AW: [ RadSafe ] Determining Radon

[Franz Schönhofer]

O.k., now I understand that the original post should not have stated
"radon contamination", but "radon progeny contamination". To be really
on the safe side, probably "Rn-222 progeny" could have been mentioned,
because there are some industries, where thoron- (Rn-220) progeny plays
a role. 

What was missing in the original post as well is a description about the
remediation in question. What is it? A factory full with waste from
production of radium-paint for dials? Is a site which produced in the
beginning of last century radium for medical and other purposes? Is it
an underground mine or is the work done in open air, like a uranium mine
tailing or former open pit mining? This all will influence the
concentration of radon and additionally the equilibrium factor, which
differs quite a lot at above mentioned places. 

Next missing information, which would be really necessary to answer the
question for radon progeny contamination: What are the radionuclides
present which necessitate remediation? Is it plutonium and/or uranium
from the weapons industry, uranium from mining and processing or is it a
steel work which has been contaminated by melting down a Co-60 or Cs-137
source? These are totally different scenarios which might have totally
different solutions. If you deal with for instance dust from uranium
mill tailings you will also have to deal with long-lived radon progeny.


Next necessary information: What are the concentrations of the
radionuclides which could cause contamination and could be interfered by
radon progeny? 

How and what for is your PCM-2 calibrated? Thanks to Dallas Jenkins who
sent me information about this instrument. I had no time to read all of
the 121 pages of the paper, but it seemed to me that only counts per
minute were used both for alpha and beta and so far I did not find any
conversation to Bq/cm2 (or if you like pCi/square inch), which in my
opinion is the only valid criterium for contamination. What are your
release criteria for contamination? I can hardly believe it would be
cpm, because this makes no sense from the radiation protection
standpoint. You can use cpm of course after having calibrated your
instrument accordingly as a derived quantity. 

Next item: There exist portable gamma-spectrometric systems. The
portable germanium detectors might be a little to expensive and would of
course need a very well experienced (and expensive) person to operate.
Small hand-held, NaI(Tl) based ones have become available during the
last years. Check the advertising in Health Physics or other scientific
journals or try a Google search. You would have to check whether they
would be usable for your purpose and whether they can detect the amount
of radon-progeny you need to detect. But you would have to know the
latter one yourself, which seems not to be the case.

You should of course provide the personell with antistatic clothes and
underwear in order to inhibit the "plate out" of radon progeny on them.
"Antistatic" actually means "non synthetic", which by the way is
healthier anyway. Accumulation of progeny would not be possible and
wrong alarms due to progeny would be avoided. 

You may make or let make a survey of radon (yes, radon, not progeny) in
the working environment and assuming an equilibrium factor typical for
this environment to estimate what a maximum contamination of a worker
might be. You may take this value into account to use it as a criterium
whether your PCM-2 values excess a maximum contamination value.  

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> It appears Franz seems more interested in proclaiming the virtue of
his
> education rather than helping you with the problem. While "radiation
> professionals" like Franz may have their place in the industry, public
> relations would obviously NOT be one of them.

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In my opinion it appears to me, that when the persons asking a question
- whether on RADSAFE or in everyday life, they should specify their
questions as accurate as possible. In our small shops throughout Europe
everybody would laugh at you if you entered a bakery and said "I want a
bread" or you sit down in a café and order "coffee". You would have to
specify the bread you want or if you do not speak French, Italian,
Spanish, German, Czech etc. I assure you it helps to point to the item
of your desire. The same is true for radiation protection questions on
RADSAFE. The request contained practically no information which would
make it possible to give any advice. 

I have criticized before and will continue the attitude to buy some
instrument and then ask what to do with it. I'll also criticize that
there seems to be a trend to solve even the most complicated problems
like this one by applying the cheapest possible instrumentation. My
standard comparison: You cannot transport 50 ton blocks of granite with
a Volkswagen. 

I dare say that I have wide-spread experience in many fields of
radiation protection, but this is because of my continuing interest in
anything radioactive or nuclear. I am not proclaiming anything nor am I
proud, I am not working for the industry and I think I have helped a lot
of people with their questions, also on RADSAFE. I have not and am not
working for the industry and you are right, that I would not be good in
public relations for instance for a company, because I would never be
able to recommend an instrument for an application I would not be 100%
sure that it works. 


Have I helped now with the problem - probably not, because I put more
questions on the circumstances of the problem, without which knowledge
no help is possible. I spent more than an hour to write this. I think
that these questions should be answered by the companies which sell the
instruments. Did you ever ask them?


Franz