Georgia Power announces Vogtle Unit 4 reaches initial criticality

Georgia Power announced today that Unit 4 at the Vogtle nuclear expansion project near Waynesboro, Georgia, has safely reached initial criticality. Initial criticality is a key step during the startup testing sequence and demonstrates that — for the first time — operators have safely started the nuclear reaction inside the second reactor. This means atoms are being split and nuclear heat is being made, which will be used to produce steam. Now that the Unit 4 reactor has reached criticality, operators will continue to raise power to support synchronizing the generator to the electric grid and begin producing electricity. Then, operators will continue increasing power through multiple steps, ultimately raising power to 100%. Georgia Power is the largest electric subsidiary of Southern Company.