# Limerick Generating Station

The Limerick Generating Station is a nuclear power plant in Pennsylvania located next to the Schuylkill River in Limerick Township, Montgomery County, northwest of Philadelphia. The facility has two General Electric boiling water reactor (BWR) units, cooled by natural draft cooling towers. According to its owner, Constellation Energy, the two units are capable of producing 2,317 megawatts of power, which combined would provide electricity to around 2 million households. Constellation owns and operates this facility following their separation from Exelon Corporation in 2022. With the exception of refueling outages, Limerick Generating Station continuously operates at 100% power. The plant is connected to the grid, and transmits power, via multiple 500kv transmission lines.
Limerick is a black start plant, meaning it does not require grid power for stator excitation. For critical standby power, Limerick depends on eight Fairbanks Morse 38 8-1/8 diesel engine generator sets that each deliver 3000 kilowatts of power and are capable of achieving rated speed within ten seconds of start.
The cooling towers for the Limerick Generating Station can be seen for miles away in parts of Montgomery, Chester, and Berks counties, and can be seen from the top of the tallest buildings in Philadelphia, including the One Liberty Observation Deck at Liberty Place.

## History

In 1969, the Philadelphia Electric Company (now PECO Energy, a subsidiary of Exelon) announced plans to build a nuclear power plant on a site along the Schuylkill River in Limerick Township, Montgomery County, approximately 30 miles northwest of Center City, Philadelphia. Community protests by the Keystone Alliance and other delays pushed the start of construction by the Bechtel Power Corporation to June 1974.
Limerick Unit 1 first attained criticality (began producing nuclear power, at limited capacity) on December 22, 1984 and was certified for commercial operation on February 1, 1986.
Limerick Unit 2 attained criticality on August 1, 1989, and commercial operation began on January 8, 1990.
On July 27, 1994, an F3 tornado struck the area surrounding the Limerick Generating Station. The tornado narrowly missed the station by two miles, but caused considerable damage to a nearby housing development in Limerick Township.
President George W. Bush visited the Limerick Generating Station in May 2006 to discuss nuclear power and its role in the Advanced Energy Initiative, which he announced at the 2006 State of the Union Address. He toured the facility, including a trip to the control room of the plant.
On October 20, 2014, the Nuclear Regulatory Commission (NRC) granted extensions for Limerick Units 1 and 2 for another 20 years. The units are now licensed to operate until 2044 and 2049 respectively.
Unit 2 of the station was scrammed from 100% power to a shutdown on June 1, 2016, at 9 am. The reactor was shut down due to an electrical fault, causing the recirculation pumps to stop. The steam bypass valves that lead to the main condenser were opened and Limerick went through a normal hot shutdown process.

