Homepage Forums Aneutronic Contenders Billy's Cheap fission alternative

This topic contains 74 replies, has 17 voices, and was last updated by  vansig 1 year, 1 month ago.

Viewing 15 posts - 61 through 75 (of 75 total)
  • Author
    Posts
  • #13564

    Alex Pollard
    Participant

    vansig wrote:

    here is a nice chart we should all familiarize ourselves with,
    https://xkcd.com/radiation/

    That chart doesn’t distinguish between ionizing radiation such as an x-ray or beta particle, and radioactive material which one may breath and then have sitting in your tissues emitting for the rest of one’s life. The difference is enormous. I have no problem with one-off exposure to ionizing radiation, instead it is fallout from Fukushima etc which accumulates in the food chain, e.g. fish, and finds its way into our bodies, permanently, that worries me.

    #13565

    delt0r
    Member

    Err yes it does. Otherwise you get *nothing* from a banana. Most alpha and some beta emitters give you *zero* does outside the body. Since they lack the energy to penetrate the layers of dead skin.

    And no it does not even get close to accumulating permanently. Many of these elements have quite short biological half lives. The best example being Iodine.

    #13566

    Alex Pollard
    Participant

    There is a big difference between diffuse exposure to ionising radiation and a radioactive particle consisting of radioactive atoms with long half-lives constantly peppering away at a small volume of surrounding body tissue. The chart doesn’t appear to account for that qualitative difference and so understates the risk from nuclear fallout.

    #13567

    delt0r
    Member

    I think you don’t understand what i am saying at all. A Sv takes that into account. Neutrons for example give a much higher number since they do more damage. Alpha radiation *outside* the body give you zero does as it does not penetrate the dead skin. All elements have a half life in the body and don’y stay there forever and typically far far less than a half life. I worked around radioactive isotopes. It not inaccurate.

    Did you even watch the video I posted?

    #13568

    Alex Pollard
    Participant

    Yes in the video the guy goes to various places with above-normal radiation levels. The doses he receives are pretty trivial but at one point near Fukushima he removes his face mask because it’s probably “overkill”. Well I think that marks him out as foolish. Because getting a particle of plutonium or uranium stuck in his lungs will probably give him cancer. The chance of that is quite low but why take the chance? The *average* radiation dose is low because not everyone gets a bit of highly radioactive material stuck in inside them. But if one unluckily ingests that particle (breathes it, eats it) and it remains there, then all the radiation charts in the world won’t help, cancer is very likely. That is, the risk is much higher even though the average radiation does is not hugely more than otherwise. So there is a qualitative difference between bits of radioactive fuel being released into the environment vs other ionizing radiation of various types.

    Do the xkcd numbers for Fukushima come from Geiger Counters? Or from air filters? I can’t tell from the xkcd references such as http://www.mext.go.jp/component/a_menu/other/detail/__icsFiles/afieldfile/2011/03/18/1303727_1716.pdf

    Numbers from Geiger Counters won’t tell us the risk of ingesting a radioactive particle. The exposure number for 3 mile island is external exposure, so I presume they are omitting what I am talking about. And there is nothing in the chart about bio-accumulation of radioisotopes in Pacific fish. If xkcd were trying to down play the risks of uranium they couldn’t have done a better job.

    #13569

    delt0r
    Member

    Oh lord. (in Leela voice). No a particle of plutonium or uranium will not give you cancer. Its too small and the dose too low. Oh and you have shit like that in dirt, in dust and especially in rocks. You are just jumping onto the radiation boggy man hype without understanding yourself.

    Sv is a measure of *absorbed* dose. As in active tissue has absorbed the ionizing radiation. Your exposure is calculated taking all that into account! Yes absorbed dose including bio available materials and there respective bio half life. Bio accumulation is not magic, We understand it and can calculate and measure it. The vast majority of radioactivity from spent fuel or a bomb are in the form of elements that don’t bio accumulate much at all and all have quite short half lives.

    If this is the level of understanding here… We have no hope.

    #13623

    Alex Pollard
    Participant

    By particle I mean a single microscopic particle of radioactive material, made up of millions of radioactive atoms, such as what was released in Fukushima. Can you provide a reference stating such a particle cannot induce cancer?

    #13625

    delt0r
    Member

    Stop being so lazy and look it up yourself. Or even better. Do the math yourself. Its not a mystery, its not magic and its something i would expect any senior year high school students to be able to work out.

    #13626

    Alex Pollard
    Participant

    Question answered

    #13627

    Joeviocoe
    Member

    Alex Pollard wrote: ….Can you provide a reference stating _______ cannot _________?

