BERLIN – The head of the U.N. atomic watchdog agency confirmed on Wednesday reports that Iran has begun operating centrifuges installed at an underground site, but said they had been moved from another facility so the country's overall uranium-enriching capabilities have not increased.Rafael Grossi, director-general of the International Atomic Energy Agency, told reporters in Vienna that the 174 centrifuges had been moved into a new area of the Natanz nuclear site and had recently begun operating.He said that operation of centrifuges of that type was in violation of the nuclear deal Iran had signed with world powers in 2015 — known as the Joint Comprehensive Plan of Action, or JCPOA — but would not lead to a greater overall output of.