ISIS has published the full text of the new DG Report on Implementation of Safeguards in Iran.
Eight cascades were operating and being fed on May 13, but don’t seem to be linked into a single unit:
Since the Director General’s last report, Iran has fed approximately 260 kg of UF6 into the cascades at FEP. Iran has declared that it has reached enrichment levels up to 4.8% U-235 at FEP, which the Agency is in the process of verifying. On 13 May 2007, eight 164-machine cascades were operating simultaneously and were being fed with UF6; two other similar cascades had been vacuum tested and three more were under construction.
260 kg since of UF6 is a more reasonable amount. Probably not full operation (I have to sit down this afternoon and make some educated guess about when the cascades came online). But Iran does seem to be making steady progress toward continuous operation of their centrifuges—maybe more than half the time, from a colleague’s back-of-the-envelope calculation.