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Re: Webster EDE calculation

> Can you give a reference for the Webster formula and briefly describe
> how it was derived? Why do you use it rather than some other formula?

Doug gave one of the references. Another one is in Health Physics 
Correspondence: 0017-0978/94, page 88.  I don't have the whole 
journal, so I am not sure which month is was actually published.

I can also recommend a document published by EPRI, including 
many presentations of various EDE methods (sponsored 
particularly by the NRC), EPRI's New Approach to Determining 
Effective Dose Equivalents, August 13, 1997.

I agree with Ken that the collar weighting factor of 0.04 appears to 
be too small. Logically, one would expect a higher factor for the 
collar considering that when a single dosimeter is worn on the 
collar, a weighting factor of 0.3 is used. If one determines that 
when wearing two dosimeters, generally the dosimeter under the 
Pb apron showns no deep dose. If that is true, the collar dose * 
0.04 is the EDE. Therefore, if there is determined to be no deep 
dose under the apron, and the lab decides to only wear the single 
collar dosimeter, the factor increases from 0.04 to 0.3. I believe 
that the collar weighting factor should be consistent, 0.3 whether a 
single dosimeter is worn and when two dosimeters are worn. If the 
chest badge is assumed to show no dose ... why should the collar 
be different depending on the number of dosimeters worn? I believe 
the previous to be true AFTER a study has been performed wearing 
the two dosimeters.

-----------------------
Sandy Perle
Technical Director
ICN Dosimetry Division
ICN Plaza
3300 Hyland Avenue
Costa Mesa, CA 92626
(800) 548-5100 x2306
(714) 668-3149 Fax

sperle@icnpharm.com or sandyfl@earthlink.net

ICN Dosimetry Website:
http://www.dosimetry.com


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