The Department of the Treasury (OFAC) has published regulations recently concerning the need to obtain a "general license" for academic exchanges between Iranian and US universities, as well as the import and export of online educational services.
These regulations, as well as U.S. government passed legislation in 2012 impacts students from certain countries, in particular Iran and Syria, who may wish to obtain degrees or participate in research projects in the energy and nuclear science related fields.
For more information about export control requirements, please see the ORPC's page for Visiting Students and Scholars.
Visa questions and application procedures may be found on the IES home page.