Seem to recall Slow alarm 30 min 3E-9 uCi/cc Fast alarm ~30, 5 sec periods (150 sec) 3 DAC
Manual has those time periods and likely efficiency and the default is a factor of 10 between the fast and slow alarm. Up to the customer to set. You also need to keep an eye on the fast and slow MDC to know how much margin you have to your alarm set points. If the MDC, as driven by bkg, increases above the alarm set point the green operation light will extinguish and no alarm or error will occur. As an example, If you put your AMS-4 right up to the Rx cavity rail and increase bkg, you'll actually decrease it's sensitivity or time to respond. Try to minimize bkg and keep an eye on the margin between the MDCs and the alarm set points for best operation. If you're a PWR heavily laden in Co-58 you might try a diff nuclide with a less restrictive DAC or enter your own effective DAC calc into the AMS-4 Glen Vickers, CHP Exelon Corp RP Technical Lead 815-216-2723 (work/cell) From: Derek Hultquist [mailto:[email protected]] Sent: Wednesday, May 03, 2017 7:57 AM To: 'Lamons, John' Cc: [email protected] Subject: [EXTERNAL] [powernet] RE: Setting of Continuous Air Monitors At Cook we use 3E-9 uCi/cc with the AMS-4 Thanks, Derek Hultquist Health Physicist D. C. Cook NPP (269) 465-5901 x2088 From: Lamons, John [mailto:[email protected]] Sent: Wednesday, May 03, 2017 8:54 AM To: [email protected]<mailto:[email protected]> Subject: [EXTERNAL] [powernet] Setting of Continuous Air Monitors This is an EXTERNAL email. STOP. THINK before you CLICK links or OPEN attachments. ________________________________ I would like to benchmark what set point the industry uses for CAM units (ie AMS-4). We recently had a question from the NRC as to why we set our units at 10.59 Bq/ft^3 (1.01 e-8 uCi/cc) instead of the posting limit, .3 DAC (about 3e-9 uCi/cc). Thanks for the help. John Lamons Health Physicist Comanche Peak Nuclear Power Plant This Email message and any attachment may contain information that is proprietary, legally privileged, confidential and/or subject to copyright belonging to Exelon Corporation or its affiliates ("Exelon"). This Email is intended solely for the use of the person(s) to which it is addressed. If you are not an intended recipient, or the employee or agent responsible for delivery of this Email to the intended recipient(s), you are hereby notified that any dissemination, distribution or copying of this Email is strictly prohibited. If you have received this message in error, please immediately notify the sender and permanently delete this Email and any copies. Exelon policies expressly prohibit employees from making defamatory or offensive statements and infringing any copyright or any other legal right by Email communication. Exelon will not accept any liability in respect of such communications. -EXCIP
