Supplement to the Sequoyah Nuclear Plant Unit 2 Steam Generator Replacements Environmental Assessment
Hamilton County, Tennessee
On May 27, 2011, TVA issued a supplement to the 2009 final environmental assessment (EA) and finding of no significant impact for the planned replacement of the four Unit 2 steam generators at Sequoyah Nuclear Plant. The proposed project would involve off loading the 65-foot-long, 15-foot-diameter cylindrical steam generators from transport barges, cutting a 45-foot by 22-foot-oval hole in the roof of the Unit 2 concrete shield building, removing the old steam generators through the hole, installing the new steam generators, repairing the roof of the shield building, and storing the old steam generators on site in a special shielded building. The replacement work is scheduled to occur during an outage in 2012.
Steam generators use heat from the nuclear reactor to generate steam, which then is used to propel the generators to produce electric power. Over time, components in the steam generators tend to degrade, causing decreased power generation efficiency. Replacement of the existing steam generators, which were installed over 20 years ago, will allow power to be produced by Unit 2 efficiently and reliably.
The 2009 EA documented the potential effects of the project to various environmental resources, including floodplain function and values. However, a detailed analysis of potential effects to on-site drainage patterns during the probable maximum flood or following the probable maximum precipitation event was not conducted, as the locations of auxiliary facilities and structures were not known at that time. The 2011 supplemental EA evaluates these potential effects.
PDF files require Adobe Acrobat Reader.
Revised Finding of No Significant Impact (PDF, 85 kb)
Supplemental Environmental Assessment (PDF, 681 kb)
2009 Finding of No Significant Impact (PDF, 26 kb)
2009 Environmental Assessment (PDF, 644 kb)
For additional information or a printed copy of the document, please contact:
James F. Williamson Jr.
Contract Senior NEPA Specialist
Tennessee Valley Authority
400 West Summit Hill Drive, WT 11D
Knoxville, TN 37902