Natrium Reactor

Basics

Reactor Type Liquid Metal Reactor

Reactor Description Fast pool type LMR

Electric Output (MWe) 345

Thermal Output (MWt) 840

Size

Large

Spectrum

Fast

Developer Terra Power

Pilot Site Details Naughton PP, Kemmerer, Wyoming

Details

Use (goal of commercial operation) Electric power generation

Deployment medium Land-based

Design Lifetime (Years) 80

Fuel

Fuel class

HALEU

Fuel Type Metallic U-Zr Alloy

Fuel Cycle Closed, Envisaged

Refuelling Cycle 18 Months

Cooling & Temperature

Reactor cooling of primary loop Sodium

Reactor moderator N/A

Reactor Outlet Temperature (°C) 500

Status

Design status Detailed design

Licensing status

Mar 2026 - NRC clears its Office of Nuclear Reactor Regulation to issue construction permit for Unit 1 of Kemmerer power station; operation permit will be a separate process
Dec 2025 - Final safety evaluation issued by NRC (prerequisite for construction permit)
Oct 2025 - Favourable environmental impact statement issued by NRC (prerequisite for construction permit)
Jan 2025 - Wyoming Industrial Siting Council issued permit on its permit for non-nuclear construction and operational activities on the plant (not under the jurisdiction of the NRC)
Nov 2024 - TerraPower completed environmental scoping activities, NRC issued environmental scoping report
Mar 2024 - TerraPower filed construction application for Unit 1 of Kemmerer power station with US NRC
Since 2020 - Pre-application activities with NRC; a steady stream of topical reports and white papers

Deployment timeline

2028-2029: Expected pilot operation
2026: Target date to start nuclear-related construction
2025-2026: Target detailed design phase
Final safety evaluation with NRC for Unit 1 of Kemmerer power station expected in Aug 2026
GE Hitachi Natrium fuel factory at Willmington, NC, expected to be completed in 2025
Jun 2024: First dig at Kemmerer site; Work began on non-nuclear sodium test and fill facility

Agreements and Engagement

Mar 2025 - Agreement announced with Hyundai Heavy Industries to collaborate on scaling up and manufacturing
Oct 2024 - TerraPower awarded Idaho-based Premier Technology a contract for the design, testing, and fabrication of the sodium-air heat exchanger and air stack equipment, part of the plant’s cooling and passive safety systems
In 2023 - TerraPower signed a partnership agreement with Energy Northwest, a cooperation agreement with SK and KHNP, and selected Western Service Corporation (WSC), James Fisher Technologies, BWXT Canada, and Curtiss-
Wright Flow Control Service for engineering services Kemmerer demonstrator
In 2023 - Expanded agreements with Japan Atomic Energy Agency, Mitsubishi Heavy Industries and South Korea's SK Group
In 2023 - Agreement signed to cooperate with Centrus Energy to establish commercial-scale production for HALEU for the Natrium demonstrator
In 2022 - Deal signed GE Hitachi to build a Natrium fuel manufacturing facility at Wilmington, North Carolina
Nov 2021 - Retired coal-fired Naughton plant near Kemmerer announced as pilot site
Jun 2021 - TerraPower and utility PacifiCorp signed agreement to deploy Natrium in Wyoming
In 2020 - US DOE awarded TerraPower seven-year matching funding as part of the Advanced Reactor Demonstration Programme (ARDP)

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