John Tierney today:

Meanwhile, there was a surprise on the hard path, too. Once utilities stopped building reactors, the share of electricity from nuclear power was projected to decline steadily as the oldest reactors were retired. But then several new “merchant energy” companies began assembling fleets of reactors sold off by local utilities. The new owners standardized operations, retrained workers and brought in human-factor engineers to redesign the famously indecipherable control panels.
Under the old owners, the reactors were balky white elephants operating only 60 percent of the time. By improving maintenance and preventing mistakes, the new owners kept them running 90 percent of the time and won permission to upgrade their capacities. So even as the nuclear industry was shrinking in the last two decades as the oldest reactors shut down, the remaining ones were profitably generating an increasing share of the country’s electricity.
Today about 20 percent of electricity in America is generated by nuclear power, which is about 20 times the contribution from solar and wind power. Nuclear power also costs less, according to Gilbert Metcalf, an economist at Tufts University. After estimating the costs and factoring out the hefty tax breaks for different forms of low-carbon energy, he estimates that new nuclear plants could produce electricity more cheaply than windmills, solar power or “clean coal” plants.
The outlook could change, of course, if new nuclear plants turn out to be more expensive than expected, or if engineers make breakthroughs in other technologies. (To debate these possibilities, go to www.nytimes.com/tierneylab.) Given the uncertainties, Dr. Metcalf cautions, it would be risky to bet everything on nuclear power as the answer to global warming.
But it seems even riskier to bet on just the soft path, as so many greens are doing, either by flatly opposing nuclear power or by setting so many conditions that no plants could be built for decades, if ever. (Mr. Obama says nuclear power is necessary but should not be expanded until security and safety issues are addressed.)