Thorium Reactors

Reading the comments from the link at my last post, there was a reference to an article on Liquid Fluoride Thorium Reactors (LFTR) at Wired Magazine. I read it and it is an incredible post -- well worth reading for a great introduction to this technology that was developed from the '50s through the '70s but scotched by Admiral Hyman Rickover who preferred the Uranium reactors because they could be used to manufacture Plutonium for weapons. Thorium does not go Ka-Boom. We have enough Uranium for about 500 years of reactor operation at current levels of generation. Using current known reserves of Thorium, this gets pushed up to several tens of thousands of years. The comments are well worth your time to read as a lot of knowledgeable people are chiming in with their anecdotes, numbers, corrections to numbers, etc... From Richard Martin writing at Wired Magazine - December 21, 2009:

Uranium Is So Last Century � Enter Thorium, the New Green Nuke
The thick hardbound volume was sitting on a shelf in a colleague�s office when Kirk Sorensen spotted it. A rookie NASA engineer at the Marshall Space Flight Center, Sorensen was researching nuclear-powered propulsion, and the book�s title � Fluid Fuel Reactors � jumped out at him. He picked it up and thumbed through it. Hours later, he was still reading, enchanted by the ideas but struggling with the arcane writing. �I took it home that night, but I didn�t understand all the nuclear terminology,� Sorensen says. He pored over it in the coming months, ultimately deciding that he held in his hands the key to the world�s energy future.

Published in 1958 under the auspices of the Atomic Energy Commission as part of its Atoms for Peace program, Fluid Fuel Reactors is a book only an engineer could love: a dense, 978-page account of research conducted at Oak Ridge National Lab, most of it under former director Alvin Weinberg. What caught Sorensen�s eye was the description of Weinberg�s experiments producing nuclear power with an element called thorium.

At the time, in 2000, Sorensen was just 25, engaged to be married and thrilled to be employed at his first serious job as a real aerospace engineer. A devout Mormon with a linebacker�s build and a marine�s crew cut, Sorensen made an unlikely iconoclast. But the book inspired him to pursue an intense study of nuclear energy over the next few years, during which he became convinced that thorium could solve the nuclear power industry�s most intractable problems. After it has been used as fuel for power plants, the element leaves behind minuscule amounts of waste. And that waste needs to be stored for only a few hundred years, not a few hundred thousand like other nuclear byproducts. Because it�s so plentiful in nature, it�s virtually inexhaustible. It�s also one of only a few substances that acts as a thermal breeder, in theory creating enough new fuel as it breaks down to sustain a high-temperature chain reaction indefinitely. And it would be virtually impossible for the byproducts of a thorium reactor to be used by terrorists or anyone else to make nuclear weapons.

Weinberg and his men proved the efficacy of thorium reactors in hundreds of tests at Oak Ridge from the �50s through the early �70s. But thorium hit a dead end. Locked in a struggle with a nuclear- armed Soviet Union, the US government in the �60s chose to build uranium-fueled reactors � in part because they produce plutonium that can be refined into weapons-grade material. The course of the nuclear industry was set for the next four decades, and thorium power became one of the great what-if technologies of the 20th century.

Again, be sure to read the comments as there is a lot of great discussion going on -- be sure to note Ken Ricci, johnkclark, georgeherbert and kfsorensen.