Text

Transmittal of Final Accident Sequence Precursor (ASP) Analysis
	ML12166A519
Person / Time
Site:	Surry
Issue date:	06/14/2012
From:	Cotton K; Plant Licensing Branch II
To:	Heacock D; Virginia Electric & Power Co (VEPCO)
	Sreenivas, V
References
	IR-11-003
	Download: ML12166A519 (24)
	v • d • e

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 14, 2012 Mr. David A Heacock President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

SURRY POWER STATION, UNIT NOS. 1 AND 2, TRANSMITTAL OF FINAL ACCIDENT SEQUENCE PRECURSOR (ASP) ANALYSIS

Dear Mr. Heacock:

The enclosure provides the final result of the Accident Sequence Precursor (ASP) analysis of an event which occurred at Surry Power Station, Units 1 and 2 (Plant) as documented in licensee event report (LER) 280/11-001 and inspection report (lR) 05000280/2011003. The event occurred on April 16, 2011; Plant experienced a complete loss of offsite power to the Reserve Station Service Transformers (RSSTs) A and B, for about 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months and 3 minutes. This resulted in a turbine trip and subsequent reactor trip. Due to the station blackout Signal, the circulating water outlet motor operated valves throttled closed to approximately 25% open and the Alternate AC Diesel Generator automatically started as designed. In addition, the auxiliary feedwater pumps started and all reactor coolant pump motors tripped as designed. RSSTs A and B were energized by offsite power. On April 17th, offsite power was restored to Emergency Bus 1J (Unit 1) and Emergency Bus 2H (Unit 2). The ASP analysis calculated a conditional core damage probability (CCDP) of 9x10-5 for Unit 1 and 7x10-5 for Unit 2.

The U.S. Nuclear Regulatory Commission (NRC) established the ASP Program in 1979 in response to the Risk Assessment Review Group Report (see NUREG/CR-0400, dated September 1978). The ASP Program systematically evaluates U.S. nuclear power plant operating experience to identify, document, and rank the operating events most likely to lead to inadequate core cooling and severe core damage (precursors).

As described in the NRC Regulatory Issue Summary (RIS) 2006-24, "Revised Review and Transmittal Process for Accident Sequence Precursor Analyses," the Office of Nuclear Regulatory Research implemented several process changes to the ASP Program. In accordance with the RIS, this event has a CCDP less than or equal to 1 x 1 0-4; therefore, a formal licensee review was not requested.

For more information about the ASP Program, see the annual ASP Program status report at http://www. nrc.gov/reading-rm/doc-collections/comm ission/secys/20 10/2010 0125/20100125scy.pdf

D. Heacock

- 2 The enclosure containing the final analysis report is provided for your information.

Sincerely, aren Cotton, Project ~r Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-280 and 50-281

Enclosure:

Final Precursor Analysis cc: Distribution via Listserv

Final Precursor Anal~sis 4mmttnJ.i4*"tij,idiiji44i'?1,'iWi,'*'bi,;e.,i.tai.,.¢t!At¥I'<<4U1t,',IU41¥Jiij.

Surry Power Station, Unit 1 and 2 Dual Unit Loss of Offsite Power Due to Switchyard Damage Caused by a Tornado Event Date: 04/16/2011 LER: 280/11-001 IR: 50-280/11-03 Unit 1 CCDP = 9x10-5 Unit 2 CCDP = 7x105 EVENT

SUMMARY

____________~__~~~~~__~~~____~~

Event Description. At 1849 on April 16, 2011, Surry Power Station Units 1 and 2 experienced a complete loss of offsite power (LOOP) to the Reserve Station Service Transformers (RSSTs)

A and B, for about 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months and 3 minutes. This condition resulted from damage inflicted in the switchyard from a tornado. This resulted in a turbine trip and subsequent reactor trip.

Emergency Diesel Generators (EDGs) auto started and loaded. Due to the station blackout (SBO) signal, the circulating water outlet motor operator valves throttled closed to approximately 25% open and the Alternate AC (MC) Diesel Generator automatically started as designed. In addition, the auxiliary feedwater (AFW) pumps started and all reactor coolant pump (RCP) motors tripped as designed.

The swing EDG, EDG 3, automatically loaded onto the Unit 1 Emergency Bus 1J leaving the Unit 2 Emergency Bus 2J de-energized as designed. At 1917, EDG 3 was transferred to Bus 2J and the MC Diesel Generator was aligned to Bus 1J, thus providing power to all emergency buses. At 2352, RSSTs A and B were energized by offsite power. On April 17th, at 0035, offsite power was restored to Bus 1 J. At 0153, offsite power was restored to the Unit 2 Emergency Bus 2H. Offsite power was restored to the two remaining Emergency Buses, 1 H and 2J on April 17, 2011 at 1803 and 2109, respectively. Additional information is provided in References 1 and 2.

Key Event Details. The following event details are significant to the modeling of this event analysis:

A tornado led to a dual-unit reactor trip and LOOP event.

Offsite power recovery to an emergency bus was possible five hours and three minutes after the LOOP occurred.

ANALYSIS RESUL TS """-_................--:.......~....:..-_,;"".",......................................;

Conditional Core Damage Probabilities. The point estimate conditional core damage probabilities (CCDPs) for this event is 9.3x10-5 for Unit 1 and 7.2x10-5 for Unit 2.

The Accident Sequence Precursor Program acceptance threshold is a CCDP of 1 x 1 0-6 or the CCDP equivalent of an uncomplicated reactor trip with a non-recoverable loss of secondary plant systems (e. ~., feed water and condensate), whichever is greater. This CCDP equivalent for Surry is 3x 1 0-.

Enclosure 1

LER 280/11-001 Dominant Sequence. The dominant accident sequences are LOOPWR Sequence 02-06 (CCDP =4.6x 10-5) which contributes 50% of the total internal events CCDP for Unit 1 and LOOPWR Sequence 17-03-10 (CCDP =2.2x 10-5) which contributes 30% of the total internal events CCDP for Unit 2. Additional sequences that contribute greater than 1 % of the total internal events CCDP are provided in Appendix A.

The dominant sequence is shown graphically in Figures B-1 and B-2 in Appendix B. The events and important component failures in LOOPWR Sequence 02-06 are:

Weather-related LOOP occurs, Reactor scram succeeds, Emergency power succeeds, AFW succeeds, Power-operated relief valves successfully close (if opened),

Rapid secondary depressurization succeeds, RCP seal cooling fails, RCP Seal 1 integrity is maintained, RCP Seal 2 integrity fails, Operators fail to restore offsite power within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , High pressure injection fails, The events and important component failures in LOOPWR Sequence 17-03-10 are:

Weather-related LOOP occurs, Reactor scram succeeds, Emergency power fails, AFW succeeds, Power-operated relief valves successfully close (if opened),

Rapid secondary depressurization succeeds, RCP Seal 1 integrity is maintained, RCP Seal 2 integrity is maintained, Operators fail to restore offsite power within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , Operators fail to recover an EDG within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , Analysis Results. Appendix A provides tables that include the following:

Modified basic events and initiating event frequencies, including base and change case probabilities/frequencies.

Dominant sequences (including CCDPs).

Sequence logic for all dominant sequences.

Fault tree definitions.

Sequence cutsets.

Definitions and probabilities for key basic events.

MODELING ASSUMPTIONS Analysis Type. The Surry Unit 1 and Unit 2 SPAR models created in April 2012 were used for this event analysis. This event was modeled as a weather-related LOOP initiating event.

2

LER 280/11-001 Analysis Rules. The ASP program uses Significance Determination Process results for degraded conditions when available. However, the ASP Program performs independent analysis for initiating events.

Unique Design Features. Surry, Units 1 and 2 have the following unique design features associated with its emergency electrical distribution system.

EDG 1 provides power to Emergency Bus 1 Hanly.

EDG 2 provides power to Emergency Bus 2H only.

EDG 3 (swing diesel) provides power to Emergency Buses 1 J and 2J. The swing EDG was aligned to Bus 1 J during the event. EDG 3 is available for the unit of concern unless the dedicated diesel generator for the other unit is not available. In that case, the swing diesel will be aligned to the other unit.

The Me Diesel Generator can be aligned to either Emergency Bus 1 J or 2H given that the diesels that normally align to these buses have failed.

The diesel generators do not require cooling water.

Unit 1 Unit 2 Bus 1H Bus 1J Bus 2J Bus 2H Figure 1. Surry, Units 1 and 2 simplified diagram of emergency electrical distribution system.

Modeling Assumptions. The following modeling assumptions were determined to be vital to this event analysis:

This analysis models the April 16, 2011 dual-unit reactor trip at Surry Unit 1 and 2 as a LOOP initiating event.

Offsite power recovery to an emergency bus was possible five hours and three minutes after the LOOP occurred.

3

LER 280/11-001 Basic Event Probability Changes. The following initiating event frequencies and basic event probabilities were modified for this event analysis:

Unit 1

The LOOP initiating event frequency (IE-LOOP) was set 1.0 to represent the operational event that occurred at Surry Unit 1 on April 16. 2011. All other initiating events frequencies were set to zero.

