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Reactor TrackerUnited States

Natrium Demonstration (Kemmerer)

Natrium (sodium-cooled fast reactor + molten salt storage) · 345 MWe · Under construction · commercial operation est. 2031

Current state

StatusUnder construction
DesignNatrium (sodium-cooled fast reactor + molten salt storage) (SFR, SMR)
Net capacity345 MWe
CountryUnited States
VendorTerraPower
Owner / operatorTerraPower / PacifiCorp offtake
Construction start2024-06-10
Original COD target2030
Current COD estimate2031
Schedule slippage+1 years

Notes

First US utility-scale advanced reactor in construction; coal-to-nuclear flagship. HALEU supply is the program watch item.

Milestone log

  • 2024-06-10Non-nuclear construction began at Kemmerer, Wyoming (source)
  • 2026-03-04NRC issued Part 50 construction permit — first commercial non-light-water US power reactor permit in 40+ years (source)
  • 2026-04-23Nuclear construction officially commenced; owner expects construction complete by February 2031 (source)

The milestone log is append-only: corrections are recorded as new entries, never rewrites. Full history via /api/v1/changes.

Sources

  1. https://www.terrapower.com/