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Back in May 2012, I happened to be on a drive while National Public Radio here in the United States was broadcasting a Science Friday story, "Is Thorium A Magic

Back in May 2012, I happened to be on a drive while National Public Radio here in the United States was broadcasting a Science Friday story, "Is Thorium A Magic Bullet For Our Energy Problems?" http://www.npr.org/2012/05/04/152026805/is-thorium-a-magic-bullet-for-our-energy-problems http://www.npr.org/2012/05/04/152026805/is-thorium-a-magic-b... Many of the issues considered in that story are glossed over by advocates of thorium reactors. The author of the blog post kindly submitted here explicitly admits, "My last article about thorium as an alternative nuclear reactor fuel drew way more readers than I expected. I intentionally glossed over the complexities of specific reactor designs for the sake of simplicity, but in this article I want to go deeper." He mentions a number of interesting technical trade-offs involved in using thorium reactor fuel and the latest reactor designs as compared to earlier nuclear reactor designs, but the tone is still largely a tone of credulity, without a lot of examination of non-nuclear means of generating electrical power. The Physics Stack Exchange discussion of thorium reactors is interesting, http://physics.stackexchange.com/questions/20034/what-practical-issues-remain-for-the-adoption-of-thorium-reactors http://physics.stackexchange.com/questions/20034/what-practi... as is the article from The Guardian in June 2011, "Don't believe the spin on thorium being a greener nuclear option." http://www.guardian.co.uk/environment/2011/jun/23/thorium-nuclear-uranium http://www.guardian.co.uk/environment/2011/jun/23/thorium-nu... Advocacy groups are already mobilizing to cast doubt on thorium reactors, with webpages like "Thorium Fuel – No Panacea for Nuclear Power" http://ieer.org/resource/factsheets/thorium-fuel-panacea-nuclear-power/ http://ieer.org/resource/factsheets/thorium-fuel-panacea-nuc... (with a link to an interesting fact sheet, http://ieer.org/wp/wp-content/uploads/2012/04/thorium2009factsheet.pdf http://ieer.org/wp/wp-content/uploads/2012/04/thorium2009fac... that gets into the practicalities and economics of using thorium as a reactor fuel). It's not clear yet that thorium offers any economic or political advantages over the uranium that fuels the nuclear reactor that provides much of my home electricity. The two nuclear reactors here in Minnesota result in lower-than-average cost for electricity here, compared to the rest of the United States, and have had a perfect safety record. Ongoing concern about where to store high-level radioactive waste on a long-term basis has made many politicians here reluctant ever to approve another nuclear plant in this state, despite the perfect safety record and inexpensive electricity we enjoy with the current plants. Minnesota, as a matter of state policy, is strongly promoting wind energy, fitting the wind-swept prairie geography of much of the state. I'm not aware of any part of the world where local politics would make a thorium plant more likely than another wind power plant or natural-gas-fired power plant. So maybe thorium power generation is a technical solution looking for a problem.

apendleton 14y ago
Not necessarily disagreeing with your main thrust, but this sentence: "So maybe thorium power generation is a technical solution looking for a problem." goes a bit too far. Certainly, there are it might be a political solution in search of a problem, but there are technical problems around waste, proliferation, and safety that MSRs at least attempt to address, and they also don't produce greenhouse gases the way fossil-fuel-driven generators do, and have fewer outstanding technical question-marks than renewables (at least as baseload power, a role for which huge technical challenges will need to be solved before they can be considered viable). That still may not be good enough, but there are clearly problems in current energy production that will need to be solved somehow. Also, aside: that guardian article isn't terrible, but the author gets half-lives backwards the way lots of authors seem to, implying that elements with long half-lives are bad, I suppose because we'll need to bury them for longer. It's the elements with short half-lives that are scary; they decay really fast and give people radiation poisoning/cancer/whatever. An element with a 16-million-year half-life is barely emitting anything at all; that's the category of waste that can, as the author of this post says, be buried in a shallow pit in the desert.
- hmc 14y ago
  The main problem I see nuclear having is its image, it is for that which MSRs could potentially provide a solution.
- yk 14y ago
  I would argue that for the purpose of nuclear waste disposal the relation between half life and problem is a bit more complicated than "getting it backwards." The short half life isotopes are easily disposed of, because we know how to build an organizational structure, that oversees the disposal. For example, to securely store nuclear waste with an half life of a decade on can simply coat it in some plastic and put it in a mine with a warning nailed to the entrance. With very large half life times on the other hand there is no big problem to begin with, as you stated. But the intermediate timescale poses problems, since there the nuclear waste is radioactive enough to be dangerous and we do not have a good idea how a facility looks like, that can survive one hundred thousand years.

apendleton 14y ago

Not necessarily disagreeing with your main thrust, but this sentence: "So maybe thorium power generation is a technical solution looking for a problem." goes a bit too far. Certainly, there are it might be a political solution in search of a problem, but there are technical problems around waste, proliferation, and safety that MSRs at least attempt to address, and they also don't produce greenhouse gases the way fossil-fuel-driven generators do, and have fewer outstanding technical question-marks than renewables (at least as baseload power, a role for which huge technical challenges will need to be solved before they can be considered viable). That still may not be good enough, but there are clearly problems in current energy production that will need to be solved somehow. Also, aside: that guardian article isn't terrible, but the author gets half-lives backwards the way lots of authors seem to, implying that elements with long half-lives are bad, I suppose because we'll need to bury them for longer. It's the elements with short half-lives that are scary; they decay really fast and give people radiation poisoning/cancer/whatever. An element with a 16-million-year half-life is barely emitting anything at all; that's the category of waste that can, as the author of this post says, be buried in a shallow pit in the desert.

hmc 14y ago
The main problem I see nuclear having is its image, it is for that which MSRs could potentially provide a solution.
yk 14y ago
I would argue that for the purpose of nuclear waste disposal the relation between half life and problem is a bit more complicated than "getting it backwards." The short half life isotopes are easily disposed of, because we know how to build an organizational structure, that oversees the disposal. For example, to securely store nuclear waste with an half life of a decade on can simply coat it in some plastic and put it in a mine with a warning nailed to the entrance. With very large half life times on the other hand there is no big problem to begin with, as you stated. But the intermediate timescale poses problems, since there the nuclear waste is radioactive enough to be dangerous and we do not have a good idea how a facility looks like, that can survive one hundred thousand years.