ML18337A398

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C-SGTR RASP Handbook Vol 5 Worksheet CDF Sequences to Estimate LERF Public v3
ML18337A398
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Issue date: 12/04/2018
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This excel file is to provide the CDF sequences and calculation summary for the SPAR model example that was used to estimate LERF from C-SGTR sequences as documented in Appendix 2-D of the RASP Handbook Volume 5.

Table D-2 Summary Table07/27/2017CategoryIn 38 CDF seqs.in Residue (seqs.39-711)Total CDF subject to csgtr challengep(csgtr)CDF (csgtr)LERF (csgtr)Plant CDF =2.95E-051.15E-063.07E-0596.26%1HDL no RCS loop clearing4.90E-061.90E-075.09E-060.0241.2E-071.2E-07 2HDL with RCS loop clearing2.09E-078.13E-091.00E-08 11.0E-081.0E-08 3Non HDL CDF with subsumed FSG0.053.3E-083.3E-08 4ATWS with failure of pressure relief3.79E-071.47E-083.94E-070.052.0E-082.0E-08 5Large SSB0.023.0E-093.0E-09Totals =5.49E-061.9E-071.9E-07% of plant CDF 18%0.6%Note: No CAT-2 sequences were in the top 38 sequences. An examination of lower CDF sequences indicated thatCAT-2 frequency is expected to be at the order of 1E-08, which is used in this table.

A more rigourous calculation can be done by examining the cutsets with B1 and B2 seal failures coincident with AFW failures.3.9E-09This EXCEL fileRASP Manual Section referring to this document.

Sequence List (4)C-SGTR RASP Handbook worksheet CDF sequences to estimate LERF Public v2.xlsx 3 1 2/03/2018Conclusion: For this selected example plant CDF model, based on the top 33 CDF sequences, about 18% of the CDF would be subject to C-SGTR, as shown below. These top 33 sequences make up 96% of total plant CDF from internal events.CDF Seqs 1-382.95E-0504/24/2015 0:00HDL Cat-1 only in 1-384.90E-06VOGTLE SPAR MODELDominant Sequence ResultsHDL Cat-2 only in 1-382.09E-071-3839-7111-711Cat-4 only in 1-383.79E-07Totals=3.07E-05Plant CDF = 2.95E-051.15E-063.07E-05Plant CDF % = 96.26%3.74%100.00%Event TreeSequence CDFDescription AFWLOOPEDG RCS Pressure (/RSD or LPI)RCP SLOCA, OR LOCACategoryRPS, RCSPRESS 1LONSW04-02-101.67E-05IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, /RSD, /BP1, BP2, HPI, SSC1low182 gpm OK-1 2LOACA202.50E-06/RPS, AFW, MFW, FABFailshighcat-1 3LOACA02-02-032.23E-06/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, /HPI, /SSC, RHR, LPRlow182 gpm OK-1 4LOACA02-02-091.91E-06/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, HPI, /SSC1, LPIlow182 gpm OK-1 5LONSW04-03-108.36E-07IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, /RSD, BP1, /BP2, HPI, SSC1high76 gpm OK-1 6LOACA195.74E-07/RPS, AFW, MFW, /FAB, SSCR, HPRFailshighcat-1 7ISL-RHR 