    = formula for logic flaw.

    You are asking someone to prove a negative. It is up to you to prove the affirmative. But I suspect if you tried, you will find out how wrong you are.

    #13735

    bcreighton7
    Participant

    bcreighton7 wrote:

    Molten salt reactors are not restricted to Thorium, in fact you get all the same advantages (and disadvantages) with U in such a design. For example reprocessing U cycles give very similar waste.

    Indeed molten salt was proposed to fix many of the issues with thorium. But lets be clear. It is *not* proven. A small demo reactor (or 2) was operated, *without* breeding and *without* in situ reprocessing. There was corrosion problems and fixes proposed but not validated. To get to a proper deployment status your talking about 10-20 years full size demo first. And that is a estimate from the industry, you know the people that actually build these things.

    Hi,
    Yes, that is why I said

    It has a proven working model at least, and if we built out one, we may end up with a commercially viable plant within 10 years which could be used to replace the nuclear reactors which are now coming up for retirement while potentially keeping their electric generation systems. I’m sure there are still engineering problems to face on a full scale plant, but if the hype is to be believed it has many advantages over our current nuclear reactors:

    I realize the LFTR reactor I am talking about still has engineering challenges to work out, but it was proven to work. I don’t think it is pie in the sky. At this point, fusion is still literally pie in the sky ie in the sun. Moving the physics of the sun to the earth will be a bit of an engineering challenge I think. While I believe Dr Lerner and team may well reach net energy with the beryllium anode, the challenge is to be able to repeat the fusion billions of times and convert the energy, and at this point we can’t confirm we will even get past the tungsten anode. If it ends up feeding impurities into the reaction, the challenges will really begin.
    It seems to only make sense to have another viable and at least somewhat proven nuclear power source. Plus we are living at a time of some financing challenges for fusion. While I think this will certainly change for focus fusion once net energy is reached, there will still be nuclear engineering challenges to address.

    looks like someone in my home state thinks this technology is going to work at a commercial level – even sooner than I thought. They changed up the design to avoid some engineering issues.
    http://www.world-nuclear-news.org/NN-Martingale-reveals-its-ThorCon-liquid-fuel-reactor-design-07011501.html

    #13741

    Alex Pollard
    Participant

    Joeviocoe wrote:

    ….Can you provide a reference stating _______ cannot _________?

    = formula for logic flaw.

    You are asking someone to prove a negative. It is up to you to prove the affirmative. But I suspect if you tried, you will find out how wrong you are.

    So you can’t provide a reference either.

    #13744

    BSFusion2
    Member

    Joeviocoe wrote:

    ….Can you provide a reference stating _______ cannot _________?

    = formula for logic flaw.

    You are asking someone to prove a negative. It is up to you to prove the affirmative.

    Alex, pay no attention to Joevioce. His ‘logic’ would fasely imply that the statement “prime numbers greater than 3 cannot be diveded evenly (whole number) by 3” is unprovable.

    #13745

    Joeviocoe
    Member

    BSFusion2 wrote:

    ….Can you provide a reference stating _______ cannot _________?

    = formula for logic flaw.

    You are asking someone to prove a negative. It is up to you to prove the affirmative.

    His ‘logic’ would fasely imply that the statement “prime numbers greater than 3 cannot be diveded evenly (whole number) by 3” is unprovable.

    Alex Pollard wrote: Can you provide a reference stating such a particle cannot induce cancer?

    I haven’t said that you “Cannot prove a negative”… Mathematics is full of negative proofs.
    But this is NOT an easily quantified mathematical question where we have already defined all attributes of a prime number.
    The question was about what can induce cancer. We didn’t invent cancer like we’ve invented mathematical constructs like prime numbers. We don’t know every possible attribute in the world of physics or biology, like we do mathematics.

    More importantly, this statement was said just to turn the burden of proof around on someone else because Alex could not prove the positive.
    When someone asks to prove the argument’s negative,… it generally means they’ve run out of rational points, and are looking to pass the responsibility of evidence. This is convenient because it allows them to declare “winner by default”.
    THAT is the logical flaw that I pointed out.

    #13770

    vansig
    Member

    Let’s step out from the meta-discussion about whether you can prove stuff mathematically to ask, “can you prove it with science?” because you cant show whether a single particle does or does not induce cancer. but magnitudes of radiation are a significant matter. please study this chart,

    https://xkcd.com/radiation/

Viewing 15 posts - 61 through 75 (of 75 total)

You must be logged in to reply to this topic.