South Korea ? South Korea sent a shipload of oil to North Korea today, a move expected to trigger the communist nation to shut down its only working nuclear reactor in a landmark first step toward dismantling its atomic bomb program.

The chief U.N. inspector, Mohamed ElBaradei, said he expects the agency’s monitoring of the shutdown of the North’s Yongbyon reactor will start “early next week” and the initial inspection is expected to be completed “within a maybe month or so.”

A South Korean ship – the 6,750-ton No. 9 Han Chang – departed for North Korea from the port of Ulsan on South Korea’s southeast coast, carrying an initial batch of 6,200 tons of heavy fuel oil being given to the North for its agreement to shut down Yongbyon.

The ship was expected to arrive Saturday in the North’s northeastern port of Sonbong and will take some 48 hours to unload.