Agreed. As far as I understand it, the Russian deal dealt in yellowcake - which can also be used for civilian (nuclear fission) purposes. But I did not plunge too deeply into the details on that one.

Who says that they are building bigger centrifuges? Are there no other reasons for building them?

IAEA has released very little substantial materials besides their resolutions on this matter, but the press officer has released tentative hints. We'll have to wait on the IAEA report early March to see what's left of this. Note that the press isn't helpful on the issue as the focus is on enrichment only. Never mind that there's a difference between civilian and military use. Yet now everything that links to enrichment is Bad. Chalk that one up to bad press reporting.

According to the opinion of people working at ECN Petten, one of the two locations in the Netherlands with nuclear technology, bigger centrifuges are only meant for nuclear weapons.