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Results of Airborne/Dust Concentration
- To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
- Subject: Results of Airborne/Dust Concentration
- From: "Mark B. Mattheiss 303-299-7911" <DENMBM@AM.DAMES.COM>
- Date: Wed, 20 Mar 1996 06:47:22 -0700 (PDT)
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Many thanks to all who responded with information. This is a complicated issue
and many hours of research have been dedicated to the derivation of thumbrules
and assumptions. The real example and proposed solution I came up with are as
follows:
Given a pile of gypsum (calcium sulfate) with known concentrations of
Ra-226/228 (sample analysis) of 25 pci/g, if the air is monitored with a PDM-3
MiniRam for particulate matter, the nuisance dust level for gypsum as per the
ACGIH TLV Book is 10 mg/m3. A conservative estimate based on studies
(performed by Dames & More Risk Assessment Group)at the INEL facilities
indicate a maximum concentration of radionuclides caused by intrusive
activities would be 30%. If 30% of the 10 mg/m3 was due to Ra-226 alone, the
activity of the air is 7.5E-10 uci/ml. As per 10CFR20 App B the DAC for Ra-226
is 3E-10 uci/ml. Therefore if real time monitoring is performed and nuisance
dust is maintained below 10 mg/m3 (via wetting of the soil) the DAC for Ra-226
will never be reached.