Eric, V. C. Summer had a contractor last outage (November - December, 2009) that came in with implanted I-125 seeds to treat his prostate cancer. They had been implanted the previous May (2009). The WBC NaI detectors did not see the 28 or the 35.5 keV photons from the I-125 (although a small increase in the low energy portion of the background can be seen if one looks hard for it). We wrote an OE to document the incident - OE30151 on 12/8/09. This describes our experience with the I-125. The bottom line was that although we did not see anything during the WBC, once the worker got in the RCA and started working, he could not exit cleanly because our exit monitor (RADOS RTM 860 TS) and friskers could easily detect the I-125 low-energy photons. This is explained in more detail in the OE. If you have any questions, give me a call and I can take you through our experience.
Greg Gowdy, PhD, CHP Sr. Staff Health Physicist V. C. Summer Nuclear Station Jenkinsville, SC 29065 (803)-345-4426 (work) (803)-873-1561 (cell) [cid:[email protected]] 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]>
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