For instance, read the following from Epstein's site (especially the last part!):
What are Russia's four main contributions to Iran's nuclear program?
Russia, as the prime subcontractor for Iran's nuclear program, is providing:
1) Six nuclear reactors for Iran. Four are at Bushehr and two are at Akhvaz.
2) A uranium-conversion plant at Bushehr that can be used for uranium enrichment.
3) An exemption in the UN resolution on Iran. In its draft resosultion the Russians have exempted materials, equipment, technology" used at Bushehr 1. This exemption will allow Iran to convert the lightly-enriched fuel in the light-water nuclear reactor into weapon-grade 235. It need only remove fuel rods from Bushehr, then extracting their pellets, and feed this enriched uranium into its centrifuges. The centrifuges could then produce weapon-grade U-235 in less than 2 month. (Iran could keep the operation secret by substituting dummy rods for those it removed from the Bushehr reactor.)
4) The reactor-grade uranium for Bushehr 1 (which goes into operation in October 2007.)
Russia may be also making unofficial contributions. The International Atomic Energy Agency (IAEA) laboratory at Seibersdorf, Austria, ascertained that Iranian centrifuges made indigenously in Iran not imported gear showed traces of on enriched uranium with a purity level of 36 percent U-235. Russia appears to have been the source of this enriched uranium, since the IAEA lab also found a "likely match" between the atomic signatures of the 36% uranium used in Russian submarines and the traces gathered from Iranian centrifuges. Then there is the polonium 210 used to explode the bomb. The AIEA determined that Iran has obtained polonium 210, an isotope. And the likely source is Russia, which uses it (in combination with beryllium) to ensure the chain reaction leading to a nuclear explosion begins at the right time.
See what I mean???