Re: Elevated Gross Beta Readings

[Franz Schoenhofer <schoenho@via.at>]

At 08:09 23.03.2000 -0600, you wrote:
>Franz, shame on you for your personal attacks on Noel! 

Sorry, I am stubborn and I am not ashamed at all. Just at the contrary I
still adhere to my heretic thoughts. Hopefully I will not be burnt at the
stake like other heretics several centuries ago! 

Although maybe not
>attributable to Tokaimura 

I have not questioned the fact that elevated gross-beta measurements might
have been recorded, I exactly protested against the link of these
measurements to Tokaimura - and hardly anybody could deny, that such a link
cannot exist. So why should I be ashamed?


Gross beta or gross alpha or gross beta/alpha measurements could only be
used as an indicator - of not only limited, but of no use for
interpretation. Any increase has to be checked by further investigations
using gamma-spectrometry and if necessary radiochemical analysis for beta-
and alpha-emitting radionuclides. 

That the gross beta measurement of aerosols is subject to fluctuations is
nothing new - this occurs even in times when no accident occurs in
Tokaimura and - forgive me - in Thailand. It is subject to diurnal
variations and even more seasonal variations. Variations of an order of
magnitude or even more within a few days are absolute normal. The cause is
always variations of natural radionuclide concentrations like that of radon
daughter products during inversion layers, winds blowing etc. You can only
get a mean value, when you have deviations from that. 

I am very proud that I have been able to stop in the early eighties the use
of gross beta measurements of aerosols in Austria, replacing it with
routineously sampled aerosols with high volume samplers and high
resolutions gamma-spectrometry. I did not see any use in maintaining two
different systems of measurement. This might be of course a different
situation, when there is the question of nuclear power plant surveillance.
Nevertheless in NPP's there should be done a nuclides specific measurement
even in these cases in order to be able to demonstrate the natural origin
of the increased gross-beta value. 

I cannot imagine, what difficulties we would have had in Austria, if
aerosol contamination would have been evaluated by gross-beta-measurements
during the time of the Chernobyl accident. There is a clear difference
between the impact referring to doses of for instance I-131 and Cs-137
regarding wide spread contamination and future contamination of food
originating from early fallout.

Best regards,

Franz


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


Office:
Hofrat Dr. Franz Schoenhofer
Bundeskanzleramt (Federal Chancellery), VI/8
Radetzkystr. 2
A-1031 Vienna
AUSTRIA

phone: -43-1-71172-4458
fax: -43-1-7122331

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