Reactor restarts & life extensions
Returning retired US units (Palisades, Crane/TMI-1, Duane Arnold; 2,225 MWe) to service and raising output at existing plants.
2 leading companies in reactor restarts & life extensions, one segment of nuclear & small reactors — SMRs, reactor restarts, new large builds and the uranium/enrichment fuel chain behind them
new market segment · researched 2026-11-14
Small modular reactors (SMRs)Large nuclear reactorsReactor restarts & life extensionsUranium miningUranium enrichment & HALEUNuclear fuel & components
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Leading reactor restarts & life extensions companies
2 companies, with the scale each source states. Scale is the whole company's unless the row says otherwise.
| Company | Where | What they do | Scale |
|---|---|---|---|
| Holtec International ↗ | Jupiter, FL, United States since 1986 | Restarting Palisades (805 MWe, Michigan); SMR-300 design planned for Palisades; spent-fuel storage | restart capacity (Palisades): 805 MWe net (2026) ↗ |
| Constellation Energy CEG ↗ | Baltimore, MD, United States since 1999 | Largest US nuclear fleet operator; restarting Crane Clean Energy Center (TMI-1, 819 MWe) under a 20-year Microsoft PPA | revenue: 25.533 USD billions (2025) ↗ |
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The nuclear & small reactors market
The whole market this segment sits in.
installed capacity (operable reactors, net) · world405,667
↗MWe (443 reactors) · 2026
Growth, segments, risks and every company in nuclear & small reactors →
Quick answers
- What are reactor restarts & life extensions?
- Returning retired US units (Palisades, Crane/TMI-1, Duane Arnold; 2,225 MWe) to service and raising output at existing plants. They are one segment of the nuclear & small reactors market.
- Who are the leading reactor restarts & life extensions companies?
- Holtec International (United States), Constellation Energy (United States).
- Which reactor restarts & life extensions companies are publicly traded?
- Constellation Energy (CEG).
- How big is the nuclear & small reactors market?
- For the whole nuclear & small reactors market, not this segment alone: installed capacity (operable reactors, net) (world) 405,667 MWe (443 reactors), 2026 — World Nuclear Association.