Three Mile Island Nuclear Generating Station

Three Mile Island Nuclear Generating Station is a decommissioned nuclear power plant on an island in the Susquehanna River in Londonderry Township. The facility includes two reactor units with concrete containment shells and four hyperbolic cooling towers rising above the flat riverbank.

The plant began operation in 1974 and experienced a partial meltdown in reactor Unit 2 on March 28, 1979, the most severe accident in United States commercial nuclear power history. The facility shut down permanently in 2019 after Unit 1 continued operating for several more decades.

The name refers to the river island location where the facility sits, while the site itself became a lasting symbol in debates about nuclear energy risks. The four large cooling towers still dominate the landscape and remain visible from nearby roads.

The site remains closed and inaccessible to the public, with strict security measures still in place. Environmental monitoring continues across an area extending roughly 10 miles (16 km) from the facility even after decommissioning.

An agreement with Microsoft plans to reopen the facility under the new name Christopher M. Crane Clean Energy Center. The restart of power generation would make it one of the few plants to be reactivated after decommissioning.

Location: Londonderry Township

Inception: 1970

Website: http://exeloncorp.com/locations/power-plants/three-mile-island

GPS coordinates: 40.15205,-76.72491

Latest update: December 4, 2025 19:02