Slashdot Mirror

← Back to Stories (view on slashdot.org)

Nuclear 'Asteroids' Due In A Few Hundred Years

Posted by timothy on from the happy-birthday-to-you-happy-birthday-to-you dept.

easyCoder writes "In this space.com article, it mentions a RORSAT satellite that has been leaking radioactive coolant, leaving little droplets of it in orbit around our planet. However, further down, it also mentions this, quoted here for maximum impact: 'After a RORSATs tour-of-duty was over, the reactor's fuel core was shot high above Earth into a "disposal orbit." Once at that altitude the power supply unit would take several hundred years before it reentered the Earth's atmosphere.' Wow. So ... our great-grandchildren can expect a lovely day, partly cloudy with the occasional nuclear reactor plummeting down from outer space."

7 of 589 comments (clear)

  1. I doubt it. by Skynet · · Score: 4, Interesting

    I would hope in a few hundred years we have the technical expertise to do an "orbital cleanup" job and get rid of all the crap floatind around the Earth.

    Maybe zap them with laser beams!

    --
    Execute? [Y/N] _
  2. Just how much material are we talking about here? by RollingThunder · · Score: 4, Interesting

    How much material are we talking? Will this be a major event to the earth, or will the upper atmosphere just shrug and eat it up?

    It's a pretty freaking big planet. If we're talking about 5kg of fissionables, that seems pretty small to me compared to the daily dosage the planet gets from the sun - although I do understand there's one hell of a difference between solar radiation and vaporous uranium - the latter's toxic as well as radioactive, iirc.

  3. Re:They'll be able to deal with it.... by Anonymous Coward · · Score: 4, Interesting

    "I mean we're meant to be progressing in our knowledge and abilities, no?"

    The environmentalist, anti-nuke, anti-industry, anti-technology groups are going to do everything in their power to see that we don't.

  4. Two conclusions: by gad_zuki! · · Score: 4, Interesting
    Our grandchildren will be living in a new stone age after WWIII and this won't really matter or they will have the tech to take care of this long before it becomes a threat.

    The above blatantly stolen from Einstein
    "I don't know how the third world war will be fought," Albert Einstein once remarked, "but I do know that the fourth one will be fought with sticks and stones."
  5. The hazard is to spacecraft, not us by Phil+Karn · · Score: 4, Interesting
    The article correctly emphasizes the hazard (from collisions) to orbiting spacecraft, and (correctly) says very little about the radiation hazard to us on the ground.

    In no way will I excuse the extreme sloppiness of the Russians in all things nuclear, but the radiation hazard from these things has been greatly exaggerated to sell newspapers, books and TV spots. Several of these orbiting Soviet reactors failed to go into their disposal orbits and have already fallen back to earth -- and we're still here. Yes, you could say we were lucky that they fell in relatively remote areas. But most of the earth's surface is still sparsely populated (such as the 70% that's covered by water).

    Another thing to remember about spent reactor fuel is that its radioactivity falls rapidly with time. While a reactor operates, a significant fraction of the generated power comes from the decay of short-lived fission products. This radioactive decay heat continues even after the chain reaction has been shut down; that's why emergency core cooling is so important in terrestrial reactors. Depending on the reactor design and the fuel, a few hundred years may be enough for its radioactivity to decay to that of the uranium ore from which it was originally made. This point is often lost in the shrill criticism of permanent high-level waste disposal sites.

    I do have one question about the physical properties of the NaK coolant: what is its vapor pressure? This particular alloy was chosen partly because it's a liquid at or just above room temperature, so it must have some vapor pressure that would cause it to slowly sublime in the vacuum of space. That sublimation would occur much more quickly for small droplets than large. Anybody have numbers?

  6. Re:why this is hooey by Gordonjcp · · Score: 5, Interesting
    Yes indeed. Even now, consider that you can run diesel engines on straight vegetable oil (as long as you keep it all warm and the seals aren't attacked). You can use washing soda and a tin bucket to crack waste veg oil down to the same carbon chain length as ordinary mineral diesel, and run it in an *unmodified* diesel engine. You can run petrol engines on practically anything that you can turn into inflammable vapours, alcohol, LPG, methane from your septic tank, whatever.


    I already run biodiesel in my car. It goes better than it does on the gunk they sell in petrol stations, and it's closer to carbon-neutral than fossil fuels. So, it's win-win. Only drawback is that when you sit for a minute to let the turbo cool before you switch off, the smell of chips, or popcorn, or pakora, or whatever was cooked in the oil, makes you *really* hungry...

  7. Re:Lets keep this a secret by gewalker · · Score: 4, Interesting

    Actually, there is scientific evidence that not only is low-level radiation exposure harmless, it is actually good for you, and the optimium level is well above the normal background radiation.

    Here Here and here for example.

    It is true that any ionizing radiation can damage cellular material, but the human immune system seems to derive benefit from practicing fending off such low-level damage.

    The evididence is not conclusive for low-level radiation benefits, but there are several good studies that suggest that it is, and not one scientific study that suggest the opposite as far as I know. If so, I would like to see it. Nearly all nuclear radiation threat assesments is based on extrapolation from high-level radiation exposes.