Only a small fraction of Uranium is usable for fission without breeding. There is (IIRC from a LFTR youtube) 4-10x as much thorium as uranium. The other issue

Only a small fraction of Uranium is usable for fission without breeding. There is (IIRC from a LFTR youtube) 4-10x as much thorium as uranium. The other issue is most designs are solid fuel rod, and they waste a huge percentage of the fuel once "spent". Nuclear isn't price competitive with existing wind/solar, and any new nuclear project is 10-20 years away, and with wind/solar in substantial/active cost improvement and economies of scale, nuclear may never be competitive. I loved those LFTR presentations, and I would like to think a scalable LFTR solution could be made price competitive with wind/solar once it stabilizes, but right now probably not. LFTR can use thorium (still needs a fissile uranium starter plug), and can probably breed non-fissile uranium, I've heard it can breed existing nuclear waste into usable fuel as well. It uses 99% of the fuel according to the sales brochure, which I view as a massive huge advantage: it takes all the handwringing and NIMBY about waste storage out of the equation. IMO that should be a table stakes for any "new nuclear" design. It's basically meltdown proof with the plug, isn't pressurized, and somewaht self-regulating in temperature if I understand the neutron economy and expansion/contraction of salts. Also a "table stakes" aspect of any new nuclear project IMO. Scalability is probably the biggest path forward to competitive fission as well, the original MSR at ORNL was allegedly closet-sized. Massive concrete dome designs lend too much to boondoggle management and cost overruns. Scalability would enable nuclear to compete with the current kings of scalable power generation: wind and especially solar. Maybe pebble bed can get a lot of the same table stakes as LFTR. Maybe a LFTR could serve as an onsite fuel reprocessor for a more economical design if LFTR isn't broad market feasible. I'm not a nuclear engineer, I'm just a fan of the ultracool engineering and science. But the economics don't line up for nuclear currently.