option2b–vogtle.pptVIP

Option 2b Template Example Phillip Grissom – Southern Nuclear Based on Vogtle (more or less) 2012-10-19 Plant Information Westinghouse 4-Loop PWR 99.97% Nukon insulation ~ 20 ft3 of Interam fire barrier in ZOI 120 lbs Latent Debris (2x sampled amount) GEH Stacked Disk Strainers 765 ft2 per each of 2 RHR trains , separate CS strainers (2) TSP Buffer GSI-191 Status Strainer Head Loss and In-vessel issues remain open Assuming Original 2007 Bypass Test (193 FA) 111 gm/FA, very conservative but not rev’d by NRC Previous chemical effects testing provided very promising results, but not accepted by NRC Completed Laser scan of entire containment for insulation replacement contingency –both Units Dose = 1083 mrem for 1 unit GSI-191 Closure Decision Essentially 100% Nukon high fiber plant Replace all insulation with RMI implement extensive stringent containment cleanliness program – Option 1 Replace most insulation with RMI, follow PWROG program, additional modification for debris bypass filter, and testing for reduced chemical effects, transport, head loss and bypass – Option 2a or 3 Full Risk Informed (Vogtle and STP are very similar for this issue) - Option 2b GSI-191 Closure Decision – Option 2b Believe we could solve deterministically for Vogtle, but NRC approval and test results have some uncertainty Fully risk informed solution, with ample testing and analysis to get best estimate results is very promising and provides insurance for very low probability event Anticipate re-performing plant specific transport, head loss, bypass and fuel testing for DBE conditions as well as lesser events Planning for modification to add debris bypass filter Key Testing Anticipated Chemical Effects for multiple break sizes and range of important parameters Debris bypass filter – proof of concept testing Strainer bypass – multiple scenarios Strainer head loss – multiple scenarios Debris transport, head loss, strainer bypass at DBE conditions PWROG testing for BAP with fiber, Fuel F