North Korea has apparently closed down its main nuclear reactor; an indication some fear could mean the Communist nation is gearing up to reprocess more nuclear weapons material.
Both South Korea and the United States have confirmed that the main reactor at North Korea's Yongbyon nuclear power plant has been shut down. Security specialists claim there are several reasons why that could have taken place.
Officials are giving most weight to the fear that North Korea has completed the task of producing spent fuel rods laced with weapons-grade plutonium.
Additional possibilities for the shut down are less threatening - that the reactor ran into mechanical trouble or that North Korea is bluffing in an attempt to raise anxieties about its nuclear weapons program.
