mdsolar writes "Recent satellite imagery suggests that North Korea has restarted a small nuclear reactor, allowing the secretive nation to potentially bolster its stockpile of plutonium for weapons, a U.S. research institute said Thursday. The North had said five months ago that it would restart key operations at its Yongbyon nuclear facility 'without delay.' The report from the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies indicates that it is quietly going ahead with that pledge — and facing few apparent problems in firing up a reactor mothballed for six years. Commercial satellite images from Aug. 31 show two plumes of white steam rising from a turbine building adjacent to the reactor. That steam is an essential byproduct of the reactor's operation, and its venting suggests the 'electrical generating system is about to come online,' the report said."