SS-18 ICBM said:Nearly all, just one facility might be needed. And you can always hide paper trails. Criminals have been mastering that for decades now. Iran is not an entity that is to be underestimated. Underestimation was a mistake Bush did, underestimating the threat of terrorism.
Like Sadaam

Of course you know that uranium hexaflouride can only be imported from China, we're not talking subtle trails here and the Iranians are seriously relying on Russia and China for technology. We're not talking heroin here, this is a material that leaves clear evidence wherever it is produced and factories that require hundreds of technicians to be trained many of which are trained by outside contractors not to mention the actual contracting itself, you can be pretty sure that the US knows the location of every facility in Iran, hell you can find this information on the internet.
Again though if you think weapons inspectors are easy to fooled then look to Iraq ,these guys are getting pretty good at their jobs.