With Russia continually failing to meet its contractual agreement to supply fuel for Iran's Bushehr nuclear power plant, Iran is being proven very wise not to trust even Russia to return nuclear fuel to Iran if Iran were to ship it own low enriched uranium off to Russia for processing to a higher level of enrichment. Not trusting France or the USA to keep its word on anything it says was already a no-brainer for Iran, but Russia once had a chance to gain some credibility and trust with Iran. The big news is that Iran if needs to have someone else enrich uranium to the 20% level needed for a medical reactor, it proves that Iran cannot process uranium to the much much higher levels needed to make a bomb, making all the baseless accusations that Iran is building nukes even less believable.

"Russia says the plant is purely civilian and cannot be used for any weapons program, as Iran will return all spent fuel rods to Russia". How will Russia react when Iran does not return the spent fuel rods but uses them to produce weapon grade uranium? (Ref North Korea)