[natmaka]

Regarding known and exploited or rapidly exploitable deposits, we are very, very far from millions of years: "As of 2017, identified uranium reserves recoverable at US$130/kg were 6.14 million tons (compared to 5.72 million tons in 2015). At the rate of consumption in 2017, these reserves are sufficient for slightly over 130 years of supply"

Source: https://en.wikipedia.org/wiki/Uranium_mining#Peak_uranium