Constellation’s Three Mile Island Nuclear Restart Gets Boost with FERC Waiver

Why It Matters

The approval accelerates the return of a large baseload nuclear asset, bolstering regional grid reliability and supporting corporate clean‑energy commitments amid tightening capacity constraints.

Key Takeaways

• FERC granted Constellation a waiver to transfer 760 MW CIRs.
• Transfer could let Crane nuclear deliver full 835 MW before 2030.
• DOE order forces Eddystone units to stay online, freeing their CIRs.
• Transmission upgrades delayed to 2030, risk limiting Crane’s output.
• Constellation signed 20‑year power deal with Microsoft for nuclear energy.

Pulse Analysis

The three‑mile‑island site, once synonymous with a 1979 accident, is poised for a dramatic comeback. Constellation’s $1.6 billion investment to restart the 835‑MW Crane reactor reflects a broader industry trend of reviving legacy nuclear plants to meet decarbonization goals. By securing a FERC waiver, the company sidesteps a PJM‑mandated transmission bottleneck, allowing it to reallocate 760 MW of capacity interconnection rights from the aging Eddystone facility. This regulatory flexibility is rare, given PJM’s usual strict adherence to market rules, and underscores the agency’s willingness to prioritize grid resilience over procedural rigidity.

The waiver’s practical impact hinges on the Department of Energy’s emergency order that forces Eddystone’s two units to remain operational as pure energy resources. Because those units cannot use their capacity rights, Constellation can transfer them to Crane, effectively increasing the nuclear plant’s interim deliverability. While the physical transmission upgrades—high‑voltage 765‑kV and 500‑kV lines—are not expected until late 2030, the CIR transfer could allow Crane to operate near its rated capacity as early as late 2027. This early output is critical; operating a nuclear reactor below design power for extended periods can cause vibration and wear, jeopardizing reliability and increasing maintenance costs.

From a market perspective, the restart aligns with a 20‑year power purchase agreement Constellation signed with Microsoft, which seeks reliable, carbon‑free electricity for its data centers across the PJM footprint. The deal illustrates how corporate buyers are leveraging long‑term contracts to lock in clean energy while providing financial certainty to generators. If Crane reaches full output ahead of schedule, it could set a precedent for other dormant nuclear sites, encouraging similar regulatory accommodations and reinforcing nuclear’s role in the United States’ transition to a low‑carbon grid.