Terrapower: traveling wave reactor design

TerraPower is the first spin-off of Intellectual Ventures, and Bill Gates is the principal owner of TerraPower, although there are others who have a level of ownership.

…our group looked at renewable sources of energy to see if they could be counted on to provide for the needs of the United States and the planet. We advocate the pursuit of renewable sources of energy, but the fact is that they just can’t provide the electric power that the world will need. That is why we will unfortunately end up burning even more coal, which has its well-known environmental problems, unless we use nuclear. — John Gilleland

I’m continuing to research the Terrapower story – first post here. Bill Gates investment doesn’t mean this is the best Gen IV+ reactor design, but it is very encouraging to see private funds at risk on a concept that appears to be very early stage (compared to the very well-developed Integral Fast Reactor (IFR)).

And it is very encouraging to see that the Terrapower CEO is willing to speak “truth to power” by revealing what every serious student of energy policy knows – that the consequence of the environmental activists focus on renewables is more and more coal generation. When American president Obama starts exhorting exactly this truth from his bully pulpit then I would have some confidence that serious solutions are again on the table.

The above quotation is from an interview with Terrapower CEO John Gilleland in the April 2008 Nuclear News. From the interview we gain a few more small insights into the reactor design. Excerpts:

How does the traveling-wave reactor work? The basic concept is to use depleted ura- nium as a fuel and to need no more than a small amount of enriched uranium to start a reactor. The reactor would be able to operate for decades without refueling and without chemical separations. In a certain sense, the way the reactor works is well known. It’s the typical breeding concept and standard physics—U-238 going to 239, to neptunium, and finally to plutonium-239—but with a twist, which is the traveling wave. In a sense, the wave can be visualized as two waves—a breeding wave moving just ahead of a burn- ing wave that consumes the bred material. Visualize a cylinder a few meters long that contains U-238 or depleted uranium. A nugget of uranium enriched to 10 percent is put at one end of the cylinder and a wave 40 centimeters wide is built up that breeds and burns plutonium and produces a gigawatt of electricity as it propagates from one end to the other. It would take 50 to 60 years for the wave to go from one end to the other for a reasonable-sized core.

How did you get involved in the project? Lowell Wood, an internationally recognized scientist-technologist, played a major role in drawing my interest. Other major players in the project are Nathan Myhrvold, founder of Intellectual Ventures, and Bill Gates, the chairman and cofounder of Microsoft. They looked around at the various energy systems and came up with this desire to improve nuclear and expedite its respon- sible deployment around the world. When I was called on in December 2006, I thought I would come in and tell them what was wrong with their thinking. But, basically, after researching the project, I never left. TerraPower is the first spin-off of Intellectual Ventures, and Bill Gates is the principal owner of TerraPower, although there are others who have a level of ownership.

What convinced you that the traveling wave could work? We looked back at some of the work done by Edward Teller and Lowell Wood on the breed/ burn concept. It seemed to us that the concept had promise, but, quite honestly, it looked like something that could not be readily achieved. But we decided that if we ran into certain problems, we could see if there was a way to walk around them. That is more or less what the effort has been about since then. Our mission is to try to bring the concept far enough along by using a serious physics and engineering effort such that a major nuclear player would consider the concept and then embark on developing the traveling-wave reactor for commercial deployment.

Why build a better mousetrap? To provide some background, our group looked at renewable sources of energy to see if they could be counted on to provide for the needs of the United States and the planet. We advocate the pursuit of renewable sources of energy, but the fact is that they just can’t provide the electric power that the world will need. That is why we will unfortunately end up burning even more coal, which has its well-known environmental problems, unless we use nuclear. We felt that the full deployment of nuclear could be achieved if we improved some things, namely the risk of proliferation, the economics of new reactors, the fuel supply, and the waste issue. We decided to form a group and start with a blank slate to see if we could address those things.

Here is a fragment from a Bill Gates interview on his interest in Terrapower

That’s been really exciting to take this idea of gathering top scientists from a broad set of areas and think about problems that can be solved. And in the case of the foundation, you know, Nathan (Myhrvold) has used that ability to convene great scientists to look at things like how do you deliver vaccines without having to use as many refrigerators, or how do you pasteurize milk in a better way, some very interesting things. And then I also sit down with that group when they’re looking at their rich world applications, including things around energy, and one of those has actually led to creating a company called TerraPower, which is focused on a new, very radically improved nuclear power plant design, which is a hard thing to get done, but extremely valuable if it comes through.

