Thorium: The Wonder Fuel That Wasn't 204
Lasrick (2629253) writes "Bob Alvarez has a terrific article on the history and realities of thorium as an energy fuel: For 50 years the US has tried to develop thorium as an energy source for nuclear reactors, and that effort has mostly failed. Besides the extraordinary costs involved, In the process of pursuing thorium-based reactors a fair amount of uranium 233 has been created, and 96 kilograms of the stuff (enough to fuel 12 nuclear weapons) is now missing from the US national inventory. On top of that, the federal government is attempting to force Nevada into accepting a bunch of the uranium 233, as is, for disposal in a landfill (the Nevada Nuclear Security Site). 'Because such disposal would violate the agency's formal safeguards and radioactive waste disposal requirements, the Energy Department changed those rules, which it can do without public notification or comment. Never before has the agency or its predecessors taken steps to deliberately dump a large amount of highly concentrated fissile material in a landfill, an action that violates international standards and norms.'"
Is this about Thorium or Uranium 233? (Score:5, Interesting)
Interesting caption to use as the summary.
questionable presentation (Score:5, Interesting)
Statement of ridiculousness include;
For a terrorist, however, uranium 233 is a tempting theft target; it does not require advanced shaping and implosion technology to be fashioned into a workable nuclear device. The Energy Department recognizes this characteristic and requires any amount of more than two kilograms of uranium 233 to be maintained under its most stringent safeguards, to prevent “onsite assembly of an improvised nuclear device.” As for the claim that radiation levels from uranium 232 make uranium 233 proliferation resistant, Oak Ridge researchers note that “if a diverter was motivated by foreign nationalistic purposes, personnel exposure would be of no concerns since exposure would not result in immediate death.”
But this material is actually extremely difficult to make a warhead out of or use in any weaponized manner other than a dirty bomb. But with little effort, its easy to find that U-233 has the "unavoidable co-presence of uranium-232[6] which can make uranium-233 very dangerous to work on and quite easy to detect." That was conveniently ignored.
So, while it could be used in a dirty bomb, there are much easier, more tempting targets for that. Particularly when its material stored in a highly protected area. "No concerns"? Give me a break.
As for the Nevada waste thing. What he describes as a simple "landfill" is actually a waste area within the Nevada National Security Site.
Its easy to see right through the BS this author has laid out. Its a shame he doesn't seem to care about his own credibility. Just another asshat that does nothing but talk. Its a shame, because there are legitimate issues here to discuss, and it helps when the facts are laid out in a responsible manner.
Calling Kirk Sorenson (Score:4, Interesting)
This trash piece gets things wrong on so many levels it isn't funny. For the real deal, follow Kirk Sorensen's blog.
Watch this video by McDowell, he lays it out. All that so called "waste" is fuel for a SNACR reactor design that would eliminate the waste entirely.
http://www.youtube.com/watch?v=P9M__yYbsZ4
Re:Never before??? (Score:3, Interesting)
And at the supposed "clear up" after accidentally dropping nukes at Palomares in Spain. Where it has since been discovered that they just dug some shallow trenches and buried a pile of plutonium. Guess they hoped no one would ever notice...
Re:Sihg... Not valid. (Score:3, Interesting)
Thorium reactors being a total non-starter is about the only thing this article has gotten right. Everyone hand-waves the most critical and problematic issues with thorium fuel.
Thorium fuel reactors WILL require fuel reprocessing. This is a toxic, messy, and dangerous process. All thorium proponents paint this issue as a trivial issue to be worked out but 50 years later all we have are a handful of research reactors facing the same problem.
The above reason is why molten salt reactors don't work. There is no known way to prevent the mass of molten fissile fuel from building up unwanted reaction products that will eventually stop the reactor from working. Either by creating gasses that have to be contained, eating away the reactor container, or creating elements that poison the nuclear reactions and stop them all together.
Thorium fuel is the favorite meme of so many uninformed tech nerds because they hear some similarly uninformed tech evangelists blathering on about it endlessly. Thorium may be useful in the future but right now it's about as viable as fusion. Always 20 years away from working.
