Geiger counter?

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Trantor
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Geiger counter?

Post by Trantor »

Sorry for posting here, but the "general discussion"-forum is on maintenance.

And no, i don´t want to stir up panic (Arioch, if you don´t want to have a discussion on this, please feel free to cancel it).

But looking on the recent events in Fukushima i´d like to know if some of you living near the american westcoast have access to independent geiger counters?

I myself bought a Gammascout® (it also measures alpha and beta, and is calibrated to less than 5% error) years ago because we in hamburg live inbetween three old reactors, two of them in pretty poor condition, just to monitor possible "events".
And yes, we had "smaller" "events", who weren´t confirmed by the authorities, but measured by enviromentalist groups - and by me.
It was only in the low digits at about 3µSv/h (about 60 times ambient), but i´d still consider it at least annoying that our so-called "radiation-protection-authorities" didn´t do anything about it. They didn´t even confirmed it.
Don´t get me wrong, i´m not a tin-hatter, but i´ve seen desinformation already.

So, now i saw a map with a prediction for radiation on the american westcoast, and they predicted pretty high increases. Don´t get me wrong: An increase of 100 times above ambient isn´t life-threatening, but still significant nevertheless.
For comparison: Ambient radiation in Hamburg/Germany right now is 0.04 µSv/h (microsievert per hour).

What i found on the internet were only official sites so i ask here if some of you maybe have better (independent) data, because this is the only "international/american" techgeekforum i´m in.
;)
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Re: Geiger counter?

Post by Mjolnir »

3 µSv/h is only about 10x worldwide average background (2.4 mSv/year, 0.3 µSv/h), and could have been a wide variety of things...there could be some bananas or brazil nuts in the vicinity, or construction activity raising dust with above-average radioactivity, etc. Getting accurate measurements of such low radiation levels with even a calibrated geiger counter is difficult. There's a lot of gamma counters on the market, but I doubt there's any commonly available and affordable instruments that can measure the impact of Fukushima on our west coast.

Most of the radioactive materials released from Fukushima so far are things like iodine-135, xenon-135, and nitrogen-13, with short half lives (7 hours, 9 hours, and 10 minutes). This stuff is especially hot near the reactor where it's released, but aside from simple dilution into the atmosphere, most of it will have decayed by the time it reaches the US.

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Re: Geiger counter?

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Mjolnir wrote:3 µSv/h is only about 10x worldwide average background (2.4 mSv/year, 0.3 µSv/h), and could have been a wide variety of things...
On a typical day with winds from north-west, ambient in Hamburg was a normal 0,04µSv/h. After i got a call, i drove to Tespe, just southeast of NPP Kruemmel. Radiationlevel there changed between 0,15 and 0,80 with an overall-average of about the mentioned 0,30µSv/h. Some spikes showed 3,5µSv/h.
So even while the measurement didn´t met scientific standards something was going on.
On the next day radiation in Tespe was almost back to normal, without any spikes.
Mjolnir wrote:there could be some bananas or brazil nuts in the vicinity, or construction activity raising dust with above-average radioactivity, etc.
Yes, it is interesting to see that radiation level slightly raises when farmers bring out mineral fertilizer.
But on that februaryday there was no such action.
Mjolnir wrote:Getting accurate measurements of such low radiation levels with even a calibrated geiger counter is difficult.
That´s correct, but it is still interesting to see that something changes. And i´m interested to see, if it is round about measuring tolerance (let´s say +/- 100%), or if there´s significantly more (say >factor 10).
Mjolnir wrote:There's a lot of gamma counters on the market, but I doubt there's any commonly available and affordable instruments that can measure the impact of Fukushima on our west coast.
Well, for example every Gammascout delivered is uniquely calibrated to less than 5%, including a certificate from University Mannheim (and the Geiger-Mueller-Tube itself is made in Germany *cough*) and is equipped with a Lifetimebattery, so batterychanges have no impact on accuracy.

But i absolutely agree that different handling will definitely lead to different data.
Mjolnir wrote:...but aside from simple dilution into the atmosphere, most of it will have decayed by the time it reaches the US.
Well, that´s what i´m interested in, one way or another. ;)
sapere aude.

