Waxaa jiray afar kayd weyn oo loo yaqaan ee uranium ee 1940: ee Colorado, ee waqooyiga Kanada, ee Joachimsthal ee Czechoslovakia, iyo ee Congo Belgian. oo dhan laakiin Joachimstal ahaayeen in gacmaha xulufada. A November 1942 sahan lagu ogaaday in tiro ku filan oo uranium la heli karo si ay u qanciso shuruudaha mashruuca. Nichols diyaarin Waaxda Arrimaha Dibadda ee kontaroolada dhoofinta in la dhigo on oksaydhka uranium iyo wada xaajoodka iibsiga 1,200 tan oo gaaban (1,100 tons) ee macdanta uranium ka Congo Belgian in lagu kaydiyaa in bakhaar ku Staten Island iyo kaydinta haray ee macdanta macdanta in la bedelay plutonium, iyo, in ay foomka la xoojiyay, ee bamka atomiga laftiisa. Waxaa jiray afar kayd weyn oo loo yaqaan ee uranium ee 1940: ee Colorado, ee waqooyiga Kanada, ee Joachimsthal ee Czechoslovakia, iyo ee Congo Belgian.
Sanadkii 1942