Re:Dispose of U233? (Score:4, Interesting)
I believe that the Nevada Flats facility is basically just "storage" in this context. However, if you read this [doe.gov], you will see that most of the material is in other forms, such as "Molten Salt Reactor (MSRE) traps, Oxide powders and Zero Power Reactor Plates," and that potentially critical material will be "downblended," "driving the U-233 concentration below criticality and security concerns. It is to be dissolved and then downblended with depleted uranium so it can be disposed safely."
In other words, it's not like that they will put bomb components into a landfill, but everything will be converted to some form where it would be fairly complicated to make a bomb out of it.
Re:Is this about Thorium or Uranium 233? (Score:5, Interesting)
Which is an interesting statement, given that the US government has never been able to successfully produce a working U233 bomb. In fact they've invested a lot of effort into Pu239 and U235, which would be pointless if all they had to do was bread common-as-muck (literally) Thorium into a useful nuclear weapons material for a fraction of the cost.
The reality is that U233 is almost entirely useless on it's own: off the top of my head you might be able to use it to make workable tampers for Plutonium implosion bombs; the evidence suggests that's actually the only place U233 has ever been used in a working weapon. That still wont get you far without the Pu and U235 (for the primary).
About the author (Score:4, Interesting)
Apparently Robert Alvarez does not think that people do background checks. This article was dated June 13, 2011:
http://atomicinsights.com/why-does-anyone-trust-robert-alvarezs-opinions-about-nuclear-energy/
Re:Is this about Thorium or Uranium 233? (Score:5, Interesting)
Thorium 232 + a neutron -> Uranium 233.
Not exactly ;^)
Th232 + neutron -> Th233 (which isn't as stable stable)
Then two stages of beta- decay
Th233 -> Pa233 + electron + anti-neutrino
Pa233 -> U233 + electron + anti-neutrino
The problem is with U232 production is because all of these intermediate products are also fissile in the reactor (e.g., can interact w/ stray fast neutrons and undergo extra neutron decay before undergoing beta- decay resulting in U232 instead of U233).
However, the issue isn't that U232 is so unstable it decays with products that emit large amounts of gamma radiation (which in the decay chain, Tl208 is a big gamma emitter so it's really dangerous), it's mostly that you can't use chemistry to separate U232 from U233 (since only the mass is different, not the valence electrons). You either have to use advanced techniques (e.g, laser isotope separation), or modify your reactor parameters so that U232 production is reduced.
The ironic thing is that purported proliferation resistance of U233 is because reactors can be deliberately tweaked to increase the concentration of U232 to denature the U233. However, as I understand it, there is no particular technical reason to do this other than proliferation resistance (except to make it more dangerous to potential nuclear power plant workers as if that was a goal). If a rogue country wanted to operate a Th reactor to create large amounts of U233 w/o a limited amount U232 contamination, apparently it's not that hard to do (basically replacing the fuel more frequent schedule than normal, since most of the U232 yield comes at the end of the fuel cycle where there are more high energy neutrons bouncing around)...
That, plus a failure to ever produce a non-fizzle U233 bomb, means that this really isn't a good fission bomb source material.
If your goal is to simply produce a bomb, (not necessarily a large one with optimal yield), apparently India detonated an experimental U233 bomb as part of their Pokhran-II tests back in 1998... I don't think that bomb was a fizzle...
Re:Sihg... Not valid. (Score:5, Interesting)
Okay, maybe, MAYBE, if you were talking about a solid fuel reactor.
If you want to say "Thorium is dumb in a solid fuel reactor", I'd say "Yeah! You're right! It is!"
But take a look at a Liquid Thorium reactor
Basically you put the fuel in and pretty much let it burn through it's fuel supply.
You also have NONE of the problems involved in a solid-fuel reactor. Most of the failsafes become passive, rather than engineered.
Not only that, several of the byproducts are actually medically or scientifically useful (U238, which gets used in deep space device batteries), etc. The rest of the byproducts are things that are, yes, DREADFULLY radioactive...for a few days/weeks. Then they break down into stuff that's about as harmful as eating a banana.
What's more, Thorium is orders of magnitude more plentiful than most of the other stuff we're currently burning in reactors. Just the tailings that come up from current mining concerns can produce more power than the US uses in a year.
ON TOP OF THAT, actual use of Thorium would allow rare-earth mining to pick back up in many places around the world.
We need to do this because, otherwise, in 20 years' time, we're going to be buying Chinese-built Thorium reactors.