TerraPower

AActiveFounded 2008🇺🇸Bellevue, Washington

CEO

Chris Levesque

Overview

TerraPower is a nuclear innovation company founded by Bill Gates and focused primarily on the Natrium sodium fast reactor with integrated molten-salt energy storage. In March 2026 the NRC granted Kemmerer Unit 1 the first construction permit for a commercial-scale advanced nuclear plant in the U.S., and on April 23, 2026 TerraPower officially began plant construction in Wyoming. The company remains pre-revenue, but Natrium has moved from development into full project execution under DOE's ARDP cost-share program.

Main Products

Natrium

In Development

Sodium-cooled fast reactor with integrated molten salt energy storage, enabling flexible output from 345 MWe to 500 MWe peak.

Demonstration plant under construction in Kemmerer, Wyoming — NRC construction permit issued March 2026, targeting commercial operation by 2031.

Electrical Output345 MWe (baseload)

Peak Output500 MWe (with storage)

Reactor TypeSodium-cooled fast reactor

Energy StorageMolten salt (GigaWatt-hour scale)

Demo Plant LocationKemmerer, Wyoming

Target Operation2031

Molten Salt Energy Storage

In Development

Integrated thermal energy storage system using molten salt to decouple reactor output from grid delivery, enabling peak power output.

Part of the Natrium system — allows flexible power dispatch to complement intermittent renewables.

Storage TypeMolten nitrate salt

Peak Boost345 MWe → 500 MWe

Duration5.5+ hours at peak

PurposeGrid flexibility / renewable complement

What's Next

Execute Kemmerer Unit 1 construction

With construction now officially underway, TerraPower's central execution challenge is building Kemmerer Unit 1 on schedule and moving the first Natrium plant toward operation in 2031.

2031

First sodium reactor criticality

Targeting initial criticality of the Natrium reactor at the Kemmerer demonstration plant, marking the first sodium-cooled fast reactor to operate in the U.S. in decades.

2031

Complete the supporting Natrium fuel and sodium facilities

The first-of-a-kind Natrium build still depends on completing its supporting fuel-fabrication and sodium test-and-fill infrastructure alongside the main plant under the ARDP program.

Late 2020s

Operations & Revenue

StatusPre-revenue

Pre-revenue, but no longer just at the concept stage. Kemmerer Unit 1 now has an NRC construction permit and entered full construction in April 2026, making TerraPower one of the most advanced U.S. advanced-reactor developers by project execution status.

Pipeline & Contracts

DOE Cost-Share Funding

$2B+ from DOE's Advanced Reactor Demonstration Program to build the Natrium demonstration plant.

Private Investment & Partnerships

Significant investment from Bill Gates, SK Group, and venture partners funding reactor development and demonstration.

Key Metrics

Employees

1,000+

Est. Annual Revenue

Pre-revenue

DOE ARDP Federal Cost Share

Up to $2B

Natrium Output

345 MWe (500 MWe peak)

Kemmerer Unit 1 Status

Construction started Apr. 23, 2026

Timeline

2026NRC permit issued and full Natrium construction begins

The NRC issues the first construction permit for a commercial-scale advanced nuclear plant in the U.S., and TerraPower officially begins construction of Kemmerer Unit 1 on April 23, 2026.

2024Site work and project preparation advance

TerraPower advances early project work in Kemmerer ahead of receiving the NRC construction permit for the first Natrium plant.

2022Kemmerer site selected

Selects Kemmerer, Wyoming (former coal town) as site for first Natrium demonstration plant.

2020DOE ARDP award

Receives $2B+ cost-share award under DOE's Advanced Reactor Demonstration Program.

2019Natrium design unveiled

Pivots to the Natrium sodium-cooled fast reactor with integrated molten salt storage.

2015China partnership

Signs agreement with China National Nuclear Corporation (CNNC) for TWR development.

2010Traveling wave reactor concept

Develops the traveling wave reactor (TWR) design that can run on depleted uranium.

2008Founded

Bill Gates and a group of technologists found TerraPower to develop advanced nuclear energy.

Funding

Round	Date	Amount	Investors
Founder & early investors	2008–2018	$1B+	Bill Gates, Khosla Ventures, venture partners
DOE ARDP cost-share	2020	$2B+ (government share)	U.S. Department of Energy
Series B	2022	$750M	SK Group, Bill Gates