Nuclear power emits almost no CO2. Emissions from building the plant are saved in two or three months of operation. So, for the climate, it's green. Likely the spent fuel disposal problem can be solved.

But this NYTs article places the cost of a 1000 MW plant at $5 billion, and shows we came fairly close to another Three-Mile Island accident in 2002. This time the nuclear industry was clearly misbehaving. Now a 1000 MW wind farm costs only about $2.2 billion, but it produces only 1/3 the amount of power (the wind is rarely at top speed). Also nuclear power is far more dependable as a replacement for coal. So in fact wind is more capital intensive than nuclear, but it's likely cheaper to operate.

It's a tough call, but there's a pretty easy answer. Price carbon emissions to make coal more expensive and give wind and nuclear a fighting chance. Then see which one wins. Just stop the other subsidies to both of them. If we are not saving enough carbon, increase the price of carbon—that costs us very little if you give back the tax revenues like James Hansen says to.