Lew, Gert:
NCRP Report 78 (section 6.3) provides an example of an "typical environmental daughter activity ratio" of Rn-222/RaA/RaB/RaC equal to 1/0.9/0.7/0.7. If you converted to an equilibrium fraction, this would be MUCH higher than 0.4. In cases where measurements were not available, I've used this NCRP value as a starting point.
Good luck,
Duane.
Duane Schmidt, CHP
U.S. Nuclear Regulatory Commission
NMSS/DWM/DCB
dws2@nrc.gov
>>> "Jonkers, Gert G SIC-ASA" <Gert.G.Jonkers@opc.shell.com> 2/7/2000 10:42:38 AM >>>
Lew,
If I do remember well generally an equilibrium factor of 0.4 is used (ICRP
65 & UNSCEAR 1988). However, I am not quite sure, if that's the outdoor
equilibrium factor.
Kind Regards, Gert Jonkers
ASA - Amsterdam Services Analytical 'Special Projects'
Shell Research and Technology Centre, Amsterdam (SRTCA),
http://www.srtca.shell.nl/welcome.html
PO Box 38000, NL-1030 BN Amsterdam, the Netherlands
tel. +31 - 20 - 630 3424
fax +31 - 20 - 630 2911
e-mail Gert.G.Jonkers@OPC.Shell.COM
> ----------
> From: Cook, Lew (LCOO)[SMTP:LCOO@chevron.com]
> Reply To: radsafe@romulus.ehs.uiuc.edu
> Sent: 2000-02-07 16:28
> To: Multiple recipients of list
> Subject: Radon equilibrium fraction in outdoor air
>
> What is a good consensus number for Radon equilibrium (short half lived
> decay products only) in outdoor air?
>
> Lew
> 510 242-7040
> lcoo@chevron.com
!
!
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