The non-recovery probability for basic events OEP-XHE-XL-NR01 H (Operator Fails to Recover Offsite Power in 1 Hour). OEP-XHE-XL-NR02H (Operator Fails to Recover Offsite Power in 2 Hours). OEP-XHE-XL-NR03H (Operator Fails to Recover Offsite Power in 3 Hours). OEP-XHE-XL-NR04H (Operator Fails to Recover Offsite Power in 4 Hours) were set to TRUE because offsite power recovery to an emergency bus was not possible until five hours and three minutes after the LOOP occurred.

The default diesel generator mission times were changed to reflect the actual time offsite power was restored to the first vital bus (approximately 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months for Unit 1). Since the overall fail-to-run is made up of two separate factors. the mission times for these factors were set to the following: ZT-DGN-FR-E =1 hour (base case value) and ZT-DGN-FR-L

= 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months .

Unit 2

The LOOP initiating event frequency (IE-LOOP) was set 1.0 to represent the operational event that occurred at Surry Unit 2 on April 16. 2011. All other initiating events frequencies were set to zero.

The non-recovery probability for basic events OEP-XHE-XL-NR01 H (Operator Fails to Recover Offsite Power in 1 Hour). OEP-XHE-XL-NR02H (Operator Fails to Recover Offsite Power in 2 Hours). OEP-XHE-XL-NR03H (Operator Fails to Recover Offsite Power in 3 Hours), OEP-XHE-XL-NR04H (Operator Fails to Recover Offsite Power in 4 Hours) were set to TRUE because offsite power recovery to an emergency bus was not possible until five hours and three minutes after the LOOP occurred.

The default diesel generator mission times were changed to reflect the actual time offsite power was restored to the first vital bus (approximately 7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months for Unit 2). Since the overall fail-to-run is made up of two separate factors. the mission times for these factors were set to the following : ZT-DGN-FR-E =1 hour (base case value) and ZT-DGN-FR-L

=6 hours.

REFERENCES

1. Surry Power Station Unit 1, ilLER 280/11-001-Reactor Trip on Both Units Due to Loss of Offsite Power" dated June 14, 2011. (ML11178A032)

2. U.S. Nuclear Regulatory Commission. "Surry Power Station NRC Integrated Inspection Report 05000280/2011003." dated July 28, 2011. (ML112092845) 4

I LER 280/11-001 Appendix A: Analysis Results Unit 1 S~mmary of Conditional Event Changes _~_~~~_______

Event DUAL-UNIT-LOOP IE-LOOPWR OEP-XHE-XL-NR01 HWR OEP-XHE-XL-NR02HWR OEP-XHE-XL-NR03HWR OEP-XHE-XL-NR04HWR Condo Description Value LOOP AFFECTING BOTH UNITS LOSS OF OFFSITE POWER INITIATOR 0NEATHER-RELA TED)

OPERATOR FAILS TO RECOVER OFFSITE POWER IN 1 HOUR 0NEATHER-RELATED)

OPERATOR FAILS TO RECOVER OFFSITE POWER IN 2 HOURS 0NEATHER-RELATED)

OPERATOR FAILS TO RECOVER OFFSITE POWER IN 3 HOURS 0NEATHER-RELATED)

OPERATOR FAILS TO RECOVER OFFSITE POWER IN 4 HOURS 0NEATHER-RELATED)

ZT-DGN-FR-L 1 glESEL GENERATO~ F~ILS TO RUN EPS-DGN-FR-DG1 DIESEL GENERATOR 1 FAILS TO RUN EPS-DGN-FR-DG2 DIESEL GENERATOR 2 FAILS TO RUN

-- -1 EPS-DGN-FR-DG3 DIESEL GENERATOR 3 FAILS TO RUN EPS-DGN-FR-SBO SBO DIESEL GENERATOR FAILS TO RUN Dominant Sequence Results Only items contributing at least 1.0% to the total CCDP are displayed. ______--.___~_~_............,

Event Tree Sequence CCDP

% Contribution Description LOOPWR 49.6%

02-06 { 62E-S 18.7%

LOOPWR I 17-06 1.45E-5 15.6%

LOOPWR 17-03-04 3.46E-6 3.7%

LOOPWR j 17-03-10 1.75E-5 LOOPWR 16 3.03E-6 3.2%

LOOPWR 02-11 2.30E-6 2.5%

LOOPWR 17-45 1.30E-6 1.4%

Total 9.33E-5 I 100.0%

Referenced Fault Trees TRUE 5.82E-1 1.00E+0 4.83E-3 TRUE 6.87E-1 TRUE I 5.59E-1 TRUE 4.80E-1

.1 TRUE 4.24E-1 5.42E-3 2.47E-2 9.17E-3 2.B4E-2 I

9.17E-3 I

2.84E-2 9.17E-3 ~ 84E-2 1.09E-2 3.01E-2 IRPS-L, IEPS, IAFW-L, IPORV-L, LOSC-L, IRSD, IBP1, BP2, OPR-02H, HPI-L IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, IBP2, OPR-04H, DGR-04H, AFW-MAN, SG-DEP-L T1 IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, BP2, 1 OPR-04H, DGR-04H IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, IBP2, OPR-04H, DGR-04H, IAFW-MAN, ICST-REFILL LT1, SG-DEP-L T2, PWR-REC-24H IRPS-L, IEPS, AFW-L, FAB-L IRPS-L, IEPS, IAFW-L, IPORV-L, LOSC-L, IRSD, BP1, IBP2, OPR-02H, HPI-L IRPS-L, EPS, AFW-B, OPR-01 H, DGR-01 H Fault Tree AFW-B Description AUXILIARY FEEDWATER AFW-L AUXILIARY FEEDWATER AFW-MAN MANUALCONTROLAFW BP1 RCP SEAL STAGE 1 INTEGRITY (BINDING/POPPING)

BP2 RCP SEAL STAGE 2 INTEGRITY (BINDING/POPPING)

DGR-01H__ J OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR A-1 I

LER 280/11-001 Fault Tree Description DGR-04H DIESEL GENERATOR RECOVERY (IN 4 HR)

EPS Emergency Power

~

FAB-L FEED AND BLEED HPI-L HIGH PRESSURE INJECTION LOSC-L SURRY 1 & 2 LOSS OF ALL RCP SEAL COOLING USING LOOP-FTF OPR-01H OFFSITE POWER RECOVERY IN 1 HR OPR-02H OFFSITE POWER RECOVERY IN 2 HRS J

OPR-04H OFF SITE POWER RECOVERY (IN 4 HR)

PWR-REC-24H LATE POWER RECOVERY (24 HR)

SG-DEP-LT1 DEPRESSURIZE SGs (DEPENDENT)

SG-DEP-LT2 DEPRESSURIZE SGs (DEPENDENT)

Cutset Report - LOOPWR 02-06 Only items contributing at least 1 % to the total are displayed.

CCDP Total%

Cutset 4.62E-5 100 Displaying 4315 of 4315 Cutsets.

2.87E-6 6.21 I E-LOOPWR,EPS-DGN-TM-DG 1,RCS-MDP-LK-BP2,SWS-1 01 A-OPEN,SWS XHE-XM-ISOL 2

2.76E-6 5.98 IE-LOOPWR, EPS-DGN-TM-DG 1,MCW-MOV-OO-1 06D,RCS-MDP-LK-BP2 3

2.76E-6 5.98 IE-LOOPWR,EPS-DGN-TM-DG1,MCW-MOV-OO-1 00C,RCS-MDP-LK-BP2 4

2.76E-6 5.98 1 IE-LOOPWR,EPS-DGN-TM-DG 1,MCW-MOV-OO-1 06B,RCS-MDP-LK-BP2 5

2.76E-6 5.98 I IE-LOOPWR,EPS-DGN-TM-DG1,MCW-MOV-OO-1 00A,RCS-MDP-LK-BP2 6

2.58E-6 5.57 IE-LOOPWR,DCP-BAT-LP-1 BAT A4HR,EPS-DGN-TM-DG1,MCW-LGC-FC LOGICB,RCS-MDP-LK-BP2 7

1.83E-6,

3.97 IE-LOOPWR, EPS-DGN-FR-DG1,RCS-MDP-LK-BP2,SWS-1 01 A-OPEN,SWS XHE-XM-ISOL 8

1.77E-6 3.82 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-106D,RCS-MDP-LK-BP2 9

1.77E-6 3.82 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-100C,RCS-MDP-LK-BP2 10 1.77E-6 3.82 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-106B,RCS-MDP-LK-BP2 11 1.77E-6 3.82 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-1 OOA,RCS-MDP-LK-BP2 12 1.65E-6 3.56 IE-LOOPWR,DCP-BAT-LP-1 BATA4HR,EPS-DGN-FR-DG1,MCW-LGC-FC LOGICB,RCS-MDP-LK-BP2 13 1.44E-6 3.1 IE-LOOPWR,EPS-DGN-TM-DG1,MCW-XHE-XM-LVL,RCS-MDP-LK-BP2 14 9.17E-7 1.98 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-XH E-XM-L VL,RCS-MDP-LK-BP2 15 5.78E-7 1.25 I E-LOOPWR,EPS-DGN-FS-DG1,RCS-MDP-LK-BP2,SWS-1 01A-OPEN,SWS XHE-XM-ISOL 16 5.57E-7 1.2 IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 06D, RCS-MDP-LK-BP2 17 5.57E-7 1.2 I E-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 OOC, RCS-MDP-LK-BP2 18 5.57E-7 1.2 IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 06B,RCS-MDP-LK-BP2 19 5.57E-7 1.2 IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 00A,RCS-MDP-LK-BP2 20 5.19E-7 1.12 IE-LOOPWR, DCP-BAT -LP-1 BAT A4HR,EPS-DGN-FS-DG 1,MCW-LGC-FC LOGICB,RCS-MDP-LK-BP2

~--~--

A-2

LER 280/11-001 Cutset Report - LOOPWR 17-03-10 Only items contributing at least 1 % to the total are displayed.

