Even the limit oft cited of "100 years" only refers to current proven mines. It does not include any estimated reserves and the results of additional prospecting.
There are large swaths of nations that have never even been prospected for Uranium deposits.
FWIW it's really not clear that there's such a limit on the uranium supply. Could be 4 billion years with seawater harvesting and reprocessing, etc.
https://whatisnuclear.com/blog/2020-10-28-nuclear-energy-is-...