Operations at the nuclear power plant were ceased on 9 February for maintenance.
In addition to refueling and regular maintenance and testing, the plant underwent upgrade to its systems and components.
Southern Nuclear will now perform a series of fuel rod pattern adjustments in boiling water reactors following deep down powers and outages, to ensure efficient use of nuclear fuel.
Southern Nuclear Hatch Plant vice-president David Vineyard said: "The work we perform during our outages is a significant investment in our facility. Unit 2 is positioned not just for the next 24 months, but for years of continued safe and reliable electricity production."
Nearly 1,500 additional workers from General Electric, Williams, Westinghouse and Areva and other partners have performed specialized tasks at the plant during the upgrade, the company said.
Southern Nuclear operates six nuclear plants, including Edwin I. Hatch, for Alabama Power and Georgia Power. Two new nuclear units are under construction at Plant Vogtle.
