Nuclear energy has never exceeded a few percent of the world energy production. Most of it is heavily government subsidized and/or part of nuclear weapons programmes.
Since Uranium is a finite resource, it is not at all clear if supplying the world's demand using nuclear power would be sustainable for more than a few years. Many types of breeder reactors have been proposed and tested over the decades, but so far with very limited success.
In contrast to relying on true regenerative sources of energy, this makes a full commitment to nuclear energy a huge gamble. On top of that, the nuclear waste problem is still largely unsolved. All attempts at long term storage in the German nuclear programme have ended in extremely expensive failures.
There is lots of Uranium in the sea and we use it very inefficiently at the moment, so potentially Uranium based power can be sustainable almost indefinitely.
I recommend reading this chapter from "Sustainable Energy - without the hot air" by David JC MacKay if you want to know more (with calculations!). It is an excellent book for reading about the facts of energy generation.
Sure, there are plenty of interesting proposals for Uranium extraction and breeders. What worries me is that despite decades of large-budget research, most of them have never been successfully demonstrated. I don't think that hoping for all the technological problems to disappear is a very good strategy.
On top of that, even with current easily accessible Uranium sources, nuclear energy is significantly more expensive than both fossil fuels and renewables. I don't see that getting better with even more complicated reactor technologies.
Since Uranium is a finite resource, it is not at all clear if supplying the world's demand using nuclear power would be sustainable for more than a few years. Many types of breeder reactors have been proposed and tested over the decades, but so far with very limited success.
In contrast to relying on true regenerative sources of energy, this makes a full commitment to nuclear energy a huge gamble. On top of that, the nuclear waste problem is still largely unsolved. All attempts at long term storage in the German nuclear programme have ended in extremely expensive failures.