CCDP Total%

Cutset I 1.75E-5 1 00 Disp~ying 754 of 754 Cutsets.

l 6.83E-6 39.1 I IE-LOOPWR,AFW-XHE-XM-C NTRL,DCP-BAT -LP-1 BAT A4H R,DCP-BAT -LP 1BATB4HR, EPS-DGN-C F-FRALL, EPS-XH E-XL-NR04H,1RCS-MDP-LK-BP2 2

1.91 E-6 10.9 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1 BATA4HR,DCP-BAT-LP I 1 BATB4HR,EPS-DGN-C F-FSALL, EPS-XH E-XL-NR04H,IRCS-MDP-LK-BP2 3

4.41E-7 2.53 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1BATA4HR,DCP-BAT-LP 1 BATB4H R,EPS-DGN-FR-DG3, EPS-DGN-TM-DG 1,EPS-XH E-XL-NR04H, EPS XHE-XM-SB01 J,IRCS-MDP-LK-BP2 I

2.53 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1 BATA4HR,DCP-BAT-LP 4+-4.41E-7 1 BATB4HR,EPS-DGN-FR-DG 1,EPS-DGN-TM-DG3,EPS-XHE-XL-N R04H, EPS XH E-XM-SBO 1 J,1RCS-MDP-LK-BP2 5

3.17E-7 1.81 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1BATA4HR,DCP-BAT-LP 1 BATB4H R,EPS-DGN-FR-DG3, EPS-DGN-TM-DG 1,EPS-DGN-TM-SBO,EPS-XHE XL-NR04H,/RCS-MDP-LK-BP2 6 ~ 3.17E-7 1.81 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT -LP-1 BAT A4HR,DCP-BAT-LP 1 BATB4HR,EPS-DGN-FR-DG 1,EPS-DGN-TM-DG3, EPS-DGN-TM-SBO, EPS-XHE XL-NR04H,1RCS-MDP-LK-BP2 7

2.82E-7 1.62 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1 BATA4HR,DCP-BAT-LP 1 BATB4HR,EPS-DGN-FR-DG1,EPS-DGN-FR-DG3,EPS-XHE-XL-NR04H,EPS XHE-XM-SB01 J,IRCS-MDP-LK-BP2 8

2.41E-7 1.38 IE-LOOPWR,AFW-XHE-XM-C NTRL,DCP-BAT-LP-1 BAT A4H R,DCP-BAT-LP 1 BATB4HR, EPS-DGN-FR-DG3,EPS-DGN-FR-SBO, EPS-DGN-TM-DG 1,EPS-XHE XL-N R04H,IRCS-MDP-LK-BP2 9

IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1BATA4HR,DCP-BAT-LP 1 BATB4HR,EPS-DGN-FR-DG1,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS-XHE I

2.41E-7 1.38 XL-NR04H,IRCS-MDP-LK-BP2

I IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-1BATA4HR,DCP-BAT-LP 1'0 12.02E-7 I 1 BATB4HR, EPS-DGN-FR-DG 1,EPS-DGN-FR-DG3, EPS-DGN-TM-SBO,EPS-XHE

~16 1 XL-NR04H,IRCS-MDP-LK-BP2 Cutset Report - LOOPWR 17-06 Only items contributing at least 1% to the total are_disp~ayeg, CCDP Total%

Cutset 1.45E-5 100 Displaying 733 of 733 Cutsets.

1 5.69E-6 39.1

, IE-LOOPWR,EPS-DGN-CF-FRALL,EPS-XHE-XL-NR04H,RCS-MDP-LK-BP2

~

2 1.59E-6 1 0.9 IE-LOOPWR,EPS-DGN-CF-FSALL,EPS-XHE-XL-NR04H,RCS-MDP-LK-BP2 3

3.68E-7 2.53 IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-TM-DG3,EPS-XHE-XL-NR04H,EPS XHE-XM-SBO 1 J, RCS-MDP-LK-BP2 4

3.68E-7 2.53 L IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG1,EPS-XHE-XL:NR04H,EPS XHE-XM-SB01J,RCS-MDP-LK-BP2 5

6

--+-

I 2.64E-7 2.64E-7 1.81 1.81 i IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 I E-LOOPWR, EPS-DGN-FR-DG3,EPS-DGN-TM-DG 1,EPS-DGN-TM-SBO, EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 7

2.35E-7 1.62 I IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-DG3,EPS-XHE-XL-NR04H,EPS XHE-XM-SB01J,RCS-MDP-LK-BP2 8

2.01E-7 1.38 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS-DGN-TM-DG1,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 9 ~01E-7 1.38 IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 A-3

LER 280/11-001 CCDP Total%

Cutset 10 1.69E-7 1.16 IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 Cutset Report - LOOPWR 17-03-04 Only items contributing at least 1% to the total are displayed.

CCDP Total%

Cutset 3.46E-6 100 Displaying 4B7 of 4B7 Cutsets.

1.36E-6 39.2 IE-LOOPWR,EPS-DGN-CF-FRALL,EPS-XHE-XL-NR04H,EPS-XHE-XL NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK-BP2 2

3.79E-7 10.9 IE-LOOPWR,EPS-DGN-CF-FSALL,EPS-XHE-XL-NR04H,EPS-XHE-XL NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK-BP2 3

B.75E-B 2.53 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG1,EPS-XHE-XL-NR04H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB01J,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK BP2 4

B.75E-B 2.53 IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-TM-DG3,EPS-XHE-XL-NR04H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB01J,OEP-XHE-XL-NR24H4WR,IRCS-MDP-LK BP2 5

6.2BE-B 1.B1 I E-LOOPWR, E PS-DG N-FR-DG3, EP S-DG N-TM-DG 1,EPS-DG N-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK I

I BP2 6

6.2BE-B 1.B1 I IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK I BP2 7

5.59E-B 1.62 IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-DG3,EPS-XHE-XL-NR04H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB01J,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK

~

BP2 B

4.7BE-B 1.3B IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS-DGN-TM-DG1,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK t

BP2 9

4.7BE-B 1.3B IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS I XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR'/RCS-MDP-LK I BP2 10 4.01 E-B 1.16 I IE-LOOPWR,EPS-DGN-FR-DG1,EPS-DGN-FR-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP-LK BP2 Cutset Report - LOOPWR 16 Only items contributing at least 1% to the total are displayed.

CCDP Total%

Cutset 3.03E-6 100 9.22E-7 30.4 I

I 2

4.BOE-7 15.9 3

4.31E-7 14.2 4

9.92E-B 3.27 I

5 6.34E-B 2.09 Displaying 420B of 420B Cutsets.

IE-LOOPWR,AFW-XH E-XM-XTI E, CDS-XVM-CC-C N 150, HPI-XH E-XM-FB IE-LOOPWR,AFW-SYS-LK-SGCKVS,AFW-XHE-XM-XTIE,HPI-XHE-XM-FB IE-LOOPWR,AFW-PMP-CF-ALL,HPI-XHE-XM-FB IE-LOOPWR,AFW-XHE-XM-XTIE,CDS-XVM-CC-CN150,DCP-BAT-LP 1 BATA4HR,EPS-DGN-TM-DG1,PPR-MOV-FC-RC1535 IE-LOOPWR,AFW-XHE-XM-XTI E,CDS-XVM-CC-CN 150, DCP-BAT-LP

~ BAT~4H ~EPS-DGN-FR-DG1,PPR-MOV-FC-RC1535 6

5.19E-B 1.71 IE-LOOPWR,AFW-MDP-TM-1 P3B,AFW-TDP-FR-1 P2,AFW-XHE-XM-XTI E, DCP-t SAT-LP-1 SATMHR,E PS-DG N-FR-DG1,PPR-MOV-FC-RC 1535 7

5.17E-B I

1.71 IE-LOOPWR,AFW-SYS-LK-SGCKVS,AFW-XH E-XM-XTI E, DCP-BAT-LP 1 BATA4HR,EPS-DGN-TM-DG1,PPR-MOV-FC-RC1535 --

B 5.14E-B 1.7 l.!.§-LOOPWR,AFW-XHE-XM-XTI E, CDS-CKV-CC-CN 151, HPI-XH E-XM-FB A-4

LER 280/11-001 CCDP Total%

Cutset 9

4.64E-8 I 1.53 IE-LOOPWR,AFW-PMP-CF-ALL,DCP-BAT-LP-1BATA4HR,EPS-DGN-TM DG 1,PPR-MOV-FC-RC 1535 --------.-....

