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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 11:57am PT
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a "scintillometer" is not an ionizing radiation detecting instrument (it detects light, optical or radio) and calculates the changes in refractive index along the path the radiation takes from a transmitter.
A scintillation counter is an instrument that detects ionizing radiation. The active material of the instrument has the property that it emits light with the passage of charged particle that have sufficient kinetic energy to ionize that material. Neutral radiations like neutrons and photons (gamma-rays) interact with the nuclei (in the case of neutrons) and electrons (in the case of gamma-rays) that have enough energy in their recoil to ionize the material (in the case of neutrons, the material usually has a large fraction of hydrogen or helium and the recoiling proton does the trick).
A gamma-ray is a high energy photon emitted by a nucleus undergoing a transition from one nuclear energy level to another. These energy level schemes are specific for every nucleus and serve to identify the nuclei emitting them. While many of these levels are known, nuclei represent a complex system, an n-body, strongly coupled quantum system where many (most) of the levels are not measured. However, there are very characteristic gamma-rays that are used to identify nuclei, including unstable nuclei (those that undergo decay).
A large detector enables the measurement of the energy of the radiation. Let's concentrate here on the gamma-rays. A sequence of reactions occurs. The initial reaction is either a "Compton scatter" where the gamma-ray interacts with an atomic electron, knocking it out of the atom (ionizing the atom) OR the gamma-ray produces an electron-positron pair (the positron is an "anti-electron" it has charge +e whereas the electron has charge -e). This second case can only happen if the gamma-ray has sufficient energy (greater than twice the electron mass= 2.*0.511 MeV = 1.022 MeV). In this case the gamma-ray is "absorbed." In the more common Compton scatter the electron flies off, as does the gamma-ray (but with less energy than it had before the scatter).
This process repeats until all the original kinetic energy is dissipated by the particle production. This is known as an "electromagnetic shower."
The size of the shower, measured by the number of secondary electrons that are produced by the shower, is proportional to the energy of the incident gamma-ray. The shower also has a physical size set by the interaction length, which depends on the atomic number of the material and its density.
BASE109's detector is large because it wants to contain the entire shower, which gives it better energy resolution. If the detector is too small, the electrons "leak" out in to the air and do not cause the material to scintillate.
The detector used in the OP video is a "geiger counter" which works differently, the ionizing radiation ionizes a gas in a chamber that has a large electrostatic potential which causes the electrons to move. As the electron kinetic energy increases in this field, the electrons cause more ionization in the gas. The current generated by this charge is detected and is the source of the audible "click." But this counter does not measure the energy of the radiation, only the presence of radiation.
A schematic but useful description is here:
http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/landform_glossary_radio
Once you have the energy spectrum you can compute the fraction of each nuclei in your sample.
This method is used extensively in geology, here's a quick link with some examples:
http://www.kgs.ku.edu/Dakota/vol3/KCC/kcc06.htm
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 12:12pm PT
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Sketch uses innuendo, in this case the suspicion that I somehow benefit from saying the radiation levels are not significant, to undermine the authority of the discussion above. Interesting reaction, as I was just conveying what I know when asked. I wasn't aware that I had any other agenda.
For the record, I don't have anything at stake regarding nuclear energy.
As for Ron, his inability to make a quantitative assessment of anything puts him at a disadvantage. Having to choose whom to trust, he picks those with a viewpoint that he finds compatible with his own. Those with contrary viewpoints are rejected based solely by association, rather than on any facts.
Both of these behaviors are exhibited to excess on "the other thread."
While exposure to radioactive material can be detrimental to health, it has always amazed me that people are completely nonchalant using chemicals that are much more hazardous. I presume that this is a perception that chemicals are a part of the "natural" world, and that radioactivity is not. However, as pointed out above, we live in a radioactive world,
http://en.wikipedia.org/wiki/Natural_background_radiation
with the majority of our exposure coming from unavoidable sources.
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 12:36pm PT
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the solution to most radioactive contamination is to wait, as the intense radiation is due to short lived nuclear products. Each "half-lifetime" of the isotope represents the time that half of them have decayed. So depending on how much of that isotope was made, the amount of the isotope remaining is exponentially decreasing with time.
The half-life is another characteristic specific to an isotope and can be used to identify that isotope.
Once the levels of radioactivity drop to the background level, or below, the low level exposure effects are expected to be no different than that of our natural exposure.
