My general caution with energy is people often talk past each other. One side will say "(blank) is currently impractical and wildly expensive" while the other side will say "no you're wrong, long term forecasts expect the cost to come down with technology improvements likely to expand functionality." Both sides miss the time scale the other is using. I'm probably just as guilty of this. Utilities tend to be in the first camp. Nobody wants serial number 1. It's too much risk for an industry that demands extremely high uptime.
I don't know much about McKibben, but Googling him I see he's a part of 350.org. Metric, a band I like, had 350.org at shows in the lobby a year or so ago. Just stealing the line from his Wikipedia article: I agree with that entirely. If the goal is carbon reductions, nuclear can play an important role at the expense of nuclear waste and risks. But many of the people actively concerned about carbon emissions are similarly concerned about nuclear waste and risks. And my thought on that is holding firm on no nuclear directly results in more coal and natural gas use. When we were being taught multiplication and division, I remember being shown a film (may have been actual film; this was about 1988) with a skit where someone was hired to cut a 10" piece of candy into three, 3" pieces. And if they wasted any, they'd be fired. In the skit, the factory said they just couldn't find someone to do this simple task. So the employee cut three pieces and ate the leftover 1". I think of that when I see calls for low or no carbon wind and solar energy supplies. While coming from a good place, it's impractical (at today's costs) and ends up with a very flawed system meeting nobody's goals.McKibben has been quoted as saying that he personally believes increased use of nuclear power is necessary to reduce carbon emissions, yet he is reluctant to publicly promote nuclear energy because such a position “would split this movement in half”.
Founder of 350.org. He's got about a chapter and a half in this book (starts on pp. 57) where his argument is that nuclear is nice and all, but much of the economies it gains are due to subsidies and externalities. He quotes a study that puts the real-world capital expenditure cost of new nuclear plants at 17 to 22 cents per kWH. Not only that, but from a real world standpoint you have to consider the community response and regulatory antagonism nuclear power faces which push nuclear reactors years late and over budget."Bottom line: building enough conventional nuclear reactors to eliminate a tenth of the threat of global warming would cost about $8 trillion, not to mention running electricy prices through the roof. You'd need to open a new reactor every two weeks for the next forty years and, as the analyst Joe Romm points out, you'd have to open ten new Yucca Mountains to store the waste. Meanwhile, uranium prices have gone up by a factor of six this decade because we're - you guessed it - running out of the easy to find stuff and miners are having to dig deeper."