What do you think of Bill Gates’s TerraPower’s TWR design?

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More from reddit.com Science AMA Series with members of the UC Berkeley Department of Nuclear Engineering. Here’s the question What do you think of Bill Gates’s TerraPower’s TWR design? Do you think it could be a viable element in a carbon-neutral energy future?

And Prof. Rachel Slaybaugh’s reply:

The TWR is a large sodium-cooled fast breeder reactor. Things about it that make it attractive are that it:

  • gets much more energy out of the mined resources than typical reactors (enhancing sustainability)
  • can establish a fleet of reactors that don’t require fuel enrichment or fuel reprocessing (reducing fuel costs and proliferation concerns). The initial plant requires enriched uranium, but its follow-ons do not.
  • has strong safety characterisitics. The low-pressure liquid metal coolant can naturally circulate and dump heat to atmosphere indefinitely without any power whatsoever.

It also has some drawbacks. Most notably designing materials that will be able to withstand the amount of radiation required. Another challenge is that the plant is large and low-leakage. To get the Traveling Wave going, the plant has to conserve as many neutrons as possible. Large fast reactors have some inherent issues with stability, so TerraPower probably has to do some tricky stuff to keep the plant safe. It’s not impossible, but it’s probably difficult.

For the future? If they can overcome the challenges I think it could certainly be part of a low carbon future.