Long Mott Generating Station (four Xe-100 modules) construction permit: NRC construction permit review for Long Mott Energy, LLC (Dow / X-energy project) — under review. Sourced dates and schedule.
Background: NRC reactor licensing process, explained · The ADVANCE Act, explained: what changed and where the NRC stands
Current state
| Type | Construction permit |
| Outcome | Under review |
| Applicant | Long Mott Energy, LLC (Dow / X-energy project) |
| Facility | Long Mott Generating Station (Calhoun County, Texas) |
| Docket | 50-614 |
| Submitted | 2025-03-31 |
| Docketed (accepted for review) | 2025-05-12 |
| NRC planned schedule | 18 months |
| NRC target date | — |
| Final safety evaluation | — |
| Decision | — |
| Review time (docketed → decision) | — |
| Submitted → decision | — |
| NRC-reported review duration | — |
| NRC-reported resources vs estimate | — |
Review time is measured in average months from the date the NRC docketed the application to the decision. The NRC's own reported durations may measure to the final safety evaluation instead.
Notes
NRC target for the final safety evaluation: 2026-11. Post-ADVANCE Act filing. Environmental review done as an EA/FONSI (issued 2026-05-18, FR 2026-10073) instead of an EIS. ~28,500 staff hours estimated (schedule letter). Docketed: Conflict: the same FR notice's DATES line says 'The application was docketed on March 31, 2025.' NRC project page: 'Docketing Decision Letter Issued/Acceptance Review Complete | 05/12/2025 – A'. The acceptance-letter date (May 12, 2025) is used here. Final safety evaluation: Not yet issued; target November 2026 (NRC page 'Final SE issued. | November 2026 – T'). Advanced SE completed 'August 2026 – A'. Decision: Under review; NRC page lists '_Construction Permit Decision_ | TBD'.
Timeline
- 2025-03-31 — Application received: “The application for the construction permit was received on March 31, 2025.” (source)
- 2025-05-12 — Accepted for review (docketed): “The NRC staff provided LME notice of the acceptance and docketing determination by letter dated May 12, 2025” (source)
- 2026-09-22 — Commission mandatory hearing. (source)
The timeline is append-only: corrections are added as new entries. See the NNN Data License Terms for reuse of the event history.
Also tracked
- long-mott-1 in the Reactor Project Tracker
- long-mott-2 in the Reactor Project Tracker
- long-mott-3 in the Reactor Project Tracker
- long-mott-4 in the Reactor Project Tracker
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See all 75 reviews in the NRC Licensing Review Tracker →
Sources
- https://www.nrc.gov/facilities-safety/new-reactors/advanced-reactors/who-were-working-with/advanced-reactor-application-projects/long-mott-energy-llc
- https://www.nrc.gov/facilities-safety/new-reactors/advanced-reactors/who-were-working-with/advanced-reactor-application-projects/long-mott-energy-llc/application-documents
- https://www.federalregister.gov/d/2025-07662
- https://www.federalregister.gov/d/2025-10505
- https://www.nrc.gov/docs/ML2511/ML25115A247.pdf
- https://www.nrc.gov/docs/ML2515/ML25155B841.pdf
- https://www.nrc.gov/docs/ML2604/ML26043A457.pdf
- https://www.federalregister.gov/d/2026-10073
- https://www.federalregister.gov/d/2026-16975
- https://www.nrc.gov/regulations-legislation/effectiveness-efficiency-and-timeliness-initiatives-that-support-unleashing-american-energy/licensing-efficiencies