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Liquid Lithium to Contain Fusion Reactors

Posted by michael on from the hot-enough-for-you dept.

nigelc writes: "ABCNews.com reports on Liquid Metal walls for a fusion reactor, and how it may solve some of the temperature problems. Probably only of scientific interest to most of us, unless you're into some serious overclocking.""

2 of 42 comments (clear)

  1. Hooboy, Better Think Twice About This... by cybrpnk · · Score: 5, Interesting

    I used to work in Oak Ridge in the nuclear program years ago and those guys LOVE to consider using liquid metals to cool things. Back in the 1970s it was the the Clinch River Breeder Reactor, which was gonna turn plentiful inert (U-238) uranium into vast quantities of power-packed plutonium in a machine cooled with liquid sodium. Wow - CRBR never got built.

    Logically, a layperson would consider a liquid metal to be a very dangerous material to have around, but if you've already got pounds and pounds of plutonium you are juggling around, sodium doesn't seem so nasty anymore. They would still be talking about using sodium if it weren't so darn reactive - read corrosive. That's where our friend lithium comes in - less reactive, less corrosive. Ha.

    There aren't any electric generator turbines that run on liquid lithium pressure so there's gonna be a lithium-to-water-to-steam heat exchanger loop in there somewhere in a functional fusion powerplant. Lithium is gonna come in contact with water somehow, by accident (or design) and make hydrogen gas which is not only explosive, but turns into radioactive tritium when bombarded by the neutrons put out by ANY reactor - fission or fusion.

    Playing around with explosive hydrogen gas near a reactor is often done deliberately and may be a hidden agenda here. Don't kid yourself - America needs tritium. It is a prime ingredient in nuclear weapons and however much of it you've got, you've only got half that much 12 years later. This means unless you replenish your tritium stockpile you loose half of your nuclear weapons arsenal every 12 years. So far this hasn't been a problem because we are retiring nukes rapidly after winning the Cold War and we are scavinging tritium for our online weapons from the ones we retire. Sooner or later the US will run out of recycled tritium.


    We used to make tritium at Savannah River Nuclear Plant but that was closed for environmental reasons years ago. Now the US is going to refurbish that old reactor and start it back up. Sooner or later we're gonna have to switch over to something else besides World War II factories like Savannah River. When that happens, and it's a fusion reactor with a lithium core, remember that there's something else in going on with that liquid metal coolant...

  2. And think again, without paranoia by Spamalamadingdong · · Score: 4, Informative
    Logically, a layperson would consider a liquid metal to be a very dangerous material to have around...
    Like solder? It can burn you, you know. But so can a great many solid materials and vapors (even water). You do have the toxicity of lead-based solders, but they're toxic even when they're in solid form.
    Lithium is gonna come in contact with water somehow, by accident (or design) and make hydrogen gas [gcsechemistry.co.uk] which is not only explosive, but turns into radioactive tritium when bombarded by the neutrons put out by ANY reactor - fission or fusion.
    The lithium will breed tritium under neutron bombardment whether water is involved or not; the production of hydrogen is a chemical reaction caused by the decomposition of water, the production of tritium is a nuclear reaction caused by the neutron-induced fission of lithium-6 into helium-4 and hydrogen-3.

    Lithium is a lot less active (and thus corrosive) than sodium, but it's not suitable as a coolant for fission reactors because it has this pesky tendency to capture neutrons. In a fusion reactor which needs tritium anyway, this is an advantage.

    Playing around with explosive hydrogen gas near a reactor is often done deliberately and may be a hidden agenda here.
    Just FYI, people play around with "explosive hydrogen gas" for lots of reasons in lots of places. You'll find people playing with hydrogen in every plant which manufactures vegetable shortening from oil, because hydrogenating the oil is part of the process to allow it to solidify at room temperature. Ditto every plant which manufactures nitrogen fertilizers (which starts with fixation via the Haber process, N2 + 3 H2 -> 2 NH3).

    A little more information and a little less paranoia would serve you well.

    --
    Scientists restrict study to entire physical universe; creationist