Conventional Nuclear & Restarts

Conventional nuclear — large-scale light-water reactors (LWRs) built and operating since the 1960s-1990s — is experiencing a strategic renaissance driven by AI power demand. The US has 93 operating reactors generating ~20% of US electricity. These plants are already permitted, built, and licensed; restarting or uprating them is far faster and cheaper than building new nuclear. The 2024-2026 period has seen a structural shift: nuclear plants that were slated for retirement are being restarted or life-extended specifically to serve hyperscaler PPAs.

The Crane Clean Energy Center (formerly Three Mile Island Unit 1, closed 2019) is the defining example. Constellation Energy secured a 20-year PPA with Microsoft, received a FERC waiver (June 1, 2026) to transfer 760 MW of Capacity Interconnection Rights, and is targeting restart in 2027. The NRC decision on the restart license was expected as early as June 2026. The plant requires NRC relicensing and a water intake permit (73.2 million gallons/day from the Susquehanna River) before restart.

Palisades Nuclear Plant (Michigan, closed 2022) is being restarted by Holtec International with DOE loan guarantees — a first for any previously shut US reactor.

Beyond restarts, the existing fleet is valuable: operators like Constellation (largest US nuclear fleet), Vistra, and Public Service Enterprise Group (PSEG) are signing multi-decade PPAs at prices far above their operating costs.

Key Claims

• US nuclear fleet: 93 reactors, ~97 GW capacity, ~20% of US electricity. Evidence: strong (NRC, EIA)
• Crane Clean Energy Center (TMI Unit 1) restart: FERC waiver granted June 1, 2026; NRC decision expected mid-2026; target 2027 restart, 835 MW for Microsoft. Evidence: strong (Bloomberg, Utility Dive)
• Existing nuclear is the fastest path to new carbon-free baseload — no new site permitting, existing grid connection, workforce in place. Evidence: strong (DOE)
• Constellation Energy: largest US nuclear fleet operator — Calvert Cliffs, Dresden, Limerick, Quad Cities, Nine Mile Point, Ginna, and others; Clinton and Braidwood for Meta. Evidence: strong
• Nuclear plants generate power 92-95% of the time (capacity factor) vs 25-35% for solar, 35-45% for wind. Evidence: strong (EIA)
• Life extension to 80 years: NRC has approved 20-year license renewals for multiple plants, extending operational lives from 60 to 80 years.

Benchmarks & Data

• US nuclear capacity factor: 92-95% (vs solar 25-35%, wind 35-45%)
• US nuclear fleet: 93 reactors, ~97 GW, ~800 TWh/year
• Crane Clean Energy Center: 835 MW, 2027 restart target
• LCOE for existing nuclear (US): estimated $30-50/MWh operating cost (no capital recovery)
• New nuclear LCOE: $90-150/MWh (BNEF estimates, heavily site-dependent)

Open Questions

• Will Palisades restart succeed? (First-ever in US history; technically and regulatorily unprecedented)
• How many of the ~8 reactors currently on life-extension applications will be approved before 2030?
• At what PPA price does it become economic to uprate existing reactors (increase MW output)?
• Can Constellation maintain its fleet while managing the Crane restart simultaneously?

Related Concepts

• Uranium Fuel Cycle — fuel supply for the fleet
• Power Purchase Agreements — how the fleet monetizes in the new era
• IPPs & Merchant Power — business model of operators
• Small Modular Reactors — the next generation after conventional

Changelog

• 2026-06-15 — Initial compilation from web research (Bloomberg, Utility Dive, Constellation filings)