estimates of biological half life vary, but ALL the sources do indicate that it does self-cleans. Albiet it takes a while, however FAR less than it's radiological half-life. I guess that means that you *could* say that it bio-accumulates, meaning that if you keep eating it, your level of it increases over time, at least for a few years. But when you stop, it drops, and pretty fast at that. In any case, it's not an acute exposure risk, only a long-term lifetime exposure one. You don't get apocalypses out of radioactive cesium.
Spent fuel is spent for a reason. The reason being, that it's getting difficult to sustain criticality with it, due to the low proportion of fissile u235 remaining in it, as well as the prevalence of neutron capturing isotopes. http://en.wikipedia.org/wiki/Neutron_poison
Now, had the fuel pool completely lost all water during the actual incident (when there was very fresh fuel in it), problems would have been possible, because the fuel was still capable of getting hot enough to melt itself, and IF enough of them did that, you *could* get criticality in the puddle of uranium slag on the bottom of the dried out pool. A year out? No. there's no reasonable chain of events that leads to a "meltdown" in a spent fuel pool.
How worried are you about extinction level asteroid strikes? http://www.telegraph.co.uk/science/space/9943048/Nasas-advice-on-asteroid-hitting-Earth-pray.html
Or an actual, literal zombie apocalypse? http://www.popsci.com/science/article/2011-02/fyi-could-scientists-really-create-zombie-apocalypse-virus
There are always "scientists" willing to say *anything*. That's why it's important to look at the facts yourself.
As for the "chain reaction meltdown" where a meltdown at fukushima "sets off others? That's just stupid. Consider the mechanics of that. Either they're saying that the chain reaction in the spent fuel of fukushima will emit neutrons *far enough away* through multiple layers of concrete, steel, and water shielding, to start a reaction in those pools (roughly the equivalent of me shining a flashlight in NY and starting a forest fire in Colorado), or they're claiming.... what? What is the mechanism by which a melt at one results in a melt at another? Is it plausible, given real world physics and conditions? No, this is nothing more or less than attention seekers succeeding.
That said, future reactors should avoid putting the spent fuel pools on the top floor of the reactor building. DUMDUMDUM!
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timeasmymeasure
no subject
Date: 2013-09-30 06:19 pm (UTC)http://www.nuc.berkeley.edu/node/3165
estimates of biological half life vary, but ALL the sources do indicate that it does self-cleans. Albiet it takes a while, however FAR less than it's radiological half-life. I guess that means that you *could* say that it bio-accumulates, meaning that if you keep eating it, your level of it increases over time, at least for a few years. But when you stop, it drops, and pretty fast at that. In any case, it's not an acute exposure risk, only a long-term lifetime exposure one. You don't get apocalypses out of radioactive cesium.
Spent fuel is spent for a reason. The reason being, that it's getting difficult to sustain criticality with it, due to the low proportion of fissile u235 remaining in it, as well as the prevalence of neutron capturing isotopes.
http://en.wikipedia.org/wiki/Neutron_poison
Now, had the fuel pool completely lost all water during the actual incident (when there was very fresh fuel in it), problems would have been possible, because the fuel was still capable of getting hot enough to melt itself, and IF enough of them did that, you *could* get criticality in the puddle of uranium slag on the bottom of the dried out pool. A year out? No. there's no reasonable chain of events that leads to a "meltdown" in a spent fuel pool.
How worried are you about extinction level asteroid strikes?
http://www.telegraph.co.uk/science/space/9943048/Nasas-advice-on-asteroid-hitting-Earth-pray.html
Or an actual, literal zombie apocalypse?
http://www.popsci.com/science/article/2011-02/fyi-could-scientists-really-create-zombie-apocalypse-virus
There are always "scientists" willing to say *anything*. That's why it's important to look at the facts yourself.
As for the "chain reaction meltdown" where a meltdown at fukushima "sets off others? That's just stupid. Consider the mechanics of that. Either they're saying that the chain reaction in the spent fuel of fukushima will emit neutrons *far enough away* through multiple layers of concrete, steel, and water shielding, to start a reaction in those pools (roughly the equivalent of me shining a flashlight in NY and starting a forest fire in Colorado), or they're claiming.... what? What is the mechanism by which a melt at one results in a melt at another? Is it plausible, given real world physics and conditions? No, this is nothing more or less than attention seekers succeeding.
That said, future reactors should avoid putting the spent fuel pools on the top floor of the reactor building. DUMDUMDUM!