency and better conservation.
The nuclear industry has made new plants unnecessary by increasing efficiency at existing plants, Lochbaum said. Eventually he believes, a new technology will replace nuclear and fossil fuels.
"Nuclear power was the technology of the 20th century. Now other technologies will come to the forefront in the 21st century, like horses to cars, a natural progression," he said.
None of the companies in the new nuclear consortiums have committed to building a plant. Rather, they hope to keep the option open for the future, by advancing new, safer plant designs and learn whether a streamlined, but untested, permitting process through the Nuclear Regulatory Commission will lower historically high construction costs.
The lengthy process of applying for a construction license, then returning to apply for an operating license drives up capital costs, but the new method would combine the construction and operating license.
Constellation, the parent of Baltimore Gas and Electric Co., belongs to the largest consortium, NuStart Energy Development. The group intends to spend some $400 million, which would be matched by the Department of Energy.
The group seeks to analyze sites for a new plant, then work to complete details for reactors that have been designed (but not yet built) by Westinghouse and General Electric, also consortium members. The one-time engineering work would also include having those designs certified by the NRC.
"At the end of the day, you would have both of these U.S. technologies positioned to be marketed for immediate sale and deployment in the U.S.," said Marilyn Kray, president of NuStart Energy and vice president of project development for energy company and consortium member Excelon Corp.
Having engineering work done on the more advanced designs that are easier to build and easier to operate could be the key to getting new plants being built, said Brown, the University of Massachusetts expert.
"The linchpin here is if you can build the plants for the right price, going forward that's a win-win. That's what's getting everyone excited. ...These could be the most economical plants around," he said.
After the Energy Department reviews plans, one or all groups could submit their applications to the Nuclear Regulatory Commission, which would need to approve the plans.
After the NRC's approval, any combination of members could use the license to build a new plant by about 2010, which is the year set by the Energy Department program. Some say it's conceivable that a company could announce plans to build a plant sooner.
Constellation owns five nuclear reactors that generate 55 percent of the company's power output, It has been acquiring from companies shedding them.