TVA’s newest reactor at Watts Bar reached 100% power this week.  This makes a total of 7 reactors in the TVA fleet which accounted for more than 40% of TVA’s power generation this week for the first time in their 83-year history.

The Unit 2 reactor reached full power after TVA restarted the new unit on Monday following a four-week outage caused by a fire at one of the main transformer’s in the Watts Bar switch yard last month, TVA spokesman Jim Hopson said Friday. TVA is continuing power ascension tests of the new reactor at Watts Bar, which is the first new reactor to be added to America’s electric grid in more than two decades.

TVA must operate the new reactor for 20 consecutive days at full power and complete a series of tests before it is declared a commercial nuclear unit and is brought into TVA’s rate base.

As of last year TVA had budgeted for the unit to be operational by the end of June, but final tests of the equipment delayed the startup. Then on Aug. 30, a fire in a switch yard transformer forced the unit to be idled and the transformer replaced. The damaged transformer is critical for TVA to distribute the 1,150 megawatts of electricity generated by each of the two Watts Bar units.

TVA is using the new nuclear plant to make up for power previously generated by 18 coal-fired unit’s TVA has or soon will shut down.