STP response: We perform a daily check with at least 10 TLDs irradiated to Cs-137 with approximately 300-500 mrem of dose prior to reading the TLDs to check the TLD reader response for the photon counter. In addition, the tray has run controls in the 1st, 26th, and 49th position in the tray and a back ground controls (less then 10 mrem) in the 2nd, 27th, and 50th position with the remaining slots for personnel TLDs to ensure that the TLD reader is still responding correctly while reading personnel TLDs. We participate in an inter-comparison test (Battelle or NVLAP) on an annual basis and have QC tests performed each quarter which we irradiate the TLDs ourselves to various ranges of gamma, beta, and neutron mixtures. Since we are on a semi annual TLD change out period we also run a set of blind controls at least once during each processing cycle. All of these tests are in addition to the TLD reader calibration which is verified or calibrated annually.
Laura Stoicescu South Texas Project [email protected]<mailto:[email protected]> 361-972-4095 ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Courtenay, Christopher C Sent: Wednesday, October 27, 2010 11:46 AM To: [email protected] Subject: Powernet: Dosimetry Processing Practices For those who process TLDs: Do you perform a daily/weekly/monthly QC check on the TLD readers by irradiating TLDs to various levels (i.e. 3 sets of 5 TLDs to 10, 100, and 1000 mrem or some other combination) and ensure TLD group statistics are within acceptable limits? This would be in addition to any TLD reader calibrations and calibration checks/verifications. Chris Courtenay Engineer, Duke Energy 980-875-5005 "To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be."
