VIENNA (Reuters) – The U.N. nuclear watchdog said on Thursday it is preparing to send a mission to the radioactive waste facilities at Chernobyl after Ukraine informed it that Russian troops controlling the site had pulled out and the remainder were likely to as well. “The IAEA is in close consultations with Ukrainian authorities on sending the Agency’s first assistance and support mission to (Chernobyl) in the next few days,” the International Atomic Energy Agency said in a statement, adding that Ukraine “presumed” the remaining Russian troops were preparing to leave. (Reporting by Francois M…