The Byron Clean Energy Center is a nuclear power plant located in Ogle County, Illinois, east of the Rock River. The reactor buildings were constructed by Commonwealth Edison and house two Westinghouse Four-Loop pressurized water reactors, Unit 1 and Unit 2, which began operation in September 1985 and August 1987 respectively. The plant is owned and operated by Constellation Energy.
The plant provides electricity to northern Illinois and the city of Chicago. In 2005 it generated on average about 2,450 MWe, enough power to supply about 2 million average American homes. The station employs over 600 people, mostly from Ogle and Winnebago counties, and features two prominent cooling towers.
The Byron plant has been subject to some controversy with respect to a lawsuit in 1981 with concerns over tritium contamination in groundwater. Tritium contamination at Byron and other Illinois nuclear power plants led the state of Illinois to pass legislation requiring plants to report such contamination to the state within 24 hours.
History Construction on Byron Clean Energy Center began in 1975, at a 1,782-acre (7.2 km) site, 17 miles (27 km) southwest of Rockford, Illinois, south of the city of Byron in Ogle County. The firm of Sargent & Lundy acted as consulting engineer during construction and Babcock & Wilcox oversaw the completion of the reactor vessels. Before construction was completed on the reactor vessels and facilities, at least three groups joined in a 1981 lawsuit to halt Byron Nuclear Generating Station's completion. The League of Women Voters, DeKalb Area Alliance for Responsible Energy, and others were involved in the lawsuit over the safety of and need for the plant. In 1984 the Atomic Safety and Licensing Board, a division of the U.S. Nuclear Regulatory Commission (NRC), stopped the planned nuclear station at Byron by refusing its owners, then Commonwealth Edison, permission to begin operation. The decision stemmed from concerns about the quality control of independent contractors hired during construction. Ultimately, the board overturned its decision in October 1984 and permission was granted to operate after a re-inspection of over 200,000 items and components within the plant.Anonymous. "Foes of nuclear plant in Illinois find fight is over," (ProQuest), The New York Times, 18 February 1985, p. 11. Retrieved 30 August 2007.
Byron Station consists of two pressurized water reactors, termed Byron Unit One and Byron Unit Two, and the surrounding grounds and facilities. Byron Unit One received its operating license from the NRC on February 14, 1985 and Unit Two received its license on January 30, 1987."Byron 1, Facility Finder Info, U.S. Nuclear Regulatory Commission. Retrieved 30 August 2007."Byron 2, Facility Finder Info, U.S. Nuclear Regulatory Commission. Retrieved 30 August 2007. On September 16, 1985, Unit One entered commercial service and power began to be generated at Byron. The operating licenses for the two reactors are set to expire two years apart: Initially, Unit One's license expired on October 31, 2024, and Unit Two's on November 6, 2026. On May 29, 2013 Exelon Generation Co. applied to renew the licences and on November 19, 2015, based on a final safety evaluation report (July 6, 2015) and a supplemental environmental impact statement (July 15, 2015), the Nuclear Regulatory Commission renewed both operating licenses for an additional 20 years. The renewed licenses authorize Unit One to operate through October 31, 2044, and Unit Two through Nov. 6, 2046.
In August 2020, Exelon decided to close the plant in September 2021 for economic reasons, despite the plant having licenses to operate for another 20 years. Exelon stated it would continue discussions with policymakers to try to obtain support to prevent the closure. In August 2021, Exelon stated a proposed $15/MWh federal production tax credit (PTC) would not be legislated in time to avoid closing Byron and Dresden. However, by September 13, 2021, the Illinois Senate approved a bill containing nearly $700 million in subsidies for the state's nuclear plants, including Byron, causing Exelon to reverse the shutdown order.
Facilities and output
The two Westinghouse four-loop pressurized-water reactors each have an electrical output of over 1,000 MWe. Byron has 2 units capable of generating 2347 net megawatts (MW) of electricity. In 2009 the reactors operated at 96.4% capacity and produced 19.7 million MWh of electricity; enough power for 2 million average American households."Byron Station," Power Generation, Exelon Nuclear. Retrieved 7 August 2010. The two cooling towers at Byron rise 495 feet (151 m) over the site.