For isotopes that have chemical properties similar to biologically metabolic elements, those metabolic processes can concentrate the radioactivity in particular areas. This increases the exposure in those areas. For instance ¹³¹I is essentially undifferentiated from naturally occurring iodine, which concentrates in the thyroid. ⁹⁰Sr (strontium-90) has a biological activity similar to Calcium and concentrates in bone, which is adjacent to blood cell production.
So the immediate consequences of airborne contamination is the wide dispersal and quick uptake (the half-life of ¹³¹I is 8-days, http://en.wikipedia.org/wiki/Iodine-131 ). There is another time period which is important, the "biological half-life" which measures how long the isotope stays in the body. This may be longer than the isotope half-life, but in cases where it is not, the isotope may be expelled in metabolic byproducts, before it decays.
responding the the disaster in the days following the dispersal could lead to high exposures. As far as I know, however, the cancers that these exposure cause take some time to develop.
desalination is just that, it takes the salt out of the water. What contaminants and at what levels remain?
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 12:48pm PT
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the half-life of ¹³¹I is 8 days, two years, 720 days, is 90 half lives, so the radiation now is attenuated by a factor of 2⁻⁹⁰ ≈ 10⁻³⁰
so for the radiation levels to be, say twice the background level, then two years ago the radiation levels would have had to have been 10³⁰ times background... that would have been a disaster. It isn't what happened.
¹³⁷Cs has a half-life of 30 years and is more of a "problem," the biological half-life is 70 days.
http://en.wikipedia.org/wiki/Caesium-137
Caesium is not concentrated in the body, it is highly reactive, chemically.
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 12:58pm PT
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...and many of the listings have proven to be true.
which ones? and why would you post things that were not true?
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 01:05pm PT
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I've worked around radiation my entire professional career... creating it, detecting it, studying it... it is not a faded memory but an everyday activity.
How do you check the truthfulness of the web reports?
Why would you post things you haven't verified by what ever means?
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Banquo
climber
Amerricka
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Topic Author's Reply - Dec 28, 2013 - 01:17pm PT
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While exposure to radioactive material can be detrimental to health, it has always amazed me that people are completely nonchalant using chemicals that are much more hazardous.
I figure those people on the beach in the video were more at risk due to the massive doses of ultraviolet radiation than whatever the Geiger counter was measuring.
Ron - it is impossible to assess your own competence. You have to get others to do that. I propose you ask Ed if you are competent in this area.
This is of interest:
http://www.nytimes.com/2013/05/26/magazine/why-rational-people-buy-into-conspiracy-theories.html?_r=0
Conspiracy theories also seem to be more compelling to those with low self-worth, especially with regard to their sense of agency in the world at large. Conspiracy theories appear to be a way of reacting to uncertainty and powerlessness.
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TGT
Social climber
So Cal
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Dec 28, 2013 - 01:33pm PT
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Everybody needs a monster in the closet.
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John M
climber
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Dec 28, 2013 - 01:48pm PT
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If theres nothing to worry about,, then why is that poor lil seal going bald and bleeding from his lungs.??
don't know. do you? why do you presume its from fukushima? with all of the other thousands of stupid things we humans do. Do you have proof its from fukushima?
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Banquo
climber
Amerricka
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Topic Author's Reply - Dec 28, 2013 - 01:51pm PT
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Bad haircut on that seal. Where, when was it taken? Who did what diagnosis?
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 01:54pm PT
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Ron, certainly just posting something and asserting it is "the truth" is not sufficient to establish the content of that posting as true.
Certainly, time and again, when your posts have been challenged you've simply denied the challenge, without any additional information, merely stating that in your experience, you are right. So it is a fools errand to actually address your posts, as you have no intention of engaging in a discussion.
I might get around to some of the posts, but I still wonder why you would post something that you haven't checked out its validity, as you imply above.
It calls into question your procedure for establishing validity, which I suspect has more to do with whether or not you agree with it: valid - agreement, not valid - don't agree.
That's not science, certainly, but then I'd never accuse you of being scientific, or even knowing what that might mean.
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survival
Big Wall climber
Terrapin Station
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Dec 28, 2013 - 01:58pm PT
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The wheels on the bus go round and round, round and round, round and round.
Ed, your last post to Ron was FUNNY!!
