The newest reactor at the Watts Bar Nuclear Plant began generating electricity over the weekend.
The Tennessee Valley Authority synced Unit 2 reactor to the grid for the first time Friday and licensed operators have begun an initial test run of generation equipment.
The team is using this run to collect data to be sure generating equipment is prepared for continuous full-power operation later this summer.
"This is another major step in fully integrating Watts Bar Unit 2 as the seventh operating unit in TVA's nuclear fleet," TVA Chief Nuclear Officer Joe Grimes said in a statement. "It is rewarding to see TVA taking the lead on delivering the first new nuclear unit of the 21st century and providing safe, affordable and reliable electricity to those we serve."
The next step is full-plant testing of systems and controls at increasing reactor power levels up to 100 percent power by this summer.
Combined with Watts Bar Unit 1, the plant will supply power to roughly 1.3 million homes in the TVA service area.
This story was updated June 5 at 11:55 p.m. with minor edits.