With the newer breeders (FAST), the main difference is safety. You don't need the same control mechanisms because they automatically cool down due to the physics of them so that they don't melt down. I'd imagine that FAST reactors eliminating the need for ever increasing safety tech and complexity of it for conventional reactors would be a cost savings (or at least make it close). Not to mention the clean up costs when you compare to a conventional reactor that could melt down, even if it's rare.
I'm not saying that the engineers are idiots. But there are some engineers (supported by government or corporate funds) still building new prototypes and testing new designs, such as FAST. Especially in the US, a driving reason that new designs aren't used is that there have been few built I'm recent decades - partially due to lower cost alternatives and also due to public opinion.
I'm not saying that the engineers are idiots. But there are some engineers (supported by government or corporate funds) still building new prototypes and testing new designs, such as FAST. Especially in the US, a driving reason that new designs aren't used is that there have been few built I'm recent decades - partially due to lower cost alternatives and also due to public opinion.