TerraPower—with the backing of Bill Gates—has a radical vision for the reactors of tomorrow
Bill Gates founded and is guiding a start-up called TerraPower LLC, where he serves as chairman, Mr. Gates has become a player in a field of inventors whose goal is to make nuclear reactors smaller, cheaper and safer than today’s nuclear energy sources.
Terrapower recently completed a basic design for a reactor that theoretically could run untouched for decades on spent nuclear fuel. Now the company is seeking a partner to help build the experimental reactor, and a country willing to host it.
TRAVELLING WAVE REACTOR
Robert A.Guth explained the technology in his WSJ article brilliantly:
To understand how a traveling-wave reactor works, think of a wood-burning stove. Today’s reactors use dried wood—enriched uranium-235—that burns hot and quickly. A traveling-wave reactor would start with a little bit of dried wood to get a hot flame going, but most of the fuel would be green, or wet, wood—depleted uranium-238. The wet logs wouldn’t burn as hot as the dried ones, but they would continue to burn long after the hot flame goes out.
Burning the enriched uranium would shoot neutrons into the depleted uranium making up roughly 90% of the fuel. That process would produce plutonium, which would create energy as it continued to get hit by even more neutrons. It’s a slow, controlled reaction that could continue over many years without need of human intervention. And in TerraPower’s design, the core of the reactor, where fission takes place, would be small: a cylinder about 10 feet wide and 13 feet long.
Another plus: Large supplies of depleted uranium are available as a byproduct of today’s water-cooled reactors. Removing it from those reactors and reprocessing it for reuse is a costly procedure, and a source of worry that radioactive material might fall into the wrong hands. Reducing the need for reprocessing could save money and reduce the risk of nuclear proliferation.
The idea for traveling-wave reactors has been around for decades but was mothballed amid waning U.S. interest in nuclear power. Then came a boost in the 1990s from a research paper by scientists at Lawrence Livermore National Laboratory, including Edward Teller, the father of the hydrogen bomb and the brain behind Ronald Reagan’s Star Wars missile-defense initiative; and an acolyte of Mr. Teller’s named Lowell Wood.