Xe-100
X-energy's pebble bed, 80 MWe per module, with Dow and Amazon as first customers.
Helium-cooled pebble-bed HTGR. The Long Mott application describes modules at approximately 200 MWt and 80 MWe, with four modules per plant; ARIS 2024 reports 82.5 MWe for the basic design. The Long Mott review is a site construction permit, not a generic design certification.
- Stated output
- 200 MWt · 80 MWe net/gross basis not stated · per unit
- Maturity
- Basic design
- Developer
- X Energy, LLC
- Origin
- United States
Energy and applications
Published magnitudes; this is not an engineering diagram.
Three different states
Maturity, licensing and deployment are not equivalent.
Maturity
Basic designHow far the published engineering has progressed.
Licensing and review
1 regulatory readingWhat a regulator decided, where and on what date.
Linked deployment
0 geolocated unitsWhich projects or units are linked to the design.
Linked deployment
No geolocated nuclear unit is linked to this design.
Licensing and review
What a regulator decided, where and on what date.
| Jurisdiction | Reading | Method | Date |
|---|---|---|---|
| United States | Under review | 10 CFR Part 50 construction permit application for the four-module Long Mott site; not a design certification | 2026-08-31 |
Technical sources
- IAEA ARIS · SMR Catalogue 2024IAEA · 2024
- U.S. NRC · Long Mott Xe-100 construction permit applicationRegulator · 2026-08-31
How it works and why it matters
The Xe-100 is a 200 MWt, 80 MWe pebble-bed reactor per module, conceived for four-module plants. Its first project is a Dow chemical complex at Seadrift, Texas, and in 2024 Amazon announced an investment for up to 5 GW of this technology.
It is under NRC licensing; the construction permit application for Seadrift was filed in 2025. Its TRISO fuel will be made at the company's own plant in Oak Ridge.
Quick facts
| Power | 80 MWe per module |
|---|---|
| Status 2026 | licensing |
| Customers | Dow, Amazon, Energy Northwest |