The Sequoyah Nuclear Plant is a

nuclear power plant A nuclear power plant (NPP), also known as a nuclear power station (NPS), nuclear generating station (NGS) or atomic power station (APS) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power st ...

located on located east of Soddy-Daisy, Tennessee, and north of

Chattanooga Chattanooga ( ) is a city in Hamilton County, Tennessee, United States, and its county seat. It is located along the Tennessee River and borders Georgia (U.S. state), Georgia to the south. With a population of 181,099 in 2020, it is Tennessee ...

, abutting Chickamauga Lake on the

Tennessee River The Tennessee River is a long river located in the Southern United States, southeastern United States in the Tennessee Valley. Flowing through the states of Tennessee, Alabama, Mississippi, and Kentucky, it begins at the confluence of Fren ...

. 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, India and Canada). In a PWR, water is used both as ...

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 to ...

, 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 A containment building is a reinforced steel, concrete or lead structure enclosing a nuclear reactor. It is designed, in any emergency, to contain the escape of radioactive steam or gas to a maximum pressure in the range of . The containment is ...

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, after the Cumberland Fossil Plant northwest of Nashville, but actually generates more power. Following the restart of Brown's Ferry Unit 1, that plant became TVAs 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 a spent fuel pool for at least one year and often as much as ten years. Casks are typically steel cylinders that are ...

facilities at Sequoyah and purchased special storage containers for the purpose of storing

spent nuclear fuel Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and ...

. 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 nuclear meltdown of the Unit 2 reactor (TMI-2) of the Three Mile Island Nuclear Generating Station, located on the Susquehanna River in Londonderry Township, Dauphin County, Pennsylvania, Londonderry T ...

. 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 hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with a half-life of ~12.33 years. The tritium nucleus (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the ...

-producing burnable absorber rods at Sequoyah for the

U.S. Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear we ...

. The process of irradiating tritium-producing rods produces tritium, which is used in

nuclear weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission, fission (fission or atomic bomb) or a combination of fission and nuclear fusion, fusion reactions (thermonuclear weap ...

and for various forms of research into

nuclear fusion Nuclear fusion is a nuclear reaction, reaction in which two or more atomic nuclei combine to form a larger nuclei, nuclei/neutrons, neutron by-products. The difference in mass between the reactants and products is manifested as either the rele ...

for commercial power production. TVA began irradiating tritium-producing rods at its Watts Bar Nuclear Plant in 2003. As of February 2007, TVA had no plans to produce tritium at Sequoyah.

Name

Sequoyah Sequoyah ( ; , , or , , ; 1770 – August 1843), also known as George Gist or George Guess, was a Native American polymath and Constructed script, neographer of the Cherokee Nation. In 1821, Sequoyah completed his Cherokee syllabary, enabl ...

was

Cherokee The Cherokee (; , or ) people are one of the Indigenous peoples of the Southeastern Woodlands of the United States. Prior to the 18th century, they were concentrated in their homelands, in towns along river valleys of what is now southwestern ...

, part of the Overhill Cherokee, 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 its creation. He first experimen ...

circa 1820. Many Cherokee sites were flooded during the TVA construction of Tellico Dam (1967-1979). Naming the site after a local Native American 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 Tennessee River.

Electricity production

Surrounding population

The NRC 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. 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 NRC'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