This story was updated Feb. 20, 2018, at 10:44 p.m. with more information.
More than 2,100 TVA employees and contractors have started to install new equipment to boost the power output at the utility's oldest nuclear power plant by more than 14 percent.
Following a record-long 653-day run of power generation at the Browns Ferry Nuclear Power Plant, TVA idled the Unit 3 reactor at Browns Ferry over the holiday weekend and started Saturday to install equipment to add another 155 megawatts of generating power from the boiling water reactor.
Similar upgrades are planned on the two other units at Browns Ferry as part of a $475 million program to boost overall power by 465 megawatts by the spring of 2019.
The extra power from the Extended Power Uprate, or EPU, is projected to produce enough additional electricity to power 280,000 more homes and will help TVA boost the share of power it gets from its nuclear power plants to 40 percent.
The power upgrade is far less costly than building new nuclear generation. TVA spent $4.7 billion to add a 1,200 megawatt Unit 2 reactor at Watts Bar in 2016 — or more than $3.9 million per installed megawatt — compared with only $1.02 million per megawatt for the upgraded Browns Ferry units. At Plant Vogtle in Georgia, the new AP1000 reactors are projected to cost more than $6.4 million per megawatt.
The upgrades at Browns Ferry are being done during scheduled refueling and maintenance outages. TVA spokesman Jim Hopson said that in addition to the traditional outage work of loading 344 new fuel assemblies, a final round of modifications will be installed that will boost the power generation on the Unit 3 reactor by this spring.
"Outages are always important because it's our opportunity to do the work necessary to safely and reliably generate electricity for the next two years," said Lang Hughes, Browns Ferry site vice president. "There is added importance to this and our next two outages because we will complete the remaining work needed to operate each unit at extended power uprate conditions to serve the energy needs of the Tennessee Valley."
More than 15,600 work activities are scheduled during this month's outage at Browns Ferry, including maintenance and upgrades of plant equipment, inspections and repairs on reactor components and installing modifications to improve safety margins.
The NRC has approved power uprates 163 times at U.S. commercial nuclear reactors, collectively adding an estimated 23,707 megawatts of generating capacity, according to figures compiled by the Nuclear Energy Institute, a trade group for the nuclear power industry. Equipment and technology advances have allowed reactors to be modified to generate more steam and to use what steam they do produce to more efficiently generate more electricity, NEI spokesman Matt Wald said.
In 2006, the NRC approved 20-year license extensions for all three reactors at Browns Ferry beyond the original 40-year life of the license.
Contact Dave Flessner at firstname.lastname@example.org or at 757-6340.