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Re: Geiger counter?

Post by Mjolnir »

Mjolnir wrote:Most of the radioactive materials released from Fukushima so far are things like iodine-135, xenon-135, and nitrogen-13, with short half lives (7 hours, 9 hours, and 10 minutes). This stuff is especially hot near the reactor where it's released, but aside from simple dilution into the atmosphere, most of it will have decayed by the time it reaches the US.
Also iodine-131, the major thyroid hazard. It has a half life of 8 days.

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Re: Geiger counter?

Post by Trantor »

Mjolnir wrote:Also iodine-131, the major thyroid hazard. It has a half life of 8 days.
And that means 50% of it arrives in america. :?
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Re: Geiger counter?

Post by Mjolnir »

Trantor wrote:
Mjolnir wrote:Also iodine-131, the major thyroid hazard. It has a half life of 8 days.
And that means 50% of it arrives in america. :?
...if you packed it all up and shipped it over.

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Re: Geiger counter?

Post by Trantor »

Mjolnir wrote:
Trantor wrote:
Mjolnir wrote:Also iodine-131, the major thyroid hazard. It has a half life of 8 days.
And that means 50% of it arrives in america. :?
...if you packed it all up and shipped it over.
:arrow: No need to pack:

Image
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Re: Geiger counter?

Post by Arioch »

I don't think winds are quite that predictable.

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Re: Geiger counter?

Post by Mjolnir »

Trantor wrote: :arrow: No need to pack:
That image is a hoax. It's complete nonsense. The units don't even make sense...the rad is a unit of absorbed radiation, and the numbers are wildly out of touch with reality.

Are you getting your news from that site? At a glance, everything it's reporting about the event is completely, insanely incorrect. "Reactor #4 Completely Breached, In Full Meltdown, Releasing Lethal Radiation"...two reactors have experienced partial melts but are now half full of water, a third has some likely fuel damage and is also half full of water, two are undamaged and in cold shutdown...and reactor #4 is empty! It's fuel was unloaded about a hundred days ago. This is part of the main remaining problem, as it's still quite hot and now boiling water off in a spent fuel pond.

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Re: Geiger counter?

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Mjolnir wrote:That image is a hoax. It's complete nonsense. The units don't even make sense...the rad is a unit of absorbed radiation, and the numbers are wildly out of touch with reality.
(Something wrong with you? Why the harsh tone?)

The one i wanted to show at first was a dynamic flash animation, so i have no direct link. This picture was just quickly googled for illustration. In the flash-animated pic they showed the way of the clouds until now, and for the next days calculated with the weather prediction for the northern pacific and the west coast.
Mjolnir wrote:Are you getting your news from that site? At a glance, everything it's reporting about...
No, i follow different media. I don´t even know the site. I just googled "fukushima radiation wind" and took the first simple pic.

But this totally misses the point. All i asked was for independend data.
Maybe someone has some good links?
sapere aude.

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Re: Geiger counter?

Post by Trantor »

Arioch wrote:I don't think winds are quite that predictable.
Well, a part of the radiation/particles will follow the westerlies.
So in case they reach america i´d be interested in data. ;)

Edit: So, now i found a still of the animation:
Image
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Re: Geiger counter?

Post by Mjolnir »

Trantor wrote:(Something wrong with you? Why the harsh tone?)
You posted a hoax image that portrays the western half of the US having lethal exposures of radiation in 10 days, a wild, ridiculous exaggeration. The person who made that image and apparently most of the people writing for that site are writing blatant lies to whip up a panic that drives traffic to their site, strengthens their position, and can get people killed. In past radiation scares, people have poisoned themselves on antiseptic iodine and taken other risky actions out of misinformed fears hyped up by the sensationalist media and people looking for a spectacle or a chance to grab some sort of power or influence. Are you still wondering about my tone?

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Re: Geiger counter?

