** FILE ** The exterior of the Arak heavy water production facility in Arak, Iran, 360 kms southwest of Tehran, is seen on in this Oct. 27, 2004, file photo. Seven international envoys are getting a look inside two key Iranian nuclear sites in a tour that Tehran hopes will build support ahead of more talks on its disputed atomic work. The envoys will see the unfinished heavy water reactor near Arak on Saturday, Jan. 15, 2011, and the uranium enrichment facility near Natanz later. (AP Photo/Fars News Agancy)