Three Mile Island Nuclear Station, Unit 1

Life cycle timeline consisting of 6 various stages of status (Pre-Licensing, Licensing, Construction, Operating, Operating with Intent to Decommission, Decommissioning) with the current status(s) shown in color, and the other available status are greyed out

Location: Middletown, PA (10 miles SE of Harrisburg, PA) in Region I
Operator: Exelon Generation Co., LLC
Operating License: Issued - 04/19/1974
Renewed License Issued  - 10/22/2009
License Expires - 04/19/2034
Docket Number: 05000289

Reactor Type: Pressurized Water Reactor
Licensed MWt: 2,568
Reactor Vendor/Type: Babcock & Wilcox Lowered Loop
Containment Type: Dry, Ambient Pressure

Plant Diagram

Press Releases
Upcoming Meetings
Past Meetings

No information exists at this present time.

1.0 Site Identification

License Status: SAFSTOR
Permanantly Shutdown: 9/20/2019
Fuel Removed: 11/13/2016
Docket No.: 50-289
Project Manager: Amy Snyder

2.0 Site Status Summary

The Three Mile Island Nuclear Station Unit 1 (TMI-1) was a 2,568 MWt pressurized water reactor that began operation in 1974 and is owned by Exelon Generation, LLC.  By an indirect transfer, the owner’s name is changing to Constellation Energy Company in early 2022.

Spent fuel has been moved into dry storage. NRC will continue to provide licensing oversight and inspections of the plant until the plant is completely decommissioned, including inspections of the Independent Spent Fuel Storage Installation (ISFSI) until the spent fuel is permanently removed from the site and the license is terminated.

Significant Decommissioning Licensing Documents:

3.0 Major Technical or Regulatory Issues


4.0 Estimated Date for Closure

Calendar year 2079

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Page Last Reviewed/Updated Tuesday, September 05, 2023