Watts Bar Nuclear Generating Station

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Watts Bar Nuclear Plant
Watts Bar-6.jpg
Watts Bar Nuclear Power Plant Units 1 & 2 cooling towers and containment buildings.
Watts Bar Nuclear Generating Station is located in Tennessee
Watts Bar Nuclear Generating Station
Location of Watts Bar Nuclear Plant in Tennessee
Country United States
Location Rhea County, near Spring City, Tennessee
Coordinates 35°36′10″N 84°47′22″W / 35.60278°N 84.78944°W / 35.60278; -84.78944Coordinates: 35°36′10″N 84°47′22″W / 35.60278°N 84.78944°W / 35.60278; -84.78944
Status Operational
Construction began 1973
Commission date Unit 1: May 27, 1996
Unit 2: Oct 22, 2015
Operator(s) Tennessee Valley Authority
Nuclear power station
Reactor type pressurized water reactor
Reactor supplier Westinghouse
Cooling source Tennessee River
Cooling towers 2
Power generation
Units operational 1 x 1,121 MW
1 x 1,180 MW (Pre-Commercial Testing)
Capacity factor 102.3%
Annual generation 10,050 GWh

The Watts Bar Nuclear Power Plant is a Tennessee Valley Authority (TVA) nuclear reactor used for electric power generation. It is located on a 1,770-acre (7.2 km²) site in Rhea County, Tennessee, near Spring City, between the cities of Chattanooga and Knoxville. Watts Bar Unit 1 is the most recent civilian reactor to come on-line in the United States. Watts Bar supplies enough electricity for about 650,000 households in the Tennessee Valley.

The plant, construction of which began in 1973, has two Westinghouse pressurized water reactor units: Unit 1, completed in 1996, and Unit 2, completed in 2015. Unit I has a winter net dependable generating capacity of 1,167 megawatts. Unit 2 has a projected capacity of 1,150 megawatts.

Unit 2 construction project[edit]

Unit 2 was 80% complete when construction on both units was stopped in 1988 due in part to a projected decrease in power demand.[1] In 2007, the TVA Board approved completion of Unit 2 on August 1, and construction resumed on October 15.[2] The project was expected to cost $2.5 billion, and employ around 2,300 contractor workers. Once finished, it will create an estimated 250 permanent jobs.[3] Unit 2 is expected to be the first new nuclear reactor to come online in the USA in nearly two decades[4] and likely the last Generation II reactor.[5]

In response to severe damage to Japan's Fukushima-Daichi nuclear facility as a result of the 2011 Tohoku earthquake, the NRC issued 9 orders to improve safety at domestic plants. Two applied to Watts Bar Unit 2 and required design modifications: "Mitigation Strategies Order"[6] and "Spent Fuel Pool Instrumentation Order".[7] In February 2012, TVA said the design modifications to Watts Bar 2 were partially responsible for the project running over budget and behind schedule.[1] On April 5, 2012, TVA released a revised construction schedule and cost estimate for the Unit 2 project, stating that the new target start date for Unit 2 would be by December 2015.[8] As of December 2012, the plant's cost estimate was US$4–4.5 billion.[9]

TVA declared construction substantially complete in August 2015 and requested that NRC staff proceed with the final licensing review; on October 22, the NRC approved a forty-year operating license for Unit 2, marking the formal end of construction and allowing for the installation of nuclear fuel and subsequent testing.[10] On December 15, 2015 TVA announced that the reactor is fully loaded with fuel and is ready for criticality and power ascension tests. Initial crticality of the reactor and at-power tests are expected to begin in early 2016. [11] Commercial Operation is expected to begin in Spring 2016.[12]

Tritium production[edit]

The Nuclear Regulatory Commission operating license for Watts Bar was modified in September 2002 to allow TVA to irradiate tritium-producing burnable absorber rods at Watts Bar to produce tritium for the U.S. Department of Energy's (DOE's) National Nuclear Security Administration. The Watts Bar license amendment currently permits TVA to install up to 240 tritium-producing rods in Watts Bar Unit 1. Planned future license amendments would allow TVA to irradiate up to approximately 2,000 tritium-producing rods in the Watts Bar reactor.

TVA began irradiating tritium-producing rods at Watts Bar Unit 1 in the fall of 2003. TVA removed these rods from the reactor in the spring of 2005. DOE successfully shipped them to its tritium-extraction facility at Savannah River Site in South Carolina. DOE reimburses TVA for the cost of providing the irradiation services, and also pays TVA a fee for each tritium-producing rod that is irradiated.

Surrounding population[edit]

Watts Bar's cooling towers, with the Tennessee River in the foreground

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.[13]

The 2010 U.S. population within 10 miles (16 km) of Watts Bar was 18,452, an increase of 4.1 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 1,186,648, an increase of 12.8 percent since 2000. Cities within 50 miles include Oak Ridge (37 miles to city center).[14]

Seismic risk[edit]

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Watts Bar was 1 in 27,778, according to an NRC study published in August 2010.[15][16] It should be noted that seismic damage is not synonymous with nuclear disaster.

See also[edit]


  1. ^ a b DiSavino, Scott (March 16, 2012). "TVA cuts contractors at Alabama Bellefonte nuclear site". Reuters. 
  2. ^ "WATTS BAR-2". PRIS. International Atomic Energy Agency. June 29, 2013. Retrieved June 29, 2013. 
  3. ^ "TVA: Watts Bar Nuclear Plant". Tennessee Valley Authority. February 10, 2008. Archived from the original on February 12, 2012. Retrieved March 14, 2012. 
  4. ^ "TVA moves toward 2012 startup of Watts Bar II". timesfreepress.com. Chattanooga Times Free Press. July 20, 2009. Retrieved March 14, 2012. 
  5. ^ Testa, Bridget (2012). "Three Generations of Nuclear Power Plants in the U.S.". Retrieved 2015-04-08. 
  6. ^ "Mitigation Strategies". nrc.gov. Retrieved 2015-11-09. 
  7. ^ "Spent Fuel Pool Instrumentation Order". nrc.gov. Retrieved 2015-11-09. 
  8. ^ "TVA Releases Cost, Schedule Estimates for Watts Bar Nuclear Unit 2" (Press release). Spring City, TN, USA: Tennessee Valley Authority. April 5, 2012. 
  9. ^ "Watts Bar Unit 2 Performance On Track" (Press release). Spring City, TN, USA: Tennessee Valley Authority. December 20, 2012. Retrieved June 30, 2013. 
  10. ^ "Watts Bar nuclear reactor granted operating license - first new U.S. reactor in 19 years". timesfreepress.com. Retrieved 2015-10-22. 
  11. ^ "TVA Loads Fuel into New Watts Bar Unit 2". tva.gov. Retrieved 2015-12-15. 
  12. ^ "Watts Bar Unit 2 Issued Operating License". tva.gov. Retrieved 2015-11-09. 
  13. ^ "NRC: Backgrounder on Emergency Preparedness at Nuclear Power Plants". Fact Sheets. Nuclear Regulatory Commission. January 2009. Retrieved March 14, 2012. 
  14. ^ Dedman, Bill (April 14, 2011). "Nuclear neighbors: Population rises near US reactors". NBCNews.com. Retrieved May 1, 2011. 
  15. ^ Dedman, Bill (March 17, 2011). "What are the odds? US nuke plants ranked by quake risk". NBCNews.com. Retrieved April 19, 2011. 
  16. ^ "MSNBC Media" (PDF). 

External links[edit]