33.89E-07ISL-RPT-RHR, /ISL-DIAG, ISL-REC-RHRISL low OK-3 8TRANS21-163.79E-07RPS, RCSPRESSATWS highcat-4ATWS Pres. Spike 9MLOCA033.49E-07/RPS, /HPI-ML, /AFW-ATWS, /SSC, HPR, LPRlowMLOCA OK-210TRANS203.15E-07/RPS, AFW, MFW, FABFailshighcat-111LOOPWR16-03-102.61E-07/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, /BP2, OPR-04H, DGR-04H, AFW-MAN, SG-DEP-LTFailsLoopFailshigh21 gpmcat-112LOOPWR16-062.18E-07/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, BP2, OPR-04H, DGR-04HLate failsLoopFailshigh182 gpmcat-113LONSW04-04-102.09E-07IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, /RSD, BP1, BP2, HPI-ML, /ACC, /AFW-ATWS, /SSC, LPIlsc480 gpmcat-214 LOOPGR152.08E-07/RPS-L, /EPS, AFW-L, FAB-LFailsLoophighcat-115LOOPGR16-03-101.73E-07/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, /BP2, OPR-04H, DGR-04H, AFW-MAN, SG-DEP-LTFailsLoopFailshigh21 gpmcat-116LOOPWR16-451.64E-07/RPS-L, EPS, AFW-B, OPR-04H, DGR-04HFailsLoopFailshighcat-117ISL-RHR 41.50E-07ISL-RPT-RHR, ISL-DIAGISL low OK-318LOOPGR16-061.44E-07/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, BP2, OPR-04H, DGR-04HLate failsLoopFailshigh182 gpmcat-119LODCA02-02-031.21E-07/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, /HPI, /SSC, RHR, LPRlow182 gpm OK-120 TRANS02-02-091.19E-07/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, HPI, /SSC1, LPIlow182 gpm OK-121 LOOPSC151.13E-07/RPS-L, /EPS, AFW-L, FAB-LFailsLoopcat-122LOACA02-03-031.12E-07/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, BP1, /BP2, /HPI, /SSC, RHR, LPRlow76 gpm OK-123LODCA02-02-091.09E-07/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, HPI, /SSC1, LPIlow182 gpm OK-124 LOOPGR16-451.08E-07/RPS-L, EPS, AFW-B, OPR-04H, DGR-04HFailsLoopFailscat-125LODCB02-02-091.06E-07/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, HPI, /SSC1, LPIlow182 gpm OK-126RXVRUPT 21.00E-07RXVESSEL OK-427MLOCA109.74E-08/RPS, HPI-ML, /ACC, /AFW-ATWS, /SSC, LPIlowMLOCA OK-2 Sequence List (4)C-SGTR RASP Handbook worksheet CDF sequences to estimate LERF Public v2.xlsx 4 1 2/03/2018 2 8 LOAC A02-03-099.54E-08/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, BP1, /BP2, HPI, /SSC1, LPIlow76 gpm OK-129LONSW04-14-108.46E-08IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, RCPT, HPI-ML, /ACC, /AFW-ATWS, /SSC, LPIlow OK-130LOOPGR02-02-098.46E-08/RPS-L, /EPS, /AFW-L, /PORV-L, LOSC-L, /RSD-L, /BP1, BP2, /OPR-02H, /RPS, /AFW, HPI, /SSC1, LPILooplow76 gpm OK-131SLOCA038.38E-08/RPS, /AFW, /HPI, /SSC, RHR, LPRlowSLOCA OK-132SGTR128.23E-08/RPS, /AFW, /HPI, SGI, REFILL1, ECASGTR33 TRANS02-02-037.91E-08/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, /HPI, /SSC, RHR, LPRlow76 gpm OK-134LOOPSC02-02-097.21E-08/RPS-L, /EPS, /AFW-L, /PORV-L, LOSC-L, /RSD-L, /BP1, BP2, /OPR-02H, /RPS, /AFW, HPI, /SSC1, LPILoop182 