The Tennessee Valley Authority’s Watts Bar Nuclear Plant Unit 2 returned to operation on July 1 after completing a scheduled steam generator replacement that will help support decades of reliable generation of carbon-free energy. The Watts Bar team also completed refueling and maintenance activities to return the unit to full generating capacity, supplying energy for 650,000 homes.
“Removing all four of Unit 2’s original steam generators and installing the four upgraded models, which weigh more than 800,000 pounds each, is a significant engineering and operational project that our team completed safely and successfully,” said Tony Williams, Watts Bar site vice president. “Along with the new, more efficient steam generators, our team completed numerous maintenance activities that have the unit ready for its next 18-month cycle of reliable and affordable carbon-free power generation for the 10 million people across the region who count on reliable energy every day.”
The steam generators, each 67-feet in length, are heat exchangers used in the pressurized water reactors, such as Watts Bar. As the name indicates, the components use heat generated by the reactor to create steam that drives the turbines, which turn a generator to create electricity that’s sent directly to the power grid. The original steam generators on Watts Bar Unit 1 were replaced in 2006.
For the steam generator replacement project alone, the team made more than 4,000 welds, and poured more than 850,000 pounds of concrete. They also completed more than 26,000 work activities, including replacing 88 of Unit 2’s 193 fuel assemblies, performing inspections of reactor components and other plant systems, digital upgrades of main turbine controls and feedwater heaters, installation of new, more reliable low pressure turbine blades, replacing or servicing plant equipment and installing enhancements to help the unit continue safe, reliable operation for years to come,, officials said.