Exelon does for both. Our process has you either determine the instrument efficiency with a source that simulates self-absorption (such a Mylar covered standards or a simulated filter paper) or if an electro-deposited standard is used, factor in a 30% sample attenuation by multiplying the measured (electro-deposited) efficiency by 0.7.
This is in part based on an article by Robert McFarland titled "Determination of Alpha-Particle Counting Efficiency for Wipe-Test Samples", Radioactivity & Radiochemistry Vol. 9, No. 1, 1998. I prefer the having the self-absorption included in the efficiency as it is less numbers for RPTs to remember and/or plug in to a calculator. Jeffrey J. Cady, CHP, RRPT Mgr RP Technical Support Exelon Nuclear Dresden Station 6500 North Dresden Road Morris, IL 60450-9765 Phone: (815) 416-2719 [email protected] <mailto:[email protected]> ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Rouse, Raymond Lawrence Sent: Monday, January 23, 2012 9:56 AM To: [email protected] Subject: Powernet: Attenuation factors for alpha Does your facility use an attenuation factor for alpha contamination. Do you use this for air samples, smears or both? If so what factor do you use? What basis from which the factor came from? Raymond Rouse Radiation Protection ALARA Superintendent Watts Bar Nuclear Plant PO Box 2000 Spring City, Tn 37381 (423)-365-1881 [email protected] <mailto:[email protected]> ----------------------------------------- ************************************************** This e-mail and any of its attachments may contain Exelon Corporation proprietary information, which is privileged, confidential, or subject to copyright belonging to the Exelon Corporation family of Companies. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank You. **************************************************
