U.S.-based, The Southern Company (SO) has announced that Unit 4 at its Vogtle Nuclear plant has reached initial criticality. This is a crucial step in the start-up testing sequence. The company also mentioned that the initial criticality stage has been reached safely, which means operators have started the nuclear reaction inside the reactor for the first time. The nuclear fuel in the reactor will split the atoms and generate heat, which will be used to produce steam later. Following this achievement, Vogtl ...