Fast breeder reactors make sense when uranium is expensive or scarce. They and their reprocessing facilities are universally more complex, expensive, and unreli

Fast breeder reactors make sense when uranium is expensive or scarce. They and their reprocessing facilities are universally more complex, expensive, and unreliable than their water-cooled brethren. In today's fracking world, we need to bring nuclear costs down. Breeders will make costs go up, almost for sure (I study the history of this, and current efforts, very carefully). Honestly just disposing of nuclear waste in deep geologic repositories is a really pragmatic and relatively cheap approach for now. If we do end up ramping nuclear to 50% of the world energy supply, then breeding will likely become important. With breeders, we can use uranium dissolved in seawater effectively forever (hundreds of millions or even billions of years at 10x world scale consumption, effectively fully renewable).