Post by Trantor »

Mjolnir wrote:
Trantor wrote:(Something wrong with you? Why the harsh tone?)
You posted a hoax image that portrays the western half of the US having lethal exposures of radiation in 10 days, a wild, ridiculous exaggeration. The person who made that image and apparently most of the people writing for that site are writing blatant lies to whip up a panic that drives traffic to their site, strengthens their position, and can get people killed. In past radiation scares, people have poisoned themselves on antiseptic iodine and taken other risky actions out of misinformed fears hyped up by the sensationalist media and people looking for a spectacle or a chance to grab some sort of power or influence. Are you still wondering about my tone?
You are an impolite person.
I explained how i found/chose the pic. Meanwhile i also googled a bit, and learned this pic was a hoax (Edit: I didn´t even noticed "RAD", or better: As an european i´m unfamiliar with that unit. I think these are the little differences we could learn from each other, good will assumed...)
I also explained before that 100x ambient level is not directly harmful, and that i´m reasonably interested in (independent) data.

But i´m not a native english speaker (see my location), and i also don´t follow hoax/tinhatter/treehugger-sites.
Fortunately, i found a static site with the animation mentioned before:

http://www.nytimes.com/interactive/2011 ... aphic.html
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Re: Geiger counter?

Post by Arioch »

That tone is pretty mild for Mjolnir. While it could perhaps have been more politely stated, his post was factual and was not attacking. What I was trying to say in a more polite way was essentially the same thing he said in much more detail: the image you posted is pretty obviously inaccurate.

It would have been helpful if you had posted a link to the source article with it, so that people could have checked it (without having to search for it).

A reliable prediction of how much radiation will affect various areas doesn't exist, because there are too many unknowns. First and foremost, a meltdown hasn't happened yet. If it did, it might release a lot of radiation or a little. Depending on which way the local and global winds blow, this radiation could go anywhere; it's as unpredictable as the weather. But it's very unlikely that dangerous doses could reach America or Europe, except in the most "perfect storm" conditions of the worst possible meltdown and the most perfect weather patterns.

If Mjolnir's tone seems shrill, it may be because like me, he's fed up with all the media fearmongering that's been going on for the past week. I'm sure that's not what you intended to do.

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Re: Geiger counter?

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Arioch wrote:That tone is pretty mild for Mjolnir.
Well, candidate #1 for the "foe-button". 8-) :mrgreen:
Arioch wrote:What I was trying to say in a more polite way was essentially the same thing he said in much more detail: the image you posted is pretty obviously inaccurate.

It would have been helpful if you had posted a link to the source article with it, so that people could have checked it (without having to search for it).
Well, apologies, it was just meant for illustration. So i thought it wasn´t important to post a link. I recognized that it had a very simplified trace, but i am unfamiliar with the unit "rad".
If it stated something like "mSv/h", the hoax would have become clear, even to me. ;)
Arioch wrote:A reliable prediction of how much radiation will affect various areas doesn't exist, because there are too many unknowns.
I am aware of that. ;)
Arioch wrote:First and foremost, a meltdown hasn't happened yet.
In our media they reported a partial core-meltdown. Or do you mean meltdown like in "china-syndrome", with full hull breach and sinking into earth?

Well, at least there´s an indication that at least some parts of the core or the rods in the pools are out of control: When the helicopters landed, they said they encountered a radiation of 4mSv/h in 300m. So if you calculate factor 8 (2³) for every bisection of distance, you´ll get roughly 130Sv/h in 10m distance to the source of radiation. That´s roughly consistent with the 300 Sv/h in ~8m distance under the core they encountered back in ´86 in Chernobyl.

But that get´s way off now. ;)

(Although i remember Chernobyl very well, and i also remember all the barred areas back then and the huge irradiation of southern germany (up to 120.000 becquerel/m² - some areas are still irradiated with Cs 137 in a way that people there are not allowed to hunt/eat wild pigs/deers. If someone has questions, i´ll be glad to answer)
Arioch wrote:But it's very unlikely that dangerous doses could reach America or Europe, except in the most "perfect storm" conditions of the worst possible meltdown and the most perfect weather patterns.
Let´s hope so.
Arioch wrote:If Mjolnir's tone seems shrill, it may be because like me, he's fed up with all the media fearmongering that's been going on for the past week.
Is your media even worse than ours? :shock:
Arioch wrote:I'm sure that's not what you intended to do.
No. I´m no scaremonger. See post #1. ;)

I´m just an old child that likes to play with tech gadgets of all kinds/price tags. From geiger counters to racecars. ;)
sapere aude.