gpm OK-135LOOPWR156.64E-08/RPS-L, /EPS, AFW-L, FAB-LFailsLoopcat-136TRANS21-146.24E-08RPS, /RCSPRESS, MFW, /AFW-ATWS, BORATIONATWS37LODCB02-02-035.57E-08/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, /HPI, /SSC, RHR, LPRlow OK-138LOMFW205.44E-08/RPS, AFW, MFW, FABFailscat-139LOACA02-04-125.18E-08/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, BP1, BP2, HPI-ML, /ACC, AFW-ATWSFails480 gpm40 LOOPGR16-10-24.81E-08/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, BP1, BP2, /OPR-02H, /HPI, /SSC, LPRLoopFails480 gpm41LOCHS124.62E-08/RPS, AFW, FABFailscat-142LOOPSC16-10-24.10E-08/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, BP1, BP2, /OPR-02H, /HPI, /SSC, LPRLoopFails480 gpm43LOOPGR16-04-24.07E-08/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, BP2, /OPR-04H, /HPI, /SSC, LPRLoopFails44LOOPGR16-04-74.00E-08/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, BP2, /OPR-04H, HPI, /SSC, LPILoopFails45LOACA02-02-103.82E-08/RPS, /AFW, /PORV, LOSC, /RCPT, /RSD, /BP1, BP2, HPI, SSC146LOMFW21-163.79E-08RPS, RCSPRESScat-4Pres. Spike47LOCHS13-163.22E-08RPS, RCSPRESScat-4Pres. Spike48LOACA21-152.86E-08RPS, /RCSPRESS, MFW, AFW-ATWSFails49SGTR192.84E-08/RPS, AFW, /HPI, /SGI, FABFailsSGTR50LOOPWR02-02-092.71E-08/RPS-L, /EPS, /AFW-L, /PORV-L, LOSC-L, /RSD-L, /BP1, BP2, /OPR-02H, /RPS, /AFW, HPI, /SSC1, LPILoop51LOOPGR02-052.60E-08/RPS-L, /EPS, /AFW-L, /PORV-L, LOSC-L, /RSD-L, /BP1, BP2, OPR-02H, HPI-LLoop52ISL-LPI 32.27E-08ISL-RPT-LPI, /ISL-DIAG, ISL-REC-LPIISL low53LOACA02-14-122.12E-08/RPS, /AFW, /PORV, LOSC, RCPT, HPI-ML, /ACC, AFW-ATWSFails54 LOOPPC152.08E-08/RPS-L, /EPS, AFW-L, FAB-LFailsLoopcat-155LOOPSC16-03-101.99E-08/RPS-L, EPS, /AFW-B, /PORV, /RSD-B, /BP1, /BP2, OPR-04H, DGR-04H, AFW-MAN, SG-DEP-LTFailsLoopFails56LODCB201.86E-08/RPS, AFW, MFW, FABFails57LLOCA 21.79E-08/ACC, /LPI, LPR-LLLLOCA OK-258SGTR091.72E-08/RPS, /AFW, /HPI, /SGI, SSC, REFILL1, ECA59LONSW04-06-101.67E-08IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, RSD, /BP1, /O1, /BP2, O2, HPI, SSC160LONSW04-08-101.67E-08IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, RSD, /BP1, O1, /BP2, /O2, HPI, SSC161LONSW04-09-101.67E-08IEFT-LONSCW, /RPS, /AFW, /PORV, LOSC-NSW, REC-NSW, /RCPT, RSD, /BP1, O1, /BP2, O2, HPI, SSC1 Sequence List (4)C-SGTR RASP Handbook worksheet CDF sequences to estimate LERF Public v2.xlsx 5 1 2/03/2018 OK-1No C-SGTR challenge because AFW OK; RSD OK (RHR pump operation pressure range is reached in RCS).

OK-2No C-SGTR challenge because of MLOCA or LLOCA; RCS pressure is not high.

OK-3No C-SGTR since: AFW is most likely OK (not querried in the ET); RCS likely depressurized either by break size or by operator action.

