Natrium Demonstration (Kemmerer)

Current state

Notes

First US utility-scale advanced reactor in construction; coal-to-nuclear flagship. HALEU supply is the program watch item. EPC transition Sep 2026 (operator + WNN + ANS + ENR provenance). TerraPower-Meta framework for up to 8 units and Hyundai E&C as fleet EPC reported Sep 2026 — single source each, not asserted.

Milestone log

• 2024-06-10 — Non-nuclear construction began at Kemmerer, Wyoming (source)
• 2026-03-04 — NRC issued Part 50 construction permit — first commercial non-light-water US power reactor permit in 40+ years (source)
• 2026-04-23 — Nuclear construction officially commenced; owner expects construction complete by February 2031 (source)
• 2026-09-15 — Bechtel files Virginia WARN notice: ~200 Reston HQ positions affected, reductions from ~Nov 16; cites failure to agree with TerraPower on the project's next phase (source)
• 2026-09-22 — Bechtel and TerraPower part ways; TerraPower to rebid the ~$4B EPC contract. Bechtel stays to complete the Sodium Test & Fill Facility; 2030 completion / 2031 operation targets reaffirmed (source)

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

NNN coverage

Sources

1. https://www.terrapower.com/
2. https://www.ans.org/news/article-8417/terrapower-bechtel-part-ways-on-natrium-project/
3. https://www.world-nuclear-news.org/articles/bechtel-steps-away-from-terrapower-project
4. https://www.enr.com/articles/63689-terrapower-reopens-epc-competition-for-4b-natrium-nuclear-project