Most probably you overlooked the fact that all Iranian Nuclear sites are, not only open to the UN inspection, but any activity is monitored by the UN atomic agency's experts. You are probably confusing between Iran and Israel. This is Israel that do not provide information nor access to the UN atomic agency.
Russia is not and will not launch infantry operations in Syria, says senior lawmaker (Reuters)
from the article: 'Major powers to ease sanctions if Iran shuts down Fordow nuclear plant'