U.S. Nuclear Plants

Three Mile Island
Pennsylvania �

Unit 1�� Nuclear system supplied by Babcock and Wilcox
Capacity Net MW(e)	Generation in 2003 Megawatthours	Capacity Factor	Type	On-line Date	License Expiration Date
816	6,197,031	86.5 %	PWR	April 19, 1974	April 19, 2014

� PWR= Pressurized Light Water Reactor

Description: The Three Mile Island station is located on 814 acres of an island near the state capitol at Harrisburg.� Three Mile Island may be the most widely known nuclear power plant in the United States due to an accident to its number 2 reactor.� The second reactor was permanently shut down following an accident on March 28, 1979.�A combination of equipment malfunctions and human error led to a loss of coolant.� It remains the most significant accident on record at a U.S. nuclear power plant.

Ownership: Three Mile Island (TMI) is owned by Exelon. It is operated by AmerGen Energy Company.

The Impact of the Nuclear Industry on Pennsylvania

Highlights : The First (U.S.) EIA Highlights Shippingport Power Plant
Nuclear-provided Electricity Generation
Competition in the State Electricity Market
Environmental Trends: Emissions levels
Various Links to related sites.

Sources: Capacity, for purposes of this report, is the net summer capability as reported in Energy Information Administration (EIA) survey form 860, "Annual Electric Generator Report." Capacity Factor is a calculation in which the maximum possible generation (based on net summer capability) is divided into the actual generation than multiplied by 100 to get a percentage. Generation is the electricity output reported by plant owners on EIA survey form 902. Type of Unit: All U.S. commercial reactors currently in operation are one of two types: BWR (boiling water reactor) or PWR (pressurized light water reactor). The type is identified in EIA's Nuclear Power Generation and Fuel Cycle Report. Both the On-line Date and the License Expiration Date are reported annually in Information Digest by the U.S. Nuclear Regulatory Commission.

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