It is hilarious reading a scientist try to make sense with Duck Dynasty guy. You guys are killing me here.
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John M
climber
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Dec 28, 2013 - 02:12pm PT
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well, since they have elevated levels of radiation,, im guessin FUKU.. Since they were located squarely in the predicted target zone of radiation from FUKU, im guessing FUKU. Since they eat on fish also showing up with elevated radiation problems,, again,, im guessing FUKU. And since they weren't that way PRE FUKU,, yup,, im guessing FUKU..
I have no idea if you could be right, but what I do know is that you could be wildly wrong because Fukushima is not the only thing we have been dumping into the ocean. It could be that something else has finally reached a critical level.
Right now Fukushima is the bogeyman. It is a major problem, but we should be careful in assigning it all blame.
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John M
climber
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Dec 28, 2013 - 02:25pm PT
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Sure its about dollars, but it could also be about hiding some other egregious thing we are doing to the ocean. Blame it on Fukushima, thats the obvious answer, while we go on polluting in other ways. Maybe Fukushima is just the tipping point of some of the die offs. Maybe its really something else we are doing and Fukushima is just the straw that broke the camels back. At this point, we just don't know.
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nah000
climber
canuckistan
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Dec 28, 2013 - 02:51pm PT
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i love graphics like the one rSin posted. /s
right in the graphic it says that it is comparing apples to oranges.
in this case it's comparing distributed, non-event sourced fallout levels ["... measured in the Baltic Sea and Black Sea... The plant was located in Ukraine, hundreds of kilometers inland." and "... measured in the 1960s off Japan. Levels were higher in the immediate areas near Bikini Atoll and other places where weapons were detonated."] with near event sourced ones ["Levels of radioisotopes measured from March to July 2011 in surface water off the coast of Japan following the disaster..."]
so why create a graphic like this?
it's sensationalist and drives clicks by giving people what at first glance can appear to be "objective confirmation" of the world they emotionally hope and/or fear exists.
the same reason a person makes a video measuring radiation in cpm [an instrument specific measure], complete with a beeping "alarm" whose level is arbitrarily set by the user, all while giving no comparisons to earlier data and implying that an easily explained phenomenen [seawater and marine sediments having a higher natural radioactivity level] is somehow insidious.
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Brandon-
climber
The Granite State.
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Dec 28, 2013 - 02:55pm PT
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Valid citations should have been in bold as well.
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survival
Big Wall climber
Terrapin Station
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Dec 28, 2013 - 03:18pm PT
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edit: Survival,, Duck Dynasty guy?? Wanna TRY and explain that one?
Ummm, you did post a pic of yourself with dead ducks on the Duck Dynasty thread right? And you're a dead critter artist. Didn't think it was that much of a stretch!! How's that for TRYING? I think most folks would get it.
Breasts for you anyway. ( * )( * )
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Ed Hartouni
Trad climber
Livermore, CA
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Dec 28, 2013 - 03:33pm PT
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my post was that the OP linked video was nonsense.
the issue of dumping into the oceans, or into the atmosphere, is not nonsense.
attributing cause to a specific event should require a well demonstrated link... I'm not sure you noticed, Ron, but I did dig up the article that at least one of your many links up above referred to. I prefer to go to the source of the information then rely on news reports, especially from news organizations I'm unfamiliar with...
I assume you just want to pick a fight... you certainly don't like be told anything.
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chill
climber
between the flat part and the blue wobbly thing
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Dec 28, 2013 - 05:16pm PT
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And the Lord of Reason doth wrote: If theres nothing to worry about,, then why is that poor lil seal going bald and bleeding from his lungs.??
Ron - you can really spew crap.
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feralfae
Boulder climber
in the midst of a metaphysical adventure
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Dec 28, 2013 - 05:51pm PT
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Mr. Hartouni wrote:
The tension between government regulations and industry interests did not achieve a safe outcome in this case.
May I provide a couple of emendations? Thank you.
The illusion of tension between political hacks who sell government regulations and greed-driven corporate industry interests who buy those politicians did not achieve a safe outcome in this case.
We are not surprised. Fukushima is just another symptom of the illness of greed.
I have enjoyed this commentary here, thank you.
feralfae
. . . and now, I go to catch up on Secret Santas and stuff. I know I own my SS giftee a bonus pack. And the BOX!!!???. Happy New Year, everyone!
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