Re: Strontium 90 vice Strontium 89

[Franz Schoenhofer <schoenho@via.at>]

At 06:44 10.08.2000 -0500, you wrote:
>
>

I respectfully disagree with your comment:


>Fission produces both 89Sr and 90Sr......  on a curie basis, a vastly greater
>amount of the shorter-lived 89Sr.  

Do you refer to an amount or to an activity concentration? These numbers
are related, but totally different.


If 90Sr is found without accompanying 89Sr,
>it simply means that the fission product is so old that the 89Sr has died
away
>(at least a couple of years old).   

Sr-89 is much shorter lived and will have decayed within at least weeks. 

And 89Sr is a whole lot easier to find in a
>sample than the pure beta-emitter 90Sr.  

No, Sr-89 is as well a pure beta-emitter, but its energy distribution is
different from Sr-90 (and especially its short-lived daughter Y-90), so it
can for instance be identified and quantified with liquid scintillation
spectrometry in the presence of both Sr-90 and Y-90.


If the strontium in any environmental
>or tooth sample is 90Sr, then it is clearly fallout.  If it came from Oyster
>Creek it would have to be mostly 89Sr.

No, Sr-90 is the long lived and therefore the decisive radioisotope of
Sr-90. Sr-89 would only be observable for a very short time of release,
which most probably would not be long enough to allow for incorporation
into teeth.

Any hypothetical release of Sr-90 (by what pathway? sure not by air, maybe
by effluents) would have to reach the children somehow. Nobody with the
tooth fairy project (the "world-renowned scientists" of Edith) have cared
to explain, how this could be achieved. There is not a single person even
pretending to be a radioecologist on this group. 

The tooth fairy project is a kind of a hoax - to raise money and to attract
public opinion to a non existing "problem" in order to exercise "public
pressure" and "concern", which is well channelled into political power.
Unfortunately it is just one among many others.

Franz





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>
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Franz Schoenhofer
Habicherg. 31/7
A-1160 Vienna
Austria
Tel.: +43-1-495 53 08
Fax.: same number
mobile phone: +43-664-338 0 333
e-mail: schoenho@via.at


Please note my new telephone number at my office!

Office:
Ministerialrat Dr. Franz Schoenhofer
Federal Ministry of Agriculture, Forestry, Environment and Water Management
Radiation Protection Department (BMLFUW I/8 U)
Radetzkystr. 2
A-1031 Vienna
AUSTRIA

phone: -43-1-71100-4458
fax: -43-1-7122331

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