Three Mile Island Restart
Microsoft's 20-year deal to restart TMI Unit 1 for AI data centers
🔄 RESTART IN PROGRESSLast updated: March 2026
OwnerConstellation Energy
LocationLondonderry Twp, Pennsylvania
Capacity835 MW
DOE Loan$1 billion (issued Nov 2025)
Current StatusRestart preparations underway
Expected Restart2028
OfftakerMicrosoft (20-year PPA)
New NameCrane Clean Energy Center
835 MW
Reactor Capacity
20 yr
Microsoft PPA
$1B
DOE Loan (Issued)
2028
Target Restart
Project Basics
- Owner: Constellation Energy
- New Name: Crane Clean Energy Center
- Location: Londonderry Township, PA
- Offtaker: Microsoft (AI data centers)
- Grid: PJM Interconnection
Why It Matters
The first major U.S. nuclear restart since the 1979 accident put Three Mile Island on the map. Microsoft's deal signals that Big Tech sees nuclear as essential for AI power demands, and that the economics of nuclear may finally work again.
📅 Timeline
-
Dec 2025U.S. Energy Secretary tours site; DOE touts $1B loan for restart
-
Nov 2025DOE Loan Programs Office issues $1 billion loan to Constellation for restart
-
2025Restart preparations advance: steam generators, turbine, and reactor components being refurbished
-
Sep 2024Constellation announces 20-year PPA with Microsoft to power AI data centers
-
2019TMI Unit 1 permanently shuts down after 45 years of operation
-
1974TMI Unit 1 begins commercial operation
-
1979TMI Unit 2 partial meltdown: worst U.S. nuclear accident (separate reactor)
📰 Related Coverage
- Loading stories...
Search all Three Mile Island Restart stories →
🔗 Related Pages