Terrapower is an American company developing molten-salt fast neutron reactors. Founded in 2006 by Bill Gates, it is developing several technologies and is designing a prototype reactor to be marketed in 2028.
Reactor technologies
Terrapower is developing three main technologies:
- Travelling-wave reactors, focused on fuel and waste utilization efficiency and the possibility of recovering uranium 238.
- MCFR molten-salt reactors, with a planned capacity of 1,200 MWe, in partnership with Southern Company.
- Smaller “natrium reactors” (375MWe), in partnership with General Electric Hitachi Nuclear Energy
Overall, all these technologies are based on the use of molten salts and passive safety systems, making them highly secure.
Travelling-wave reactors
TheTraveling Wave Reactor (TWR) is a sodium-cooled fast reactor designed to use uranium-238 as fuel. The core contains enriched uranium, which initiates the reaction. Around it, depleted or natural uranium is used as a fuel through over-breeding. The chain reaction will form a sort of concentric wave, converting U238 into plutonium, hence the name “travelling wave reactor”. The reactor will be capable of automatically moving fuel rods to sustain the reaction.
The reactor would also be highly secure, relying on passive systems to cool itself, not requiring operator intervention. What’s more, spent fuel could be stored inside the core. It can operate for a very long time without needing to be refueled.
MCFR molten-salt reactor
Terrapower is working withSouthern Company on the feasibility of a moltenchloride fast reactor (MCFR) prototype.
Natrium-cooled fast reactors
Terrapower is working with General Electric Hitachi Nuclear Energy to develop a 345MWe natrium-cooled reactor combined with molten-salt storage capable of storing around 1GWh, enabling the plant to produce 500MWe for 5.5 hours if required. It operates at ambient pressure, with the reactor operating at 350°C. Various passive cooling logics, using gravity and natural convection, guarantee its safety. On the downside, the technology uses high-assay, low-enriched uranium (HALEU) fuel (5-20% uranium 235).
Sodium has several advantages: its boiling point is extremely high, enabling the reactor to operate at normal pressure; it transmits heat extremely well (3* better than stainless steel), enabling a dense installation; it does not corrode its environment. The reactor does use water, however, notably to cool the steam created during electricity generation (as with current power plants, I suppose).
The company predicts production costs of between $2800 and $3000/KW, and an electricity price (LCOE) of around $50-60/MWh. A power plant should cost around a billion dollars.
Financing and news
One of the company’s special features is the involvement of Bill Gates, as founder, investor and Chairman of the Board.
Arcelor Mittal, developing processes to reduce the carbon footprint of steel production, invested €25 million in November 2022 through its XCarb innovation fund.
Advances in MCFR technology
In 2016, the DOE awarded a $45 million grant for the development of the MCFR reactor, including the development of a test facility (“Integrated Effects Test”) to better understand operation, including molten salt thermodynamics.
In February 2022, Terrapower and Southern Company signed an agreement to design and operate a prototype using uranium chloride incorporated in molten salts as fuel. This is scheduled for the early 2030s.
Advances in the sodium “natrium reactor
The natrium reactor seems to be the company’s main focus.
A demonstrator is to be built at a former coal-fired power station in Kemmerer, Wyoming (USA). The construction permit should be submitted to the NRC in 2023, and the operating license in 2026.
In addition to Terrapower and GE Hitachi Nuclear Energy, the project involves several national laboratories (Idaho, Argonne, Los Alamos, Oak Ridge, Pacifi Northwest) and universities (North Carolina, Oregon, Wisconsin), as well as other entities (PacifiCorp, Energy Northwest, Duke Energy Carolinas, American Centrifuge Operating, Global Nuclear Fuels Americas and Orano Federal Services). The facility is scheduled for completion in 2028, making it one of the first commercially available advanced reactors.
The project is 50% funded by the U.S. Department of Energy (DOE) up to a total of $2 billion. The operating plant would require between 200 and 250 people.
FAQ
What does TerraPower do?
TerraPower develops innovative, safe and low-carbon nuclear power generation systems.
What role does Bill Gates play in TerraPower?
Bill Gates is the founder and chairman of TerraPower.
Is TerraPower listed on the stock exchange?
No, TerraPower is still a non-public company.
Will TerraPower technology use uranium?
Yes. Its first technology, the traveling-wave reactor, should be able to run on uranium 238. The most advanced, its natrium reactor, will run on highly enriched uranium (5-20% U235), HALEU (“high-assay, low-enriched uranium”).
How many people does TerraPower employ?
TerraPower has 184 employees (November 2022).