how long does radio active pollution last

Discussion in 'General Science' started by lotusmoon, Jan 26, 2014.

  1. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    I have made a petition on Fukushima and wanted to get my facts right. please try not to be to political on this as the thread will get shut down.

    1. how long does the nuclear waste from fukushima last?
    2. are there different types of radioactive waste coming out of fukushima.

    link -
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    Last edited by a moderator: Jan 26, 2014
  2. bertus

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  3. MrChips

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    Radioactivity can last from any length of time from less than a second to millions of years depending on the specific radioisotope. The decay time is measured by a quantity known as the half-life, the length of time it takes for the radioactivity to decay to one half of its level from the time measurement begins.

    Radioisotopes with short half-lives are as much a concern as longer half-lives since they will be emitting higher levels of radiation in the short term, i.e. the atoms are giving off their radioactivity at faster rates.

    In the case of the Fukushima nuclear disaster, here are some examples of radioisotope half-lives of concern:

    Iodine-131 half-life = 8 days
    Strontium-90 half-life = 28 years
    Cesium-137 half-life = 30 years
    Plutonium-239 half-life = 24,000 years

    http://en.wikipedia.org/wiki/Radiation_effects_from_the_Fukushima_Daiichi_nuclear_disaster
     
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  4. atferrari

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    So, if worst comes to worst should I choose, having an option, Plutonium?
     
  5. bertus

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    Hello,

    Take a look at the decay-chain:
    http://en.wikipedia.org/wiki/Decay_chain

    The first step is from plutonium-239 to Uranium-235 with a half-time of 2.41 * 10⁴ years
    The next step is from Uranium-235 to Thorium-231 with a half-time of 7.04 * 10⁸ years
    etc.

    Bertus
     
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  6. lotusmoon

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    Jun 14, 2013
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    This forum is great for useful information.
    does anyone know why the radiation is dangerous - what it does to us that is unhealthy
     
  7. bertus

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  8. MrChips

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    Radioactivity decays as an inverse exponential function in the same manner as how voltage on a capacitor diminishes as the capacitor discharges through a resistor.

    In electronics, we use the formula for time constant t = RC. This is the time it takes for the decaying voltage to reach 1/e of the initial value, i.e. to reach 37% of the initial value.

    The same formula is used in radioactive decay. The time constant or decay constant is the time it takes for the radioactivity to fall to 37% of the initial value, i.e. 37% of the atoms have yet to decay.

    Half-life is the time it takes for 50% of the atoms to decay. The half-life is slightly shorter that the decay constant.

    An important observation is the length of time it takes for the initial value to decay to 1/1000 of the initial value.

    If we use time constant, it would take 7 x the time constant for the value to reach 0.1% of the initial value.

    If we use half-life, it would take 10 times the half-life to reach 0.1% of the initial value.

    Hence for a radioisotope such as Cesium-137 with a half-life of 30 years, it would take 300 years for the radioactivity to be reduced to 1/1000 of the initial radioactivity.
     
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  9. THE_RB

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    Feb 11, 2008
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    I watched a documentary on Chernobyl and the surrounding area filmed recently.

    Many years later after the accident the whole area still has low radiation levels, and the same in all the plants and animals etc.

    But surprisingly, all the plants and animals are in perfect health! A normal ecosystem. No evidence at all of a mutated SciFi wasteland.

    It has been proposed that the few percent of animals and plants that were overly succeptible to cancer just died off, and the majority of animals etc just bred up and now are all in perfect health but are slightly radioactive.

    Nature has a way of adapting to small changes and being perfectly OK with it.
     
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  10. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    Its funny but after starting to enquire into this I realize I know very little other than some words and what they emote in me.
    I am getting a bit lost while reading about radiation as there are so many words and phrases I do not understand.
    is radiation an energy released from the brake down of radio active matter, or is it a release of fast moving particles or is it both?
     
  11. WBahn

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    Mar 31, 2012
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    Thank you for at least looking into things before running off with yet another emotion-driven petition about this or that. Wish many others would make the same effort.

