Three Mile Island - Unit 2

Site Identification

Type of Site: Power Reactor Facility
Location: Middletown, PA
License No.: DPR-73
Docket No.: 50-320
License Status: DECON
Project Manager: Amy Snyder

Site Status Summary

The Three Mile Island, Unit 2 (TMI-2) operating license was issued on February 8, 1978, and commercial operation was declared on December 30, 1978. On March 28, 1979, the unit experienced an accident which resulted in severe damage to the reactor core. (For details, see the Backgrounder on the Three Mile Island Accident.)

TMI-2 has been in a non-operating status since that time. The licensee conducted a substantial program to defuel the reactor vessel and decontaminate the facility. All spent fuel has been removed except for some debris in the reactor coolant system. The plant defueling was completed in April 1990. The removed fuel is currently in storage at Idaho National Laboratory, and the U.S. Department of Energy has taken title and possession of the fuel. TMI-2 has been defueled and decontaminated to the extent the plant is in a safe, inherently stable condition suitable for long-term management. This long-term management condition is termed post-defueling monitored storage, which was approved in 1993.

There is no significant dismantlement underway. The plant shares equipment with TMI Unit 1 (TMI-1), which permanently ceased operations on September 20, 2019. TMI-1 was sold to AmerGen (now Exelon) in 1999. The license for TMI-2 was transferred from GPU Nuclear to TMI-2 Solutions, a wholly owned subsidiary of Energy Solutions, in December 2020. TMI-2 Solutions contracts with Exelon for maintenance and surveillance activities.

The licensee plans to decommission TMI-2 independently of TMI-1, but may coordinate some decommissioning activities.

Major Technical or Regulatory Issues


Estimated Date For Closure


Page Last Reviewed/Updated Wednesday, April 13, 2022