Increased NRC dose limits for hot particles - unproductive doses

["Monty Charles" <charlemw@novell1.bham.ac.uk>]

The NRC appears to have taken a decision to increase the dose limit 
for skin exposure to hot particles (DRPs)- information circulated by 
Mike Russell on powernet, 12 January 1999.  One of the arguments for 
doing this is that the current restrictions lead to increased whole 
body doses.  The stochastic risk of these whole body doses are 
considered to be unacceptable in view of the supposed low level of 
detriment from a deterministic lesion of the skin.  This seems to be 
a valid argument but of course it is difficult to compare 
stochastic risks with deterministic effects (apples and oranges).  I 
have not seen any quantitative arguments to support this view.    The 
only related quantitative information is that some EPRI information 
can be interpreted as implying that  current DRP limits give rise to 
unproductive collective doses of 3-5 person rems per outage per 
site (information to the NRC Commissioners from William D Travers, 23 
October 1998, SECY-98-245).  

Does anyone have any information which can substantiate values of 
unproductive dose.  It is also necessary to know individual 
doses for those workers most exposed to potential high DRP doses- so 
how many workers are likely to share the 3-5 person rems which are 
incurred unproductively.

Thanks for your time

Monty Charles
Dr Monty Charles
Reader in Radiation Physics
School of Physics & Astronomy
University of Birmingham
Edgbaston
Birmingham B15 2TT
United Kingdom
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