    Radiation and radioactive pollution is an extremely complicated topic. The half-life is far from the only thing that counts. There is also the type of radioactive decay that is involved and the energy that is involved. Then there is where the pollutant is when the decay happens. If an alpha-emitter is on your clothes when it decays, then probably nothing will happen. But if it was in your lungs or in your stomach or elsewhere in your body because you inhaled it or ingested it, then things are very different. Along those same lines, different elements end up different places in your body. Some will pass through your system quickly and will be unlikely to decay during that time. Others will get concentrated in different parts of your body and stay there for a long time, perhaps the rest of your life, and may be very near sensitive parts of your body when they eventually do decay. On top of that, and completely aside from the radiation, these are elements that, like all other elements, interact chemically with the world around them. Some of these compounds are chemically benign and others are quite toxic.
     
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  12. cirkuit

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    Jan 16, 2014
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    Hello Lotusmoon,

    Yes radiation is both composed of energy and of fast moving particles.

    The 'energy' part is electromagnetic waves which are very dangerous in that case because they are so high energy that they can damage your DNA. These are x-rays or gamma rays.

    The alpha radiation is basically a helium nucleus moving at a fast speed. Beta radiation is composed of a fast moving electron. I have done some experiments to understand how this radiation can be stopped by matter and it does not take much to stop alpha radiation since it is quite bulky. Beta radiation on the other hand can penetrate up to 2.5 cm skin deep. Still neither is as dangerous as the electromagnetic waves.

    The danger of radiation comes from the probability that it will hit you in a certain way and end up affecting you. That is way there is a 'safe' dose of radiation that you can be exposed to. Because the probability of it damaging your system is low. However if you are extremely unlucky, instead of that gamma ray passing harmlessly through you, it could hit an important molecule inside you and change the bonds. It's just chance.

    I hope that helped,

    Cheers
     
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  13. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    all this information is wonderful.
    presumably with the radio active water the x rays and gamma rays have moved through this? has this changed the water? or do these just travel through it?
    Is water some how holding plutonium or uranium particles that are yet to brake down?
     
  14. MrChips

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    Radiation on water can cause the creation of free radicals.

    http://en.wikipedia.org/wiki/Radiation_damage#Effects_on_water

    What is a greater concern for "radioactive water" is the presence of radioactive elements such as cesium and strontium in the water. As indicated before, it can take 300 years and more for this radiation to diminish.

    Another concern is what happens when organisms living in the ocean consume and accumulate radioactive material. This can migrate up the food chain.
     
  15. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    I would like to copy this information and give it with the petition. Are any privacy problems with that. ?
    also is it ok to provide a link or are none members unable to read information on the forum?
     
  16. MrChips

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    Oct 2, 2009
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    I think you should reconsider the effectiveness of your petition particularly when you lack substantial knowledge of radioactivity and its effects.

    Basically, the Fukushima Daiichi nuclear disaster is a global catastrophe in the making. Countries and their leaders across the globe are caught between a rock and a hard place.

    How do you acknowledge the seriousness of the problem without causing widespread alarm and panic?
     
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  17. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    I am not sure whether this response came from me wanting to link this information with the petition, I already have a link to some articles and to make thinks more private with this thread I have made the decision not to include it.

    as far as doing or not the petition, its to late, it has being going a while and has 700 signatures.

    I don't really want to get into the political wranglings of what governments want to do or not do as the last thread got closed down for just that reason.

    But I am enjoying learning about radio active pollution and the depth of the problems at Fukushima.
     
  18. MrChips

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    My response was not triggered by your request to link to this information.

    I believe that almost any number of signatures will not make any difference to the political decision process and how to solve the problem.

    I think a more useful objective would be for the public to have a better understanding on the subject matter as you are doing.
     
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  19. lotusmoon

    Thread Starter Member

    Jun 14, 2013
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    I was motivated by an inner need to try and do something towards what seemed to be an incredibly dangerous situation. it would take a momentous effort to get anywhere near enough signatures for the petition to even be handed to Ban Kimoon. but in the doing of it i feel that people are being educated and talking about the situation. hopefully this will join together with other things to somewhere at some point a resolution being found. on this particular situation I feel that looking the other way is a luxury we can not afford. and I feel that the political process can be change when the mass of public opinion is strong enough.
     
  20. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    What is your area of expertise where you feel you can make a difference in such a massive and complex situation?
     
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