Kirk Sorensen - Thorium's One-Man Band
“Thorium has already saved the earth once,” says Kirk Sorensen, founder of Flibe Energy and probably the world’s leading advocate of a thorium economy. “Radioactive thorium in the earth’s core heats the planet so that the lead at the center is molten. The constant roiling of this molten core is what creates the earth’s magnetic field. This magnetic field then diverts the solar wind, which is stream of protons released by the sun. It streams around the poles, which is what creates the Northern Lights.
"Now if the earth’s magnetic core were not diverting these outbursts then the solar wind would have long ago stripped the earth of its atmosphere, which is what happened on a planet with no molten core like Mars. Without thorium life would never had evolved.”
Sorensen is an engineering graduate of Georgia Tech who has gradually made thorium his life’s work. He thinks thorium contains enough energy to offer the planet unlimited amounts of energy into an unlimited future. Lots of other people think so as well. But none has put as much effort into the crusade as Sorensen.
Drop him a note and he’ll come to your Kiwanis Club meeting next week to give a rousing presentation in search of investment. “Thorium is a ubiquitous element,” he begins. “It’s as common as lead and three times as common as tin. It’s also four times as common as uranium and unlike uranium it does not have to be enriched in order to use it. Uranium enrichment is the most energy-intense and expensive part of the whole fuel process. There’s a huge amount of thorium sitting in a pile of phosphate tailings in Florida. Right now most of our thorium is only a by-product of other mining operations. Nobody goes out and looks for it.”
Nuclear scientists all the way back to Enrico Fermi have believed thorium was a better route than uranium to nuclear electricity. It was Fermi developed the first critical pile on a squash court at the University of Chicago in 1941. Another advocate was Alvin Weinberg, who designed the first pressurized water reactor for Admiral Hyman Rickover at the Oak Ridge National Laboratory in 1951.
But thorium had one great disadvantage. It did not produce plutonium for the atomic weapons program. The route from uranium to plutonium to an atomic weapon is fairly short, as India, North Korea and others have demonstrated. The problem of proliferation has dogged the nuclear electric effort ever since.
Another advance that has gotten short shrift is the idea of dissolving the nuclear fuel in molten salts. Current reactors use solid fuel pellets assembled in 18-foot “fuel rods” that must be cooled constantly by pumped water. If the coolant is lost, the fuel “melts down” and can escape into the environment. With molten salts, the fuel is already in liquid form and can’t melt down. A salt plug at the bottom of the vessel holds the fluid in place. If the fuel overheats, the plug melts and the fluid flows into a drain tank where the nuclear reaction loses its criticality. The plant is “walkaway safe.” Experiments in these techniques were carried out at Oak Ridge in the 1960s and 1970s but were eventually dropped because they did not fit into the weapons program.
Like the relics of a lost civilization they remained buried under generations of paperwork until Sorensen began unearthing them in the 1990s. “I was working for NASA in Huntsville and we began looking for some kind of reactor than could perform in space,” says Sorensen today. “I began exploring Oak Ridge’s work and found they had done a lot of research in the early days.
"One of the best sources was a book called Fluid Fuel Reactors written in 1958. They had a thorium reactor that operated for five years and a molten salt reactor that ran from 1965 to 1969. I began contacting some of the scientists who had had worked on these projects. They were now all in their 70s and 80s and stood by their work but said it was too late for them to get involved in anything now.”
So in 2006, Sorensen set up a website, www.energyfromthorium.com and began posting the old Oak Ridge research papers online. People began responding and interest grew. NASA thought it was a good idea but had no money for research.
Then in 2011 Sorensen decided to found his own company, Flibe, named for the fluoride, lithium and beryllium salts that dissolve the fuel. (Many people think they could come up with a more mellifluous name.) With only three employees, the ultimate goal is to come up with a design to put before the Nuclear Regulatory Commission. But right now the main activity is fund-raising.
The NRC currently gets only $150 million from Congress. The rest of its $1 billion budget is raised from by fees charged to the industry for reviewing various safety proposals and designs. The NRC charges companies $250 an hour for reviewing material and the meter is always running. “Off the record, individuals at the NRC have told us they’re very interested in our work,” says Sorensen. “But we’re a long way from putting anything formal before the NRC.”
As one of the commenters at a Sorensen lecture put it, “The NRC is like that football coach who said winning isn’t the most important thing, it's the only thing. At the NRC, safety is the only thing.”
What about other countries? “There’s lots of interest in thorium in India, the Netherlands, Australia and Russia," says Sorensen. "But everyone wants America to go first. They’ll be happy to go second.”
There is one exception. “China is moving ahead with an experimental small modular reactor that burns thorium in liquid salts. Here we talk about `all of the above.’ But in China they’re actually doing `all of the above.’”
Given these odds, Sorensen’s small modular thorium reactor is like to stay on the drawing boards until China presents one to the world in about ten years. We’ll be happy to let them go first. Because of our phobia about nuclear energy, we are gradually ceding leadership in a technology where we have pioneered since 1945. But it isn’t because people like Kirk Sorensen aren’t trying.