OK-4No C-SGTR since low RCS pressure due to vessel failureRSD = Rapid secondary depressurization.SSC = Cooldown (primary and secondary)LOSC = RCP seal cooling maintained Fault TreeDescription 1ACCACCUMULATOR 3-OF-3 2AFWAUXILIARY FEEDWATER 3AFW-ATWSAUXILIARY FEEDWATER 4AFW-BAUXILIARY FEEDWATER (BLACKOUT) 5AFW-LVOGTLE AFW USING LOOP-FTF FAULT TREE FLAGS FAULT TREE 6AFW-MANMANUAL CONTROL AFW 7BORATIONEMERGENCY BORATION 8 BP1RCP SEAL STAGE 1 INTEGRITY (BINDING/POPPING) 9 BP2RCP SEAL STAGE 2 INTEGRITY (BINDING/POPPING) 10CSITERMINATE OR CONTROL SAFETY INJECTION 11CST-REFILLCONDENSATE STORAGE TANK REFILL 12CST-REFILL-LTCONDENSATE STORAGE TANK REFILL LONG-TERM 13CST-REFILL-LT1CONDENSATE STORAGE TANK REFILL LONG-TERM 14DGR-01HOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR 15DGR-02HOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 2 HOURS 16DGR-03HOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 3 HOURS 17DGR-04HDIESEL GENERATOR RECOVERY (IN 4 HR) 18DGR-06HOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 6 HOURS 19DGR-08HOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 8 HOURS 20DGR-30MOPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 30 MINUTES 21ECADECAY HEAT REMOVAL /RECOVERY (ECA-3.1/3.2) 22 EPSEMERGENCY POWER 23FABFEED AND BLEED 24FAB-LVOGTLE FEED AND BLEED IS UNAVAILABLE using LOOP-FTF 25FAB-NSWFEED AND BLEED IS UNAVAILABLE USING LONSW-FTF 26FAB2FEED AND BLEED (1 PORV REQUIRED) 27HPIHIGH PRESSURE INJECTION 28HPI-LHIGH PRESSURE INJECTION 29HPI-MLHIGH PRESSURE INJECTION 30HPRHIGH PRESSURE RECIRC 31HPR-LHIGH PRESSURE RECIRC 32HPR-MLHIGH PRESSURE RECIRCULATION 33HPR1HIGH PRESSURE RECIRCULATION 34IE-ISL-HPIISLOCA IE 2-CKV HPI interface 35IE-ISL-LPIISLOCA IE 2-CKV LPI interface 36IE-ISL-RHRRHR pipe ruptures 37IE-LOACCWLOSS OF AUXILIARY COMPONENT COOLING WATER 38IE-LONSWLOSS OF NUCLEAR SERVICE COOLING WATER 39IE-LOOPLOSS OF OFFSITE POWER 40IE-SGTRSG TUBE RUPTURE 41IE-SLBICSTEAMLINE BREAK INSIDE CONTAINMENT INITIATOR 42IEFT-LOACWAUXILIARY COMPONENT COOLING WATER (IE FT) 43IEFT-LONSCWNUCLEAR SERVICE COOLING WATER (IE FAULT TREE) 44ISL-DIAGOperators fail to diagnose ISLOCA 45ISL-REC-HPIOperators fail to recover (isolate) ISLOCA 46ISL-REC-LPIOperators fail to recover (isolate) ISLOCA 47ISL-REC-RHROperators fail to recover (isolate) ISLOCA 48ISL-RPT-HPIHPI pipe ruptures 49ISL-RPT-LPILPI pipe ruptures 50ISL-RPT-RHRRHR/SDC pipe ruptures 51LOSCRCP SEAL COOLING MAINTAINED 