You're aware that current commercial nuclear power plants cannot power the world, right? They are thermal burner reactors. Supplying the entire world's current primary energy demand would require about 6000 1 GW(e) (which is 3 GW(th)) reactors. These would use up current uranium resource (not reserve) in about five years.

A nuke powered world will either require radically new sources of uranium (like sea water uranium extraction) or breeder reactors. Neither is available now, unlike cheap electrolyzers for making hydrogen (< $300/W in China).