Slashdot is powered by your submissions, so send in your scoop


Forgot your password?
Science Technology

Thorium Fuel Has Proliferation Risk 239

Capt.Albatross writes "Thorium has attracted interest as a potentially safer fuel for nuclear power generation. In part, this has been because of the absence of a route to nuclear weapons, but a group of British scientists have identified a path that leads to uranium-233 via protactinium-233 from irradiated thorium. The protactinium separation could possibly be done with standard lab equipment, which would allow it to be done covertly, and deliver the minimum of U233 required for a weapon in less than a year. The full article is in Nature, but paywalled."
This discussion has been archived. No new comments can be posted.

Thorium Fuel Has Proliferation Risk

Comments Filter:
  • Paywalled? (Score:5, Funny)

    by Anonymous Coward on Thursday December 06, 2012 @11:09AM (#42203727)

    "The full article is in Nature, but paywalled."

    Well, then there is no risk of proliferation.

  • Who Cares? (Score:4, Insightful)

    by Anonymous Coward on Thursday December 06, 2012 @11:10AM (#42203737)

    If global climate change is going to be as bad as some people are saying, then it makes sense to just use the damn thorium. We've been dealing with nuclear weapons for more than 70 years.

    • by AmiMoJo ( 196126 ) *

      That's not the point though. The question is: should we spend tens of billions developing thorium reactor tech and associated industries, or just carry on as we are?

      To complicate matters it isn't a rational human being making the decision, it is corporation. Therefore the only relevant metric is profit. Given that they can't expect as much government subsidy if thorium can in fact proliferate that just makes thorium reactors look even more economically unattractive.

      • Well, global warming is likely to impose costs in the hundreds of trillions of dollars range, and probably far, far more than that. And that's assuming it doesn't trigger WW3, which is a very real and terrifying, possibility - like we won't have enough problems without throwing a nuclear holocaust into the mix. So it probably makes sense to invest a tiny fraction of that to mitigate the damage.

        Meanwhile the US alone is spending several hundred billion dollars a year to maintain and expand our military to d

        • Global warming has already caused untold damages. Not from direct effects - there are none - but from its secondaries: politicians and profiteers.

    • by sjames ( 1099 )

      Meanwhile, the countries who were targeted by anti-proliferation measures have all either developed the bomb anyway or proven that they can do so if they choose.

      • by epine ( 68316 )

        Meanwhile, the countries who were targeted by anti-proliferation measures have all either developed the bomb anyway or proven that they can do so if they choose.

        Having lost that battle, let's lower the bar of admission, and recruit ever smaller and more volatile states to join the nuclear club.

        Seriously, did you snag that four digit UID on eBay?

        I actually suspect that thorium proliferation is manageable enough given the potential benefits, but I won't be pressing forward at the level of analysis you seem to

  • by dywolf ( 2673597 ) on Thursday December 06, 2012 @11:14AM (#42203795)

    Still seems lower than the traditional route. And (FTA) instead of using a special facility to directly bombard/convert the thorium into fissible U233 in a short time, they just let the stuff sit for a month and decay into U233 naturally. And the article states that using the wait-to-decay method, theres also fewer/less radiotoxic byproduct, so it seems like a cheaper/safer method to start with.

    They still turn it into U233, the bomb stuff. just a difference in timescale, facility and method. So there was always a weapon risk.

    the whole "low prolfieration" thing just came from theoretically being able to spot the facilities doing the converting...though I think leaving the stuff sitting around and waiting for it to decay would also be theoretically somewhat simple to detect.

    All in all, it seems like waiting for it to decay naturally is better, unless the ratio of fissible material is significantly worse, sufficient to outweigh the fewer toxic byproducts thing..

  • Sanctions (Score:5, Funny)

    by jbeaupre ( 752124 ) on Thursday December 06, 2012 @11:14AM (#42203799)

    If the UK gets the U-233 bomb, next thing you know they will be threatening their rich, oil producing neighbor Norway. Norway will restart heavy water production for their nuclear program. France will increase their stockpiles (and make more nuclear weapons). The Germans will opt for chemical weapons. Belgium, the Netherlands, and Luxembourg will offer Russia and the US military bases.

