The Sequoyah Nuclear Plant is a nuclear power plant located on located east of

Soddy-Daisy, Tennessee Soddy-Daisy is a city in Hamilton County, Tennessee, United States. The population was 13,070 at the 2020 census and estimated to be 13,619 in 2022. The city was formed in 1969 when the communities of Soddy (to the north) and Daisy (to the sout ...

, and north of Chattanooga, abutting

Chickamauga Lake Chickamauga Lake is a reservoir in the United States along the Tennessee River created when the Chickamauga Dam, as part of the Tennessee Valley Authority, was completed in 1940. The lake stretches from Watts Bar Dam at mile 529.9 (853 km) ...

, on the

Tennessee River The Tennessee River is the largest tributary of the Ohio River. It is approximately long and is located in the southeastern United States in the Tennessee Valley. The river was once popularly known as the Cherokee River, among other name ...

. The facility is owned and operated by the

Tennessee Valley Authority The Tennessee Valley Authority (TVA) is a federally owned electric utility corporation in the United States. TVA's service area covers all of Tennessee, portions of Alabama, Mississippi, and Kentucky, and small areas of Georgia, North Carolin ...

(TVA). The plant has two Westinghouse

pressurized water reactor A pressurized water reactor (PWR) is a type of light-water nuclear reactor. PWRs constitute the large majority of the world's nuclear power plants (with notable exceptions being the UK, Japan and Canada). In a PWR, the primary coolant (water) i ...

s. Sequoyah units 1 & 2, as well as their sister plant at Watts Bar, both have ice condenser containment systems. In case of a large

loss-of-coolant accident A loss-of-coolant accident (LOCA) is a mode of failure for a nuclear reactor; if not managed effectively, the results of a LOCA could result in reactor core damage. Each nuclear plant's emergency core cooling system (ECCS) exists specifically t ...

, steam generated by the leak is directed toward borated ice which helps condense the steam creating a lower pressure, allowing for a smaller containment building.

Description

Sequoyah's two units have a winter net dependable capacity of 2,440 megawatts,Securities & Exchange Commission filing. Available at https://www.sec.gov/ making Sequoyah the most productive of TVA's three nuclear plants. Sequoyah is the second-most powerful power plant in Tennessee, second only to the Cumberland Fossil Plant northwest of Nashville, but actually generates more power. Following the restart of Brown's Ferry Unit 1, that plant again became most productive at 3,440 MW. TVA constructed

dry cask storage Dry cask storage is a method of storing high-level radioactive waste, such as spent nuclear fuel that has already been cooled in the spent fuel pool for at least one year and often as much as ten years. Casks are typically steel cylinders that ar ...

facilities at Sequoyah and purchased special storage containers for the purpose of storing spent nuclear fuel. The storage facilities have been approved by the NRC.

History

Construction began on Sequoyah on May 27, 1970. Unit 1 was licensed by the NRC on September 17, 1980, and commercial operation began on July 1, 1981. Unit 2 was licensed on September 15, 1981 and began operation on June 1, 1982. Sequoyah was the first new nuclear plant licensed after the

Three Mile Island accident The Three Mile Island accident was a partial meltdown of the Three Mile Island, Unit 2 (TMI-2) reactor in Pennsylvania, United States. It began at 4 a.m. on March 28, 1979. It is the most significant accident in U.S. commercial nuclea ...

. On August 22, 1985, Sequoyah was shut down due to safety concerns. An independent contractor hired to analyze the safety systems of the plant had found that TVA lacked documentation proving that all of the plant's safety systems would function properly in the event of an emergency. Brown's Ferry, TVA's only other operating nuclear plant at the time, had been shut down in March 1985, due to safety concerns about a fire ten years earlier, and during this time, TVA was without nuclear power completely. On March 22, 1988, TVA was authorized by the NRC to restart both Sequoyah units. Both reactors returned to service later that year. The operating license of Sequoyah's Unit 1 was originally set to expire in 2020, and Unit 2's operating license in 2021. In 2015, the NRC renewed the operating license for both units for an additional 20 years. TVA's Sequoyah operating license was modified in September 2002 to allow TVA to irradiate

tritium Tritium ( or , ) or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with half-life about 12 years. The nucleus of tritium (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of ...

