ML21041A453

Brunswick/Nrc Pre-submittal Meeting: LAR to Adopt TSTF-505, Rev. 2 (Risk-Informed Completion Times) Presentation

ML21041A453
Person / Time
Site:	Brunswick
Issue date:	02/17/2021
From:	Duke Energy Progress
To:	Andrew Hon NRC/NRR/DORL/LPL2-2
Hon A
References
Download: ML21041A453 (19)

Text

Brunswick/NRC Pre-submittal Meeting: LAR to Adopt TSTF-505, Rev. 2 (Risk-Informed Completion Times)

February 17, 2021

Duke Energy Attendees Art Zaremba (Manager, Nuclear Fleet Licensing)

Bob Rishel (Director, Probabilistic Risk Assessment)

Heather Szews (Manager, Probabilistic Risk Assessment)

Jordan Vaughan (Lead Nuclear Engineer, Nuclear Fleet Licensing)

Art Mironenko (Senior Nuclear Engineer, Probabilistic Risk Assessment)

Alan Schultz (Nuclear Shift Manager, Operations) 2 2

Agenda Introduction (Desired Meeting Outcomes)

PRA Models and Real-Time Risk Model Overview License Amendment Request Overview Recent OE (TSTF-505 LARs and associated audits)

Implementation Timeline for LAR Submittal/Closing Remarks 3

Overview of PRA Portion of BSEP TSTF-505 LAR Consistent with TSTF-505 Rev. 2 Template No Loss of Function TS Actions are proposed PRA models updated/upgraded and peer-reviewed F&O Closure independently validated Total CDF/LERF meet RG 1.174 criteria Seismic: Penalty applied for CDF and LERF High Winds: LOOPs included in IE PRA (Other High Wind effects screened)

External Flooding: Hazard screened per the standard Unit-specific PRAs will be used for application Sample calculations presented in LAR are from Unit 1, consistent with other applications 4

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Internal Events/ Internal Flood PRA 2010 - BSEP IE and IF PRA model was subject to a full-scope peer review against RG 1.200 Rev. 2 IAW guidance in NEI-05-04.

2016 - Internal Flooding PRA, a focused scope industry peer review was conducted against RG 1.200 Rev. 2.

Closed findings were reviewed and closed in August 2017, December 2019 and May 2020 for the IE and IF PRA models using the process documented in Appendix X to NEI 05-04, NEI 07-12 and NEI 12-13, Close-out of Facts and Observations (F&Os) as accepted by NRC (ML17079A427).

There are zero open findings and all applicable supporting requirements are met at capability category II.

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Fire PRA 2011 - BSEP Fire PRA was subject to full-scope peer review against RG 1.200 Rev. 2 IAW guidance in NEI-07-12.

2015 - Fire PRA, a focused scope industry peer review was conducted against RG 1.200 Rev. 2.

Closed findings were reviewed and closed in July 2017 and August 2018 for the Fire PRA models using the process documented in Appendix X to NEI 05-04, NEI 07-12 and NEI 12-13, Close-out of Facts and Observations (F&Os) as accepted by NRC (ML17079A427).

There are zero open findings and all applicable supporting requirements are met at capability category II.

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F&O Closure Review Formal process by independent review team Assessed disposition of Findings for Internal Events, Internal Flooding, and Fire PRAs Addressed in detail in the LAR assessment Technical Adequacy section The process evaluated whether the disposition of each finding constitutes an update or upgrade 7

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Other Hazards Seismic Seismic penalty will be applied to all RICTs High Winds LOOPs included in IE PRA Hurricane, Straight-line winds and Tornado high wind hazard screened 8

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Other Hazards (continued)

External Flooding External Flooding hazard can be screened from calculations in the RICT Program.

Other Hazards No other external hazards required to be included in the RICT calculations.

