ML16307A490

10/25/2016 Presentation Slides from Public Meeting Calvert Cliffs GSI-191 Resolution Update

ML16307A490
Person / Time
Site:	Calvert Cliffs
Issue date:	10/25/2016
From:	Kimberly Green Exelon Nuclear Generation Corp
To:	Guzman R V Plant Licensing Branch 1
Guzman R V
References
CAC MF8521, CAC MF8522
Download: ML16307A490 (14)

Text

Calvert Cliffs GSI-191 ProgramThermal Hydraulic Analysis of Containment Response and Acceptable Head Loss Test SelectionOctober 25, 2016 AgendaIntroductions Objectives for MeetingThermal Hydraulic Analysis of ContainmentDemonstrate that one CS pump will be secured prior to the onset of chemical precipitationContainment pressure reduces to 2.8 psig prior to containment pool reducing to 140°FAcceptable Strainer Head Loss TestIdentify chemical effects head loss test applicable simplified risk-informed approachStaff Questions & ConcernsSchedule for Future Periodic Meetings Calvert Cliffs Option 2b Refined Closure Plan1 CCNPP AttendeesJake Smith Director Site EngineeringJohn Haydin M&CU Engineering ManagerAndre Drake Lead Responsible Engineer GSI-191Craig Sellers Project Manager GSI-191Eric Federline Project SupportCalvert Cliffs Option 2b Refined Closure Plan2 Thermal Hydraulic Analysis of ContainmentInvestigate Sump Temperature and Containment PressureLarge Break LOCA EventsCooldown Scenarios2 Containment Spray Pump + 2 Containment Air CoolersSlower Cooldown2 Containment Spray Pumps + 4 Containment Air Coolers Rapid CooldownIn all cases, pool temperature > 140°F when containment pressure reduces to 2.8 psigOne Containment Spray Pump secured at containment pressure < 2.8 psigChemical precipitants remain soluble until pool temperature reduces to 140°FCold Leg Break, Max SI, Max Instrument Uncertainty, pool = 138.8°F @ 2.48 psigCold Leg Break produces 10% to 20% less precipitateCalvert Cliffs Option 2b Refined Closure Plan3 Thermal Hydraulic Analysis Results2 CS pumps + 2 CACsHot Leg BreakTime to 140°F = 108.3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />sTime to 2.8 psig = 47.2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />sTime to secure pump = 61.1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />sPressure @ 140°F = 1.98 psigCold Leg BreakTime to 140°F = 77.8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />sTime to 2.8 psig = 63.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />sTime to secure pump = 13.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />sPressure @ 140°F = 2.58 psigCalvert Cliffs Option 2b Refined Closure Plan42 CS pumps + 4 CACsHot Leg BreakTime to 140°F = 86.1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />sTime to 2.8 psig = 23.6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />sTime to secure pump = 62.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />sPressure @ 140°F = 1.95 psigCold Leg BreakTime to 140°F = 50.0 hour0 days <br />0 hours <br />0 weeks <br />0 months <br />sTime to 2.8 psig = 38.9 hour1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />sTime to secure pump = 11.1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />sPressure @ 140°F = 2.63 psig Thermal Hydraulic Response After CS Pump TripContainment Spray primary heat removal for containment poolPressure and Temperature increase after pump tripPressure increase can auto restart CS pumpEOPs being revised to prevent auto restart of CS pumpCalvert Cliffs Option 2b Refined Closure Plan50.00.51.01.52.02.53.03.54.04.55.0101001000Containment Pressure (psig)Time (hr)CL Slower CooldownHL Slower CooldownCL Rapid CooldownHL Rapid Cooldown110120130140150160170101001000Sump Water Temperature (F)Time (hr)CL Slower CooldownHL Slower CooldownCL Rapid CooldownHL Rapid Cooldown 2010 Head Loss Testing Test 5Calvert Cliffs Option 2b Refined Closure Plan6CCNPP performed a sequence of strainer head loss tests in 2010 with varying, scaled debris loadsTest 5 is most appropriate test to use to define critical break size Largest amount of fiber fines with maximum head loss below acceptance criteria of 1.99 ft H20 when chemical precipitates formTest 5 Corresponding Plant Quantity Debris Loads211 lbsNUKON Fines542 lbsThermal Wrap Fines29 lbsGeneric Fiberglass43 lbsTemp-Mat206 lbsEpoxy Chips2269 lbsParticulate (modeled using silicon carbide)54.1 lbs of WCAP-16530 NaAlSi3O8 Head Loss Plot Test 5Calvert Cliffs Option 2b Refined Closure Plan7Non-Chemical Head LossChemical Effects Head Loss 2010 Testing Flow Rates2010 testing program added fibrous, particulate, and coating chip debris at scaled design plant flow rate of 5000 gpmDuring and after addition of chemical precipitates, flow was lowered to scaled flow rate of 2400 gpm (assumed 1 CS pump and 1 HPSI pump)Maximum recirculation flow rate at on-set of chemical effects could be as high as 2900 gpm (1 CS pump and 2 HPSI pumps)Flow sweeps performed at the end of each testTest flow rate varied from scaled plant values of ~600 gpm to ~6000 gpm, holding for 10 minutes at various incrementsCalvert Cliffs Option 2b Refined Closure Plan8 2010 Test 5 Flow Sweep DataCalvert Cliffs Option 2b Refined Closure Plan9Note Plot Shows Corresponding Plant Flow Rates used in Test Scaling Test 5 Head Loss Using Flow Sweep Data -PreliminaryDuring test, break-through occurred in debris bed as chemical precipitates were introducedIncrease maximum head loss recorded in Test 5 (1.21 feet) by ratio of flow rate increase from 2400 gpm to 2900 gpmThis is more conservative the scaling using ration of head loss increase from flow sweepsCalvert Cliffs Option 2b Refined Closure Plan10 Test 5 Flow Sweep Results -PreliminaryLinearly interpolate head loss 2900 gpm / 2400 gpm = 21% increase Maximum total head loss including clean strainer head loss:(1.21 ft

• 1.21) + 0.288 ft = 1.75 ftBelow acceptance criteria of 1.99 ft(limiting failure mode of CCNPP strainer is dearation)Calvert Cliffs Option 2b Refined Closure Plan11 Questions/ConcernsJointly Review Issues, Questions, and Concerns for Future CommunicationCalvert Cliffs Option 2b Refined Closure Plan12 Next StepsFinalize Update of CalculationsPresent Formal Risk-Informed GSI-191 Analysis and ResultsDesire Next Meeting 4Q 2016Calvert Cliffs Option 2b Refined Closure Plan13