    And god forbid if the Irish get ahold of a nuke covertly from the British! They'll turn Iceland into a burnt wasteland.

    Time to freeze British financial transactions until they give up their nuclear research. Time to end the menace before it all gets out of control.

    • Haha, you had me up until when you said the Irish would get a hold of a nuke from the British. Don't you know that the British are the people we're most likely to want to nuke?

      Nice try!

      Disclaimer: I have no intention of ever nuking Britain, or Iceland for that matter.

      • Your parent was funny, you are not.
        The british have nukes ... since the 50s or so ... previous century, obviously.

    • by Kupfernigk ( 1190345 ) on Thursday December 06, 2012 @12:44PM (#42204831)
      That's a little unfair. They were not very successful in WW1 and Germany didn't use them in WW2.

      The problem they ran into, at Verdun, was that after chemical bombardment of the enemy you cannot tell the difference between (a) dead enemy and (b) enemy pretending to be dead until you get within accurate artillery and machine gun range.

      So no, the Germans wouldn't go for chemical weapons. They would go for ballistic rockets and cruise missiles with conventional warheads, just like they did in WW2. And, back on topic, just like other Middle East countries are doing. The Iranians are far more likely to want a precision ballistic missile that can target the Knesset with a tonne or so of conventional explosive than a nuclear warhead. It is far more of a realistic bargaining tool.

    • If the UK gets the U-233 bomb, next thing you know they will be threatening their rich, oil producing neighbor Norway. Norway will restart heavy water ...

      Blah blah blah ... here's a version you can listen to [] instead. You can even sing along!

    • by CptNerd ( 455084 )
      It's okay, the German chemical weapons will be solar powered and wind-triggered.
  • Uranium reactors were originally developed over Thorium at least partially BECAUSE you could make bombs with the technology. The nuclear arms race is 'over' in the west but I'm interested to see if this revelation makes Thorium reactor research suddenly interesting to world powers.
    • Maybe we can use the new enrichment path to create material for portable power of the satellites and rovers we want to send into space and to Mars, you know, instead of buying Plutonium-238 from the Russians, like we did with Curiosity. I mean, we increase our demand and don't fill the supply but also don't expect any nuclear "proliferation"? Just because they're rocket scientists at NASA, doesn't mean they shouldn't have a basic grasp of economics 101 too...

  • by Hartree ( 191324 ) on Thursday December 06, 2012 @11:26AM (#42203939)

    This is all pretty standard and well known. It still takes hot cells and an operating reactor to do.

    And, there is nothing in it that can't be done right now regardless if there are thorium fueled reactors or not. The irradiation of the thorium can be done in existing research reactors. Thorium metal is available (it's used to increase emission in electrical filaments and in the mantles of camping lanterns).

    This seems mostly to be FUD.

    • Yes, it's been known, and for years I've been telling the "Thorium is safe" whack jobs about it, so it's good to get "official" confirmation to shut those idiots up. I'm not against nuclear power, understand, just idiots who think that there's a magic/trivial solution to all the problems - most of which are human. We might not yet be responsible enough as a species to use this stuff wisely.
    • The question is whether neutron treatment of thorium-232 is genuinely more practical than similar treatment of uranim-238. As you correctly point out, the potential exists regardless of whether a single commercial thorium reactor is ever built.

