It sure is. If the world were nuclear powered (all energy, not just grid) with burner reactors, estimates of uranium resources (not reserves) at up to 3x the current price would last about five years.
A fully nuclear world needs to use nuclear fuel efficiently, which means breeder reactors.
...and that's not a scenario that anyone is talking about employing with nuclear. We need enough for baseline load. Being able to build small modular reactors would give us scale that would help cut through the regulatory cost. By the time this crop of current reactors need to be decommissioned, we'd probably have dirt cheap grid storage figured out and could move away from them, but in the mean time, we need all the zero carbon energy we can get.
A world that gets 10% of its energy from nuclear and 90% from renewables is not substantially easier than one that gets 100% from renewables. The intermittency/seasonality issues are not solved by that relatively light sprinkling of nuclear on top. So the objections nuclear advocates use to justify nuclear over cheaper renewables are vitiated. Those problems have to be solved anyway, so why the 10% nuclear?
Nuclear really either goes big or it goes home. And you're saying it won't go big.
A fully nuclear world needs to use nuclear fuel efficiently, which means breeder reactors.