The US Federal Energy Regulatory Commission (FERC) has approved a crucial waiver, allowing Constellation Energy to fast-track the restart of Pennsylvania’s Three Mile Island (TMI) nuclear plant to supply power to Microsoft data centres. This regulatory breakthrough directly addresses severe transmission bottlenecks that threatened to delay the project by several years.
Constellation Energy aims to resurrect unit 1 of the facility – now officially renamed the Crane Clean Energy Center – and to begin delivering 835 MWe to the grid by late 2027. TMI unit 1 operated safely for decades until closing in 2019 for economic reasons. It sits adjacent to unit 2, that suffered a partial meltdown in 1979 and remains permanently disabled. Both reactors are pressurised water reactors (PWRs) designed and manufactured by Babcock & Wilcox.
Initial regional grid studies from the operator, PJM Interconnection, revealed that the plant could not fully deliver its output until 2031. This delay was caused by a requirement for extensive transmission grid upgrades, including hundreds of miles of new power lines stretching to West Virginia.
The approved FERC waiver bypasses these multi-year infrastructure delays through a creative transfer of capacity rights. Constellation was granted permission to transfer 760 MWe of capacity interconnection rights from its retiring Eddystone natural gas and oil facility near Philadelphia directly to the Crane Center. FERC concluded that this transfer would safely maximise the nuclear plant’s deliverability much sooner without impacting grid reliability or hurting other market participants.
Eddystone had previously been earmarked for closure. It is only being maintained by Constellation now under orders from the Department of Energy to keep it available for reserve power generation needs.
FERC’s action has successfully decoupled the Crane Center’s restart timeline from PJM’s backlogged transmission queue. Alongside this FERC approval, the project also cleared another parallel hurdle when the Nuclear Regulatory Commission (NRC) issued a draft finding that the restart would cause no significant environmental impacts.
“We appreciate FERC’s timely approval of Constellation’s ability to transfer the existing capacity interconnection rights from Eddystone units 3&4 to the Crane Clean Energy Center,” Constellation said in a statement. “This decision marks an important milestone in enabling Crane to deliver reliable, emissions-free energy to the PJM region as quickly as possible.”
Constellation noted the Crane plant remains on track for a 2027 restart. “We will continue working closely with stakeholders as the interconnection process advances to return this critical source of carbon-free generation to service and strengthen energy reliability.”