The plant utilizes non-contact cooling water from the Rock River, situated 2 miles (3.2 km) to the west. The water used in the process of generating electricity is cooled in the station's two cooling towers and recirculated via the plant's blowdown line back into the Rock River. Other water, from Byron's Radioactive Waste Treatment system, is transferred to the Refueling Water Storage Tank (RWST), where it is analyzed and sampled for contamination. Once it passes through analysis, the water is discharged down the blowdown line into the river."Byron Generating Station ," (PDF), Hydrogeologic Investigation Report, Conestoga-Rovers & Associates for Exelon Generation Company, LLC, Exelon Nuclear, September 2006, pp. 2–3, pp. 50–54 Retrieved 30 August 2007.
According to former plant owner Exelon, the Byron station is operated by about 850 Exelon employees and another 50 permanent contractors. Most of Byron's employees reside in Ogle and Winnebago Counties in northern Illinois. The plant paid US$31.1 million in taxes in 2009 to various local taxing bodies.
Two power uprates have been approved by the NRC for each reactor since inception. The first uprate was approved on May 4, 2001 allowing for additional 175.6 MWt for each reactor and the second occurring on February 7, 2014 allowing for an increased 58.4 MWt. These uprates represented a 5% and 1.6% percentage increase in capacity, respectively.
Electricity production +Generation (MWh) of Byron Nuclear Generation StationYearJanFebMarAprMayJunJulAugSepOctNovDecAnnual (Total)20011,729,8641,564,6731,717,2551,158,7821,751,1001,641,4861,783,8351,786,2971,695,6571,712,5481,747,3591,799,62620,088,48220021,783,1471,598,0421,197,8041,735,9141,747,4431,532,6731,760,7331,764,9311,296,9111,453,5481,700,9111,793,41219,365,46920031,792,7661,615,7811,789,9871,721,5161,777,3771,717,5791,766,4501,760,6591,424,7001,317,2271,695,4951,762,71520,142,25220041,712,5981,636,4131,485,9231,420,5521,740,7961,677,2041,728,3621,730,9181,676,2161,747,4291,693,3381,754,81520,004,56420051,752,8751,547,345998,2711,682,7081,744,5581,664,5041,727,3871,725,9071,501,9511,318,7791,697,9701,757,30219,119,55720061,774,9741,586,4401,757,6451,689,5401,744,7221,681,2111,717,4291,725,8401,091,7781,266,3521,698,8071,757,03319,491,77120071,757,3221,585,1811,717,230870,5531,603,8661,677,3911,730,4601,725,7521,680,3811,068,4111,680,7861,755,43418,852,76720081,755,9231,641,6251,514,6801,255,8881,744,7751,676,4861,724,9701,729,5171,678,2331,185,0621,696,8531,753,51419,357,52620091,753,6231,567,4831,749,7931,685,5411,737,1751,663,1571,720,8851,722,8661,181,8141,493,8171,690,3921,751,72719,718,27320101,750,8061,582,8731,744,9121,318,5061,505,5581,669,6041,718,3541,719,2341,658,6621,741,5431,696,5491,749,11119,855,71220111,750,3841,578,9891,219,635952,6641,546,5511,647,2641,689,6041,698,5941,315,9531,408,6231,663,7351,730,49918,202,49520121,686,2701,408,4871,442,7171,637,5051,678,3441,580,5531,413,3911,591,4351,011,2221,470,0591,670,8331,727,46218,318,27820131,731,7871,564,0121,666,3581,028,0461,685,5741,656,6131,706,0731,706,9561,656,7371,728,8801,677,4461,738,57919,547,06120141,699,3181,585,9591,206,6461,690,9761,746,7361,680,1721,737,5231,732,0531,624,5051,075,7361,712,2331,760,52419,252,38120151,769,6671,593,5551,529,8821,686,4471,731,0611,680,6981,730,4591,733,7711,165,4781,577,1891,515,0701,758,13619,471,41320161,735,8121,650,4991,749,1211,313,9521,260,1781,672,0511,724,9441,711,2851,658,8241,658,4971,697,7911,767,29419,600,24820171,761,4531,517,249975,8781,701,6121,747,4231,678,8691,731,1671,739,8531,653,6751