Davis-Besse responds: 1) Scenario: An employee is briefed to expect a dose a rates of between 75 -150 mR/hr in route to a work area. The RWP/Task dose rate alarm setpoint is 75 mR/hr and the employee is briefed to anticipate a dose rate alarm. The employee logs onto the wrong RWP Task and receives a dose rate alarm at 12 mR/hr because he is on the wrong task. The actual dose rates encountered were as briefed. Would you count this as an unanticipated dose rate alarm?
answer: This would be counted in the "RWP Violation" performance indicator not the "Dose Rate Alarm" bucket. Would not double dip. 2) Does your site have an acceptance band for variations in briefed dose rate alarms versus actual dose rates encountered and if so, what is the band? For example, if a worker is briefed to receive an anticipated a dose rate alarm of 100 mR/hr, is there a range above 100 that would be acceptable and then a point at which alarm would be called unanticipated? (e.g., if the band was +/- 25%, then 120 mR/hr would be an anticipated alarm but 130 mR/hr would be called an unanticipated alarm.) answer: Good question. We don't use the briefed alarm process frequently. This question has not been raised. For briefed dose rate alarms, there is not an instituted policy on this question other than criteria that stipulates unexpected radiological conditions found greater than 20%, RP personnel should consider stop work. Douglas L. Noble Manager - Radiation Protection Davis-Besse Nuclear Power Station (419) 321-7780 office (419) 304-0068 cell From: "Johnson, Graham T" <[email protected]> To: "[email protected]" <[email protected]> Date: 04/25/2013 07:23 AM Subject: Powernet: Unanticipated Dose Rate Alarm Metric (KPI) Sent by: [email protected] Duke Energy would appreciate answers to the following questions regarding counting dose rate alarms as anticipated or unanticipated in your site metrics. 1) Scenario: An employee is briefed to expect a dose a rates of between 75 -150 mR/hr in route to a work area. The RWP/Task dose rate alarm setpoint is 75 mR/hr and the employee is briefed to anticipate a dose rate alarm. The employee logs onto the wrong RWP Task and receives a dose rate alarm at 12 mR/hr because he is on the wrong task. The actual dose rates encountered were as briefed. Would you count this as an unanticipated dose rate alarm? 2) Does your site have an acceptance band for variations in briefed dose rate alarms versus actual dose rates encountered and if so, what is the band? For example, if a worker is briefed to receive an anticipated a dose rate alarm of 100 mR/hr, is there a range above 100 that would be acceptable and then a point at which alarm would be called unanticipated? (e.g., if the band was +/- 25%, then 120 mR/hr would be an anticipated alarm but 130 mR/hr would be called an unanticipated alarm.) Thanks, Graham Johnson, CHP Supervising Scientist General Office Radiation Protection Duke Energy ----------------------------------------- The information contained in this message is intended only for the personal and confidential use of the recipient(s) named above. If the reader of this message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify us immediately, and delete the original message.
