TerraPower
Bill Gates-founded developer of the Natrium sodium-fast reactor with molten-salt thermal storage
Bellevue, WA~1,000Founded 2006~$2B private + $2B DOE raisedPrivate (no recent secondary marks) valuationwww.terrapower.com
SectorsNuclear
DOE ARDP Award
Up to $2B
Cost-shared through ~2030
Natrium Reactor Output
345 MWe + 1 GWh storage
Can boost to ~500 MWe for ~5.5 hr from molten-salt buffer
Private Capital Raised
~$2B+
Gates, NVIDIA, HD Hyundai, SK Inc. across 2022 + 2025 rounds
Natrium FOAK Target
2030 (Kemmerer, WY)
Revised from original 2028 target (HALEU supply constraint)
Funding History
Total raised: ~$2B private + $2B DOE · Latest valuation: Private (no recent secondary marks)
| Round | Date | Amount | Valuation | Key Investors |
|---|---|---|---|---|
| Founding / Early | 2006-2015 | Bill Gates personal funding | — | Bill GatesVinod Khosla (Khosla Ventures)Charles River Ventures |
| DOE ARDP Award | Oct 2020 | $80M initial (up to $2B over 7 years) | — | US Department of Energy (Advanced Reactor Demonstration Program) |
| Series | Aug 2022 | $750M | — | Bill GatesSK Inc.SK Innovation |
| Strategic Round | Apr 2025 | $650M (reported) | — | Bill GatesNVIDIAHD HyundaiARCH Venture Partners |
Product Specifications
| System | Type | Status |
|---|---|---|
| Natrium | 345 MWe sodium fast reactor + 1 GWh molten-salt thermal storage (can boost to ~500 MWe for ~5.5 hr) | Construction (Kemmerer, WY); NRC CP under review |
| MCFR (Molten Chloride Fast Reactor) | Liquid-fuel fast reactor concept | R&D (Southern Company JV); MCRE pilot at INL targeted 2026 |
| TerraPower Isotopes | Medical isotope production (Ac-225, Cu-67) using HFIR + repurposed cold-war material | Commercial. First Ac-225 commercial supply Dec 2022 |
| Natrium Energy Storage System | Standalone offering for grid-scale molten-salt thermal storage | R&D / commercialization stage |
| Traveling Wave Reactor (TWR) | Original breed-and-burn fast reactor concept | Discontinued (superseded by Natrium) |
Partnerships & Investors
GE Vernova (GE-Hitachi)Strategic
Co-developer of Natrium; supplies the steam-cycle balance-of-plant and integrates GEH BWRX-300 manufacturing infrastructure.
BechtelEPC
Engineering, procurement, and construction partner for the Kemmerer FOAK Natrium plant.
PacifiCorp / Rocky Mountain PowerHost / Offtake
Host utility at Kemmerer; long-term offtake under negotiation.
Southern CompanyStrategic / JV
MCFR joint development; co-funded MCRE pilot at Idaho National Laboratory.
HD HyundaiStrategic / Investor
Apr 2025 round investor; Korean heavy-forging supply for Natrium components.
NVIDIAStrategic / Investor
Apr 2025 round investor; AI-power thesis links advanced-reactor capacity to datacenter demand.
US Department of Energy (ARDP)Customer / Cost-share
Up to $2B Advanced Reactor Demonstration Program cost share through ~2030.
Idaho National LaboratoryResearch
Host site for MCRE pilot; fuel cycle R&D collaboration.
Key Milestones
2006
Company Founded
Spun out of Intellectual Ventures by Nathan Myhrvold and Bill Gates
2010
Traveling Wave Reactor Design
Original TWR concept published; later superseded by Natrium
Sep 2015
China JV with CNNC
Agreement to build the Xiapu TWR demonstration in Fujian
Jan 2019
China JV Cancelled
US export controls block continued cooperation; TerraPower refocuses on US
Aug 2020
Natrium Design Unveiled
345 MWe sodium fast reactor with 1 GWh molten-salt thermal storage; partnership with GE-Hitachi for steam-cycle balance of plant
Oct 2020
DOE ARDP Selection
Natrium selected as one of two demonstration awards (alongside X-energy); initial $80M, up to $2B
Nov 2021
Kemmerer WY Site Selected
Former Naughton coal plant chosen for FOAK Natrium site; PacifiCorp / Rocky Mountain Power as host utility
Mar 2024
NRC Construction Permit Application
Application submitted; first non-LWR Part 50 CP application since the 1980s
Jun 2024
Groundbreaking (non-nuclear)
Construction begins on non-safety-related portions of Kemmerer Natrium plant
Apr 2025
Strategic Round with NVIDIA + HD Hyundai
$650M raise pulls in NVIDIA (AI-power thesis) and HD Hyundai (forging supply); Gates remains largest investor
2026 (targeted)
MCFR Pilot Loop
Molten Chloride Reactor Experiment milestone with Southern Company at INL
2030 (revised target)
Natrium FOAK Operation
Original 2028 target slipped due to HALEU fuel supply constraints