10 3.30E-8 t 1.09 I E-LOOPWR,AFW-SYS-LK-SGC KVS,AFW-XHE-XM-XTI E, DCP-BA T -LP 1 BATA4HR,EPS-DGN-FR-DG1,PPR-MOV-FC-RC1535 11T3.25E~8 1.07 IE-LOOPWR,AFW-MOV-CO-260A,HPI-XHE-XM-FB 12 r 3.25E-8 1.07 I

IE-LOOPWR,A~-MOV-CO-260B,HPI-XHE-XM-FB Cutset Report - LOOPWR 02-11 0!2!y items.c_o!'..t!ibuting at least 1% to the total are displayed.

CCDP Total%

Cutset Displaying 1440 of 1440 Cutsets.

2.30E-6 I I 1.44E-7 I

6.23 IE-LOOPWR,EPS-DGN-TM-DG1,RCS-MDP-LK-BP1,1RCS-MDP-LK-BP2,SWS 101 A-OPEN,SWS-XHE-XM-ISOL 2

1.38E-7 6

IE-LOOPWR,EPS-DGN-TM-DG 1,MCW-MOV-OO-1 06B,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 3

1.38E-7 6

I E-LOOPWR, EPS-DGN-TM-DG 1,MCW-MOV-OO-1 OOA,RCS-MDP-LK-BP 1,1RCS MDP-LK-BP2 4 I 1.38E-7 I

6 IE-LOOPWR,EPS-DGN-TM-DG1,MCW-MOV-OO-1 00C,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 5

I 1.38E-7 6

IE-LOOPWR,EPS-DGN-TM-DG1,MCW-MOV-OO-1 06D,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 IE-LOOPWR,DCP-BAT-LP-1BATA4HR,EPS-DGN-TM-DG1,MCW-LGC-FC 6

5 59 7f 1.29E-LOGICB,RCS-MDP-LK-BP1,1RCS-MDP-LK-BP2 7

9.17E-8 3.98 r IE-LOOPWR,EPS-DG-N-FR-DG1,RCS-MDP-LK-BP1,1RCS-MDP-LK-BP2,SWS 101A-OPEN,SWS-XHE-XM-ISOL 8

8.83E-8 9

8.83E-8 10 I 8.83E-8 f-11 -l 8.83E-8 r 12

/ 13 14 15 16 17 18 19 20 8.24E-8 7.18E-8 4.59E-8 2.89E-8 2.78E-8 2.78E-8 2.78E-8 2.78E-8 MDP-LK-BP2 2.60E-8 1.13 IE-LOOPWR,DCP-BAT-LP-1 BATA4HR,EPS-DGN-FS-DG1,MCW-LGC-FC LOGICB,RCS-MDP-LK-BP1,1RCS-MDP-LK-BP2 3.83 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-1 06B,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 3.83 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-1 00A,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 3.83 I IE-LOOPWR,EPS-DGN-FR-DG1,MCW-MOV-OO-1 00C,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 3.83

-- I IE-LOOPWR,EPS-DGN-FR-D-G1,MCW-MOV-OO-1 06D,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 ----- --

3.57 I E-LOOPWR,DCP-BAT -LP-1 BAT A4HR,EPS-DGN-FR-DG 1,MCW-LGC-FC LOGICB,RCS-MDP-LK-BP1,1RCS-MDP-LK-BP2 3.11 IE-LOOPWR,EPS-DGN-TM-DG 1,MCW-XHE-XM-L VL,RCS-M DP-LK-BP 1,IRCS MDP-LK-BP2 1.99 IE-LOOPWR,EPS-DGN-FR-DG1,MCW-XHE-XM-LVL,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 1.25 IE-LOOPWR,EPS-DGN-FS-DG1,RCS-MDP-LK-BP1,IRCS-MDP-LK-BP2,SWS I 101A-OPEN,SWS-XHE-XM-ISOL 1.21 IE-LOOPWR.EPS-DGN-FS-DG1,MCW-MOV-OO-1 06B,RCS-MDP-LK-BP1,IRCS MDP-LK-BP2 1.21

, IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 00A,RCS-MDP-LK-BP1,1RCS MDP-LK-BP2 1.21 IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 00C,RCS-MDP-LK-BP1,IRCS MDP-LK-BP2 1.21 IE-LOOPWR,EPS-DGN-FS-DG1,MCW-MOV-OO-1 06D,RCS-MDP-LK-BP1,1RCS A-5

LER 280/11-001 Cutset Report - LOOPWR 17-45 Only items contributing at least 1% to the total are displayed.

CCDP Total%

Cutset 1.30E-6 100 Displaying 2441 of 2441 Cutsets.

1.68E-7 13 IE-LOOPWR,AFW-TDP-FR-1P2,AFW-XHE-XM-XTIE,EPS-DGN-CF-FRALL,EPS XHE-XL-NR01 H 2

5.54E-8 4.27 IE-LOOPWR,AFW-TDP-FR-1 P2,AFW-TDP-FR-2P2,EPS-DGN-CF-FRALL,EPS XHE-XL-NR01 H 3

4.71 E-8 3.63 I E-LOOPWR,AFW-TDP-FR-1 P2,AFW-XH E-XM-XTI E,EP S-DG N-CF -F SALL, EP S XHE-XL-NR01 H 4

3.25E-8 2.5 I E-LOOPWR,ACP-DG3-ALIGN-AWAY,AFW-TDP-FR-1 P2,EPS-DGN-FR DG2,EPS-DGN-TM-DG1,EPS-DGN-TM-SBO,EPS-XHE-XL-NR01 H 5 I 3.25E-8 2.5 IE-LOOPWR,ACP-DG3-ALIGN-AWAY,AFW-TDP-FR-1 P2,EPS-DGN-FR

-j DG1,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NR01 H 6

2.81 E-8 2.16 IE-LOOPWR,AFW-TDP-FR-1 P2,EPS-DGN-CF-FRALL,EPS-XH E-XL-NR01 H,EPS XHE-XM-SB02H 7

2.77E-8 2.13 I E-LOOPWR,AFW-TDP-FS-1 P2,AFW-XH E-XM-XTI E, EPS-DG N-C F-FRALL, E PS XHE-XL-NR01 H 8

2.47E-8 1.91 I E-LOOPWR,ACP-DG3-ALIGN-AWA Y,AFW-TDP-FR-1 P2, EPS-DGN-FR DG2,EPS-DGN-FR-SBO,EPS-DGN-TM-DG1,EPS-XHE-XL-NR01 H 9

2.47E-8 1.91 I E-LOOPWR,ACP-DG3-ALIGN-AWA Y,AFW-TDP-FR-1 P2,EPS-DG N-FR DG1,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS-XHE-XL-NR01 H 10 2.30E-8 1.77 IE-LOOPWR,AFW-TDP-TM-1 P2,AFW-XHE-XM-XTIE,EPS-DGN-CF-FRALL,EPS XHE-XL-NR01H 11 2.08E-8 1.6 IE-LOOPWR,ACP-DG3-ALIGN-AWA Y,AFW-TDP-FR-1 P2, EPS-DGN-FR DG 1,EPS-DGN-FR-DG2, EPS-DGN-TM-SBO,EPS-XHE-XL-N R01 H 12 2.01 E-8 1.55 I E-LOOPWR,AFW-TDP-FR-1 P2, EPS-DGN-CF-FRALL, EPS-DGN-TM-SBO,EPS XHE-XL-NR01 H 13 1.58E-8 1.22 IE-LOOPWR,ACP-DG3-ALIGN-AWAY,AFW-TDP-FR-1P2,EPS-DGN-FR DG1,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-XHE-XL-NR01 H 14 1.55E-8 1.19 IE-LOOPWR,AFW-TDP-FR-1 P2,AFW-TDP-FR-2P2, EPS-DGN-CF-FSALL,EPS XHE-XL-NR01H 15 I 1.53E-8 1.18 I E-LOOPWR,AFW-TDP-F R-1 P2,EPS-DG N-C F-FRALL, EP S-DG N-F R-SSO, EPS XHE-XL-NR01 H Referenced Events Event Description Probability ACP-DG3-ALIGN-AWAY I DG3!-LIGNED T_O OPPOSITE UNIT

-L 5..:.~~

AFW-MDP-TM-1 P3B AFW MDP 1-FW-P-3B UNAVAILABLE DUE TO T&M AFW-MOV-CO-260A AFW CROSS-TIE 2-FW-MOV-260A DIVERTS FLOW AFW-MOV-CO-260B I AFW CROSS-TIE 2-FW-MOV-260B DIVERTS FLOW AFW-PMP-CF-ALL AFW-SYS-LK-SGCKVS T ~OMMO~ CAUSE FAILURE OF AFW PUMPS( BOTHUNlTS) rSTEAM LEAKAGE THRU CKVS 27.58 & 89 (PSA)

AFW-TDP-FR-1P2 I AFW TURBINE DRIVEN PUMP 1-FW-P-2 FAILS TO RUN AFW-TDP-FR-2P2 UNIT 2 AFW TO PUMP 2-FW-P-2 FAILS TO RUN 3.98E-3 8.13E-7 8.13E-7 1.08E-5 1.00E-4 3.95E-2 3.95E-2 AFW-TDP-FS-1 P2 AFW TURBINE DRIVEN PUMP 1-FW-P-2 FAILS TO START I

