Tracker · Application
Long Mott Energy, LLC
The staff of the U.S. Nuclear Regulatory Commission (NRC) is currently engaged in review activities for the construction permit application from Long Mott Energy, LLC (LME), for the Xe-100 power reactor to be located in Calhoun County, Texas. The Xe-100 project is supported by the U.S. Department of Energy’s Advanced Reactor Demonstration program and would be used to demonstrate the X Energy Xe-100 reactor technology.
- Who
- Long Mott Energy, LLC
- Design
- Xe-100
- Reactor type
- Xe-100
- Status
- Under review
- What
- Application for a construction permit for an advanced power reactor
- When
- March 31, 2025 (date of application submittal)
- Site
- Calhoun County, Texas
- NRC page reviewed
- Monday, September 14, 2026
Dockets
Status timeline
Dates are printed as the NRC page prints them, including the actual (A) or target (T) mark.
| Milestone | Completion date |
|---|---|
| Application Tendered | 03/31/2025 |
| Acceptance Review Start | 04/01/2025 – A |
| Docketing Decision LetterIssued/Acceptance Review Complete | 05/12/2025 – A |
| Review Schedule Established/Schedule Letter Issued to Applicant | 06/10/2025 – A |
| Draft Safety Evaluation — Safety Evaluation (SE) sections drafted, and information gaps identified. | February 2026 – A |
| *Advanced Safety Evaluation — All SE sections available for Advisory Committee on Reactor Safeguards review. | August 2026 – A |
| Final Safety Evaluation — Final SE issued. | November 2026 – T |
| **Develop Initial Environmental Assessment (EA) Inputs — Draft EA sections and appendices developed, open items identified, audit plan and information needs issued, and site audit conducted. | 09/26/25 – A |
| Revise Environmental Assessment — Initial EA sections updated; site audit completed, and information needs resolved. Applicant submittals completed. Appendices completed and EA prepared. | 12/19/25 – A |
| Finalize Environmental Assessment and Related Activities — Legal review and management approvals of EA/FONSI conducted; EA correspondence prepared. | 04/14/26 – A |
| Issue Environmental Assessment and Finding of No Significant Impact — EA/FONSI concurrence completed; Audit Summary Issued; publication and issuance activities completed (including all related correspondence). | 05/18/26 – A |
| Hearing | TBD |
| Construction Permit Decision | TBD |
NRC activity table
The NRC page in this snapshot does not list a product activity table.
Related Federal Register notices
Included when a notice shares a docket printed on the NRC page, or when the notice title repeats the project or design name. Other NRC notices are left out.
- Long Mott Energy, LLC; Long Mott Generating Station; Notice of Hearing
Notice · 2026-16975 · August 20, 2026
- Long Mott Energy, LLC; Long Mott Generating Station; Environmental Assessment, Finding of No Significant Impact, and Exemptions
Notice · 2026-10073 · May 20, 2026
- Atomic Safety and Licensing Board Panel; Before Administrative Judges: [names omitted]; In the Matter of: Long Mott Energy, LLC (Long Mott Generating Station); Memorandum and Order (Notice of Hearing)
Notice · 2026-03415 · February 20, 2026