Re: Alpha Sampling

[WERNER.K.PAULHARDT@bge.com]

     Robert,
     
     There are at least two publications dealing with Activity Levels of 
     TRU in waste streams from US Power Reactors.
     
     1. EPRI NP-1052, April 1979
     2. EPRI NP-4037, June 1985
     
     Most recently was an NRC Inspection Report - Haddam Neck 96-12.  You 
     can obtain this report from : 
     http://www.nrc.gov/OPA/reports/hn9612.htm.
     
     I'd also be interested in further discussion of this topic from all of 
     you Radsafers out there.
     
     After reading Haddam Neck, you may want to try an convince you staff 
     that hanging your hat totally on your air sampling program is not a 
     very safe risk.  Too many variables. 
     
     My recommendation is:
     
     Take some comprehensive surveys, air samples and smear samples, of 
     various areas throughout your plant.  Each sampling path should be 
     representative of the sources/potential sources of intake (e.g., I 
     don't think you would necessarily see the same nuclides in the 
     Auxiliary Building as you would in the Fuel Pool etc. may not even see 
     TRU in some aux bldg areas.)  Send the samples off to a lab for 
     composite analysis.  From the analysis, develop correlation factors 
     and correlate TRU off of Ce144 or Co60 or any of the others mentioned 
     in the EPRI report, that are present in your samples. Another method 
     would be to correlate Pu239/240 from Ce144 and correlate the rest of 
     the TRU from the calculated Pu239/240.  If you have, say LLD levels of 
     Ce144, use Co60 to correlate Ce144 and then use Ce144 to correlate the 
     rest of the TRU. At some point, fecal samples come into play also.  
     Haddam Neck saw small amounts of Co60 during in-vivo bioassay however 
     they calculated some sizeable bone doses from the TRU (don't know if 
     this issue has been resolved yet).  Read the report.  
     
     We have an alpha air sample program and we are currently evaluating 
     the TRU issue ourselves so any communication on the subject would be 
     appreciated.
     
     Thanks,
     
     Werner Paulhardt
     Supervisor-Dosimetry
     Calvert Cliff Nuclear Power Plant
     Lusby, MD.  20657
     (410) 495-4773
     werner.k.paulhardt@bge.com
     
     The above comments are my own and do not necessarily reflect the 
     opinion/policy/programs of BGE.
     


______________________________ Reply Separator _________________________________
Subject: Alpha Sampling
Author:  radsafe@romulus.ehs.uiuc.edu at Internet
Date:    4/30/97 10:07 PM


I am examining the methodology used for determining the alpha sampling 
requirements for airborne and surface contamination at the nuclear power 
plant where I work.  We have very low alpha contamination levels as 
determined by 10CFR61 waste stream analyses, and from a practical 
standpoint, very large air samples or very long count times are needed 
to achieve the minimum detection capability for alpha.
     
Some of the possibilities for practical solutions that our staff have 
suggested include using a beta/gamma to alpha ratio or a single nuclide 
(such as Cerium-141) to alpha ratio to estimate alpha activity, or to 
determine a beta/gamma or Ce-141 level above which, alpha counting 
should be performed.
     
If you know of work that has been done in this area, I would appreciate 
knowing about it, or of contacts on this subject.
     
If posting on radsafe is not desired, please email information to me at 
rmleib@centerior.com
     
Thank you.
     
Robert M. Leib