TVA coal plant in hot water
Aug 3 - McClatchy-Tribune Regional News - Dave Flessner Chattanooga Times/Free Press, Tenn.
Tennessee's largest coal-fired power plant is in hot water this summer, forcing TVA to scale back some of its power generation. Extra water added to the river by the U.S. Army Corps of Engineers since has helped, but TVA officials said water temperatures on the Cumberland River remain above normal. Those temperatures require TVA to scale back power output at the Cumberland plant to limit the amount of hot water dumped into the river, they said. "The Cumberland River is giving us some touchy moments," TVA President Tom Kilgore told the utility's board this week. Mr. Kilgore said he does not expect similar problems at the agency's other plants on the Tennessee River. But he said "it's a touchy situation" amid the worst drought in the Tennessee Valley in more than a decade. For the first time this summer, TVA is operating at full power six nuclear reactors and four major coal plants along a 250-mile stretch of the Tennessee River. River water is used at TVA power plants to help cool steam used to generate electricity. TVA is using its cooling towers throughout the year for the first time at both Sequoyah and Watts Bar this year to help limit its thermal impact on the Tennessee River. The Cumberland Fossil Plant, the largest in the TVA system, has been "derated" and its nighttime power output reduced to help limit hot water going into a slower-flowing Cumberland River this year. The U.S. Army Corps of Engineers, which operates the dams on the Cumberland River, has reduced the level and flow of the Cumberland this year to facilitate repairs at Wolf Creek Dam. Bob Sneed, chief of the water management section in the Nashville District for the Corps, said this summer's drought has worsened the problem. "The flows out of the Cheatham Dam, which is just upstream of the Cumberland Plant, have been running only 30 to 50 percent of normal this summer, and as a result the water is running quite a bit warmer and that has led to some thermal issues for Cumberland," he said. Despite a wetter-than-normal July in Chattanooga, rainfall in the first seven months of the year was more than 12 inches below normal. TVA estimates runoff into its reservoirs this year is 31 percent below normal. "At this point, we're doing OK with the minimum flows on the Tennessee River," TVA spokesman Gil Francis said Thursday. "Going forward, it's going to be a function of how much rain you get and how much flow you get and what the temperatures are." Stephen Smith, executive director of the Southern Alliance for Clean Energy, said he worries that building and expanding more power plants on the Tennessee River could aggravate problems, especially with global warming. "There is a limit to the amount of thermal capacity of the Tennessee River, and if we add another reactor at Watts Bar, build two reactors at Bellefonte and expand the units at Browns Ferry like TVA is talking about, we're going to have real problems," he said. The Tennessee Department of Environment and Conservation issues national pollutant discharge elimination system permits to limit thermal effects from water discharged from power plants. Tisha Calabrese-Benton, TDEC communications director, said all of TVA's power plants remain within their permitted water temperatures this summer. Mr. Kilgore said TVA has monitors at all of its plants and has tried to anticipate problems from hotter weather through the balance of the summer. E-mail Dave Flessner at dflessner@timesfreepress.com To subscribe or visit go to: http://www.timesfreepress.com |