Eric: In a previous life I had an individual with I-125 seeds that we were required to allow in the RCA. He alarmed Beta portal monitors, but not the gamma sensitive monitors. Using a standard NaI WBC, no peaks were detected in the noise.
Look at where he worked, for PCE risk. Check his clothes like he alarmed a monitor. Frisk him, and ensure no counts other than where the seeds are embedded. Document in the Corrective Actions program the condition, actions taken, and conclusions. Have your RPM approve the release, and let him go. From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, October 07, 2010 12:03 PM To: [email protected] Subject: Powernet: Anyone have experience with I-125 brachytherapy and monitor response? We have a welder coming for our outage who has been treated for prostate cancer with ~30 millicuries of I-125 brachytherapy seeds. I-125 emits very low energy gammas, predominately 28 keV. He should be down to about 15 millicuries right now and we wonder if the NaI detectors in the Whole Body Contamination Monitors will see those gammas or if the energy discrimination (for which we don't have any data) and will eliminate them. Does anyone have any useful experience with I-125 and detectability by WBCM's and portal monitors? We have to decide very quickly whether to let this guy fly here for work. Thanks, Eric Eric M. Goldin, CHP Southern California Edison <[email protected]>