52LOSC-ACCWLOSS OF SEAL COOLING 53LOSC-LVOGTLE RCPSL USING LOOP-FTF FAULT TREE FLAGS 54LOSC-NSWLOSS OF SEAL COOLING 55LOSC-TTLOSS OF SEAL COOLING (TURBINE TRIP) 56LPILOW PRESSURE INJECTION 57LPI-NSWLOW PRESSURE INJECTION - LONSW 58LPRLOW PRESSURE RECIRC 59LPR-LLLOW PRESSURE RECIRCULATION 60LPR-NSWLOW PRESSURE RECIRCULATION - LONSW 61MFWMAIN FEEDWATER 62 O1RCP SEAL STAGE 1 INTEGRITY (O-RING EXTRUSION) 63 O2RCP SEAL STAGE 2 INTEGRITY (O-RING EXTRUSION) 64OPROFFSITE POWER RECOVERY 65OPR-01HOPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 66OPR-02HOFFSITE POWER RECOVERY IN 2 HRS 67OPR-03HOPERATOR FAILS TO RECOVER OFFSITE POWER IN 3 HOURS 68OPR-04HOFFSITE POWER RECOVERY (IN 4 HR) 69OPR-06HOFFSITE POWER RECOVERY IN 6 HRS 70OPR-08HOPERATOR FAILS TO RECOVER OFFSITE POWER IN 8 HOURS 71OPR-30MOPERATOR FAILS TO RECOVER OFFSITE POWER IN 30 MINUTES 72PORVPORVs ARE CLOSED 73PORV-BVOGTLE PORVs/SRVs OPEN DURING STATION BLACKOUT 74PORV-LVOGTLE PORVs/SRVs OPEN DURING LOOP 75PORV1VOGTLE PORVS/SRVS OPEN DURING TRANSIENTS (AFW FAILED) 76PORV2PORVs ARE CLOSED 77PWR-RECLATE POWER RECOVERY 78PWR-REC-06HLATE POWER RECOVERY (6 HR) 79PWR-REC-07HLATE POWER RECOVERY (7 HR) 80PWR-REC-09HLATE POWER RECOVERY (9 HR) 81PWR-REC-15HLATE POWER RECOVERY (15 HR) 82PWR-REC-24HLATE POWER RECOVERY (24 HR) 83RCPTREACTOR COOLANT PUMPS TRIPPED 84RCSPRESSRCS PRESSURE LIMITED 85REC-NSWNSCW RECOVERY 86REFILLRWST REFILL 87REFILL1RWST REFILL 88 RHRRESIDUAL HEAT REMOVAL 89RPSREACTOR TRIP 90RPS-LREACTOR SHUTDOWN 91RSDRAPID SECONDARY DEPRESSURIZATION (<1710 PSI IN 2 HR) 92RSD-BRAPID SECONDARY DEPRESS 93RSD-LRAPID SECONDARY DEPRESS 94RXVESSELREACTOR VESSEL RUPTURES 95SG-DEP-LTDEPRESSURIZE SGs 96SGIFAULTED STEAM GENERATOR ISOLATION 97 SSCCOOLDOWN (PRIMARY & SECONDARY) 98SSC1COOLDOWN (PRIMARY & SECONDARY) 99SSCRSECONDARY SIDE COOLING RECOVERED Event TreeInitiatorDescription 1ISL-HPIIE-ISL-HPIVogtle SI cold leg discharge ISLOCA 2ISL-LPIIE-ISL-LPIVogtle RHR discharge ISLOCA 3ISL-RHRIE-ISL-RHRVogtle RHR suction ISLOCA 4LLOCAIE-LLOCAVogtle large loss-of-coolant accident 5LOACAIE-LOACAVogtle loss of vital ac 1AA02 bus 6LOACCWIE-LOACCWVogtle loss of auxiliary component cooling water 7LOCHSIE-LOCHSVogtle loss of condenser heat sink 8LODCAIE-LODCAVogtle loss of vital dc 1AD1 bus 9LODCBIE-LODCBVogtle loss of vital dc 1BD1 bus 10LOMFWIE-LOMFWVogtle loss of main feedwater 11LONSWIE-LONSWVogtle loss of nuclear service cooling water 12LOOPGRIE-LOOPGRVogtle loss of