6.49E-3 AFW-TDP-TM-1 P2 AFW TDP 1-FW-P-2 UNAVAILABLE DUE TO T&M J_ 5.39E-3 AFW-XHE-XM-CNTRL OPERATOR FAILS TO CONTROL AFW TDP I

3.00E-1 AFW-XHE-XM-XTIE OPERATOR FAILS TO INITIATE AFW CROSSCONNECT I

1.20E-1 CDS-CKV-CC-CN151 ECST M/U CHK VALVE 1-CN-151 FAILS CLOSED 1.07E-5 A-6

LER 280/11-001 Event Description Probability CDS-XVM-CC-CN150 ECST M/U VALVE 1-CN-150 FAILS CLOSED 1.92E-4 DCP-BAT-LP-1BATA4HR BATIERY 1A 1-EPD-B-1A FAILURE AT 4 HOURS

~ 1.00E+O

DCP-BAT-LP-1 BATB4HR BATIERY 1B 1-EPD-B-1B FAILURE AT 4 HOURS 1.00E+O EPS-DGN-CF-FRALL COMMON CAUSE FAILURE OF DIESEL GEN ~RATORS TO RUN 4.0BE-5 EPS-DGN-CF-FSALL 1.14E-5 START EPS-DGN-FR-DG1 1 DIESEL GENERATOR 1 FAILS TO RUN COMMON CAUSE FAILURE OF DIESEL GENERATORS TO 9.17E-3 EPS-DGN-FR-DG2 J DIESEL GENERATOR 2 FAILS..TO RUN _

9.17E-3 EPS-DGN-FR-DG3 DIESEL GENERATOR 3 FAILS TO RUN 9.17E-3 EPS-DGN-FR-SBO SBO DIESEL GENERATOR FAILS TO RUN I 1.09E-2 EPS-DGN-FS-DG1 DIESEL GENERATOR 1 FAILS TO START

___~9E-3 EPS-DGN-TM-DG1 I DIESEL GENERATOR 1 UNAVAILABLE DUE TO T&M 1.43E-2 EPS-DGN-TM-DG2 r DIESEL GENERATOR 2 UNAVAILABLE DUE TO T&M

- -- -1.43E-2 EPS-DGN-TM-DG3 I_DIESEL GENERATOR 3 UNAVAILABLE DUE TO T&M__

1.43E-2 EPS-DGN-TM-SBO I SBO DIESEL GENERATOR UNAVAILABLE DUE TO T&M 1.43E-2 EPS-XHE-XL-NR01 H I OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 B.71E-1 HOUR EPS-XHE-XL-NR04H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 4 6.9BE-1 HOURS EPS-XHE-XL-NR24H4 OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 24 4.16E-1

, HOURS (GIVEN FAILURE AT 4)

EPS-XHE-XM-SB01 J EPS-XHE-XM-SB02H HPI-XHE-XM-FB IE-LOOPWR MCW-LGC-FC-LOGICB MCW-MOV-OO-100A MCW-MOV-OO-100C MCW-MOV-OO-106B

~CW-MOV-OO-106D MCW-XHE-XM-LVL OPERATOR FAILS TO ALIGN SBO DIESEL TO BUS 1J 2.00E-2 OPERATOR FAILS TO ALIGN SBO DIESEL TO BUS 2H 2,OOE-2 OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING 4.00E-2 LOSS OF OFFSITE POWER INITIATOR (WEATHER-RELATED)

I 1.00E+O LOGIC TRAIN B NON-ESSENTL SW ISOLLOSS OF FUNCTION T B.98E=4 (PSA)

CONDENSER OUTLET 1-CW-MOV-100A FAILS OPEN 9.63E-4 CONDENSER OUTLET 1-CW-MOV-100CD FAILS OPEN

~ 9'63E-4

CONDENSER INLET MOV1-CW-MOV-106B FAILS OPEN --

9:63E-4 CONDENSER INLET MOV1-CW-MOV-106D FAI,LS ~OP.§ ~ _

9.63E-4 LEVEL INSTRUMENTS 1-CW-LS-102/103 CCF MISCALIBRATED I 5.00E-4 (PSA)

~

OEP-XHE-XL-NR24H4WR OPERATOR FAILS TO RECOVER OFFSITE POWER IN 24 HOURS (GIVEN FAILURE AT 4, WEATHER)

PPR-MOV-FC-RC 1535 1 BLOCK VALVE 1535 CLOSED DUE TO PORV LEAKING RCS-MDP-LK-BP1 RCP SEAL STAGE 1 INTEGRITY (BINDING/POPPING OPEN)

FAILS RCS-MDP-LK-BP2 RCP SEAL STAGE 2 INTEGRITY (BINDING/POPPING OPEN)

FAILS SWS-101A-OPEN PROBABILITY OF 1-SW-MOV-101A ALIGNED OPEN SWS-XHE-XM-ISOL FAILURE TO VERIFYIISOLATE SWS/CW INLET MOVS (AP-12, STEP 11) 1.43E-1 3.00E-1 1.25E-2 2.00E-1 5.00E-1 2.00E-3 A-7

LER 280/11-001 SummaI)' of Conditional Ey'~n~ Changes Condo Event DUAL-UN IT-LOOP Description LOOP AFFECTING BOTH UNITS Value TRUE IE-LOOPWR LOSS OF OFFSITE POWER INITIATOR 1.00E+0 (WEATHER-RELATED)

OEP-XHE-XL-NR01 HWR OPERATOR FAILS TO RECOVER OFFSITE TRUE POWER IN 1 HOUR (WEATHER-RELATED)

OEP-XHE-XL-NR02HWR OPERATOR FAILS TO RECOVER OFFSITE TRUE OEP-XHE-XL-NR03HWR POWER IN 2 HOURS (WEATHER-RELATED)

OPERATOR FAILS TO RECOVER OFFSITE I TRUE POWER IN 3 HOURS (WEATHER-RELATED)

OEP-XHE-XL-NR04HWR OPERATOR FAILS TO RECOVER OFFSITE TRUE POWER IN 4 HOURS (WEATHER-RELATED)

ZT-DGN-FR-L DIESEL GENERATOR FAILS TO RUN 6.50E-3 EPS-DGN-FR-DG1

- DIESEL GENERATOR 1 FAILS TO RUN 1.02E-2 EPS-DGN-FR-DG2 I E I,E.S.E_ L <?,ENERATO_R 2 FAILS TO RUN

~02E-2 EPS-DGN-FR-DG3 I DIESEL GENERATOR 3 FAILS TO RUN j1.02E-2 Nominal Value 5.82E-1 4.83E-3 6.87E-1 5.59E-1 4.80E-1 4.24E-1 2.47E-2 2.84E-2 2.84E-2 2.84E-2 EPS-DGN-FR-SBO SBO DIESEL GENERATOR FAILS TO RUN 1. 20E-2~

3.01 E-2 Dominant Sequence Results Only items contributing at least 1.0% to the total CCDP are disl2layed.

Event Tree Sequence CCDP

% Contribution LOOPWR 17-03-10 30.0%

LOOPWR 17-06 1.79E-5 25.0%

LOOPWR 02-06 1.31 E-5 18.4%

LOOPWR 16 6.03E-6 8.4%

--+

LOOPWR 17-45 4.85E-6 6.8%

LOOPWR 17-03-04 4.26E-6 I 6.0%

I Total '

7.15E-5]

100.0%

Referenced Fault Trees Fault Tree Description Description IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, IBP2, OPR-04H, DGR-04H, AFW-MAN, SG-DEP LT1 IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, BP2, OPR-04H, DGR-04H IRPS-L, IEPS, IAFW-L, IPORV-L, LOSC-L, IRSD, IBP1, BP2, OPR-02H, HPI-L IRPS-L, IEPS, AFW-L, FAB-L IRPS-L, EPS, AFW-B, OPR-01 H, DGR-01 H IRPS-L, EPS, IAFW-B, IPORV-B, IRSD, IBP1, IBP2, OPR-04H, DGR-04H, IAFW-MAN, ICST REFILL-LT1, SG-DEP-L T2, PWR-REC-24H AFW-B

AUXILIARY FEEDWATER AFW-L AUXILIARY FEEDWATER AFW-MAN

~ MAN ~ALCONTROLAFW BP2 RCP _SEAL STAGE 2 INTEGRITY (BINDING/POPPING)

DGR-01H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 HOUR I DGR-04H DIESEL GENERATOR RECOVERY (IN 4 HR)

J EPS EMERGENCY POWER IS UNAVAILABLE FAB-L FEED AND BLEED HPI-L HIGH PRESSURE INJECTION A-a

LER 280/11-001 Fault Tree Description LOSC-L I SURRY 2 LOSS OF ALL RCP SEAL COOLING USING LOOP-FTF OPR-01 H 1 OFFSITE POWER RECOVERY IN 1 HR OPR-02H OFFSITE POWER RECOVERY IN 2 HRS

<?P'R-.04H_

I 9FFSI!E POW~R RECO\\f §'~Y (IN 4 HR)

PWR-REC-2~

LATE POWER RECOVERY (24 HR)

SG-DEP-LT1

!DEPRESSURIZE SGs (DEPEN DENT)

SG-DEP-L T2 DEPRESSURIZE SGs (DEPENDENT)

Cutset Report - LOOPWR 17-03-10 Only items contributing at least 1% to the total are displayed.

