On Wed, Jun 29, 2022 at 10:09 PM spudboy100 via Everything List < everything-list@googlegroups.com> wrote:
> *do Thorium 232-->U233 as a fuel cycle and would it be safe enough* > Yes. All Uranium breeders produce massive amounts of Plutonium which is a bad thing if you're worried about people making bombs. Thorium reactors produce an insignificant amount of Plutonium, they do produce Uranium-233 and theoretically you could make a bomb out of that, but it would be contaminated with Uranium-232 which would take a billion dollar isotope separation plant to decontaminate. Uranium-232 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 location if you tried to hide it, and the gamma rays would destroy its electronic firing circuits, and degrade its chemical explosives. But as long as the U-232 and U-233 remain inside the LFTR they are safe because it will quickly burn them up, in fact that's what powers the reactor. As far as I know a U-233 bomb was attempted only twice, in 1955 the USA set off a Plutonium/U233 composite bomb, it was expected to produce 33 kilotons but only managed 22; the only pure U-233 bomb I know of was set off in 1998 by India, but it was a fizzle, a complete flop, it produced a minuscule explosion of only equivalent to 200 tons of TNT due to pre-detonation. For these reasons even after nearly 80 years no nation currently has U233 bombs in their arsenal because if you want to kill people on a mass scale Uranium-235 and Plutonium-239 are far more practical than Uranium-233. A Thorium reactor only produces about 1% as much radioactive 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. The fundamental reason for this is because the starting material of a LFTR is Thorium 232, lower down on the periodic table than Uranium 238 so much less nasty transuranium stuff is produced. A LFTR 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 (by gravity, mechanical pumps are not needed) into a neutron absorbing 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, so it's walk away safe. 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's also why the containment building in common light water reactors need to be so much larger than the reactor itself and why the walls of it needs to be so thick. With Thorium nothing is under pressure and there is no danger of a disastrous phase change, like ultra hot pressurized water turning into steam, so the super expensive containment building can be made much more compact. And because LFTR reactors work at much higher temperatures than conventional reactors you have much higher thermodynamic efficiency; in fact they are so hot the waste heat could be used to desalinate sea water or generate hydrogen fuel from water. > > *so the public wouldn't object (protest, riots, etc)?* > Of course environmentalists will protest! Environmentalists are not serious people so they will protest *ANY* large scale energy project. Natural gas kills fewer people than oil because of pollution and oil kills fewer people than coal, but that distinction makes no difference to environmentalists, they are equal opportunity protesters. Environmentalists never saw an energy source that was actually built that they didn't hate, although they might like some provided they stay strictly on the drawing board. Solar cells in the desert harm super rare desert species, wind power turbines are ugly and disrupt natural wind patterns and kill little birdies, geothermal causes earthquakes, and nuclear power is the power that must not be named, this despite the fact nuclear has by far the best safety record of any energy source. Environmentalists will not be satisfied unless something is 100% safe, 99.99999% simply will not do, and it must have precisely zero impact on the environment. And that's just not realistic. Never before in the history of life on this planet has 8 billion large animals of the same species existed, in order to keep that many individuals alive (much less happy) some disruption in the environment is inevitable, but some do not recognize this fact. When you get down to practicalities the only advice environmentalists can give us is to freeze to death in the dark. And that's why I say environmentalists are not serious people. > > *I'd am more interested (if doable) with Lead-Bismuth moderated > reactors,* > That's a type of fast breeder reactor that turns common non-fissile Uranium 238 into fissile Plutonium 239 that can be easily used to make bombs. Maybe it has some potential but the only ones who ever used this type of reactor was the Soviet Union in their submarines, and the results were not pretty. All crew members of submarines that used this type of reactor received life-shortening amounts of radiation, and the submarine K-64 was so accident prone that even before its reactor completely melted down and killed 22 members of its crew the ship was given the nickname "The Widowmaker". They even made a Hollywood movie about it. John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> qq9 > -- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv2rUCah%2BHZSKxvep3u7HL8GJyY%2Br-sJ1LGrB80QeiD3KQ%40mail.gmail.com.