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Re: Geiger counter?

Post by Mjolnir »

Sorry I offended you...I regard this as a very serious matter that some sickeningly unethical people are abusing for their own short-sighted gain, with potentially global costs. Please be more careful.

Trantor wrote:Well, at least there´s an indication that at least some parts of the core or the rods in the pools are out of control: When the helicopters landed, they said they encountered a radiation of 4mSv/h in 300m. So if you calculate factor 8 (2³) for every bisection of distance, you´ll get roughly 130Sv/h in 10m distance to the source of radiation. That´s roughly consistent with the 300 Sv/h in ~8m distance under the core they encountered back in ´86 in Chernobyl.
Assuming a point source at the core, radiation falls off with the square, not the cube of distance. 3.6 Sv/h at 10 m. The core, and especially the pool, are not point sources though, they are extended sources...radiation won't fall off as fast in the near field where they have a significant angular size, because it falls off as a sum of 1/r^2 from many sources spread over a finite volume. Plus there's the airborne materials that the helicopter is flying through...4 mSv/h is not dangerous for a brief exposure, but breathing air that's contaminated enough to produce even a fraction of such a dose rate can easily produce a much higher dose in the long run.

The measurements elsewhere are just not consistent with any sort of major breach. Radiation at the power station's perimeter is 646.2 µSv/h. Damage is suspected on two containment vessels, but it'd have to be something like a possibly intermittent gas leak.

The smallest reactor has been estimated to have a 70% core melt, another 30%, another some degree of damage. These reactors shut down and were cooling toward cold shutdown for an hour before the tsunami took out cooling...a situation better in some ways than TMI, which scrammed due to coolant loss while producing power during coolant problems. The reactors have the control rods fully inserted and can not produce a chain reaction, though they are still producing enough decay heat to melt parts of the support structures and eventually the fuel itself if cooling is interrupted. It's a very different event than what occurred at Chernobyl reactor 4, which blew apart in a steam explosion caused by an uncontrolled power spike with most control rods removed as they attempted to bring up a core poisoned by xenon-135.

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Re: Geiger counter?

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Mjolnir wrote:Sorry I offended you...I regard this as a very serious matter
Me too. ;)
Mjolnir wrote:Please be more careful.
Blame it on the language-barrier. 8-)
Mjolnir wrote:Assuming a point source at the core, radiation falls off with the square, not the cube of distance. 3.6 Sv/h at 10 m. The core, and especially the pool, are not point sources though, they are extended sources...radiation won't fall off as fast in the near field where they have a significant angular size, because it falls off as a sum of 1/r^2 from many sources spread over a finite volume. Plus there's the airborne materials that the helicopter is flying through...
Ah, there. I confused sphere-surface with -volume. Thanks for correction!
Mjolnir wrote:4 mSv/h is not dangerous for a brief exposure, but breathing air that's contaminated enough to produce even a fraction of such a dose rate can easily produce a much higher dose in the long run.
Exactly.
Mjolnir wrote:The measurements elsewhere are just not consistent with any sort of major breach. Radiation at the power station's perimeter is 646.2 µSv/h. Damage is suspected on two containment vessels, but it'd have to be something like a possibly intermittent gas leak.
The smallest reactor has been estimated to have a 70% core melt, another 30%, another some degree of damage. These reactors shut down and were cooling toward cold shutdown for an hour before the tsunami took out cooling...a situation better in some ways than TMI, which scrammed due to coolant loss while producing power during coolant problems. The reactors have the control rods fully inserted and can not produce a chain reaction, though they are still producing enough decay heat to melt parts of the support structures and eventually the fuel itself if cooling is interrupted.
Yes, that matches.
I just really hope those rods in the (empty?) SFPs don´t ignite.
BTW: TMI or Three Mile Island is not a common term in germany, although it has a lemma on the german wikipedia. Older people refer to it as "Unfall von Harrisburg" or "Harrisburg Disaster".
Mjolnir wrote:It's a very different event than what occurred at Chernobyl reactor 4, which blew apart in a steam explosion caused by an uncontrolled power spike with most control rods removed as they attempted to bring up a core poisoned by xenon-135.
Yep, and the subsequent graphite-fire that sent radioactive fallout high up into the atmosphere.

