Nuclear fuel, like lithium is a supply chain problem not an Erlich/Simons end-of-resources problem. Nuclear fuel UNLIKE lithium, has bizarre qualities that the waste stream from some kinds of reactors in turn, is valuable fuel. Not that we want prolifration from breeder reactors, but the point "fuel is the bottleneck" has some caveats. Supply chain logistics around fuel, including whole-of-life treatment of the outputs, is a problem.