That is changing.
As California grapples with global warming, energy-industry leaders, environmentalists and policy-makers are subtly but significantly starting to shift their thinking about the controversial power source.
"Nuclear power has to be part of the solution," Stanford University President John Hennessy said at an alternative-energy gathering in Palo Altothis spring. "Can we really understand the notion of risk? Nuclear plants versus carbon emissions which will kill and has killed more people?"
The audience applauded.
Unlike natural gas and coal, nuclear energy does not produce greenhouse gas and is becoming an alternative-energy dark horse.
In California, however, with its strong environmental stance and a 31-year-old ban on construction of new reactors, nuclear power faces immense political and practical hurdles.
Later this month the state's energy commission plans to tread carefully when for the first time it will review new ways to handle the radioactive waste produced by nuclear energy the biggest legal obstacle to building new plants in California. One possible option could be to reprocess, or recycle, the waste.
"We want to understand how the issues have changed regarding reprocessing if in fact it's a viable option or not or just another pipe dream," said John Geesman, a member of the California Energy Commission. "And this is a field filled with pipe dreams."
Other states where nuclear energy isn't as controversial are moving more quickly. The federal Nuclear Regulatory Commission expects applications for as many as 28 new nuclear reactors during the next two years.
That construction boom is spurred by a growing demand for electricity, volatile natural gas prices, concerns about global climate change and federal subsidies. There are 104 operating nuclear reactors in the United States, producing about 20 percent of the country's electricity. The last one opened in 1996.
Dennis Spurgeon, the Bush administration's senior nuclear technology official, said new plants could be running by 2015.
"It's not a pipe dream; it's happening," said Spurgeon, whose experience in energy dates back to the Ford administration. "The existing reactors are very safe. The new ones are even better."
And while many planned nuclear plants have never been built because of the high construction costs and lengthy review processes, the Nuclear Regulatory Commission believes there's enough momentum that some of the expected plant applications will result in construction.
"This time, we are taking it very seriously," said agency public affairs officer David McIntyre. "Our agency has been reorganized to prepare for these applications coming in. We're hiring people right and left. Congress has given us a budget increase."
Even some environmentalists are willing to consider nuclear energy.
"We think global warming is such a tremendous planetary problem that we're not going to refuse to look at it," said Karen Douglas, director of the California climate initiative of Environmental Defense. However, the group does not support an expansion of nuclear-power capacity until issues such as safety, security, waste and nuclear-weapons proliferation are resolved, she said.
Critics such as the Natural Resource Defense Council's Ralph Cavanagh, who has staunchly defended the California moratorium, said talk of a nuclear revival is "as predictable as the spring." He said there are still concerns about waste disposal, the lingering threat of nuclear proliferation and the high costs of building plants.
"The nuclear renaissance tends to be built around idle talk by people with vague ideas around economic development," Cavanagh said.
Other opponents, including Julie Enszer of the Nuclear Policy Research Institute, also raise concerns about the safety of nuclear waste. Americans are still worried about the potential for accidental exposure to radioactive nuclear waste, she said.
"People in the U.S. are still opposed to nuclear power and that hasn't really abated since the partial meltdown of Three Mile Island" in Pennsylvania in 1979. Since then, California in particular has led the nation in the anti-nuclear movement, she said.
"People around the country look to Californians to carry that mantle," she said.
As the nation enters a new nuclear era, the California Environmental Protection Agency's Dan Skopec said climate change provides the perfect opportunity to revisit the controversial power source.
"We need to have a debate on nuclear," said Skopec, who was appointed undersecretary for the agency by Gov. Arnold Schwarzenegger.
In California, one of nine states with laws that hinder nuclear-power-plant construction, about 13 percent of California's energy currently comes from two operating nuclear plants, PG&E's Diablo Canyon and Southern California Edison's San Onofre Generating Station.
There are two separate pushes for more.
A group of Fresno businessmen formed the Fresno Nuclear Energy Group, which plans to introduce a statewide ballot measure next year seeking to override California law and allow voters to decide if they want a $4 billion nuclear plant in that area.
"If your goals are going to be cheap energy to keep the economy rolling and to stop global warming and provide clean energy, the available options at this point in time are very few," John Hutson, president and chief executive of the group.
If approved, the plant could be built in four years, he said.
Patrick Moore, a founder of Greenpeace who has infuriated many in the environmental community because of his stance for nuclear power, said he is "very supportive" of the Fresno strategy.
"If it isn't done, California will never meet its CO2 objective in a millions years," Moore said.
Assemblyman Chuck DeVore, R-Irvine, proposed a bill this year that would lift California's statewide construction ban.
Not surprisingly, the bill died in committee. DeVore said he'll bring it back year after year.
"When rate payers have blackouts and brownouts and they see their residential energy costs spike through the roof, eventually they will call for a real solution," DeVore said.
