I wouldn't use a hard value alone. I would use the value in the vendor documentation as they would best know the limitations of their detectors and peak search algorithms.
I would get the gamma spec of the work area air sample or smear to verify before I wrote off a peak, regardless of error. Three of the last 4 events I've responded to, I found the WBC improperly identified radionuclides. It's not that the library was bad, but that the mix for the event was different than anticipated by the library. The plant mix had greater amounts of nuclides such that some of their lower abundance peaks were causing false ID of other radionuclides in the library. I used the gamma isotopic to tune the library so the WBC results were clean. It should be a rare event that you throw something out on %error if the peak sensitivity is set correctly where it's identifying peaks above bkg. Often times those peaks are lower abundance peaks of other radionuclides in the spectrum, but lower in activity so the peaks aren't well formed. Glen Vickers Exelon Corp RP Technical Lead, CHP 815-216-2723 (work/cell) From: [email protected] [mailto:[email protected]] On Behalf Of Richard W Adams (Generation - 3) Sent: Thursday, October 24, 2013 1:38 PM To: [email protected] Cc: Bob Simmons (Generation - 3) Subject: Powernet: Whole Body Count - MCA - Gamma Spec Peak Error Consideration North Anna Power Station is reviewing their current practice of evaluating and accepting the identification of peaks in the various MCA's used at the site. This includes whole body counters (WBC) and count room MCAs. We would appreciate information about your standards and bases for accepting or rejecting peaks that have a high relative error noted in the print outs from your software and how you came to and justify that particular standard. Thanks in advance for responding directly to Rick Adams at [email protected]. Upon request, I will make the final results available to anyone that requests and supplies information by November 21, 2013. An example is included below along with space that I'd appreciate you using so I can cut and paste the results. If you do not want your plant named in what I share please say so. Again thanks for your consideration. Station WBC Software % Error to throw out value Other factors considered Basis Document Source Example Plant Genie-2000 60 When results are greater than 40%, then the results are provided to the Exposure Control Supervisor for evaluation. 60% is a hard standard that can be applied with no other input. Site specific documentation referencing NUREG-XXXX and INPO Guideline 2020-14 Station WBC Software % Error to throw out value Other factors considered Basis Document Source Answer this if similar considerations for other systems MCA Software % Error to throw out value Other factors considered Rick Adams, CHP North Anna Power Station 1022 Haley Drive Mineral Virginia 23117 Phone: 540-894-2869 Fax: 540-894-2408 CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and/or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you. This e-mail and any attachments are confidential, may contain legal, professional or other privileged information, and are intended solely for the addressee. If you are not the intended recipient, do not use the information in this e-mail in any way, delete this e-mail and notify the sender. -EXCIP
