Regarding Polonium 210
Radioactive isotopes are much in the news lately because of last week's death of former Russian spy Alexander Litvinenko. The specific isotope found in Litvinenko's body is a really nasty one if you're trying to kill someone -- Polonium 210. In the non-spy world, polonium is best known for it's very high power density, although its relatively short half-life makes it not very suitable for things like longer space missions. For the nuke geeks out there, 210Po84 is made by a β- decay chain from Pb-210 to Bi-210 to Po-210; the Polonium alpha decays to Pb-206 with a half-life of a little over 138 days, with a decay energy of about 5.4 MeV. This relatively moderate half-life, which means it lasts long enough to deliver it to the target but still decays rapidly enough to cause serious damage, makes it one of the "worst" alpha emitters.
Still, unless it's ingested, it's not going to cause random bystanders any problems -- despite the warnings of articles like this one that persist in calling it "plutonium". Much like "depleted uranium", this is one of those things that probably serves to scare the public about anything having to do with radiation more than anything else. Remember -- if it's an alpha emitter, it can't hurt you unless it gets inside your body, and if it has a long half-life, it most likely won't even hurt you then.
(Disclaimer: I should point out that as a former Navy nuke, I have a kind of institutional disdain for alpha-emitters; it's the neutron-emitters that scare the crap out of me. Contributing to this is the "Great Neutron Conspiracy" that exists in the Navy Nuclear Program. For those who don't believe in the GNC, I would ask you: why is it that dosimeters that monitor for neutrons are sent off the boat to be read? And why are the neutron-"detecting" radiacs the only ones we have to send away for calibration? Kinda makes you go "hmmm", doesn't it?)
posted by Bubblehead at 7:54 PM
10 Comments:
While studying RADCON in NNPS, I remember having very vivid 'nightmares'/imaginings about the effects of radioactive particles in the body, especially those big, honkin' alphas just rippin' through cells and tissues and leaving a terrible mess in their wake.
Yet, while I could "see" (in my mind) the effects at the microcscopic level, I had difficulty putting that together with the macrocosmic pathology--that is, what the visible effects on the patient would be. Sadly, the death of Mr. Litvinenko has accomplished that for me. WHAT A NIGHTMARE.
11/30/2006 7:36 AM
BH, very nice summation.
Here are the really tricky questions I hope you might help your readers answer:
Since traces of Pollonium 210 have now been found on several British airliners, is it safe to conclude that it was NOT being transported in containers (such as a small vial)?
Pedestrian sources on the web suggest alpha emitters are undetectable with standard airport radiation monitors, and even specialized, mica-window geiger multipliers would have difficulty detecting a sample in a vial. If true, what detection method is likely being used on the British planes?
11/30/2006 8:30 AM
I don't think they said they've actually found Po-210; just something "radioactive". Since the decay daughter of Po-210 is stable Pb-206, I don't imagine they found it that way. I imagine it's more just taking the civilian equivalent of a -56 and picking up alpha traces. You're right, though, that inside a well-sealed vial, it would be basically indetectable -- the tenth-thickness of 5 MeV alphas in air is only several centimeters, so it would be only a millimeter or so of glass or plastic. Whoever was carrying it was probably handling the capsule (or whatever it was in) at some point, so that's how the alpha contamination got on the planes.
Or, it might turn out to be completely coincidental.
11/30/2006 3:18 PM
Thanks, BH. Imagine someone handling the capsule. This will really be interesting if authorities share it all.
11/30/2006 6:10 PM
"If true, what detection method is likely being used on the British planes?"
Swipes
12/01/2006 6:35 AM
"A single gram of 210Po generates 140 watts of power." (Wikipedia, "Po-210")
A small vial of Po-210 would sure be a "hot potatoe".
Wiki also provides:
Applications
When it is mixed or alloyed with beryllium, polonium can be a neutron source: beryllium releases a neutron upon absorption of an alpha particle that is supplied by 210Po. It has been used in this capacity as a neutron trigger for nuclear weapons. Other uses include:
* Devices that eliminate static charges in textile mills and other places.[1] However, beta sources are more commonly used and are less dangerous. Another alternative is to use a high voltage direct current power supply to ionize air positively or negatively.[2]
* Brushes that remove accumulated dust from photographic films. The polonium used in these brushes is sealed and controlled thus minimizing radiation hazards.
* As 210Po, a lightweight heat source to power thermoelectric cells.
* Russian secret services allegedly use polonium for smudging currency bills so that they can trace them. [1]
* Radioactive poison [3].
BH's -- "Or, it might turn out to be completely coincidental." Seems likely.
But what led the investigators to start swiping airplanes??
12/01/2006 10:33 PM
For a solid summary & update on Litvinenko's poisoning (and why planes were tested for alpha contamination), see:
http://www.timesonline.co.uk/article/0,,2087-2484295,00.html
12/02/2006 7:06 PM
Remember the choice of four cookies: The alpha, gamma, nuetron and beta cookies. Eat one, throw one away, hold one in your hand and put the other in your pocket.
12/02/2006 7:45 PM
One thing I found interesting in one news report is that Po-210 is commercially available. However, to purchase enough to poison someone would be in the millions. Who would have those kinds of resources?? Not a very subtle way to kill someone, and it looks like the trail leads to Moscow...
12/03/2006 9:49 PM
thanks for this wonderful post tour jobs this is really helpful.
3/31/2010 10:54 PM
Post a Comment
<< Home