> With enrichment, the world's known uranium supplies (5.5 million tons) would last about 30,000 years at present usage rates How does it matter if you enrich

> With enrichment, the world's known uranium supplies (5.5 million tons) would last about 30,000 years at present usage rates How does it matter if you enrich or you use a natural uranium reactor? The amount of fissile material is exactly the same. > if used with fast breeder reactors But that's breeding, not enrichment. > but in addition, there's about 4.5 billion tons dissolved in seawater. ...aaaand there goes your requirement for a breeder. Breeders may very well turn out not to be worth the bother.