Re: Be-7 detections in ambient air samples

["Tom Johnson" <tjohnson@radtrain.com>]

Dear Bill,
We had the same problem on HEPA filters at a power plant I worked at.

You can back calculate and demonstrate that all the Be-7 comes from the
atmosphere if you know the airflow and time of operation, AND use the
"normal" concentration of atmospheric Be-7 given by The Radiological Health
Handbook by Bernie Shleien, Revised Edition (Black and yellow one) page 286.
The table gives the specific activity in air as 0.01 Bq/kg air.

I can't remember if the calculations worked out, but I did not hear about
the problem again, so....

Let me know if this helps. Give me a call if you need specifics.
Tom Johnson
tjohnson@radtrain.com
1-800-871-7930

>The only natural source we've been able to fing would be from upper
atmosphere interactions with N and O.  >Does anyone have any information
regarding the presence of Be-7 in ambient air samples, such as possible
>sources, "normal concentrations", etc.?


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