Re: Skin Dose from Multiple Plane Sources

[sandy_perle@email.fpl.com]

     To answer your question one has to make some assumptions, since you 
     haven't been specific enough.
     
     ~~The three assumptions below assume same location of the dose~~ 
     received
     
     Assumption 1:
     ------------
     
     If the organ received the exposure from two different sources for the 
     same time period, and to the same location, then the dose is the total 
     dose received at that location, which IS the highest dose as defined 
     in 10 CFR 20. This is your item a)
     
     Assumption 2:
     
     If the same organ (same area) is receiving dose from two plane 
     sources, but for different time periods, you have to make another 
     interpretation. For time period 1, where only source A is exposing the 
     organ, there is dose A. For time period 2, where source A is exposing 
     the organ, there is dose B. The total dose for this would then be the 
     components of Dose A + Dose B.
     
     Assumption 3:
     
     If assumption 2 is modified where Source A is continually exposing the 
     same location, and then source B is added later on, the dose is still 
     all of dose A and the component of Dose B.
     
     
     If the assumption is that the areas measured are ~~ different 
     locations on the same organ~~ then the assumptions change.
     
     Assumption 1:
     
     Conclusion for this is the total dose must be measured for each 
     location of exposure received, and then the highest dose is then 
     reported for the organ. It is NOT the sum of the separate or 
     continuous dose received at each location. This again is based on part 
     20, reporting the HIGHEST dose.
     
     I'll be interested in the other response received to this question.
     
     
     Sandy Perle
     Supervisor Health Physics
     Florida Power and Light Company
     Nuclear Division
     
     (407) 694-4219 Office
     (407) 694-3706 Fax
     
     sandy_perle@email.fpl.com
     
     HomePage: http://www.lookup.com/homepages/54398/home.html


______________________________ Reply Separator _________________________________
Subject: Skin Dose from Multiple Plane Sources
Author:  radsafe@romulus.ehs.uiuc.edu at Internet-Mail
Date:    1/30/96 9:40 AM


     I am looking for a broad cross section of opinions on the following 
     subject. I have received a couple of different opinions and I also 
     have my own.  I am hoping that if enough opinions are expressed that 
     we should statistically gravitate toward the true answer (interesting 
     concept, huh?).
     
     If a person has multiple plane sources on the same organ (i.e. 
     SDE,WB), how should the dose be reported?
     
     a. Add the cumulative dose from both plane sources since they are both 
     supplying dose to the same organ (skin)
     
     b. Take the highest dose calculated of the two and use it to represent 
     the entire contamination event.
     
     c. Calculate the dose to 1 cm^2 of skin from the highest detector 
     reading (i.e. 15.5 cm^2 GM) and use it to represent the entire 
     contamination event.
     
     
     
     Please feel free to refer to existing reference documents, none of 
     which I have yet to find.  This is a serious enquiry and I would be 
     more than happy to keep statistics and references based upon responses 
     and later repost the results.  I have my own opinion, but I wouldn't 
     want to bias any of the responses.
     
     
     Glen Vickers
     HP, Nuclear Power Generation
     815-458-2801 ext. 2792
     BRZGV@ccmail.ceco.com