A technology called the molten-salt reactor first went online in 1965 at Oak Ridge National Laboratory, but was scrapped in the 1970s because it wasn't good for making nuclear weapons. If entrepreneurs can revive the technology, it could safely and cleanly power billions of people for millions of years using a common element: thorium.

Listen for more about thorium plus Bill Nye and more in the latest episode of our podcast, Codebreaker, produced with Marketplace. Subscribe on iTunes or wherever you get your podcasts.

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