I've heard some persuasive arguments that nuclear has a fairly high carbon footprint when you look at the whole process from extracting the uranium, using concrete to build numerous facilities (power stations, reprocessing plants, storage bunkers) and finally managing the waste product for centuries into the future.
I've also heard persuasive arguments that the potential to substitute to nuclear is limited by the scarcity of uranium as a resource. As supply dwindles the purity declines and more resources will be spent extracting uranium and more waste produced i.e the waste from which the uranium has to be extracted.
Which isn't to mention the nuclear industries other 'green' credentials.
I've heard similar - I've yet to do the reading to make my own mind up.
IMHO:
If it is the case, then we're left with reduction in energy consumption as the immediate strategy?
Against: It requires buy-in on a level that requires a rapid acceleration of awareness, or (stick version) drastic measures that are politically unacceptable.
Pros: There's no technical impediment or build-time issues. If attitudes change, it can happen quite quickly.