Nuclear power, that oft-maligned source of clean energy, got a boost earlier this year when TerraPower announced plans to team up with Toshiba to build a hot tub-sized traveling-wave nuclear reactor. Now TerraPower is moving even closer to commercialization with news that investors—including Khosla Ventures and Charles River Ventures—are backing the startup with a cool $35 million. TerraPower claims it has already raised tens of millions of dollars, though it won't give exact figures.
Unlike light-water nuclear reactors that run on enriched uranium, TerraPower's traveling-wave reactors run on depleted uranium that only needs to be replaced every 60 to 100 years. Based on known uranium reserves, TerraPower believes that its reactors could power the world for thousands of years without having to chemically reprocess fuel.
TerraPower explains the science behind traveling-wave reactors:
A nuclear fission reactor produces and controls the release of energy from splitting atoms of certain heavy elements. The nuclear power plants of today require a full core of fuel made from enriched uranium. The TWR, in contrast, initially contains only a small amount of enriched uranium, which is used to kick off the chain reaction through a core of depleted uranium. The wave of fission would move slowly through this depleted uranium core, splitting many more of the uranium atoms than a conventional reactor would.
But TerraPower isn't ready to power the world quite yet. The startup is working on a 500-megawatt reactor, according to the New York Times—that's only half the size of conventional reactors planned by other companies. Ultimately, though, TerraPower hopes to build a gigawatt-sized reactor that can light up an entire city (in a good way). This all depends, of course, on our willingness to accept that nuclear power is a viable (and safe) source of future energy alongside wind, solar, and geothermal sources.