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RICT Program Real-Time Risk Model Real-Time Risk Model as currently used for existing Maintenance Rule a(4)

Configuration Risk Management Program Uses PHOENIX Risk Analysis Software Incorporates RICT/RMAT calculation features 10 10

License Amendment Request Based on TSTF-505, Revision 2 and NEI 06-09 20 different Technical Specifications (TS) impacted by proposed change for both Units 1 and 2 Various instrumentation TS are proposed to be in scope of RICT Program Modes 1 and 2 only New TS Section 5 Program for RICT Program Variances from TSTF-505, Revision 2 Subtle differences in Condition/Required Action wording TSTF-505 Conditions/LCOs exist that are not in the BSEP TS Re-typed/clean TS pages not included RICTs proposed for some plant-specific TS Actions not in TSTF-505, Rev. 2 11 11

TS 3.5.1, ECCS - Operating Conditions B and H are plant-specific and are not in NUREG-1433/TSTF-505, Rev. 2 Condition B applies to one CS subsystem inoperable concurrent with one LPCI pump 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to restore the CS subsystem or LPCI pump to operable status remaining OPERABLE low pressure ECCS subsystems and the remaining pump in the inoperable LPCI subsystem provide adequate core cooling during a LOCA Condition H applies to the HPCI System inoperable concurrent with one required ADS valve 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to restore the HPCI System or ADS valve to operable status 12 Remaining ADS valves and low pressure ECCS subsystems perform safety function 12

TS 3.7.2, Service Water System and Ultimate Heat Sink Condition A (opposite unit in Mode 4 or 5) - with a unit in this condition, sufficient cooling water can still be provided to the DGs Condition C - Operable CSW pump and NSW pumps are adequate to perform the heat removal function Condition E - the OPERABLE NSW pumps are adequate to perform the heat removal function.

Condition F - OPERABLE SW pumps (both CSW and NSW pumps) are adequate to perform the heat removal function 13 Condition G - adequate heat removal capability from remaining SW pumps 13

TS 3.8.7, Distribution Systems The above LCO and Condition A is for Unit 1; Unit 2 is similar except the inoperable load groups buses are E1 and E2 In Condition A, and with Unit 2 in MODE 4 or 5, the remaining AC electrical power distribution load groups can support the minimum safety functions necessary to shut down the operating reactor and maintain both reactors in a safe condition, assuming no single failure in the remaining AC electrical power distribution load groups.

If Unit 2 is in MODE 1, 2 or 3, then the ACTIONS of Unit 2 Specification 3.8.7 requires restoration of the associated AC electrical power distribution subsystem within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of the inoperability 14 14

Recent OE Key issues from other TSTF-505 audits, including Harris:

Potential loss of function Conditions - none for BSEP Defense-in-depth principles associated with instrumentation TS Reactor Protection System (RPS) Instrumentation - TS 3.3.1.1 Feedwater and Main Turbine High Water Level Trip Instrumentation - TS 3.3.2.2 Anticipated Transient Without Scram Recirculation Pump Trip (ATWS-RPT) Instrumentation - TS 3.3.4.1 Emergency Core Cooling System (ECCS) Instrumentation - TS 3.3.5.1 Reactor Core Isolation Cooling (RCIC) System Instrumentation - TS 3.3.5.2 Primary Containment Isolation Instrumentation - TS 3.3.6.1 Treatment/Credit for FLEX in the PRA Models OE from Harris TSTF-505 LAR/RAI Responses and other industry TSTF-505 LAR OE 15

Implementation Operations owns implementation Cross-functional team supporting implementation RICT implemented in Modes 1 and 2 only Real-Time Risk and PRA Models updated to support the RICT Program Procedure changes and training Industry OE (Benchmark, Risk-Informed TS Task Force, TSTF) 16 16

Procedures and Training Existing fleet RICT Program procedures and revised site-specific procedures will address the following:

The new BSEP RICT Program (responsibilities, definitions, plant conditions for which the program applies etc.)

Calculation of risk management action times (RMAs) and RICTs Development and implementation of RMAs Use of the CRMP software tool (i.e., PHOENIX or the real-time risk model) with the RICT Program Three levels of training for the RICT Program is proposed:

Level 1 - User Training Level 2 - Management Training Level 3 - Site Awareness Training 17 17

Closing Remarks Next Steps:

Submit LAR by early April 2021 Revise site-specific implementing procedures in parallel and subsequent to NRC staff review of LAR; leverage existing fleet procedures that were developed for Harris for the RICT Program Conduct training for RICT Program Ready to implement RICT Program within 180 days of receipt of SE 18 18

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