It’s enough for hundredthousand of years, if only one time happens a SuperGAU. Only once is enough.
And the nuclear waste is dangerous as fuck for also hundredthousand of years.
And you can produce 30, 40 or maybe 50 years electric energy, and it needs the same time to decontaminate and dismantle a nuclear powerplant. And before it takes 20, 30 or mor years, to build such a plant… This is not cheap, not safe and not sustainable.