Brad,
Browns Ferry uses whole numbers. After our upgrade of HIS-20 we now have the option of recording either method to the database. We have tried the dosimeters reading tenths of a millirem at BFN in the past but it was determined it was hard to read the decimal and was very short lived. The next generation of dosimeters has a larger display and that may help with that concern, but I have not tested it yet The question I have on switching is how did that effect your ALARA estimates and TLD/DRD discrepancy There is no way to really know if you are gaining or losing dose by rounding dose to a whole number. I would like to see your summary of the plants that are using both methods. Did it make a difference between PWRs and BWRs? With the lower doses received I can see more PWRs going that way Chuck Creamer Charles E. Creamer Health Physicist Tennessee Valley Authority Browns Ferry Nuclear Plant P.O. Box 2000 (Mail Stop NAB-1G-BFN) Decatur, Al. 35609-2000 Phone: 256-729-2983 Fax: 256-729-3101 Pager: 1-800-323-4853, pin 30-053 mailto:[email protected] <mailto:[email protected]> From: [email protected] [mailto:[email protected]] On Behalf Of Bradley A Krupp Sent: Monday, August 06, 2012 7:19 AM To: [email protected] Subject: Powernet: ED display in tenths follow up questions Based upon industry benchmarking Fermi changed the display on our DMC2000 EDs to show tenths of a millirem rather than whole numbers. Out of 27 sites that responded (representing 45 units), 22 of them (representing 37 units) were displaying dose in tenths of a millirem. If anyone is interested in a summary I can send it to them. There have been some concerns voiced and documented in our corrective action process with the wisdom in doing this resulting in my additional questions below. When you implemented displaying tenths of a milirem how did you handle concerns such as: 1. Use of them in High Radiation or Locked High Radiation areas where it may be hard to see the decimal point on the display. 2. Use of them during outages where lighting is limited and your ED is in a bag inside your pocket making it hard to read. 3. What are the advantages of using tenths on the display? 4. Use of tenths isn't ALARA because its hard to read and takes more time to determine what your dose is potentially causing you to receive additional dose. Sorry for the long list. Thanks in advance for your assistance and have a great day! Brad Krupp