I´m glad that our opinions roughly match.
And i´m fine with keeping politics away from this board. (We have elections coming up in germany - i bet you can imagine what that means... :mrgreen: )
sapere aude.

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Re: Geiger counter?

Post by Mjolnir »

Trantor wrote:I just really hope those rods in the (empty?) SFPs don´t ignite.
Those are the main worry right now, and I would wager those are the main source of radiation, especially measured from a helicopter flying above them. Normally a thick layer of water and the structure of the building itself would provide radiation shielding, but the pools are low and the roof and walls of the upper floors have been blown off. Toward the sides, adjacent fuel rods and building structure would absorb more radiation.

The fuel itself is an oxide ceramic, it's not metallic uranium and plutonium. Plutonium forms in the reactor over time, but even discounting oxidation during operation, that doesn't give you a chunk of plutonium metal. The fire hazard is due to the zirconium cladding. While a fire would be quite bad, it wouldn't be the massive plutonium fire that I've seen claimed elsewhere. In particular, I just don't see a mechanism for Kaku's "roman candles" claim. From what I've read on the subject, the main release of radioactive material would be iodine and cesium vapor released from heat-cracked fuel pellets, and some particulates carried in the smoke. Notably worse than iodine and xenon-contaminated steam vented from the reactors, but still an event that pales in comparison to the tsunami that caused it.

They've got power to the site now. Last I heard, they were focusing on getting reactor 2's cooling systems back on external power, but hopefully they have pumps and intact plumbing that can refill those ponds, or at least keep them cool so water added by other means doesn't keep boiling off.

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Re: Geiger counter?

Post by Mjolnir »

As for the image, it is an estimate of distribution of material by wind currents, with no reference to the amount released or decay/absorption by the ocean over time, and it illustrates why I made my statement about having to pack it up and ship it over. The material spreads out, dilutes, and takes indirect paths. We won't get 50% of the released radioactive material, we'll get a tiny fraction.

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Re: Geiger counter?

Post by Trantor »

Mjolnir wrote:As for the image, it is an estimate of distribution of material by wind currents, with no reference to the amount released or decay/absorption by the ocean over time, and it illustrates why I made my statement about having to pack it up and ship it over. The material spreads out, dilutes, and takes indirect paths. We won't get 50% of the released radioactive material, we'll get a tiny fraction.
Those 50% were meant for iodine-131, with a half life of 8 days if it travels 8 days. Sorry, i wasn´t precise enough. And of course it´ll be dispersed, so a quite concentrated cloud like in europe in ´86 is not very likely.
Remembering Chernobyl IMHO the main concern is Cs-137. It´s half-life is 30,8 years, and as i stated before, huge parts of southern germany are still irradiated in a way that eating meat from wild pigs is quite dangerous. Wild pigs still have to be checked for radiation, with some of them still exceeding 7000Bq per kg meat. Threshold in germany is 600Bq/kg, and in bavaria every third wildpig is above that. But it is still profitable for hunters, as they get more compensation than they would get on the market.
Eating a Schnitzel with an activity of 2000Bq leads roughly to a dose of 0,06mSv.


But i´m deviating, sorry.

I´m still interested in independend or amateur data, one way or another. ;)



Edit: There are also possibly positive effects from slightly increased ambient radiation, it´s called radiation hormesis. There are people living in some areas in Iran with an ambient radiation roughly 100x higher than hamburg, and they life long and prosper.
So not everything is bad, it´s the dose (sic!) that makes the poison. ;)


Edit2: When do we move over page discussion? I remember Page 70, whith Alex eager to see the ships firing. Now it´s clear who is (also?) shooting beams with a greenish tint...


Edit3: As i stated gefore i prefer relaxed and factful sources of data. Via Reuters i found austrias central organisation for geodynamics and meteorology. They also provide dispersion maps. It´s in german, but it´s not hard to understand. Enjoy.
sapere aude.

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