CCDP t-2.15E-5 I 3.83E-6 2

9.62E-7 3

9.55E-7 4

6.90E-7 5

6.87E-7 6

5.77E-7 7

4.93E-7 8

4.93E-7 I

9 4.93E-7 ~ 2.3 j

I 4.12E-7 1.92 10 I 11 3.54E-7 1.65 12 3.54E-7 1.65 13 3.52E-7 1.64 J

Total%

Cutset 100 Displaying 931 of931 Cutsets.

17.8 IE-LOOPWR,ACP-DG3-ALIGN-AWA Y,AFW-XHE-XM-CNTRL,DCP-BAT -LP 2BATA4HR,DCP-BAT-LP-2BATB4HR,EPS-DGN-CF-FRALL,EPS-XHE-XL NR04H,1RCS-MDP-LK-BP2 4.48 IE-LOOPWR,AFW-XHE-XM-CNTRL, DCP-BAT -LP-2BAT A4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-TM-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XM-DG32J,EPS XHE-XM-SB02H,IRCS-MDP-LK-BP2 4.45 I E-LOOPWR,AC P-DG3-ALIGN-AWA Y,AFW-XH E-XM-C NTRL, DCP-BAT -LP 2BATA4HR,DCP-BAT-LP-2BATB4HR,EPS-DGN-CF-FSALL,EPS-XHE-XL NR04H,IRCS-MDP-LK-BP2 3.22 I I E-LOOPWR,AFW-XHE-XM-CNTRL, DCP-BAT -LP-2BAT A4H R,DCP-BAT -LP 2BATB4HR,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NR04H,EPS 3.2

~E~~;~~-~~~:~::~~~~~~~~~~:~DCP-BAT-LP-2BAT A4H R,DCP-BAT -LP I

2BATB4HR,EPS-DGN-FR-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XM-DG32J,EPS XHE-XM-SB02H,IRCS-MDP-LK-BP2 I

2.69 I E-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT -LP-2BAT A4H R, DCP-BAT -LP 2BATB4HR,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS-XHE-XL-NR04H,EPS 2.3 2.3 XHE-XM-DG32J,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-2BATA4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-XHE-XL-NR04H,EPS XHE-XM-SB02H,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL, DCP-BAT -LP-2BAT A4HR,DCP-BAT -LP 2BATB4HR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-XHE-XL-NR04H,EPS XHE-XM-SB02H,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-2BATA4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NR04H,EPS XHE-XM-DG32J,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-2BAT A4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-XHE-XL-NR04H,EPS XHE-XM-DG32J,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT -LP-2BAT A4HR,DCP-BAT-LP 1

2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,EPS I

XHE-XL-NR04H,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-2BATA4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,IRCS-MDP-LK-BP2 IE-LOOPWR,AFW-XHE-XM-CNTRL,DCP-BAT-LP-2BATA4HR,DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-XHE-XL-NR04H,EPS XHE-XM-SB02H,IRCS-MDP-LK-BP2 A-9

LER 280/11-001 CCDP Total%

Cutset 14 2.96E-7 1.38 I E-LOOPWR,AFW-XHE-XM-C NTRL, DCP-BAT-LP-2BAT MHR, DC P-BAT-LP 2BATB4HR,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS XHE-XL-NR04H,IRCS-MDP-LK-BP2 15 2.96E-7 1.38 I E-LOOPWR,AFW-XHE-XM-CNTRL, DCP-BAT-LP-2BAT MHR, DCP-BAT -LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS XHE-XL-NR04H,IRCS-MDP-LK-BP2 16 2.53E-7 1.18 I E-LOOPWR,AFW-XH E-XM-CNTRL,DCP-BAT-LP-2BAT MHR, DCP-BAT-LP 2BATB4HR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,IRCS-MDP-LK-BP2 Cutset Report - LOOPWR 17-06 Only items contributing at le3l.st 1~ to th_e tot~1 are displayed.

CCDP Total%

Cutset 1.79E-5 Displaying 911 of 911 Cutsets.

3.19E-6 2

8.02E-7 3

7.96E-7 4

5.75E-7 5

5.73E-7 6

4.81E-7 7

4.11E-7 8

4.11E-7 9

4.11 E-7 10 f 3.43E-7

, 11 2.95E-7 12 2.95E-7 13 2.93E-7 14 l' 2.46E-7 15 2.46E-7 16 2.10E-7 17.8 E-LOOPWR,ACP-DG3-ALIGN-AWAY,EPS-DGN-CF-FRALL,EPS-XHE-XL NR04H,RCS-MDP-LK-BP2 n

4.48 IE-LOOPWR,EPS-DGN-TM-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XM DG32J,EPS-XHE-XM-SB02H,RCS-MDP-LK-BP2 4.45 IE-LOOPWR,ACP-DG3-ALIGN-AWAY,EPS-DGN-CF-FSALL,EPS-XHE-XL NR04H,RCS-MDP-LK-BP2 3.22 IE-LOOPWR,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NRO4H,EPS XHE-XM-DG32J,RCS-MDP-LK-BP2 3.2 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XM DG32J,EPS-XHE-XM-SB02H,RCS-MDP-LK-BP2 2.69 IE-LOOPWR,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS-XHE-XL-NRO4H,EPS XHE-XM-DG32J,RCS-MDP-LK-BP2 2.3 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-XHE-XL-NRO4H,EPS XHE-XM-SB02H,RCS-MDP-LK-BP2 2.3 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-XHE-XL-NRO4H,EPS XHE-XM-SB02H,RCS-MDP-LK-BP2 2.3 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NRO4H,EPS I XHE-XM-DG32J,RCS-MDP-LK-B_P_2__

1.92 I IE-LOOPWR,EPS-DGN=-FR-DG2,EPS-DGN-FR-SBO,EPS-XHE-XL-NR04H,EPS I XHE-XM-DG32J,RCS-MDP-LK-BP_2_____

1.65 J IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 1.6_5 1_IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 1.64 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-XHE-XL-NRO4H,EPS XHE-XM-SB02H,RCS-MDP-LK-BP2 1.38 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 1.38 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2 1.18 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,RCS-MDP-LK-BP2

~

A-10

LER 280/11-001 Cutset Report - LOOPWR 02-06 Only items contributing at least 1% to the total are displayed.

CCDP Total"io Cutset 1.31E-5 100 Displaying 3769 of 3769 Cutsets.

-..~-

1.68E-6 12.8 I E-LOOPWR,CPC-MDP-TM-SWP1 OA,EPS-XHE-XM-OG32J,IAS-MOC-FR 1 C1,RCS-MOP-LK-BP2 9.18 IE-LOOPWR, CPC-MDP-TM-SWP 1 OA,EPS-OG N-TM-DG3,IAS-MDC-FR 2 r 1.20E-6 1 C 1, RCS-MDP-LK-BP2 3 I 8.60E-7 6.55 I E-LOOPWR, C PC-MOP-TM-SWP1 OA, EP S-OG N-FR-DG3,IAS-MOC-F R 1C1,RCS-MDP-LK-BP2

T---

4 4.87E-7 3.71 IE-LOOPWR,CPC-MDP-TM-SWP1 OA,EPS-XHE-XM-OG32J, IAS-MDC-FS I

1 C 1,RCS-MDP-LK-BP2 1-5 4.09E-7 I

3.12 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-DGN-TM-DG3,EPS-XHE-XM SB01.I,RCS-MDP-LK-BP2 6

3.49E-7 2.66 IE-LOOPWR,CPC-MOP-TM-SWP10A,EPS-OGN-TM-DG3,IAS-MDC-FS 1 C 1,RCS-MDP-LK-BP2 7

3.42E-7 2.61 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-XHE-XM-OG32J,IAS-MDC-TM 1C1,RCS-MDP-LK-BP2 8

1 I 3.21E-7 I 2.45 IE-LOOPWR,CPC-MDP-FS-SWP10A,EPS-XHE-XM-DG32J,IAS-MOC-FR 1 C 1, RCS-MDP-LK-BP2 9 1 2.93E-7 2.24 IE-LOOPWR,CPC-MOP-TM-SWP1 OA, EPS-DGN-TM-OG3,EPS-DGN-TM I

SBO,RCS-MDP-LK-BP2 10 t 2.92E-7 ;

2.23 E-LOOPWR,CPC-MOP-TM-SWP10A'EPS-OGN-FR-OG3'EPS-XHE-XM SB01J,RCS-MDP-LK-BP2

~

11 2.50E-7 1.9 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-OGN-FR-DG3,IAS-MDC-FS 1C1,RCS-MDP-LK-BP2 12 2.45E-7 1.87 IE-LOOPWR,CPC-MDP-TM-SWP1 OA, EPS-DGN-TM-OG3,IAS-MDC-TM 1 C1,RCS-MOP-LK-BP2 13 I 2.45E-7 1.87 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-DGN-FR-SBO,EPS-DGN-TM OG3,RCS-MDP-LK-BP2 14 2.43E-7 1.85 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-DGN-FS-OG3,IAS-MDC-FR 1C1,RCS-MDP-LK-BP2 15 2.30E-7 1.75 IE-LOO PWR, C PC-MDP-FS-SWP1 OA,E PS-OGN-TM-DG3, IAS-MOC-FR 1 1C1,RCS-MDP-LK-BP2 16 2.10E-7 1.6 IE-LOOPWR,CPC-MOP-TM-SWP1 OA, EPS-OGN-FR-DG3, EPS-OGN-TM 1 SBO.:RCS-MDP-LK-BP2 17 2.10E-7 1.6 1 I E-LOOPWR,CPC-MOP-TM-SWP1 OA,EPS-OGN-FR-OG3,EPS-OGN-TM OG2, RCS-MOP-LK-BP2 j