## Electricity production

Generation (MWh) of Limerick Generation Station :
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual (Total) |
| 2001 | 1,720,999 | 1,421,555 | 1,571,281 | 1,146,121 | 1,714,981 | 1,585,203 | 1,707,221 | 1,694,826 | 1,654,876 | 1,735,777 | 1,680,970 | 1,742,643 | 19,376,453 |
| 2002 | 1,723,068 | 1,482,757 | 1,142,347 | 1,668,793 | 1,554,140 | 1,646,067 | 1,567,800 | 1,691,587 | 1,639,388 | 1,735,382 | 1,691,178 | 1,753,837 | 19,296,344 |
| 2003 | 1,753,254 | 1,550,234 | 1,130,516 | 1,519,321 | 1,714,769 | 1,653,453 | 1,696,881 | 1,607,028 | 1,624,447 | 1,731,500 | 1,674,951 | 1,743,910 | 19,400,264 |
| 2004 | 1,722,720 | 1,537,566 | 1,168,932 | 1,668,300 | 1,671,600 | 1,556,407 | 1,683,613 | 1,685,008 | 1,567,029 | 1,709,787 | 1,660,675 | 1,717,900 | 19,349,537 |
| 2005 | 1,716,885 | 1,362,085 | 1,004,085 | 1,664,188 | 1,677,581 | 1,626,264 | 1,608,325 | 1,669,489 | 1,609,470 | 1,555,876 | 1,667,420 | 1,744,182 | 18,905,850 |
| 2006 | 1,667,901 | 1,430,630 | 1,140,055 | 1,661,763 | 1,592,421 | 1,619,325 | 1,668,413 | 1,673,366 | 1,629,221 | 1,718,027 | 1,665,166 | 1,730,896 | 19,197,184 |
| 2007 | 1,730,497 | 1,556,952 | 1,096,433 | 1,316,275 | 1,684,085 | 1,628,014 | 1,675,750 | 1,634,390 | 1,625,974 | 1,697,270 | 1,674,801 | 1,733,093 | 19,053,534 |
| 2008 | 1,709,982 | 1,188,953 | 1,065,283 | 1,649,544 | 1,744,775 | 1,619,733 | 1,667,984 | 1,681,787 | 1,609,184 | 1,702,975 | 1,673,330 | 1,733,732 | 19,047,262 |
| 2009 | 1,731,717 | 1,531,939 | 1,396,490 | 1,282,135 | 1,692,512 | 1,630,879 | 1,678,051 | 1,666,118 | 1,607,336 | 1,711,319 | 1,666,889 | 1,735,461 | 19,330,846 |
| 2010 | 1,717,455 | 1,540,997 | 1,329,570 | 1,268,375 | 1,680,777 | 1,460,188 | 1,635,055 | 1,659,289 | 1,584,617 | 1,673,967 | 1,666,693 | 1,709,091 | 18,926,074 |
| 2011 | 1,716,769 | 1,440,129 | 1,427,642 | 957,152 | 1,596,256 | 1,481,722 | 1,667,199 | 1,689,269 | 1,626,067 | 1,729,101 | 1,684,638 | 1,446,559 | 18,462,503 |
| 2012 | 1,743,758 | 1,328,701 | 1,071,712 | 1,611,667 | 1,405,686 | 1,522,218 | 1,314,452 | 1,674,950 | 1,475,259 | 1,672,235 | 1,633,409 | 1,701,569 | 18,155,616 |
| 2013 | 1,751,458 | 1,576,669 | 1,522,770 | 1,127,577 | 1,704,240 | 1,648,213 | 1,680,800 | 1,701,413 | 1,651,900 | 1,730,161 | 1,698,595 | 1,748,269 | 19,542,065 |
| 2014 | 1,761,978 | 1,584,692 | 987,324 | 1,183,600 | 1,695,842 | 1,651,260 | 1,697,166 | 1,703,843 | 1,624,208 | 1,731,219 | 1,699,199 | 1,756,913 | 19,077,244 |
| 2015 | 1,751,913 | 1,461,440 | 1,622,446 | 1,091,120 | 1,437,584 | 1,645,722 | 1,689,443 | 1,695,036 | 1,628,634 | 1,723,941 | 1,686,885 | 1,497,213 | 18,931,377 |
| 2016 | 1,753,510 | 1,607,138 | 1,352,635 | 1,213,874 | 1,709,628 | 1,582,149 | 1,684,955 | 1,680,157 | 1,643,223 | 1,727,511 | 1,689,950 | 1,750,645 | 19,395,375 |
| 2017 | 1,741,930 | 1,558,680 | 1,672,939 | 1,197,273 | 956,769 | 1,649,145 | 1,676,523 | 1,594,619 | 1,651,728 | 1,409,430 | 1,693,432 | 1,750,489 | 18,552,957 |
| 2018 | 1,737,890 | 1,517,844 | 1,465,309 | 1,151,564 | 1,691,798 | 1,617,941 | 1,694,980 | 1,680,943 | 1,640,875 | 1,730,111 | 1,699,359 | 1,710,012 | 19,338,626 |
| 2019 | 1,754,824 | 1,570,155 | 1,675,109 | 1,153,115 | 1,511,770 | 1,511,990 | 1,690,451 | 1,699,453 | 1,625,116 | 1,728,335 | 1,686,400 | 1,738,876 | 19,345,594 |
| 2020 | 1,718,927 | 1,529,354 | 1,444,047 | 1,318,997 | 1,728,841 | 1,637,515 | 1,687,857 | 1,693,885 | 1,614,751 | 1,730,909 | 1,541,707 | 1,697,974 | 19,344,764 |
| 2021 | 1,748,069 | 1,559,537 | 1,540,707 | 1,357,962 | 1,263,678 | 1,643,516 | 1,691,105 | 1,690,225 | 1,646,667 | 1,720,568 | 1,696,074 | 1,751,220 | 19,309,328 |
| 2022 | 1,742,519 | 1,546,378 | 1,487,783 | 1,009,362 | 1,571,477 | 1,650,562 | 1,685,350 | 1,687,841 | 1,633,204 | 1,729,399 | 1,674,688 | 1,748,593 | 19,167,156 |
| 2023 | 1,737,403 | 1,539,868 | 1,478,157 | 1,447,736 | 1,171,119 | 1,641,193 | 1,673,235 | 1,688,894 | 1,644,281 | 1,717,282 | 1,685,930 | 1,668,977 | 19,094,075 |
| 2024 | 1,619,051 | 1,613,523 | 1,639,582 | 1,037,263 | 1,695,803 | 1,631,996 | 1,675,364 | 1,688,287 | 1,622,020 | 1,723,600 | 1,665,569 | 1,748,284 | 19,360,342 |
| 2025 | | | | | | | | | | | | | -- |

## Seismic risk

The Nuclear Regulatory Commission estimates the risk of an earthquake intense enough to cause core damage to every reactor in the U.S. According to the NRC study published in August 2010, Limerick's earthquake risk was calculated at 1 in 18,868. Following the Fukushima Daiichi nuclear disaster in 2011, government regulators announced the plant would undergo further evaluations for seismic activity risk.
A quarry is located nearby which occasionally does blasting; however, this is done with the consent of plant staff.

## Surrounding population

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.
The 2010 U.S. population within 10 miles (16 km) of Limerick was 252,197, an increase of 18.7 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 8,027,924, an increase of 6.1 percent since 2000.
Cities within 50 miles:
* Pennsylvania
** Philadelphia (28mi/45km)
** Allentown (27mi/43km)
** Reading (19mi/31km)
* New Jersey
** Trenton (Capital) (43mi/69km)
** Camden (32mi/52km)
* Delaware
** Wilmington (33mi/53km)