Constellation Energy moves one step closer to restarting the former Three Mile Island reactor in Pennsylvania after having a waiver granted by the Federal Energy Regulatory Commission (FERC) this week.
Under the waiver request granted on Monday, Constellation will be able to transfer 760 megawatts of capacity interconnection rights from its Eddystone natural-gas power plant to the former Three Mile Island reactor, now named the Crane Clean Energy Center.
Capacity interconnection rights are rights to permit a power generator to input electricity into a transmission system at a specific point of generation.
Eddystone power plant was previously scheduled to shut down its two units on May 31, 2025, but the Department of Energy issued an order to keep the plant running to meet emergency energy needs. According to the document, Constellation said that Eddystone units were not a capacity resource and that transferring their capacity interconnection rights are free.
Constellation sought the waiver, filed March 31, to avoid certain interconnection regulations that would snag its Crane power plant restart plans. Constellation previously said that the restart of the plant is expected to occur in the second half of 2027.
Issuance of the waiver helps Constellation get around PJM’s standard grid delay queue and could potentially allow the utility to deliver all energy of the Crane plant to the grid at a sooner date.
But according to a PJM Interconnection’s study, the Crane plant may not fully connect to the grid until 2031. Constellation said that the PJM Interconnection study was preliminary and is working with PJM and utilities to potentially move that date forward. FERC said that Constellation’s request met its criteria for granting waivers.
“We find that granting the waiver addresses a concrete problem. As Constellation explains, absent the waiver, Crane, an RRI [reliability resource initiative] project with 859 MW of generation capacity, may not be able to obtain full deliverability until at least December 31, 2030, long after Crane may be available to generate in 2027,” FERC said in the decision.
FERC continued, “We find that the requested waiver will allow for the transfer of CIRs [capacity interconnection rights] between the Eddystone Units and Crane, which may reduce or eliminate the number of Contingent Facilities for Crane and thereby potentially increase Crane’s interim deliverability and enable Crane to be fully operational before December 31, 2030.”
In November 2025, DOE approved a $1 billion loan to support Constellation’s efforts to restart the Londonderry Township, Penn. reactor. The restart of the Crane plant is a large part of Constellation’s plan to bring 1,200 new megawatts onto Pennsylvania’s power grid. Crane would supply 835 megawatts of the planned 1,200 megawatts.
The Crane reactor is adjacent to Three Mile Island Unit 2, which suffered an infamous partial meltdown in March 1979, leading to permanent shutdown in September 2019. The utility announced plans for the restart of the unit in September 2024.