While dark memories of nuclear accidents at Three Mile Island and Chernobyl have virtually frozen nuclear-power development in the West, energy-hungry Asia is increasingly embracing the nuclear option.
On the 50th anniversary of the birth of nuclear power, analysts say it will be the example of fresh nuclear success in Asia - where 18 of 27 new plants worldwide are being built - that may determine the future of atomic power in the West.
China and India are pursuing especially ambitious nuclear plans. Confronting cities choked with pollution but with few fuel resources, they have started up nine new plants in the past four years, and are building 10 more. Industry sources say China is aiming for a total of 30 plants in 15 years.
Those moves contrast sharply with the atom's fall from grace in the West. Though the US operates 104 plants - nearly a quarter of the global total of 442 - it has not issued a new building permit since before the 1979 accident at Three Mile Island. The story is similar in western Europe. The 1986 Chernobyl disaster sowed fear - and only one new plant is now being built, while several countries are phasing out nuclear power or rejecting it altogether.
"Despite the array of measures that have been put in place since Chernobyl to offset the possibility of a severe accident, these risks can never be brought to zero and they continue to weigh heavily on public perceptions," said Mohamed ElBaradei, chief of the UN International Atomic Energy Agency (IAEA), who was in Moscow on Sunday.
Since the atom was first harnessed for peaceful purposes - at the reactor at Obninsk, 60 miles south of Moscow, half a century ago this weekend - the history of nuclear power has proven to be a double-edged sword. While nuclear power is a "clean" fuel that emits virtually no greenhouse gases and is cheap once plants are built, it has also created a mountain of radioactive waste and facilitated the spread of weapons-grade nuclear material.
The risk of terrorism - forecast most graphically as the possibility of Al Qaeda becoming the world's ninth nuclear-weapons power - further complicates the picture. Mr. ElBaradei warned of the urgent risks last week.
"We are actually having a race against time, which I don't think we can afford," said ElBaradei. "The danger is so imminent ... not only with regard to countries acquiring nuclear weapons but also terrorists getting their hands on some of these nuclear materials, uranium, or plutonium."
Reflecting the same concern, the US Department of Energy signed in late May a $450 million deal with Russia to repatriate tons of weapons-grade highly enriched uranium (HEU) that Moscow sent to 20 reactors in 17 countries over the years. In the years following President Eisenhower's "Atoms for Peace" speech, the US shipped large quantities of highly enriched uranium (HEU) to more than 40 countries.
"There is a famous saying that 'Atoms for peace and atoms for war are Siamese twins,' " says Charles Ferguson of the Washington office of the Monterey Institute's Center for Nonproliferation Studies and coauthor of a new book on nuclear terrorism. "Maybe it's impossible to separate them. Is the IAEA the group of surgeons we would turn to? They can't do it alone. We need an enforcement mechanism."
But such concerns are a world away from the euphoria first sparked at Obninsk. "We were sure at that moment it was the beginning of something new," recalls Soviet senior engineer Arkady Karpov.
Already there are signs that nuclear power is beginning to make a comeback in the US. Three new permits are currently undergoing review and 26 existing plants have so far had licenses extended for 20 more years.
But worldwide, nuclear power accounts for just 16 percent of global electricity output - the same as in 1986. An IAEA report released this weekend notes that expert projections, based on future energy needs and expected depletion of fossil fuels, indicate that nuclear power will increase 2.5 times by 2030, to 27 percent of global output.
That trend, many say, could help ease global warming. To illustrate the difference, the IAEA figures that shutting down every nuclear plant and replacing it with nonnuclear sources would result in 600 million tons of carbon per year: twice the amount meant to be cut by the Kyoto Protocol in 2010.
But how safe is a nuclear future? "Do I ever lose sleep [over safety issues]? No. Do I ever lose a sense of concern? No, that concern is always there," says Ken Brockman, director of the IAEA's division of Nuclear Installation Safety. Lessons of past accidents now mean stricter rules and a host of backup and safety mechanisms.
"Three Mile Island led to "total public skepticism, and in some quarters it's way beyond skepticism - it's just a violent anti," says Mr. Brockman, who worked for the US Nuclear Regulatory Commission until early last year.
Today the pendulum is beginning to swing back. "I think there will be a grudging acceptance," says Brockman. "It's not like Star Trek, where the entire planet is powered by hundreds of fusion reactors, but it will be part of the [energy] mix."
"The people pushing this are industry, and even regulators like the NRC," says George Bunn, a nuclear expert now at Stanford's Center for International Security and Cooperation. "People haven't paid attention [to nuclear issues] for a long time. Chernobyl and Three Mile Island are a long way back in time. There's a new generation that doesn't remember that."
A reason for spreading nuclear materials is the 1968 nuclear Non-Proliferation Treaty (NPT) - it codifies acceptability of countries to pursue peaceful nuclear technology.
While scientists dreamed of nuclear-powered cars, aircraft, rockets, and even a dirigible, the technical liberties have been abused by several nations. India used Atoms for Peace cooperation as the "bedrock" for its secret weapons program. Israel also, before it quietly began receiving bombmaking assistance from France inthe late 1950s, considered using Atoms for Peace in the same way.
North Korea beefed up its nuclear technology legally until last year, when it withdrew from the NPT and declared its secret pursuit of the bomb. Washington argues that Iran, which was rebuked earlier this month by the IAEA for not fully cooperating with inspections, is following that same path.
Another long-term problem is the fate of nuclear waste, which "so far in the last 50 years has been piling up a lot faster than we've been able to find repositories," says Ferguson of Monterey. There is a "fundamental mismatch" between the 40-year lifespan of a nuclear plant and its residual impact.
"So you get a greenhouse gas benefit that is a tremendous long-term issue we've got to deal with," he says. "But even longer term is the spent fuel ... that will stay radioactive for 10,000 years."