Re: Tritium in concrete

["Franz Schoenhofer" <franz.schoenhofer@chello.at>]

-----Ursprüngliche Nachricht-----
Von: DWhitfil@kdhe.state.ks.us <DWhitfil@kdhe.state.ks.us>
An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Datum: Dienstag, 10. Oktober 2000 18:39
Betreff: Re: Tritium in concrete


>
>Addenum (*from* bug)
>
>*From* Sources of Tritium and its Behavior upon Release to the Environment,
>by D.G. Jacobs (1968):


This is a quite old literature citation, like the one from 1979. How old it
ever might be - I do not see any connection to the original inquiry. Tritium
is not usually, but always,
converted to HTO, It mixes rapidly with H20 and therefore it is spread
rapidly. Especially rapidly was the HTO dispersed, when it resulted from
tritium released from detonation of nuclear bombs, was carried to high
altitudes and dispersed over very large areas or rather over the whole
hemisphere, in which the weapons were detonated. Therefore the concentration
of tritium in the atmosphere, in precipitation, in drinking water, in
vegetation etc. rose characteristically according to the amount and yield of
nuclear weapons exploded in the atmosphere - much more in the Northern
Hemisphere, because of much higher yield of bombs, than in the Southern
Hemisphere. The same is true for the C-14 concentration in the environment,
though behaviour is somewhat different. "Calibration curves" are available
in the literature both for tritium and C-14 in the atmosphere and in many
other matrices. They show a characteristic maximum during the years 1963 and
1964 after the moratorium came into force, declining afterwards according to
half life, but mostly dependend on mechanisms like removal to different
sinks. Anybody interested in the calibration of C-14 and tritium in Austrian
wine (an almost perfect bioindicator) may contact me strictly privately for
the work I have done some years ago.

Let me return to the concrete: Water readily available in the late fifties
and early
sixties showed of course much higher tritium concentrations than before and
nowadays. Water used to make concrete is mostly incorporated into the matrix
as crystal water and therefore it will be bound very tightly and is not
available for exchange with environmental H2O. Crystal water can be released
by heating and condensed, so it can be analysed. (I am not a concrete
expert, but a radiochemist.)
I am sure that this could be even used to determine the year (with some
uncertainty), when the concrete was poured.

Actually I am very sure, because we had about two years ago a criminal case
in Austria, when a maniac put out bombs, which killed in one case four
people. The bomb was attached to a device which contained concrete. When a
suspect was arrasted, it was found, that the water of his drinking water
well contained elevated tritium concentrations because the water was
obviously not replenished very fast from precipitation. The water liberated
from concrete used with the bomb showed the same tritium concentration.

Hope, this answers the original question.

Franz



>
>Tritium released in the environment is usually converted to the oxide form
>quite rapidly and is dispersed like ordinary water.
>
>DJWhitfill
>
>Opinions expressed are mine and do not reflect official policies or
>positions of the Kansas Department of Health and Environment.
>
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