Nuclear electric power production carries risks, which are outweighed by the expectations of lives saved by reducing air pollution and greenhouse gas production.
While coal plants do emit more radioactivity through the chimney than nuclear plants, that radioactivity pales in comparison to that emitted by both the nuclear waste and accidents of the latter. See http://skeptics.stackexchange.com/questions/1018/do-coal-pla... for sources.
Also, nobody said coal and nuclear are the only possible technologies for creating electricity.
I disagree that nuclear waste is a problem. To the extent that it is a problem, the solution is stupidly simple: store it in Antarctica where no technologically-illiterate humans can possibly come into contact with it, and where we can reclaim it later if/when we need it.
Also, nobody said coal and nuclear are the only possible technologies for creating electricity.
They're what we have to work with. Renewable sources should be aggressively explored and developed, but they are currently not sufficient by themselves.
And you don't mind that it's not a long-term solution, as silt builds up behind the dam until your dam is worthless.
But yeah, dam away!
You can let some of the water flow take silt away, at least the silt anywhere near the dam. That might mean you don't have a huge reservoir, but you can generate a lot of power without a reservoir at all.
Second dredging actually works and is vastly cheaper.