World Power Plants

Three Mile Island Nuclear Generating Station1,839 MW Nuclear

NuclearVerified: Mar 2026

The Three Mile Island Nuclear Generating Station, located in the United States at coordinates 40.1520, -76.7249, stands as a significant contributor to the North American energy landscape, particularly as a nuclear power generation facility. With a capacity of 1839 MW, this station has been operational since its commissioning in 1970 and is recognized for its role in providing a substantial portion of Pennsylvania's electricity. Owned and operated by Exelon, Three Mile Island utilizes pressurized water reactor technology, which is a common and efficient method for generating electricity through nuclear fission. The plant's strategic location near Harrisburg enables it to supply power to a large population, enhancing grid reliability in a region that has historically relied on a mix of energy sources. Despite a challenging operational history, Three Mile Island has played a crucial role in shaping nuclear policy and public perception in the U.S., contributing to ongoing discussions about the future of nuclear energy as a clean and reliable power source. As the country aims to reduce its carbon footprint, the significance of nuclear facilities like Three Mile Island becomes increasingly evident, underscoring the need for a balanced and sustainable energy portfolio in the transition towards a low-carbon future.

Capacity
1,839 MW

1.84 GW

Commissioning Year
1970

56 years old

Owner
Exelon
Location
40.1520°, -76.7249°

United States of America, North America

Context & rankings
  • 136. largest of 10,098 plants in United States of America
  • #962 worldwide by installed capacity
  • #227 of 514 Nuclear plants worldwide
  • 0.13% of the installed capacity of United States of America
Age & fleet comparison

56 years in operation

Nuclear fleet average: 38.1 years

Operator portfolio

Exelon operates 10 plants totalling 15,655 MW

Regional density

123 plants within 100 km, 24,543 MW combined

Nearest plant: York Haven (4.4 km)

Data provenance

Source: Wikidata

Location

Coordinates:: 40.152047, -76.724911
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Carbon Footprint

Zero Direct Emissions

Three Mile Island Nuclear Generating Station is a nuclear power plant producing approximately 13693 GWh of clean electricity per year with zero direct CO₂ emissions during operation.

Lifecycle emissions: ~12 g CO₂/kWh (manufacturing, transport, decommissioning)

Technical Details

Primary Fuel Type
Nuclear
Energy Source
Non-Renewable
Country
United States of America
Continent
North America
Data Source
Global Power Plant Database

Three Mile Island Nuclear Generating Station: A Key Player in U.S. Nuclear Energy

The Three Mile Island Nuclear Generating Station, located in Pennsylvania, United States, is a notable nuclear power facility with a total capacity of 1,839 megawatts (MW). Commissioned in 1970 and owned by Exelon, this power plant plays a significant role in the American energy sector, contributing to the nation’s electricity grid and demonstrating the complexities and challenges of nuclear energy production. As one of the largest nuclear power plants in the United States, Three Mile Island utilizes nuclear fuel, specifically enriched uranium, to generate electricity through the process of nuclear fission, wherein the nuclei of uranium atoms are split to release vast amounts of energy. This energy is used to heat water, producing steam that drives turbines to generate electricity.

Three Mile Island's impact on the environment is a multifaceted issue. Nuclear power is generally regarded as a low-carbon energy source, which means that its operation contributes minimally to greenhouse gas emissions compared to fossil fuel-based power generation. This characteristic positions nuclear energy as a crucial player in efforts to combat climate change and reduce reliance on carbon-intensive energy sources. However, the plant is also known for the partial meltdown that occurred in 1979, which was the most serious accident in U.S. commercial nuclear power plant history. Although no immediate harm to the public was reported, the incident raised significant concerns about nuclear safety, leading to stricter regulations and oversight in the nuclear industry, as well as public discourse on the risks associated with nuclear energy.

Regionally, Three Mile Island has significant importance, especially within Pennsylvania. It not only provides a substantial amount of electricity to the surrounding areas but also supports the local economy through job creation and infrastructure development. The facility has been a focal point for discussions on energy policy, safety, and the future of nuclear power in the United States. As energy demands grow and the country seeks to transition to more sustainable energy sources, Three Mile Island remains a critical example of the complexities of nuclear energy, balancing the need for reliable power generation with the imperative of safety and environmental stewardship. In summary, the Three Mile Island Nuclear Generating Station exemplifies the dual nature of nuclear energy: a powerful source of electricity with the potential for significant environmental and safety challenges.

United States of AmericaEnergy Profile

10,098
Total Plants
1420.7 GW
Total Capacity
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