Uranium isn't the only fuel source, for one. Fusion reactors, if we can figure out the underlying science, world likely use hydrogen. New generation reactors can use Thorium, and breeder tractors are able to generate usable fuel from nuclear waste.

Not to mention, uranium is finite but we have enough supply of it to develop other technologies while we still reduce emissions via nuclear.

And this is discounting new technologies which could allow us to create a large artificial uranium supply.