offsite power (Grid related) 13LOOPPCIE-LOOPPCVogtle loss of offsite power (Plant Centered) 14LOOPSCIE-LOOPSCVogtle loss of offsite power (Switchyard centered) 15LOOPWRIE-LOOPWRVogtle loss of offsite power (Weather related) 16MLOCAIE-MLOCAVogtle medium loss-of-coolant accident 17RXVRUPTIE-XLOCAVogtle reactor vessel rupture 18SGTRIE-SGTRVogtle steam generator tube rupture 19SLOCAIE-SLOCAVogtle small loss-of-coolant accident 20TRANSIE-TRANSVogtle general transient

IE-SGTR CDFEvent TreeSequence CDFDescriptionAFWHPIDry SGFlagset 32SGTR 128.23E-08/RPS, /AFW, /HPI, SGI, REFILL1, ECAYesETF-SGTR 49SGTR 192.84E-08/RPS, AFW, /HPI, /SGI, FABfailsYesETF-SGTR 58SGTR 91.72E-08/RPS, /AFW, /HPI, /SGI, SSC, REFILL1, ECAYesETF-SGTR 74SGTR 228.88E-09RPSYesETF-SGTR 83SGTR 206.84E-09/RPS, AFW, /HPI, SGIfails?ETF-SGTR 106SGTR 142.70E-09/RPS, /AFW, HPI, /SGI, /SSC1, RHRfailsYesETF-SGTR 123SGTR 181.97E-09/RPS, AFW, /HPI, /SGI, /FAB, HPRfailsYesETF-SGTR 167SGTR 69.95E-10/RPS, /AFW, /HPI, /SGI, /SSC, CSI, REFILL, ECAYesETF-SGTR 238SGTR 151.90E-10/RPS, /AFW, HPI, /SGI, SSC1failsYesETF-SGTR 254SGTR 211.44E-10/RPS, AFW, HPIfailsfailsYesETF-SGTR 287SGTR 169.29E-11/RPS, /AFW, HPI, SGIfails?ETF-SGTR 391SGTR 31.76E-11/RPS, /AFW, /HPI, /SGI, /SSC, /CSI, RHR, CST-REFILLYesETF-SGTRTotal=1.50E-07ECADECAY HEAT REMOVAL /RECOVERY (ECA-3.1/3.2)REFILLREFILL1RWST REFILL SSCSSC1COOLDOWN (PRIMARY & SECONDARY)CSITERMINATE OR CONTROL SAFETY INJECTIONSGIFaulted SG isolationIEV-SGTR =2.07E-03CCDP(SGTR) =7.23E-05CDF IEV-SGTR =1.50E-07CCDP(LSSB) =1.45E-04p(csgtr)LSSB =0.02IEV-LSSB) =1.00E-03CDF(LSSB and CSGTR) = 2.89E-09 SGTRLSSB and C-SGTRComment on LSSBIEV frequency2.07E-031.0E-03Rare event, not expected to occur during plan CCDP7.23E-051.45E-042 times the CCDP of SGTR due to less favora p(csgtr)0.02From Table 2.4-1 CDF1.50E-073.E-09 C-SGTR in SSB Event TreeIE-LSSBRPSC-SGTR SSBCCDP of LSSBEnd StateNo C-SGTRSuccess OKOccurs~1C-SGTR1.00E-030.02CD with C-SGTR1.45E-043.E-09FailsTransfer to ATWS ETsmall ATWS C-SGTR ModelsIE-TRANSRPSPR-RELAFWFL-DPTP-L/R CCDPEnd StateIE-TRANSRPSPR-RELFL-DPTP-L/R CCDPEnd State 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8Success 1No ATWSSuccess 1No ATWS 1YesSmall 2No leak0.95Yes. 2200 < P< 3300Small 2No leakYes. 