That's why you use a fast neutron (breeder) reactor to extract up to 90% of the potential fissionable "fuel" from that uranium instead of just a few percent. Another option is the use of thorium of which is there is ca. 3 times as much. By the time both uranium and thorium run out there'll either be practical fusion energy or one of those new battery technologies which are always popping up.

Now we just have to invest a few hundred billion for a few decades until er have practical commercial breeder reactors, while still burning coal and gas while we wait and see whether the engineers can figure it out.