The Tennessee Valley Authority has begun the biggest equipment upgrade in part of its oldest and biggest nuclear power plant as the federal utility looks to continue to extend and improve the performance of its atomic reactors.
More than 500 extra TVA contractors and employees are at the Browns Ferry Nuclear Power Plant this month to refuel and replace the turbine equipment for the Unit 2 reactor. The workers will make 600 separate crane lifts to install new rotors weighing 327,888 pounds and new inner castings weighing up to 200,000 pounds. The new equipment and related steam piping and bellows comprise the biggest turbine upgrade at Browns Ferry in its 48-year history and will help boost the electricity output from the unit by 7 megawatts, or enough to power more than 4,000 additional homes.
"This will result in greater efficiency and improved equipment reliability which means less time in maintenance," TVA spokeswoman Malinda Hunter said. "Think of it as putting a brand-new engine, transmission and controls in a classic car."
The additional power from the Unit 2 reactor at Browns Ferry is coming just two years after TVA completed a 4-year, $475 million power upgrade at all three of the Browns Ferry reactors which collectively added 465 megawatts of additional generating capacity at the three-reactor plant. When the latest refueling and equipment replacement is complete, Browns Ferry will have a total generating capacity of more than 3.4 gigawatts, making Browns Ferry the second biggest nuclear power plant in America behind only the Palo Verde nuclear plant in Arizona.
"TVA's investment in Browns Ferry and the infrastructure of our power systems ensures that we can continue to provide reliable power for our local power companies and communities when they need us most," Browns Ferry Site Vice President Matt Rasmussen said.
With these upgrades, Unit 2 will essentially have three brand-new low-pressure turbines, which help convert steam into electricity.
While major upgrades are happening on the turbine deck, the refueling team also will load four new 3D-printed fuel assembly brackets in the reactor. The brackets demonstrate the latest innovations in additive manufacturing and artificial intelligence. They will be the first of their kind loaded into a commercial reactor.
Biggest U.S. nuclear power plants
1. Palo Verde Generating Station near Tonopah, Arizona, 3.93 gigawatts2. Browns Ferry Nuclear Plant near Athens, Alabama, 3.4 gigawatts3. Peach Bottom Atomic Power Station on the Susquehanna River in Pennsylvania, 2.77 gigawatts4. South Texas Project Generating Station near Bay City, Texas, 2.7 gigawatts5. Oconee Nuclear Station in Seneca, South Carolina, 2.62 gigawatts6. Susquehanna Nuclear Power Plant in Salem Township, Pennsylvania, 2.6 gigawatts7. Vogtle Nuclear Power Station near Waynesboro, Georgia, 2.43 gigawatts*8. Braidwood Generating Station in Braceville, Illinois, 2.39 gigawatts9. McGuire Nuclear Power Plant in Lake Norman, North Carolina, 2.38 gigawatts10. Byron Nuclear Power Station near Rockwood, Illinois, 2.34 megawatts* The generating capacity at Plant Vogtle in Georgia will be increased by 2.5 gigawatts to 4.93 gigawatts in the next t, making Vogtle the largest nuclear plant in the country, when it completes the addition of two AP1000 reactors which are currently under construction.Source: Power Technology
The components were recently manufactured at Oak Ridge National Laboratory in a joint project with TVA and the utility's fuel supplier, Framatome, as part of the lab's Transformational Challenge Reactor program.
"Being the first to use these additive manufactured components supports an innovative manufacturing approach that could pave the path for use across the existing nuclear fleet and in advanced reactors and small modular reactors," said Dan Stout, TVA's director of nuclear technology innovation.
Ala Alzaben, senior vice president of the commercial and customer center of the Fuel Business Unit at Framatome, said the 3-D printing of the components will help to reduce costs while maintaining plant safety and reliability, describing it as a "major advancement for Framatome and the nuclear energy industry".
In total, the Unit 2 outage at Browns Ferry will include more than 14,800 scheduled work activities, including the installation of 320 new fuel assemblies along with upgrades, modifications, repairs and testing of other plant equipment, inspections of reactor components and maintenance of key safety systems. Due to the equipment upgrades, the usual 4-week refueling outage is expected to last about six weeks, Hunter said.
Browns Ferry Unit 2, which began operation in 1974, is one of seven nuclear reactors TVA operates. The initial 40-year license for Browns Ferry gained a 20-year extension until 2033 and TVA is now studying getting another 20-year extension for its oldest nuclear plant.
TVA President Jeff Lyash, a former Nuclear Regulatory Commission employee who earned his senior reactor licenses at Progress Energy, said he is confident that TVA's nuclear plants can operate for 80 or more years with the right maintenance and repairs.
Collectively, TVA's nuclear fleet is the third largest in the nation and last year generated more than 40% of all electricity used by nearly 10 million people in the Tennessee Valley.
Contact Dave Flessner at dflessner@timesfreepress.com or at 423-757-6340.