18 2.10E-7 i 1.6 IE-LOOPWR, CPC-MDP-TM-SWP1 OA, EPS-OG N-FR-OG2,EPS-OGN-TM OG3,RCS-MOP-LK-BP2 19 2.01E-7 1.53 IE-LOOPWR,ACP-CRB-OO-25J3,CPC-MOP-TM-SWP10A,IAS-MOC-FR 1C1,RCS-MOP-LK-BP2 20 1.75E-7 I 1.34 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-OGN-FR-OG3,IAS-MOC-TM 1 C1,RCS-MOP-LK-BP2 21 1.75E-7 1.33 I E-LOOPWR, CPC-MDP-TM-SWP 1 OA, EP S-OGN-FR-DG3, EPS-DGN-FR SBO,RCS-MOP-LK-BP2 22 1.64E-7 1.25 IE-LOOPWR,CPC-MDP-FS-SWP1 OA, EPS-DGN-FR-DG3,IAS-MDC-FR-1 C1,RCS MDP-LK-BP2 23 1.50E-7 1.14 IE-LOOPWR,CPC-MDP-TM-SWP1 OA,EPS-OGN-FR-DG2, EPS-OGN-FR OG3,RCS-MOP-LK-BP2 24 1.48E-7 1.13 IE-LOOPWR,CPC-MDP-TM-SWP10A,EPS-SEQ-FO-OG3,IAS-MDC-FR 1C1,RCS-MOP-LK-BP2 A-11

LER 280/11-001 Cutset Report - LOOPWR 16 Only items contributing at least 1% to the total are displayed.

CCDP Total%

Cutset 6.03E-6 100 Displaying 6814 of 6814 Cutsets.

9.22E-7 15.3 I E-LOOPWR,AFW-XH E-XM-XTI E, C DS-XVM-CC-C N 150, H PI-XHE-XM-FB 2

4.80E-7 7.96 IE-LOOPWR,AFW-SYS-LK-SGCKVS,AFW-XHE-XM-XTIE,HPI-XHE-XM-FB 3

4.31 E-7 7.15 IE-LOOPWR,AFW-PMP-CF-ALL,HPI-XHE-XM-FB 4

1.38E-7 2.29 IE-LOOPWR,AFW-XHE-XM-XTIE,CDS-XVM-CC-CN150,DCP-BAT-LP 2BATB4HR,EPS-XHE-XM-DG32J,PPR-MOV-FC-RC 1536 5

1.13E-7 1.88 I E-LOOPWR,AFW-MDP-TM-2P3A,AFW-TDP-FR-2P2,AFW-XHE-XM-XTIE,DCP BAT -LP-2BATB4HR, EPS-XHE-XM-DG32J,PPR-MOV-FC-RC 1536 6

1.03E-7 1.7 IE-LOOPWR,AFW-MDP-TM-2P3A,AFW-XHE-XM-CNTRL,DCP-BAT-LP 2BATB4HR,EPS-DGN-TM-DG3,EPS-XHE-XM-SB01J,PPR-MOV-FC-RC1536 7

9.92E-8 1.65 IE-LOOPWR,AFW-XHE-XM-XTIE,CDS-XVM-CC-CN 150,DCP-BAT -LP 2BATB4HR,EPS-DGN* TM-DG3,PPR-MOV-FC-RC 1536 8

8.11E-8 1.35 IE-LOOPWR,AFW-MDP-TM-2P3A,AFW-TDP-FR-2P2,AFW-XHE-XM-XTIE,DCP BAT -LP-2BATB4HR,EPS-DGN-TM-DG3, PPR-MOV-FC-RC 1536 -

9 7.37E-8 1.22 I E-LOOPWR,AFW-M DP-TM-2P3A,AFW-XH E-XM-CNTRL, DCP-BAT -LP I 2BATB4HR,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,PPR-MOV-FC-RC1536 10 7.33E-8 1.22 IE-LOOPWR,AFW-MDP-TM-2P3A,AFW-XHE-XM-CNTRL,DCP-BAT-LP 2BATB4HR, EPS-DGN-FR-DG3,EPS-XHE-XM-SBO 1 J,PPR-MOV-FC-RC 1536 11 7.20E-8 1.19 IE-LOOPWR,AFW-SYS-LK-SGC KVS,AFW-XH E-XM-XTIE,DCP-BA T -LP 2BATB4HR,EPS-XHE-XM-DG32J,PPR-MOV-FC-RC 1536 12 7.08E-8 1.18 IE-LOOPWR,AFW-XH E -XM-XTI E,CDS-XVM-CC-C N 150,DCP-BAT -LP 2BATB4HR,EPS-DGN-FR-DG3,PPR-MOV-FC-RC 1536 13 6.46E-8 1.07 IE-LOOPWR,AFW-PMP-CF-ALL,DCP-BAT-LP-2BATB4HR,EPS-XHE-XM DG32J,PPR-MOV-FC-RC1536 14 6.16E-8 1.02 I E-LOOPWR,AFW-M DP-TM-2P3A,AFW-XHE-XM-CNTR L, DC P-BAT -LP 2 BATB4H R, EPS-DGN-FR-S BO, EP S-DGN-TM-DG3, PPR-MOV-FC-R C 1536 Cutset Report - LOOPWR 17-45 Only items contributing at least 1% to the total are displaye....d_. _-_______~__~_-~~~~

CCDP Total%

Cutset J ~.85-E-6 100 Displaying 1740 of 1740 Cutsets.

1 7.86E-7 16.2 IE-LOOPWR,ACP-DG3-AUGN-AWAY,AFW-TDP-FR-2P2,EPS-DGN-CF FRALL,EPS-XHE-XL-NR01 H 2

1.96E-7 4.04 IE-LOOPWR,ACP-DG3-AUGN-AWAY,AFW-TDP-FR-2P2,EPS-DGN-CF FSALL,EPS-XHE-XL-NR01 H 3

1.42E-7 2.92 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS XHE-XL-NR01 H,EPS-XHE-XM-DG32J 4

1.29E-7 2.66 IE-LOOPWR,ACP-DG3-ALIGN-AWAY,AFW-TDP-FS-2P2,EPS-DGN-CF L FRALL,EPS-XHE-XL-NRO~

5 1.18E-7 2.44 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS XHE-XL-NR01 H,EPS-XHE-XM-DG32J 6

1.07E-7 2.21 IE-LOOPWR,ACP-DG3-AUGN-AWAY,AFW-TDP-TM-2P2,EPS-DGN-CF FRALL,EPS-XHE-XL-NR01 H 7

1.01E-7 2.09 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS XHE-XL-NR01 H,EPS-XHE-XM-SB02H 8

1.01 E-7 2.09 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS XHE-XL-NR01 H,EPS-XHE-XM-SB02H 9

1.01E-7 2.09 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-TM-SBO,EPS XHE-XL-NR01 H,EPS-XHE-XM-DG32J A-12

LER 280/11-001 CCDP Total%

Cutset I 8.46E-8 1.74 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS 10 XHE-XL-NR01 H,EPS-XHE-XM-DG32J r1"1 7.26E-8 1.5 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS DGN-TM-SBO,EPS-XHE-XL-NR01 H I 7.26E-8 1.5 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS 12 DGN-TM-SBO,EPS-XHE-XL-NR01 H 13 I 7.23E-8 1.49 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS XHE-XL-NR01 H,EPS-XHE-XM-SB02H 14 t 6.07E-8 1.25 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS DGN-TM-DG3,EPS-XHE-XL-NR01 H

.1

~~

6.07E-8 1.25 IE-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS DGN-TM-DG2,EPS-XHE-XL-NR01 H 1.07

- 'E-LOOPWR,AFW-TDP-FR-2P2,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS

~. ~9E-8 I 1DGN-TM-SBO,EPS-XHE-XL-NR01 H Cutset Report - LOOPWR 17-03-04 Only items contributing at least 1% to the total are display.;.ed.;;...___--__-------~--~_____;

CCDP Total%

Cutset 4.25E-6 1 100 Disp-la-y-in-g-6 of 603 Cutsets.

