The Tennessee Valley Authority generated more electricity from its natural gas plants than its nuclear plants over the past quarter as unplanned outages at its nuclear plants persisted.
The federal utility generated 28% of its electricity from natural gas and 27% from nuclear from Jan. 1 to March 31, the second quarter of the agency’s fiscal year, according to its quarterly financial report.
The last quarter that TVA reported producing more electricity from a fossil fuel than from carbon-free nuclear power was the same quarter in 2015, when it got more power from coal-fired plants than nuclear plants. TVA supplies electricity to 10 million people across seven states, including nearly all of Tennessee.
(READ MORE: TVA addressing electrical issues at three of its seven nuclear units)
Though three of the utility’s seven nuclear reactors were producing little to no power Tuesday, all reactors should be back to full power by the end of the month, TVA Chief Nuclear Officer Tim Rausch said at a May 8 board meeting.
To understand the significance of nuclear slipping under natural gas, which TVA reports suggest is a first, it’s important to know the role nuclear plants play in the utility’s grid.
NUCLEAR BACKBONE
TVA has produced around 40% of its electricity each year at its three nuclear plants since it brought the second reactor online in 2016 at the Watts Bar Nuclear Plant in Spring City, Tennessee. That year also marked when TVA began producing more power from nuclear plants than coal plants.
The utility prizes its nuclear reactors as reliable sources of clean energy that can be switched on and left running for 18 months or longer before needing to be refueled with enriched uranium. Each reactor can produce enough electricity for around 650,000 homes around the clock.
TVA will spend around $6 billion in the coming decade to extend the life of its nuclear plants to 80 years while juicing additional megawatts of electricity out of them with equipment upgrades to help meet growing power demand.
The Unit 2 reactor at the Browns Ferry Nuclear Plant in Alabama ran continuously for more than 700 days before its planned refueling outage earlier this year. After coming back online in April, the reactor fell back offline Tuesday, according to data from the U.S. Nuclear Regulatory Commission.
Plant operators took the reactor offline to repair an equipment issue on the non-nuclear side of the plant, TVA spokesperson Adam May said in an email. The utility does not share the expected duration of outages, May said.
The unplanned outage on the heels of a planned maintenance outage is the latest in a string of issues for TVA’s nuclear plants this year.
GENERATORS TRIP
The generator of the Unit 2 reactor at the Sequoyah Nuclear Plant in Soddy-Daisy tripped in July, unexpectedly reducing the reactor’s electricity output to zero. TVA decided to replace the generator, a project that cost $107 million as of March 31, and the reactor remained fully offline as of Tuesday.
The utility experienced other unplanned outages at the Unit 1 reactor at Watts Bar and the Unit 3 reactor at Browns Ferry in January and February, both of which have been resolved. The Unit 2 reactor at Watts Bar began a planned refueling outage in April.
Of all the performance metrics TVA uses to calculate end-of-year payouts for its executives, only its nuclear performance is under target, the agency’s board of directors shared at its May meeting.
(READ MORE: Vacancies leave TVA board handcuffed for May meeting)
“We’ll utilize the remainder of May to ensure that we do any final tune-ups from a maintenance perspective to ensure by June that we’re ready to produce for the entire summer season with all seven units safely and reliably,” Rausch, who leads TVA’s nuclear operations, said at the meeting.
TVA applied for an operating license extension from the Nuclear Regulatory Commission for the Browns Ferry Nuclear Plant, which it anticipates the agency will grant in early 2026, Rausch said.
NATURAL GAS ASCENDS
As TVA’s nuclear plants overtook coal-fired plants, the utility added natural gas to its grid to offset the loss of coal. In a typical year, TVA generates around 21% or 22% of its electricity from natural gas plants, which burns a fossil fuel that emits lower carbon emissions than coal.
Environmental groups have advocated for years for TVA to build solar farms paired with large batteries to store power when the sun isn’t shining instead of building natural gas plants.
The clustered unplanned outages at nuclear plants have only bolstered their concerns, since natural gas is left to fill the gap.
“I think TVA needs to do a better job explaining what’s going on with their nuclear program,” said Stephen Smith, executive director of the Southern Alliance for Clean Energy, in a phone interview. “We hate to see it. We continue to argue TVA should not be building out the gas infrastructure.”
TVA plans to invest $16 billion in its grid over the next few years, adding to its long-term debt capped by Congress at $30 billion in order to build large gas plants and upgrade power infrastructure.
It is building the 1,450-megawatt Cumberland Combined Cycle Plant in Middle Tennessee to come online by the end of 2026 and a 1,500-megawatt gas plant at its Kingston Energy Complex in Roane County to come online by the end of 2027.
Contact Daniel Dassow at ddassow@timesfreepress.com or 423-757-6318.