      Research reactors have excellent neutron fluxes, but are not optimized for the sample volumes to make this a very efficient at converting U238. Commercial reactors have large volumes but terrible neutron fluxes. The produce a good amount of plutonium in a reasonabl

  • However (Score:3, Interesting)

    by maz2331 ( 1104901 ) on Thursday December 06, 2012 @11:29AM (#42203949)

    Breeding U-233 from thorium always creates enough highly radioactive U-232 that makes it unusable for weapon uses, and due to the very close atomic weight is incredibly diffuclt to remove. Random fissions during either assembly of a gun-type weapon or even an implosion mean that you're far more likely to end up with a "fizzle" (very low yield) due to starting the chain reaction too soon, than to get the actual yield that the weapon was designed for. And since the material is so dangerous to handle, the workers who have to put the thing together and maintain it are quite likely to die quickly, as will the electronics necessary to fire the weapon.

    • Re:However (Score:5, Informative)

      by Andy Dodd ( 701 ) <atd7&cornell,edu> on Thursday December 06, 2012 @11:51AM (#42204185) Homepage

      Read TFA.

      Most U-233 that comes out of a reactor is formed by protactinium-233 decay.

      While U-232 and U-233 are nearly impossible to separate (which is why Thorium has been considered to be proliferation-resistant), protactinium-233 is very easy to separate chemically, and leads to nearly pure U-233.

      • by Creepy ( 93888 )

        First of all, this is nothing new, it was covered here [] last year:
        Specifically "However looking at the aspects of protactinium separation, I'm wondering if this could be a hole in the process which would allow for much lower U-232. U-232 is the daughter product of Pa-232 just as U-233 is the daugher [sic] of Pa-233. Pa-233 has a half-life of 26.9 days but Pa-232 is only 1.3 days."

        They also say "protactinium is not easy to remove from molten salts." and "In a 2 Fluid design we can lower losses to Pa down to a

      • Read TFA.

        Most U-233 that comes out of a reactor is formed by protactinium-233 decay.

        While U-232 and U-233 are nearly impossible to separate (which is why Thorium has been considered to be proliferation-resistant), protactinium-233 is very easy to separate chemically, and leads to nearly pure U-233.

        As mentioned in a comment to TFA, U-232 comes from Pa232. U-233 comes from PA 233. So, in order to get only U-233 out you would seem to need to separate Pa233 from Pa232. Aside from (maybe) less gamma exposure, that should be no easier than separating U232 from U233.

    • by Creepy ( 93888 )

      Which is why the non-paywalled article specifically says they extract protactinium and leave the U232 and U233, which is fairly easy to do, and then let the protactinium decay to fissile U233. The problem I see is reactors like LFTR as well as small IFRs at best generate a 1.07:1 neutron ratio, which is just barely enough to produce excess protactinium that will not be later needed to provide fissionable material to sustain the reaction. Also both LFTR and IFR require nuclear bomb grade seed fissile materia

  • There's risk??? That's a four letter word! Kill it with fire!

    (Meanwhile uranium reactors are around *because* they could make bomb material.)

  • This reminded me of a three year old discussion I had on Slashdot before [] about thorium's fuel cycle yielding uranium-233 ... not sure if new evidence has come to light, can't read the Nature article.
    • I can't tell anything here, either, due to the paywall. I'd like to run their work against the probability chains to see exactly what, if anything, is new. What I do get is that the threat is from some nation-state or non-nation-state actor seizing "spent" fuel rods and chemically separating out usable fractions of U-233. I have no clue, never needed one as a matter of fact despite having the clearance, what you need to achieve a critical mass, let alone with impurity levels you cited way back when. Dam
  • Risk vs certainty (Score:4, Insightful)

    by Hatta ( 162192 ) on Thursday December 06, 2012 @11:42AM (#42204071) Journal

    There may be a risk of nuclear weapons proliferation if we replace fossil fuels with nuclear. But if we don't, there is a damned certainty that the climate will continue changing faster than it ever has in the history of the human species. We are at the beginning of a global extinction event that has a very good chance of causing our own extinction. Nuclear weapons are barely a minor concern comparatively.

    • And next thing you know, North Korea and Pakistan will have nukes! Oh, wait.

      FWIW, I don't agree with your premise, but all those who do agree with your premise ought to agree with your conclusion. You'll notice they don't, though. There's more to gain for them by suppressing nuclear power and taxing carbon emissions, so that's how it'll be (for as long as people support their authority, anyhow).

