it’s not exactly an earlier Beta-VHS feud, though standardization doubtless had something to do with the decision to use uranium. Also, thorium has a somewhat more complex fuel cycle: it has no fissile isotopes, so must always be seeded by uranium or plutonium to be useful – they convert the thorium to uranium-233, which is fissile.
But why use thorium at all, especially since using it does not foreclose the use of uranium?
The Washington Post takes a stab at it:
[Thorium] is less radioactive than the uranium that has always powered U.S. plants, and advocates say that not only does it produce less waste, it also is more difficult to turn into nuclear weapons.
Another point: there’s a lot of mined thorium in the world – almost all of it unused. We ran a post awhile ago about a rare metal mining operation called Pea Ridge that was positively stuffed to the brim with thorium – and had no market for it.
More on the thorium reactor:
“A molten-salt reactor is not a pressurized reactor,” said John Kutsch, director of the Thorium Energy Alliance, a trade group based in Harvard, Ill. “It doesn’t use water for cooling, so you don’t have the possibility of a hydrogen explosion, as you did in Fukushima.”
Kutsch calls the molten-salt reactor a “liquid-fluoride thorium reactor,” and if thorium boosters really want to use it here, they’ll have to get it through the design licensing process at the NRC. That takes time, is resource intensive and requires a company to sit tight while the bills pile up.
Those aren’t reasons not to do it, or even reasons to become discouraged, but new designs from startup companies are a tough proposition. There’s fuel fabrication plants to build and license – that takes time – and coping with an energy and manufacturing infrastructure that has been built to support light water reactors. There are a lot of hurdles on this race course. (Not that the United States and the NRC are the only ways forward – see the recently licensed AP1000 for a counter example.)
But is it impossible to clear those hurdles? No.
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Interestingly, the Post actually seeks out someone to bad mouth thorium, which is like dropping an anvil on a kitten. What’s the point?
“There are small boatloads of fanatics on thorium that don’t see the downsides,” said Dan Ingersoll, senior project manager for nuclear technology at the Oak Ridge National Laboratory in Tennessee. For one thing, he said, it would be too expensive to replace or convert the nuclear power plants already running in this country: “A thorium-based fuel cycle has some advantages, but it’s not compelling for infrastructure and investments.”
Ingersoll has a strong point here: thorium is fun to knock around because it is an element with a fan base, not just advocates and companies working on it. That can give it an air of frivolity. But his points against it only resonate if we freeze technology in place and go no further. From this perspective, it’s almost as if thorium were dismissible because it has a strong case.
And it isn’t really dismissible. “Replace or convert” need not be the only options (although replace seems eminently doable as older facilities retire some years hence). A lot of new designs are percolating through the small reactor community – TerraPower, Hyperion – so the thorium fuel cycle is not really so outlandish.
Be sure to check out the Thorium Energy Alliance here. (That web site, though. Oof!)
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Visit the Weinberg Foundation (in England) for some more hard core thorium advocacy. It even has a quote from Baroness Worthington:
The world desperately needs sustainable, low carbon energy to address climate change while lifting people out of poverty. Thorium fuelled reactors, such as the Molten Salt Reactor (MSR) pioneered by the late Alvin Weinberg, could radically change perceptions of nuclear power leading to widespread deployment.
The baroness is an environmental activist in the House of Lords. So there you go. Alvin Weinberg, who died in 2006, was a nuclear physicist also much in favor of thorium.
The Baroness Bryony Worthington.
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