Centrifuge enrichment was considered for the Manhattan Project but rejected because early experiments encountered many problems: https://www.osti.gov/opennet/m

Centrifuge enrichment was considered for the Manhattan Project but rejected because early experiments encountered many problems: https://www.osti.gov/opennet/manhattan-project-history/Processes/UraniumSeparation/centrifuges.html https://www.osti.gov/opennet/manhattan-project-history/Proce... Centrifuge uranium enrichment wasn't developed to an industrial scale until the 1960s, and it first happened outside the United States: https://world-nuclear.org/information-library/nuclear-fuel-cycle/conversion-enrichment-and-fabrication/uranium-enrichment https://world-nuclear.org/information-library/nuclear-fuel-c...