Opacity Measurement at TVA Fossil Plants
Opacity is a measurement of the amount of light that is obscured by plant emissions. When there is no visible smoke, the opacity is zero percent, meaning all of the light is able to pass through.
TVA fossil plants meet extremely rigid opacity standards, which are tracked by continuous opacity monitoring systems (COMS). In 2000 and 2002, citizen lawsuits alleging violations of the opacity standards at the Kingston, John Sevier, and Colbert fossil plants were filed against TVA. At issue was how compliance with the opacity standard must be measured. Since determining compliance with COMS data is more stringent than using the EPA test for opacity, which involves visual observations, Tennessee and Alabama have interpreted their regulations to mean that an opacity source is in compliance if opacity levels (when measured by COMS) do not exceed the opacity standard more than 2 percent of the time on a quarterly basis. Groups that believe the 2 percent condition should not be applied when compliance is determined filed the lawsuits. The John Sevier and Kingston suits were dismissed in TVA’s favor in 2001 and the Colbert lawsuit is expected to go to trial in 2004.
A cleanup project that generated hazardous waste in 2003 was the removal and replacement of four steam generators during a refueling and maintenance outage at Sequoyah Nuclear Plant. Removing the generators entailed cutting through the top of the reactor shield building and steel containment structure, which required a significant amount of welding and x-ray testing to ensure that the containment integrity was restored after the new generators were in place. The use of the x-ray solution, paint, and coating material resulted in the increased generation of hazardous waste. Replacing the steam generators, however, will improve Unit 1’s reliability and reduce maintenance work during future outages.
Minimizing the environmental impact of reportable environmental events is a top priority for TVA, regardless of how small the potential effects may be. TVA demonstrated this commitment in the case of a bald eagle’s nest located on a transmission line structure near Kentucky’s Lake Barkley. To bring the structure up to code, TVA placed insulating covers over the conductors below the eagle’s nest. However, when TVA removed an empty, deteriorating osprey nest and installed plastic spiked perch guards, it violated the Endangered Species Act. These additional modifications resulted in the adult eagle’s abandoning its nest and fledglings. TVA reported the problem to U. S. Fish and Wildlife and, with its approval, removed the perch guards and placed fish in the nest to feed the infant eagles. The adult eagle finally returned home and its young survived.
Nonrenewable fossil-fuel energy sources, such as coal, oil, and natural gas, release carbon dioxide (CO2) into the air. CO2 is considered a "greenhouse gas" because it traps heat that would ordinarily be radiated into space, a process that some scientists believe is harmful to the earth’s climate.
TVA’s renewable energy program, Green Power Switch®, helps reduce greenhouse gas emissions by offering power available from wind, solar, and methane gas technologies, which can be used with a greatly reduced impact on the climate. The data in the accompanying chart reflect the millions of tons of CO2 emissions that have been avoided as a result of TVA’s Green Power Switch program and other TVA initiatives, such as improved efficiency at TVA plants, cogeneration, the use of nuclear power, and demand-side management programs that reduce power use by TVA’s customers.
TVA has reported the amount of its CO2 emissions avoided since 1994 as part of the Climate Challenge, a voluntary program between the electric utility industry and the U.S. Department of Energy (DOE) that focuses on the stabilization and reduction of greenhouse gas emissions.
In 2002, 228 U.S. companies and other entities reported that they had undertaken 2,027 projects to reduce or sequester greenhouse gases. The electric power sector, with 99 companies reporting, had the largest proportion of participants in the program.
Download a PDF version of the full report, Voluntary Reporting of Greenhouse Gases 2002 (from the Energy Information Administration’s Web site).