On my previous Terrapower post TomChemEngineer contributed two very informed and useful comments on the traveling wave design:

Pressurized Heavy Water Reactors commonly use unenriched uranium, and several are in operation beginnng with the CANDU design, then also being built by NPCIL in India and Siemens in Argentina. Deplated Uranium is similar to unenriched uranium, so the technology is already existing to do this. In essence, the heavy water conserves neutrons, so money is spent on separating heavy water rather than spending it in enrichng the uranium. Good stuff. Needs to be developed further to use the DU feedstock. U-238 (the most common element of depleted uranium (DU)) can’t be made fissionable/ critical with current technology so these are inherently safe. The heavy water slows down the neutrons from the little bit of U-235 remaining in the DU and heats up the water. Thanks for the info. This path needs to be watched and nurtured.

It looks like this “travelling wave reactor technology” uses liquid sodium as the moderator/neutron brake and just allows the fuel to be cycled through without a big deal to change out fuel rods. This is the big advantage of using unenriched fuel rods (or depleted uranium). Same principle as the Pressurized Heavy Water Reactor (above), but also without the need to make the heavy water (deuterium oxide). Promising!

Check out the schematic sketch of the reactor design at MIT Technology Review. Lastly there is an animation of the reactor operation on the Terrapower blog (there is no audio narration).

5 thoughts on “Terrapower: traveling wave reactor design

  1. Bill Gates and Co. seem to be very interested in energy technology that forces people to be dependent upon THEIR energy sources, bot energy sources that allow people to MAKE THEIR OWN ENERGY. The fact is the nuclear and fossil energy interest have a vested interest in discrediting, halting and delaying renewable energy. I know, I am an inventor, and like most solar energy inventors we are forced to go overseas (ie China) to get our patented inventions into production. To the rich, energy is cheap, but another definition of being poor is “lack of energy”. Solar and Wind technologies have the potential of eliminating poverty, but vested interest are fearful that renewable energy will “put them out of business”. They are correct. Besides the fact that nuclear and coal technologies are dangerous energy sources, the fact is solar and renewable energy has been deliberately starved of investment capital. In fact, during the 1980s, during the Reagan/Bush eras inventors found themselves outright targets of covert operations. I know I am one of those patented inventors.

  2. Martin,
    <<Bill Gates and Co. seem to be very interested in energy technology that forces people to be dependent upon THEIR energy sources>>
    I think you need to see what Gates actually believes. I think you will find his new TED Talk instructive — his primary motivation is exactly your point “To the rich, energy is cheap, but another definition of being poor is “lack of energy”.” His wish is for energy that is half the cost of coal (or cheaper). That is why he invested in Terrapower.
    Bill’s new Gates Notes is an excellent window into his thinking on energy — he has been doing very serious homework.
    Steve

  3. While watching Bill Gares speech on TED, I was thinking that he isn’t very familiar with renewable energy, energy efficiency and new concepts around it. His speach was very basic with no new insights. There are many visionaries and practitioners out there that are already behind the early stage of grasping the energy problem and proposing new models AND implementing them for the future.

    First: Energy Efficiency can lower our energy use by 70%. House stock: Passive houses (www.passivhouse.us) use 90% less energy than a energy star rated home (without PV). This applies also to house retrofits. Transportation: A Tesla electric car is only using 2500kWh/y. Smaller Models will use even less. Industrial Sector: I have to admit that I’m not that familiar with the industrial sector. But I think we can achieve huge reductions in the energy use of industrial facilities.

    Second: renewable energy CAN deliver all the energy the world needs, but only after energy efficiency was deployed. This however doesn’t mean that we have to wait to install let’s say wind already today.

    Third: If Terra Power is able to deploy a working model of it’s new reactor model, fine, why not. It’s not forbidden to make money in a capital market. Everything that doesn’t produce CO2 is welcome. Some people still want to buy power from a utility.

    Fourth: Thinking that storage of renewable energy isn’t possible is an error often made. Storing it in batteries is indeed a bad idea. But in germany studies have shown that combining wind-, biomass-, water- and solar-plants can provide 100% of the energy needed all the time. For more details see: http://www.unendlich-viel-energie.de/de/strom/detailansicht/article/165/the-combined-power-plant.html Solar thermal plant can store energy in molten salt storage for up to 12 hours.

    So please, don’t try to slow the deployment of renewables by repeating old ideas. I was expecting more from one of the most famous technology inventors of our century!

  4. One small caveat. Bill Gates was not “one of the most famous technology inventors.” Indeed he did no invention at all. He subsumed the work of Xerox and Apple and contorted it into the Microsoft product.

  5. Forget the silly windmills,ethanol plants, filthy coal plants, They are Rube Goldburg compaired to this idea. Every morning I look at how red the sunrise is – Look at the the air quality on the national weather service site and see that we need change, The winds are sweeping this pollution across the ocean from Asia to the west coast, our pollution affects other parts of the world also.

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