      • by Hatta ( 162192 )

        all those who do agree with your premise ought to agree with your conclusion. You'll notice they don't, though

        Story of my life...

    • by Rich0 ( 548339 )

      Yeah, I don't get the big deal. Just station a garrison in every nuclear plant if you're paranoid, and a UN watch team if you must. The cost of doing that is likely trivial compared to the cost from stuff like lung cancer from coal soot, let alone nuclear proliferation.

      Just build efficient breeder reactors and do whatever makes the most sense economically, and do it under high security.

      People argue that it isn't possible to secure nuclear reactors, and that is just nonsense. We secure actual nuclear weap

      • by Rich0 ( 548339 )


        s/let alone nuclear proliferation/let alone rising sea levels/

      • by PPH ( 736903 )

        and do it under high security.

        This can go one of several ways: First option, we operate our generating facilities under the supervision of the US government, with police and/or military troops responsible for the requisite security. Not likely in the USA or other 'free market' economy. Even if the plant operations were handled by private business and the public were to provide the police force, the operator would not tolerate the required restrictions on their operations (not being able to hire the boss' idiot security risk nephew, for

  • Funny how no one right-thinking human being even seriously contemplates a massive, intrusive regulatory apparatus for fertilizer even though it did a heck of a job in the hands of Timothy McVeigh. It's also like common sense sometimes prevails...

    • It really is amazing. It is far easier to get the Ammonium nitrate from the large number of sources, then it is to steal it from the relatively few nuke plants around the world. In addition, if AQ, et. al., North Korea, Iran, Venezuela, etc want to do this, they can actually build it cheaply and make their own bomb.

      And yet, we would stop building safe nuke reactors because of some group of idiots that scream about everything.

      I swear, between the far right extremists of the world (Al Qaeda, America's Rep
  • I was worried about terrorists getting their hands on this technology, but then I read "The full article is in Nature, but paywalled.". Yay! Safe from the evil doers!
  • This isn't really news. The original version of the Smyth Report mentioned research into using Thorium. The second edition deleted that paragraph. It was the only notable change from edition to edition. We're pretty sure the KGB noticed the change and went, like, "Hmmmmm...".

  • by EuNao ( 1653733 ) on Thursday December 06, 2012 @02:47PM (#42206291) Homepage

    U233 created in a thorium reactor will be poisoned with U232 at about 0.4 percent (very dependent on design, but this is an good example of the kind of mix you will see). Even if you segment the protactinium, you are still going to have some U232 in the mix. This can not be chemically separated, and separating the isotopes of something that is hot borders on the insane. U232 has a decay chain that emits a 2.9 MeV gamma ray, and its pretty hot as far as how fast it will decay (Half life of 69 years if I remember right). It decays to Th-228 and in like 2 years into Ti-208 + nasty gamma. Very nasty stuff that will really ruin your day, and any electronics in your nuclear weapon in a hurry. You would be stupid to pick this as a nuclear fuel for a weapon, when you could just make plutonium like anyone with any sense would do. You just put some natural uranium in neutron flux of a light water reactor, wait a month or so, and separate the plutonium. Simple well known technology that works, not some crazy possibility that some PhD dreamed up because he wants to prove a point. Sure you could do it, if your an idiot who wants to make your life really hard and you have a death wish.

    Also if you are running a thorium breeder reactor you are running so close to break even on neutrons so if you remove Uranium from the cycle your ability to maintain reactor criticality will disappear. Also you have the same problem if you try and use the neutron flux to make plutonium it wouldn't work. Thorium reactors are shitty for making bombs, that is why we don't have them even though they are awesome technology that would solve so many energy problems. Thorium has little risk of being used to make bombs, and if someone is idiotic enough to do it they will die of gamma poisoning way before they have enough fuel for bombs.

Never buy what you do not want because it is cheap; it will be dear to you. -- Thomas Jefferson