It’s always seemed to me that nuclear power would have to be part of the solution of the global warming problem: even if the planet’s population were to remain constant, and even if planet-wide energy use were to remain steady, we would still have to dramatically cut CO2 per capita emissions. The problem with nuclear power–or more accurately, uranium-based nuclear power–is the waste product. Not only is radioactive waste produced, but the byproducts of the reaction can be used to build nuclear weapons. So I was very intrigued by this Wired article about thorium-based nuclear power:
When he took over as head of Oak Ridge in 1955, Alvin Weinberg realized that thorium by itself could start to solve these problems. It’s abundant — the US has at least 175,000 tons of the stuff — and doesn’t require costly processing. It is also extraordinarily efficient as a nuclear fuel. As it decays in a reactor core, its byproducts produce more neutrons per collision than conventional fuel. The more neutrons per collision, the more energy generated, the less total fuel consumed, and the less radioactive nastiness left behind.
Even better, Weinberg realized that you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. The design is based on the lab’s finding that thorium dissolves in hot liquid fluoride salts. This fission soup is poured into tubes in the core of the reactor, where the nuclear chain reaction — the billiard balls colliding — happens. The system makes the reactor self-regulating: When the soup gets too hot it expands and flows out of the tubes — slowing fission and eliminating the possibility of another Chernobyl. Any actinide can work in this method, but thorium is particularly well suited because it is so efficient at the high temperatures at which fission occurs in the soup.
Unfortunately, in 1973, the U.S. committed to uranium nuclear power since it would yield plutonium which could be used to build nukes (fucking brilliant). Fortunately, thorium is being revisited, but, as you might imagine, a concept originated in the U.S. will probably be adopted first overseas:
Overseas, the nuclear power establishment is getting the message. In France, which already generates more than 75 percent of its electricity from nuclear power, the Laboratoire de Physique Subatomique et de Cosmologie has been building models of variations of Weinberg’s design for molten salt reactors to see if they can be made to work efficiently. The real action, though, is in India and China, both of which need to satisfy an immense and growing demand for electricity. The world’s largest source of thorium, India, doesn’t have any commercial thorium reactors yet. But it has announced plans to increase its nuclear power capacity: Nuclear energy now accounts for 9 percent of India’s total energy; the government expects that by 2050 it will be 25 percent, with thorium generating a large part of that. China plans to build dozens of nuclear reactors in the coming decade, and it hosted a major thorium conference last October. The People’s Republic recently ordered mineral refiners to reserve the thorium they produce so it can be used to generate nuclear power.
In the United States, the LFTR concept is gaining momentum, if more slowly. Sorensen and others promote it regularly at energy conferences. Renowned climatologist James Hansen specifically cited thorium as a potential fuel source in an “Open Letter to Obama” after the election. And legislators are acting, too. At least three thorium-related bills are making their way through the Capitol, including the Senate’s Thorium Energy Independence and Security Act, cosponsored by Orrin Hatch of Utah and Harry Reid of Nevada, which would provide $250 million for research at the Department of Energy. “I don’t know of anything more beneficial to the country, as far as environmentally sound power, than nuclear energy powered by thorium,” Hatch says. (Both senators have long opposed nuclear waste dumps in their home states.)
There are technical challenges–thorium rods would be housed for much longer times in a corrosive salt medium, and nobody knows what this means for safety. But if these problems are surmounted (and it seems like they could be), this could put a serious dent in our CO2 emissions. And the U.S. has a 1,000 year supply of thorium.
We’ll just have to find other reasons to invade foreign countries, I suppose….