,159,9361,704,1831,772,74619,144,04420181,770,1441,597,9201,768,0351,694,9761,729,7621,666,2991,727,7081,712,4781,135,5211,755,6891,717,7901,774,70120,051,02320191,773,1111,600,5821,743,0341,178,1611,755,0911,685,2481,726,4561,735,5231,678,2961,753,1361,717,7241,771,61920,117,98120201,773,5191,632,7321,144,8071,707,6801,742,9351,676,7401,724,2631,732,4741,620,1471,287,0251,709,9971,772,57519,524,89420211,766,6071,601,1801,765,7151,703,9211,752,9231,677,0091,731,8671,696,8201,096,2221,701,1461,704,1671,772,07519,969,65220221,761,2851,599,4851,738,8471,235,7641,387,9461,674,8821,725,7301,727,3911,683,0481,756,3831,711,1751,739,82019,741,75620231,771,2111,593,0471,173,4981,700,8501,747,8861,680,3241,728,6171,727,3751,662,3601,198,2581,712,5371,769,62519,465,58820241,770,7601,651,8531,758,5561,696,0101,735,3551,658,3231,725,7661,716,2801,023,4551,637,9501,706,5881,767,81719,848,71320251,764,8841,595,2511,744,3081,154,8531,676,7561,665,8081,710,8591,721,6271,671,1201,742,1731,702,4271,764,38619,914,45220261,764,3371,557,724879,4941,634,2761,775,8931,699,6501,741,578--
Surrounding groundwater and elevated levels of tritium There are two underground aquifers within the first 230 feet (70.1 m) below the power station: the upper aquifer is known as the Galena-Platteville Aquifer and the lower aquifer is known as the St. Peter Sandstone Aquifer. The two bodies of water are separated by a layer of shale and thus not connected.
In February 2006, Exelon reported elevated tritium levels in the groundwater beneath the site. Tritium levels were elevated in two of six test wells, according to an Exelon release in February which noted that tritium concentrations of 86,000 pCi/L (2.3 MBq/L) were detected in standing water in underground concrete vaults along the plant's blowdown line."Exelon Nuclear To Launch Tritium Inspection Program At Its 10 Nuclear Stations ," (Press release), Exelon Nuclear, 15 February 2006. The company stated that the levels posed no risk to public or employee safety. The report coincided with ongoing tritium concerns at the Exelon-owned Braidwood Nuclear Generating Station near Braceville, Illinois."Exelon finds tritium near Byron nuclear plant," Associated Press via Chicago Business, 31 March 2006. Retrieved 30 August 2007. In September, elevated tritium levels were found at Byron in three monitoring wells adjacent to vacuum breaker vaults along the blowdown line. Two of the areas with elevated tritium were found in the shallow portions of the Galena-Platteville Aquifer, while the third location contained elevated tritium levels at the bottom of the same aquifer.
Tritium is a very low level beta emitter with an approximate half-life of 12.3 years and it cannot penetrate the outer dead layer of skin. The main concern with this isotope is inhalation or ingestion. None of the September levels exceeded the 20,000 pCi/L U.S. Environmental Protection Agency drinking water standard.
On April 12, 2006 the Illinois Environmental Protection Agency (IEPA) issued a violation notice to Exelon concerning Byron Nuclear Generating Station. The notice cited the company for violations of state environmental laws related to the "impairment of resource groundwater", discharging waste-containing contaminants from areas other than the permitted points, and violations of other requirements of the plant's discharge permit."Fact Sheet 1 - April 2006: Exelon Byron Nuclear Generating Station On-going Tritium Investigation ," Community Relations - Fact Sheets, Illinois Environmental Protection Agency. Retrieved 30 August 2007.