In the 1940's Fermi already saw it as the future. Then many projects, in numerous nations, progressed towards the most promising path (a sodium-cooled 'fast' b

In the 1940's Fermi already saw it as the future. Then many projects, in numerous nations, progressed towards the most promising path (a sodium-cooled 'fast' breeder) architecture and sailed OK... in the lab. Then, since the 1960's, many (some huge) projects aimed at obtaining an industrial ready-to-decline reactor. In vain, and most projects are now abandoned. https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reactors https://en.wikipedia.org/wiki/Breeder_reactor#Notable_reacto...