Joe Romm is testifying before the Senate EPW today and has a nice, concise statement on nuclear power that's worth reading. (It's based on a longer report that he wrote for the Center for American Progress here.)
Romm's less-controversial point—or at least it shouldn't be controversial, though I imagine it won't be popular—is that, at the moment, nuclear power is still far more expensive than a lot of the other alternatives to fossil fuels. American Electric Power CEO Michael Morris, for one, has given up on the economics of new nuclear plants and is getting out of the business for now. All told, thanks to countless cost overruns and material bottlenecks, electricity from new nuclear plants looks to cost upward of 12-17 cents/kWh across the plant's lifetime, according to the nuke experts at the Keystone Center (retail electricity prices currently hover around 9 cents/kWh).
And that's compared with less than 8-9 cents/kWh for wind, according to the Energy Department's recent opus on the subject, and the equivalent of 2-3 cents/kWh for many California-type efficiency programs. (Some utilities are even contracting for concentrated solar for 14-15 cents/kWh—comparable to, if not cheaper than, nuclear.) That doesn't mean nukes should be ruled out entirely—Romm concedes that they'll need to play a supporting role in decarbonizing the economy. On the other hand, if Congress has only limited resources for orchestrating a shuffle away from fossil fuels, efficiency and renewable power seem like better investments in the short term—although John McCain has argued for exactly the opposite.
Of course, one way Congress could give nuclear a boost would be to expedite the licensing process for new plants, but Romm argues against this, too, saying the "economic and safety risks are too high." I'd imagine this point will be a lot more controversial—McCain, for instance, opposes any cap-and-trade bill that doesn't have a provision for expedited licensing. I'm not sure how big a brawl this could be, although even if the licensing process was changed, the costs alone still make it unlikely that nuclear will play more than a relatively small role (say, 10 percent) in a future low-carbon diet.