Mind you, none of this already weapons grade enriched uranium has any commercial use, only military.
DEAL LETS IRAN KEEP HALF OF 98%-ENRICHED URANIUM STOCKPILE
If you don’t believe that Iran is close to assembling a nuclear bomb because of the agreement reached by Barack Obama’s administration, think again.
The agreement allows Iran to keep half of the uranium it has already enriched to 20%, and the other half is to be diluted to 5% U-235. As Powerline reports, “It takes about 8 days and only 2% of the total effort to go from the 20% HEU permitted to the 90% required for weapons grade and only 45 days and 10% of the cumulative effort from the 5% level of HEU.”
The reason for this is simple; most of the time required to make highly enriched uranium comes in the early stages. 90% of the effort is expended to reach the 5% level, 98% to reach the 20% level.
An American Enterprise Institute report states:
The work and time required to enrich uranium from its natural concentration (0.7%) to 3.5% low-enriched uranium (LEU) is an order of magnitude greater than that required to enrich 20% LEU to weapons-grade concentrations (90% U-235). That is because centrifuges must spin more than 14,000 kg of uranium ore to produce 1,373 kg of 3.5% LEU, but only 116 kg of 20% LEU to produce 15 kg of weapons-grade uranium.