Until now, California has been able to rely on low-cost coal to provide about 16 percent of its energy. But this year, state regulators effectively banned coal because they ordered utilities to buy power that is as clean as that produced by the latest generation of natural-gas-fired turbines. Coal is not.
The state needs to find replacement power, but faces tough choices. Natural gas is cheap but produces carbon dioxide. Renewable sources such as wind and solar produce no carbon but are expensive and unreliable.
That leaves nuclear energy.
Wind, now the cheapest of renewable energies, is expected to cost 6.8 cents per kilowatt-hour by 2020, according to the Federal Energy Information Institute. Natural gas, by comparison, would cost 5.6 cents per kilowatt-hour. Nuclear energy would cost 6.1 cents per kilowatt-hour. All these figures include the cost of plant construction.
Advocates argue that not including construction costs, nuclear power is the cheapest option of all. The California Energy Commission's most recent estimates put nuclear power's current cost at 1.4 cents to 1.6 cents per kilowatt-hour.
From the outside looking in, the prospect of California trying to cut carbon without more nuclear power seems idyllic at best and impossible at worst, according to business and political leaders nationwide.
"We don't believe that conservation and renewables combined will be sufficient to meet demand in our market for an extended period of time," said Brad Peck, spokesman for the Columbia Generating Station, a nuclear plant in Washington state that feeds a small amount of power to Northern California. "You simply can't conserve yourself into prosperity."
The leader of PG&E Corp., the parent company of Northern California's largest utility, agrees. "We need all of the options to meet this huge challenge and, therefore, nuclear ought to be on the table," said Chairman and Chief Executive Officer Peter Darbee.
The utility doesn't plan to push for a new nuclear-energy plant in California, he said, but will purchase power from out of state.
Tom King, chief executive of PG&E's utility unit, Pacific Gas & Electric, said the company doesn't want to force nuclear reactors on its customers until the public's perception of nuclear energy changes.
"We think it's important that we take the time to educate people ... before we put a stake in the ground and say we need nuclear."
At PG&E's Diablo Canyon, those efforts are in full swing.
During a recent tour for the San Jose Mercury News, an engineer and the communications director repeatedly noted safety and security measures. There are metal detectors and guards, like the ones at airports, searching bags before employees enter the plant. A military-style police force with automatic weapons makes rounds in the spent-fuel area. And the plant itself is a fortress, protected by rolling landscape on one side and a rock barrier on the other.
Public tours stopped after the Sept. 11, 2001, terrorist attacks.
"The industry initially for a long time wasn't interested in necessarily educating the public," said Pete Resler, Diablo Canyon's communications director. He wants to change that.
Resler's renewed interest in winning over the public also could be attributed to a looming deadline for his plant.
Diablo Canyon may have to shut down by 2010 if it doesn't win approval for more storage space. The plant provides 2,300 megawatts of electricity, enough to power about 2 million homes.
Diablo Canyon illustrates nuclear power's biggest challenge: radioactive waste. Radiation exposure, such as the kind that can be caused by nuclear waste, increases the risk of health problems, including cancer.
While nuclear power produces a relatively small amount Diablo Canyon's 22 years of waste would fill a pool about the size of a basketball court dealing with it raises big concerns.
Most nuclear reactors store waste on site in cooling pools or storage cylinders that prevent radiation leakage. Eventually, the plants will run out of storage room.
The federal government approved Nevada's Yucca Mountain as a long-term storage site, but it has faced opposition from Nevadans and some environmental groups who contend that it could not safely store the waste for thousands of years. It is now unclear when or if the storage facility the only spent-fuel storage space approved by Congress will open.
As an additional option, a growing number of industry advocates are offering the idea of recycling the waste, arguing that reprocessing or recycling could cut the volume of waste by allowing about 94 percent of the spent fuel to be reused.
France, which gets 75 percent of its energy from nuclear power, has a successful recycling operation, and the United States is studying the option. Spurgeon said the United States could open a reprocessing facility sometime after 2020.
Opponents say reprocessing would encourage nuclear proliferation, but nuclear supporters like University of California-Berkeley nuclear engineering Professor Per Peterson said such concerns need to be re-evaluated.
"The whole logic of abstaining from a technology so that others would not pick it up no longer makes sense," Peterson said.
Nobel Prize winner Steven Chu, who is also the director of Lawrence Berkeley National Laboratory, echoes the desire to rethink nuclear. He reasons that despite the fears and concerns about the energy source, nuclear power must be considered because it does not produce greenhouse gas during generation. Anything, he said, would be better than carbon-spewing coal plants.
And what of the people who don't want to consider nuclear energy in the hope that less controversial solutions like renewable energy and conservation will be enough?
"If you start thinking like that, then you doom yourself," he said.
Contact Sarah Jane Tribble at stribble(at)mercurynews.com or (408) 278-3499.