Chris, At Palo Verde, the volume of dose rate alarms attributed to "dropped" SOR/R electronic dosimeters would fall into the "Occasional (>20% and <40%)" bucket, and for all unexpected dose rate alarms we perform an exposure evaluation which includes a review of the dosimeter's histogram; however, if the alarm occurs outside of the RCA, for example dropped while logging into or out of the access control system we typically do not do as detailed an investigation such as looking at the histograms. Since these circumstances make up the bulk of the alarms we recently placed thick rubber mats at the access control terminals to reduce the frequency of these alarms.
Seth. ********************************************************************** Seth J. Kanter, CHP, RPT Sr. Health Physicist Palo Verde Nuclear Generating Station Mail Sta. 7397 5801 S. Wintersburg Rd. Tonopah, AZ 85354 Phone (623) 393-3130 Fax (623) 393-2487 Unless otherwise noted, all opinions are my own Liviu Librescu ********************************************************************** From: [email protected] [mailto:[email protected]] On Behalf Of Whitener, Christopher A Sent: Saturday, September 11, 2010 8:20 AM To: [email protected] Subject: Powernet: Dropped EDs causing Dose Rate Alarms Please categorize the volume of dose rate alarms attributed to "dropped" EDs: (1) Infrequent (< 20%) (2) Occasional (>20% and <40%) (3) Frequent (>40%) Also, do you review each histogram for unexpected dose rate alarms? Thanks for your response. Email Firewall made the following annotations --------------------------------------------------------------------- --- NOTICE --- This message is for the designated recipient only and may contain confidential, privileged or proprietary information. If you have received it in error, please notify the sender immediately and delete the original and any copy or printout. Unintended recipients are prohibited from making any other use of this e-mail. Although we have taken reasonable precautions to ensure no viruses are present in this e-mail, we accept no liability for any loss or damage arising from the use of this e-mail or attachments, or for any delay or errors or omissions in the contents which result from e-mail transmission. ---------------------------------------------------------------------
