The Barakah nuclear power plant in Abu Dhabi, a major oil producer, is being built by Korea Electric Power Corporation (KEPCO). The plant was originally due to open in 2017 but start-up of its first reactor was repeatedly delayed.
ENEC said its subsidiary Nawah Energy Company "has successfully started up Unit 1 of the Barakah Nuclear Energy Plant, located in the Al Dhafrah Region of Abu Dhabi."
The ruler of Dubai, Sheikh Mohammed bin Rashid al-Maktoum, wrote on Twitter that nuclear fuel had been loaded into the first of four units of what he called "the first peaceful nuclear energy reactor in the Arab world."
"We are now another step closer to achieving our goal of supplying up to a quarter of our nation's electricity needs and powering its future growth with safe, reliable, and emissions-free electricity," ENEC's chief executive Mohamed Ibrahim al-Hammadi said.
The Federal Authority for Nuclear Regulation (FANR), which issued an operating licence for the plant in February, said Nawah met all regulatory requirements to start operations, after regular inspections and oversight to ensure the plant's safety.
When completed Barakah will have four reactors with 5,600 megawatts (MW) capacity. The UAE has not disclosed the total planned investment in the project.