See the St. Lucie response below ...
1. A flow chart is used to drive the method to perform neutron monitoring of personnel. The process evaluates whether the work involves containment entry, ISFSI, a neutron source, or in areas outside the containment (such as by the escape hatch), etc.. For the most part, neutron to gamma ratios (vs. gamma to neutron) are used, that are based on historical surveys by location, component ID, standardized survey points, and evaluation of historical estimated to DLR dose. Once determined, a neutron correction factor (NCF) is entered into Sentinel (the RP computer system software), which automatically calculates the estimated neutron by multiplying the NCF by the SRD gamma value. We have found this to be very accurate at determining neutron dose. However, it does get a little tricky when going to multiple areas of containment (due to the varying neutron to gamma ratios), but we have NCFs to apply in those situations also. If the survey during the work activity indicates a neutron to gamma ratio different than the NCF in Sentinel, we have supervision evaluate whether to use the Sentinel NCF or manually override the NCF using the survey ratio. 2. The criteria above is specific for the work performed and area to be entered. 3. No 4. Yes ... guidance for moderated and unmoderated sources 5. Monthly in accessible areas outside of containment (including the ISFSI pad), and upon entry (or use) in containment or with source use. Good luck! [cid:image001.png@01CBE7DD.5772A170] Brent L. Robinson TECHNICAL RP SUPERINTENDENT Florida Power & Light St. Lucie Plant 6501 S. Ocean Drive Jensen Beach, Florida 34957 (772) 467-7308 brent.robin...@fpl.com<mailto:brent_robin...@fpl.com> From: Powernet [mailto:powernet-boun...@hpspowernet.org] On Behalf Of Beth Heyeck via Powernet Sent: Monday, April 16, 2018 3:33 PM To: powernet@HPSpowernet.org Cc: Beth Heyeck Subject: [Powernet] Neutron dose tracking CAUTION - EXTERNAL EMAIL We are looking at streamlining our neutron dose tracking and are wondering how other plants are performing it. 1. Which do you use for determining neutron dose for workers in Neutron Exposure Areas: a. Stay time tracking b. Gamma to neutron ratios c. Neutron sensitive SRDs d. Other 2. Do you have specific criteria for using any of the above? 3. Are there any exemptions to tracking neutron doses in Neutron Exposure Areas, and how are those documented? 4. Do you track neutron dose outside of Neutron Exposure Areas/when handling neutron sources? 5. How often do you perform neutron surveys of Neutron Exposure Areas? Elizabeth Heyeck, CHP Senior Health Physicist D.C. Cook Nuclear Plant 269-466-2545 eahey...@aep.com<mailto:eahey...@aep.com>
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