A nation in that condition can overcome. And what else is worth doing?
The challenge I see isn't that they can't mine uranium and make HTR fuel, but more that there is not much of a market for it at the moment. But the concept is still under development
which I'd summarize as "in the helium environment the pebbles experience friction that causes significant fuel damage" China and X-Energy seem to think they can solve it but it is also possible to develop prismatic fuel elements that won't slide past each other but will need disassembling the pile at refueling time.