The Nuclear Regulatory Commission has approved a plan by the Tennessee Valley Authority to increase the generating capacity at its Browns Ferry Nuclear Power Plant by 14.3 percent.

TVA requested the power upgrade at its Alabama nuclear plant, boosting the output by 155 megawatts for each of the three reactors at Browns Ferry. The $475 million equipment upgrade will begin during next spring's refueling outage for Unit 3, during the fall 2018 refueling outage for Unit 1, and during the spring 2019 refueling outage for Unit 2.

"The real advantage of the Browns Ferry investment is that we are maximizing the capability of an existing generation asset that already produces our lowest-cost, most reliable form of carbon-free baseload power," TVA spokesman Jim Hopson said Thursday. "It's a true "win-win" for the people of the Valley."

Once online, each unit's power output will increase by about 155 megawatts. Collectively, the extra 465 megawatts produced by the three units will be able to serve an additional 260,000 homes.

Including the three Browns Ferry units, 32 U.S. nuclear reactors have been approved for or implemented an extended power uprate, including 21 that are boiling water reactors like Browns Ferry.

A pair of anti-nuclear power groups, Bellefonte Efficiency & Sustainability Team and Mothers Against Tennessee River Radiation, urged the NRC last year to reject the power upgrade, claiming that the higher core temperatures from the higher power output make the plant less safe and increase the chance for a meltdown or radiation leak.

But the NRC staff determined that TVA could safely increase the reactors' output primarily by upgrading certain plant systems and components.

The NRC's safety evaluation of the proposed uprate focused on areas such as the nuclear steam supply systems, instrumentation and control systems, and accident evaluations.

Browns Ferry first began generating electricity for TVA in 1973.

Hopson said while it is possible to also modify TVA's Sequoyah and Watts Bar reactors to boost their power output, TVA has no plans to do so.

"We are not anticipating the need for additional baseload power beyond what we have already added with Watts Bar Unit 2 and the upcoming increases at Browns Ferry, at least until the 2030 timeframe," he said.

Contact Dave Flessner at dflessner@timesfreepress.com or at 423-757-6340.