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Re: AW: request for help with Wikipedia article
On begs to differ strontium can be quite mobile in the environment though perhaps not so much in air. Strontium-90 is quite soluble behaving much like calcium, unless waters from various sources (firefighting -rainfall) were contained in the ruins which would seem doubtful one would expect both groundwater and surface waters which are fed from groundwater sources to be quite contaminated.
In fact I've worked with such contaminated waters around various experimental reactors within the Oak Ridge Reservation, the sources were generally from overflowing tanks and leaking waste lines, and um questionable waste handling practices. From extensive sample analysis I can attest that Sr-90 is very mobile in the environment.
Maybe this link and quote from "Belrad" can help a bit.
From: http://www.fortunecity.com/boozers/vines/860/Nester/english/radekola.htm
The Republic of Belarus
Institute of Radiation Safety "Belrad"
RADIATION AND ECOLOGICAL CONSEQUENCES OF CHERNOBYL ACCIDENT AND EFFICIENCY OF THE CHILDREN PROTECTION IN THE CONTAMINATED AREAS OF BELARUS.
V.B.Nesterenko * Member of National Academy of Science, Professor, Doctor of Technical Sciences
"Thirteen years after the accident at the Chernobyl Nuclear Power Station, after the falling out of 70% of radionuclides on the territory of Belarus and contamination of 23% of it's territory almost 2 million people (500,000 of them are children) still live on this territory. The main dose load (> 80%) the inhabitants of these regions get with the nutrition products of the local production, which are considerably contaminated by radionuclides of caesium-137 and strontium-90"
>>> Franz Schönhofer <franz.schoenhofer@CHELLO.AT> 8/26/2004 12:48:25 PM >>>
Franz Schoenhofer
PhD, MR iR
Habicherg. 31/7
A-1160 Vienna
AUSTRIA
phone -43-0699-1168-1319
A few comments on Nathans questions and Mikes answers:
>Is it safe to assume that Cs137 is the majority of the remaining
activity?
I think so, yes. If I am wrong, I am sure someone on this list will
correct me.
--------------------
If you look at the curves showing the fission yield vs. fission products
mass numbers you see two peaks at around the mass numbers 90 and 137.
Therefore the most abundant radionuclides after fission are such ones
like Sr-90, I-131, I-132, Te-132, Cs-134, Cs-137 etc. Most of these,
including I-131, have short half-lifes, so they have decayed since long.
Sr-90 and Cs-137 are generated in approximately equal amount both mass
and activity, and they have a similar half-life. But during the
accident, the heat caused the Cs-isotopes to volatilize and they were
attached to aerosols and particles and distributed widely. Sr-90 is not
so easily volatilized, so most of it was deposited together with fuel
particles during the explosion in the vicinity of the damaged reactor or
left in the ruin with the debris.
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>I assume some C14 was generated in the moderator, and a great deal of
that
>made it into the atmosphere, but is that not a significant source of
>contamination?
You ask good questions. What you say is reasonable, and I don't know the
answer.
---------------------------------------------------------------------
There is extremely little C-14 generated in a nuclear reactor, mostly by
"strange" fission events and not by an n,gamma activation reaction,
because graphite consists of almost entirely C-12. Naturally occurring
C-14 is generated at high altitudes by a nuclear reaction involving
nitrogen and the neutrons of the cosmic rays. This also happened at low
altitude with the nuclear bombs as neutron sources. Tritium is generated
in considerable quantities only in heavy water reactors like the
Canadian CANDU by activation of deuterium with neutrons. There were no
elevated C-14 or T activity concentrations observed in precipitation in
Europe.
------------------------------------------------------------------------
--
I read the Wikipedia article, for which I have some comments - but I
will write them later. As a reliable source of numbers and facts I would
highly recommend IAEA sources.
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