7.59E-7 17.9 I E-LOOPWR,ACP-DG3-ALI GN-AWA Y,E PS-DGN-C F-FRALL, E PS-XH E-XL NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,IRCS-MDP-LK-BP2 2

1.91E-7 4.49 IE-LOOPWR,EPS-DGN-TM-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XL NR24H4,EPS-XHE-XM-DG32J,EPS-XHE-XM-SB02H,OEP-XHE-XL NR24H4WR,IRCS-MDP-LK-BP2 3

1.89E-7 4.45 IE-LOOPWR,ACP-DG3-ALIGN-AWAY,EPS-DGN-CF-FSALL,EPS-XHE-XL NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,IRCS-MDP-LK-BP2 4

1.37E-7 3.22 I E-LOOPWR, EPS-DGN-TM-DG2, EPS-DGN-TM-SBO, EPS-XHE-XL-N R04H,EPS XHE-XL-NR24H4,EPS-XHE-XM-DG32J,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 5 I 1.36E-7 3.2 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-XHE-XL-NR04H,EPS-XHE-XL L;j R24H4,EPS-XHE-XM-DG32J,EPS-XHE-XM-SB02H,OEP-XHE-XL NR24H4WR,IRCS-MDP-LK-BP2 I

6 i 1.14E-7 1 2.69 IE-LOOPWR,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-DG32J,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 7

9.78E-8 2.3 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB02H,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 8 I 9.78E-8 2.3 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB02H,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 9

9.78E-8 2.3 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-SBO,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-DG32J,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 10 I 8.17E-8 1.92 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-DG32J,OEP-XHE-XL-NR24H4WR,IRCS-MDP 11l 7.02E-8 I 1.65 LK-BP2 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-TM-DG2,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 12 7.02E-8 1.65 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-TM-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 A-13

LER 280/11-001 CCDP Total%

Cutset 13 6.98E-8 1.64 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-XHE-XL-NRO4H,EPS XHE-XL-NR24H4,EPS-XHE-XM-SB02H,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 14 5.86E-8 1.38 IE-LOOPWR,EPS-DGN-FR-DG3,EPS-DGN-FR-SBO,EPS-DGN-TM-DG2,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,IRCS-MDP LK-BP2 15 5.86E-8 1.38 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-SBO,EPS-DGN-TM-DG3,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP LK-BP2 16 5.01E-8 1.18 IE-LOOPWR,EPS-DGN-FR-DG2,EPS-DGN-FR-DG3,EPS-DGN-TM-SBO,EPS XHE-XL-NR04H,EPS-XHE-XL-NR24H4,OEP-XHE-XL-NR24H4WR,/RCS-MDP LK-BP2 Referenced Events Event Description Probability ACP-CRB-00-25J3 XFR BUS TO 2J BKR 2-EP-BKR-25J3 FAILS OPENS 2.39E-3 ACP-DG3-ALIGN-AWAY DG3 ALIGNED TO OPPOSITE UNIT 5.00E-1 AFW-MDP-TM-2P3A UNIT 2 AFW MD PUMP 2-FW-P-3A TESTAND MAINTENANCEl 3.98E-3 AFW-PMP-CF-ALL COMMON CAUSE FAILURE OF AFW PUMPS( BOTH UNITS) 1.08E-5 AFW-SYS-LK-SGCKVS STEAM LEAKAGE THRU CKVS 27.58 & 89 (PSA) 1.00E-4 AFW-TDP-FR-2P2 UNIT 2 AFW TD PUMP 2-FW-P-2 FAILS TO RUN I

3.95E-2 AFW-TDP-FS-2P2 UNIT 2 AFW TO PUMP 2-FW-P-2 FAILS TO START 6.49E-3 AFW-TDP-TM-2P2 UNIT 2 AFW TO PUMP 2-FW-P-2 TEST AND MAINTENANCE 5.39E-3 AFW-XHE-XM-CNTRL OPERATOR FAILS TO CONTROL AFW TOP 3.00E-1 AFW-XHE-XM-XTIE OPERATOR FAILS TO INITIATE AFW CROSSCONNECT 1.20E-1 CDS-XVM-CC-CN150 ECST M/U VALVE 2-CN-150 FAILS CLOSED 1.92E-4 CPC-MDP-FS-SWP10A r CPC SWS TRAIN 1-SW-P-10A FAILURES TO START i

1.36E-3 CPC-MDP-TM-SWP1 OA l CPC SWS MDP 1-SW-P-10A UNAVAILABLE DUE TO T&M' 7.12E-3

]

DCP-BAT-LP-2BAT A4HR L BATTERY 2A 2-E~ D-B-2A FAILURE AT 4 HOURS 1.00E+O DCP-BAT -LP-2BATB4HR BATTERY 2B 2-EPD-B-2B FAILURE AT 4 HOURS 1.00E+O EPS-DGN-CF-FRALL COMMON CAUSE FAILURE OF DIESEL GENERATORS TO RUN I

4.57E-5 j

EPS-DGN-CF-FSALL COMMON CAUSE FAILURE OF DIESEL GENERATORS TO 1.14E-5 START EPS-DGN-FR-DG2 DIESEL GENERATOR 2 FAILS TO RUN 1.02E-2

EPS-DGN-FR-DG3 DIESEL GENERATOR 3 FAILS TO RUN 1.02E-2 EPS-DGN-FR-SBO SBO DIESEL GENERATOR FAILS TO RUN 1.20E-2 EPS-DGN-FS-DG3 DIESEL GENERATOR 3 FAILS TO START 2.89E-3 EPS-DGN-TM-DG2 DIESEL GENERATOR 2 UNAVAILABLE DUE TO T & M 1.43E-2 EPS-DGN-TM-DG3 DIESEL GENERATOR 3 UNAVAILABLE DUE TO T & M 1.43E-2 EPS-DGN-TM-SBO SBO DIESEL GENERATOR UNAVAILABLE DUE TO T & M 1.43E-2 EPS-SEQ-FO-DG3 DG3 SEQUENCENCER FAILS 1.76E-3 EPS-XHE-XL-NR01 H OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 1 8.71 E-1 HOUR EPS-XHE-XL-NR04H I OPERATOR FAILS TO RECOVER EMEIRGENCY DIESEL IN 4 6.98E-1 HOURS EPS-XHE-XL-NR24H4 OPERATOR FAILS TO RECOVER EMERGENCY DIESEL IN 24 4.16E-1 HOURS (GIVEN FAILURE AT 4)

I EPS-XHE-XM-DG32J OPERATOR FAILS TO ALIGN DG 3 TO BUS 2J 2.00E-2 A-14

LER 280/11-001 Event EPS-XHE-XM-SB01 J EPS-XHE-XM-SB02H HPI-XHE-XM-FB IAS-MDC-FR-1 C1 IAS-MDC-FS-1 C1 IAS-MDC-TM-1 C1 IE-LOOPWR OEP-XHE-XL-NR24H4WR PPR-MOV-FC-RC 1536 RCS-MDP-LK-BP2 Description OPERATOR FAILS TO ALIGN SBO DIESEL TO BUS 1J OPERATOR FAILS TO ALIGN SBO DIESEL TO BUS 2H OPERATOR FAILS TO INITIATE FEED AND BLEED COOLING INSTRUMENT AIR COMPRESSOR 1-IA-C-1 FAILS TO RUN INSTRUMENT AIR COMPRESSOR 1-IA-C-1 FAILS TO START INSTRUMENT AIR COMPRESSOR 1-IA-C-1 UNAVAILABLE DUE TOT&M LOSS OF OFFSITE POWER INITIATOR (WEATHER-RELATED)

OPERATOR FAILS TO RECOVER OFFSITE POWER IN 24 HOURS (GIVEN FAILURE AT 4, WEATHER)

BLOCK VALVE 1536 CLOSED DUE TO PORV LEAKING RCP SEAL STAGE 2 INTEGRITY (BINDING/POPPING OPEN)

FAILS Probability 2.00E-2 2.00E-2 4.00E-2 5.89E-2 1.71E-2

~

I 1.20E-2 1.00E+O 1.43E-1 3.00E-1 2.00E-1 A-15

LER 280/11-001 Appendix B: Key Event Trees

~o 0

0 0

0 l <>iCl 0

0 0

~~

~ 0

~

Pa>",

0 0

a---cao----C[

"'l 0

0 0

~"

~ 0

~

AfWl 0

0 O----[;-C:,

0 0

0 Figure B-1. Surry Weather-Related LOOP event tree.

8-1

LER 280/11-001

"""",8 0

0 0

_~o o

0--

o o

0 0

Figure 8-2.

~o

~O 0

0 0

0 Surry SBO event tree, 8-2

D. Heacock

- 2 The enclosure containing the final analysis report is provided for your information.

Docket Nos. 50-280 and 50-281

Enclosure:

Final Precursor Analysis cc: Distribution via Listserv DISTRIBUTION:

Public LPL2-1 R/F RidsAcrs_AcnwMailCTR Resource RidsNrrDorlDpr Resource JUhle, RES ADAMS Accession No ML12166A519 Sincerely, IRA by V. Sreenivas fori Karen Cotton, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation RidsNrrPMSummer Resource RidsOgcRp Resource RidsNrrLASFigueroa Resource SWeerakkody, NRR RidsRgn2MailCenter Resource GDeMoss, RES KTetter,RES RCorreia

~ OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/LPL2-1/BC NRR/LPL2-1/PM

!I NAME II KCotton (VSreevinas for)

SFigueroa NSalgado KCotton (VSreevinas for)

LDATE 06/14/12 06/14112 06/14112 06/14/12 OFFICIAL RECORD COpy

ML12166A519

Contents

Text

SUBJECT:

Dear Mr. Heacock:

Enclosure:

SUMMARY

Enclosure:

Navigation menu

ML12166A519

Text

SUBJECT:

Dear Mr. Heacock:

Enclosure:

SUMMARY

Enclosure:

Navigation menu

Search