-producing burnable absorber rods at Sequoyah for the U.S. Department of Energy. The process of irradiating tritium-producing rods produces tritium, which is used in nuclear weapons and for various forms of research into

nuclear fusion Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manife ...

for commercial power production. TVA began irradiating tritium-producing rods at its

Watts Bar Nuclear Plant The Watts Bar Nuclear Plant is a Tennessee Valley Authority (TVA) nuclear reactor pair 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 Cha ...

in 2003. As of February 2007, TVA had no plans to produce tritium at Sequoyah.

Name

Sequoyah was

Cherokee The Cherokee (; chr, ᎠᏂᏴᏫᏯᎢ, translit=Aniyvwiyaʔi or Anigiduwagi, or chr, ᏣᎳᎩ, links=no, translit=Tsalagi) are one of the indigenous peoples of the Southeastern Woodlands of the United States. Prior to the 18th century, t ...

, part of the

Overhill Cherokee Overhill Cherokee was the term for the Cherokee people located in their historic settlements in what is now the U.S. state of Tennessee in the Southeastern United States, on the western side of the Appalachian Mountains. This name was used by 1 ...

, reportedly born in Tuskegee, a town at the confluence of the Tellico River and Little Tennessee River, upriver of the nuclear power plant. He is known for creating the

Cherokee syllabary The Cherokee syllabary is a syllabary invented by Sequoyah in the late 1810s and early 1820s to write the Cherokee language. His creation of the syllabary is particularly noteworthy as he was illiterate until the creation of his syllabary. He ...

circa 1820. Many Cherokee sites were flooded during the

's (TVA) construction of

Tellico Dam Tellico Dam is a dam built by the Tennessee Valley Authority (TVA) in Loudon County, Tennessee, on the Little Tennessee River as part of the Tellico Project. Planning for a dam structure on the Little Tennessee was reported as early as 1936 but ...

(1967-1979). Naming the site after a local Native American Indian was considered a small political token to the Cherokee in compensation for the dam-flooding and destruction of their historic sites that TVA required to control flooding on the

Surrounding population

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone of radius (concerned primarily with exposure to, and inhalation of, airborne radioactive contamination), and an ingestion pathway zone of about radius (concerned primarily with ingestion of food and liquid contaminated by radioactivity). The 2010 U.S. population within of Sequoyah was 99,664, according to 2010 U.S. Census data analyzed for msnbc.com, an increase of 13.8 percent in a decade.

Bill Dedman Bill Dedman (born 1960) is a Pulitzer Prize-winning American journalist, an investigative reporter for '' Newsday'', and co-author of the biography of reclusive heiress Huguette Clark, '' Empty Mansions: The Mysterious Life of Huguette Clark ...

, "Nuclear neighbors: Population rises near US reactors," ''

NBC News NBC News is the news division of the American broadcast television network NBC. The division operates under NBCUniversal Television and Streaming, a division of NBCUniversal, which is, in turn, a subsidiary of Comcast. The news division's var ...

'', April 14, 2011 http://www.nbcnews.com/id/42555888 Accessed April 16, 2011. The 2010 U.S. population within was 1,079,868 (increase of 13.8 percent). Cities within 50 miles include Chattanooga (14 miles to city center).

Seismic risk

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Sequoyah was 1 in 19,608, according to an NRC study published in August 2010.

References

External links

* * * * * {{Tennessee Valley Authority Facilities Energy infrastructure completed in 1981 Energy infrastructure completed in 1982 Tennessee Valley Authority Nuclear power stations using pressurized water reactors Buildings and structures in Hamilton County, Tennessee Nuclear power plants in Tennessee 1981 establishments in Tennessee