Need conversion from mrad/h to dpm/100 cm^2; beta and alpha DACs

["Strom, Daniel J" <daniel.j.strom@pnl.gov>]

Power reactor folks,

I have a couple of questions on power reactor outage operations.

1.  NRC Info notice 97-36, June 20, 1997 describes an incident in the fuel
transfer canal at Haddam Neck.  Removable beta-gamma contamination is given as
"80 mrad/hr."  I need an estimate of the conversion from mrad/hr to dpm/100
cm^2, and the variability in or range of this estimate (i.e., "1 mrad/hr is
within a factor of 2 of 5E6 dpm/100 cm^2 95% of the time."  I'd also like to
learn about what affect this conversion, e.g., age of fission products, whether
it's fission or activation, etc.

2.  In the same notice, the airborne radioactivity levels were quoted as "0.8
DAC beta and 24 DAC alpha."  What would these DACs be?  Probably a
plant-specific value for the kind of stuff they usually find, but I'd like to
know the isotope mix, the assumptions (D, W, Y mix, particle size), etc., that
are used for this kind of DAC.  How do you calculate results in DACs?  X dpm
beta-gamma per m^3 is Y DAC, and Z dpm alpha per m^3 is W DAC?

Thanks in advance for your help.

- Dan Strom

The opinions expressed above are my own, and have not been reviewed or approved
by Battelle, the Pacific Northwest National Laboratory, or the U.S. Department
of Energy.

Daniel J. Strom, Ph.D., CHP
Risk Analysis and Health Protection, K3-56, Pacific Northwest National
Laboratory
Battelle Boulevard, P.O. Box 999, Richland, WA 99352-0999 USA
(509) 375-2626 fax: (509) 375-2019 daniel.j.strom@pnl.gov


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