Mansour Haqiqatpour, deputy head of parliament’s Foreign Policy and National Security Committee, said 60 percent enrichment would be to yield fuel for nuclear submarines, which often require uranium refined to high levels.

But it would also take Iran another significant step closer to the 90 percent enrichment level needed to make atomic bombs, which the West suspects is the Islamic state’s ultimate aim. Iran says its nuclear program is for peaceful energy only…

Iran now enriches uranium to a 3.5 percent concentration of the fissile isotope U-235 – suitable for nuclear power plants – as well as 20 percent, which it says it needs for a medical research reactor.