On 17 November 2013 07:44, John Clark <[email protected]> wrote: > On Fri, Nov 15, 2013 at 4:19 PM, Russell Standish > <[email protected]>wrote: > > > For all the arguments pro and con nuclear fission, including an >> impassioned speech by a 16 year old last night to a UN Youth Voice >> competition, what never seems to be discussed is the elephant in the >> room of how much uranium resources we have.IIUC, if all fossil fuel >> > power plants were replaced by conventional fission reactors, we'd burn >> through our uranium supplies in about 50 years flat. > > > I don't know where you got that figure, I suspect that long ago in a > galaxy far far away some tree hugger pulled it out of his ass and then > repeated it so often on the internet that people started treating it as > fact. At any rate if we're running out it's hard to figure out why today > Uranium prices are the lowest they've been in 8 years. > > > So fission reactors do not solve the problem. Of course there is fast >> breeder technology, but everbody is so shit scared about all the plutonium >> that would then appear on the market, making it incredibly easy for rogue >> states to construct nuclear weapons > > > Uranium fast breeder scare the shit out of me too and for the same reason, > I don't like Plutonium. But I do like Thorium reactors, in particular > Liquid Fluoride Thorium Reactors (LFTR) . I think LFTR's are what fusion > wanted to be but never achieved, despite tens of billions of dollars poured > into it a fusion reactor has never produced one watt more power than was > put into it. Certainly LFTR's are better than conventional nuclear fission. > Consider the advantages: > > *Thorium is much more common than Uranium, almost twice as common as Tin > in fact. And Thorium is easier to extract from its ore than Uranium. > > *A Thorium reactor burns up all the Thorium in it, 100%, so at current > usage that element could supply our energy needs for many billions of > years; A conventional light water reactor only burns .7% of the Uranium in > it. We'll run out of Thorium in the Earth's crust about the same time that > the sun will run out of Hydrogen. > > * To burn the remaining 99.3% of Uranium you'd have to use a exotic fast > neutron breeder reactor, Thorium reactors use slow neutrons and so are > inherently more stable because you have much more time to react if > something goes wrong. Also breeders produce massive amounts of Plutonium > which is a bad thing if you're worried about people making bombs. Thorium > produces an insignificant amount of Plutonium. > > * Thorium does produce Uranium 233 and theoretically you could make a bomb > out of that, but it would be contaminated with Uranium 232 which is a > powerful gamma ray emitter which would make it suicidal to work with unless > extraordinary precautions were taken, and even then the unexploded bomb > would be so radioactive it would give away its presents if you tried to > hide it, destroy its electronic firing circuits and degrade its chemical > explosives. For these reasons even after 70 years no nation has a Uranium > 233 bomb in its weapons inventory. > > *A Thorium reactor only produces about 1% as much waste as a conventional > reactor and the stuff it does make is not as nasty, after about 5 years 87% > of it would be safe and the remaining 13% in 300 years; a conventional > reactor would take 100,000 years. > > *A Thorium reactor has an inherent safety feature, the fuel is in liquid > form (Thorium dissolved in un-corrosive molten Fluoride salts) so if for > whatever reason things get too hot the liquid expands and so the fuel gets > less dense and the reaction slows down. > > *There is yet another fail safe device. At the bottom of the reactor is > something called a "freeze plug", fans blow on it to freeze it solid, if > things get too hot the plug melts and the liquid drains out into a holding > tank and the reaction stops; also if all electronic controls die due to a > loss of electrical power the fans will stop the plug will melt and the > reaction will stop. > > *Thorium reactors work at much higher temperatures than conventional > reactors so you have better energy efficiency; in fact they are so hot the > waste heat could be used to desalinate sea water or generate hydrogen fuel > from water. > > * Although the liquid Fluoride salt is very hot it is not under pressure > so that makes the plumbing of the thing much easier, and even if you did > get a leak it would not be the utter disaster it would be in a conventional > reactor; that is also why the containment building in common light water > reactors need to be so much larger than the reactor itself. With Thorium > nothing is under pressure and there is no danger of a disastrous phase > change so the expensive containment building can be made much more compact. > > John K Clark >
I believe another plus point is that they can't go supercritical and melt down. Unless I have been misinformed, it's impossible to have a "China syndrome" (or Madrid syndrome in NZ :-) with a thorium reactor. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