2200 < P < 3300Medium 3CD-LeakOccurs0.950.04 11.00E-03 NoMedium 3CD-Leak 1Large 4CD-C-SGTROccursFails0.01 10.1Large 4CD-C-SGTR1.00E-05FailsNo. P >3300 5CD- C-SGTRYes0.02No. P >3300 No 5CD-C-SGTRFigure 3-1. ATWS Event Tree Top Events to Address TypeII CSGTRIE-TRANSRPSPR-RELAFWFL-DPTP-L/R CCDPEnd StateIEV RPSPR-RELAFWp(sgtr)End State 1 2 3 4 5 6 7 8Success 1No ATWSSuccess 1No ATWS 1OccursSuccess 2No C-SGTRYesInsign. ChallengeSuccess0.5 3No C-SGTRYes. 2200 < P< 3300Small 2No leakFailsFails9.50E-010.95 4C-SGTR NoMedium 3CD-Leak9.50E-10assume SGTR0.01Occurs0.50.041.00E-02 5No C-SGTR 1Large 4CD-C-SGTR2.38E-09FailsFails0.010.1 6C-SGTR5.00E-06Yes1.25E-070.05No. P >33000.55.00E-02 No 5CD-C-SGTR1.25E-070.5Sum =2.5E-07Figure 32. ATWS Event Tree Top Events to Address TypeII CSGTR - Example Quantification 5 FLDPT 6 PL/R 7 CCDPThisnoderepresentstheprobabilityofgettinga"small", ora"medium", or a"large"flawdepth,given aflawisoriginatedsincethelastrefuelingoutage.Anyflawsofdepth40%orlessareassumedidentified and their tubes are plugged, if they have occurred before the last outage.Thisnoderepresentstheprobabilityofleakor CSGTRgiventhat aflawwithdepthspecified inthe FLDPT node exists.

This isthe CCDPassignedtothesequencedefined sofarwithNode 1through 6 intheeventtree.This CCDPrepresentstheadditionalfailuresneeded toreachcoredamageendstate,giventhatthesequence in question has progressed to the point defined by Nodes 1 through 6.

RCP Seal LOCA Model in SPAR LOSCRCP SEAL COOLING MAINTAINEDRCPTREACTOR COOLANT PUMPS TRIPPEDRCSPRESSRCS PRESSURE LIMITEDRSDRAPID SECONDARY DEPRESSURIZATION (<1710 PSI IN 2 HR)480 gpm/pump seal LOCA occurs if LOSP and RCPT OR if LOSC and BP1 and BP2. Then, loop seal clearing occurs.

Table 2.3-1. Probability that a Detected Flaw Belongs to a Bin Size 0 to 1 cm 1 to 2 cm 2 to 3 cm 3 to 4 cm 4 to 5 cm 5 to 6 cm0 to 0.12.74E-034.62E-022.23E-025.38E-031.04E-031.80E-047.78E-020.1 to 0.21.86E-023.14E-011.52E-013.66E-027.08E-031.23E-035.30E-010.2 to 0.39.59E-031.62E-017.81E-021.89E-023.64E-036.31E-042.73E-010.3 to 0.43.09E-035.21E-022.52E-026.07E-031.17E-032.03E-048.78E-028.78E-020.4 to 0.58.47E-041.43E-026.90E-031.66E-033.22E-045.57E-052.41E-022.41E-020.5 to 0.62.14E-043.61E-031.74E-034.21E-048.13E-051.41E-056.08E-036.08E-030.6 to 0.75.14E-058.67E-044.19E-041.01E-041.95E-053.38E-061.46E-031.46E-035.43E-040.7 to 0.81.19E-052.01E-049.73E-052.35E-054.54E-067.86E-073.39E-043.39E-041.26E-040.8 to 0.92.71E-064.57E-052.21E-055.32E-061.03E-061.78E-077.70E-057.70E-052.86E-050.9 to 1.0small3.51E-025.93E-012.87E-016.92E-021.34E-022.32E-031.00E+001.00E+001.20E-016.98E-04TotalFlaw LengthTotalFlaw Depth %/100