(IAEA) The IAEA is an independent international organization related to the United Nations system today, founded in 1957 ('Atoms for Peace' Agency) as part of the United Nations family. Its mission is to promote and supervise worldwide safe, secure and peaceful nuclear technologies. The IAEA's three main areas of work are 'Safety and Security', 'Science and Technology', and 'Safeguards and Verification'.

Fissile isotopes such as 233U, 235U or 239Pu get exposed to a thermal neutron beam. The resulting nuclear chain reaction is controlled by moderators such as graphite, Beryllium or heavy water.
For example Mo-99, source for Tc-99m, is produced by fission of highly enriched uranium (HEU) in a few reactors around the world (monitored and controlled by The International Atomic Energy Agency).