ML19253A963

TSTF505 LAR Audit Summary

ML19253A963
Person / Time
Site:	Byron, Braidwood, Limerick
Issue date:	09/30/2019
From:	V Sreenivas Plant Licensing Branch 1
To:	Bryan Hanson Exelon Nuclear
Sreenivas V, NRR/DORL/LPL1, 415-2597
References
EPID L-2018-LLA-0567, EPID L-2018-LLA-0727
Download: ML19253A963 (10)

Text

September 30, 2019 Mr. Bryan C. Hanson Senior Vice President Exelon Generation Company, LLC President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2; BRAIDWOOD STATION, UNITS 1 AND 2; AND BYRON STATION, UNITS 1 AND 2 - AUDIT

SUMMARY

IN SUPPORT OF THE LICENSE AMENDMENT REQUEST TO ADOPT RISK INFORMED COMPLETION TIMES TECHNICAL SPECIFICATION TASK FORCE-505, REVISON 2, PROVIDE RISK-INFORMED COMPLETION TIMES - RITSTF INITIATIVE 4B FOR EXELON GENERATION COMPANY (EPID L-2018-LLA-0567 AND EPID L-2018-LLA-0727)

Dear Mr. Hanson:

By letters dated December 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML18347B366 and ML18352B063), as supplemented by letters dated February 14, 2019 (ADAMS Accession Nos. ML19045A011 and ML19050A399), Exelon Generation Company, LLC (the licensee) submitted license amendment requests to revise the technical specifications to adopt Technical Specifications Task Force (TSTF) Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF

[Risk-Informed Technical Specifications Task Force] Initiative 4b (ADAMS Accession Nos. ML18183A493 and ML18269A041) for Limerick Generating Station, Units 1 and 2 (Limerick); Braidwood Station, Units 1 and 2 (Braidwood); and Byron Station, Units 1 and 2 (Byron).

The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensee's submittal and determined that a regulatory audit would assist in the timely completion of the licensing review process. The NRC staff issued the regulatory audit plan on May 20, 2019 (ADAMS Accession No. ML19133A086).

The NRC staff conducted the regulatory audit from June 17 - 21, 2019, at the licensees headquarters in Kennett Square, Pennsylvania. The results of the regulatory audit will be used by the NRC staff to finalize requests for additional information.

The audit summary report is provided as an enclosure to this letter.

If you have any questions regarding Limerick, please contact V. Sreenivas at 301-415-2597 or via email at V.Sreenivas@nrc.gov. If you have any questions regarding Braidwood and Byron, please contact Joel Wiebe at 301-415-6606 or via email at Joel.Wiebe@nrc.gov.

Sincerely,

/RA/

V. Sreenivas, Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353 (Limerick) 50-456 and 50-457 (Braidwood)

50-454 and 50-455 (Byron)

Enclosure:

Audit Summary cc: Listserv

Enclosure AUDIT

SUMMARY

ADOPT TSTF-505, REVISION 2 EXELON GENERATION COMPANY, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 BRAIDWOOD STATION, UNITS 1 AND 2 BYRON STATION UNITS 1 AND 2 DOCKET NOS. 50-352 AND 50-353 (LIMERICK), DOCKET NOS. 50-456 AND 50-457 (BRAIDWOOD), AND DOCKET NOS. 50-454 AND 50-455 (BYRON)

JUNE 17 - 21, 2019

1.0 INTRODUCTION

By letters dated December 13, 2018 (Reference 1 and Reference 2), as supplemented by letters dated February 14, 2019 (Reference 3 and Reference 4), Exelon Generation Company, LLC (Exelon, the licensee) submitted license amendment requests (LARs) to adopt Technical Specifications Task Force (TSTF) Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF [Risk-Informed Technical Specifications Task Force]

Initiative 4b (Reference 5 and Reference 6) for Limerick Generating Station, Units 1 and 2 (LGS, Limerick); Braidwood Station, Units 1 and 2 (Braidwood); and Byron Station, Units 1 and 2 (Byron).

The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensee's submittal and determined that a regulatory audit would assist in the timely completion of the licensing review process. The NRC staff issued the regulatory audit plan on May 20, 2019 (ADAMS Accession No. ML19133A086).

The NRC staff conducted the regulatory audit from June 17 - 21, 2019, at the licensees headquarters in Kennett Square, Pennsylvania. The results of the regulatory audit will be used by the NRC staff to finalize requests for additional information (RAIs).

The regulatory audit was performed consistent with NRC Office of Nuclear Reactor Regulation (NRR) Office Instruction LIC-111, Regulatory Audits (ADAMS Accession No. ML082900195).

2.0 AUDIT ACTIVITIES AND OBSERVATIONS The purpose of the audit was to understand the calculations, analyses, and bases for the LAR, and to develop RAIs, as needed. The NRC staffs discussions with the licensee focused on internal events and fire probabilistic risk assessment (PRA) quality, PRA functionality, implementation of the risk informed completion time (RICT) program, TS limiting conditions for operation, and associated RICT program guidance documents. The licensee provided a demonstration of how it would implement the RICT. The NRC staff reviewed the applicable program documents.

The following are the specific presentation and discussion topics discussed during the audit:

The licensees presentation on an overview of the risk-informed completion time (RICT) program.

The licensees presentation on Limerick (LGS) unit dependencies including common power sources and essential service water features.

LGS Limiting Conditions for Operation (LCOs) inclusion in program scope, design criteria, and Probabilistic Risk Analysis (PRA) success criteria.

LGS PRA facts and observations (F&O) closures.

LGS PRA modeling of uncertainties.

LGS potential credit for diverse and flexible coping strategies (FLEX) equipment or actions.

Instrumentation and Controls and electrical engineering topics related to plant configuration and operations pertaining to systems related LCOs.

The licensees presentation on the real time risk PARAGON tool, with examples of RICT calculations and derivation of risk management actions (RMAs) from PRA insights.

Discussion of common audit questions between LGS and Byron and Braidwood (B/B) to support the NRC staffs draft RAI development:

Discussion of LGS audit questions to support the NRC staffs draft RAI development.

The licensees presentation of B/B reactor unit dependencies.

Discussion of B/B potential Loss of Function LCOs.

Internal events and fire PRA modeling for B/B.

Disposition of PRA assumptions and sources of uncertainties for B/B.

Audit Exit:

The NRC staff discussed each question/discussion topic in the Audit plan, and shared preliminary thoughts on any changes to the original set of questions/discussion topics. There were no regulatory decisions made regarding the final set of questions. The NRC staff stated that they planned to issue a formal RAI within 30 days of the Audit. The RAIs were issued on July 10, 2019 (ADAMS Accession No. ML19192A031).

3.0 AUDIT PARTICIPANTS NRC

Participants:

Biro, Mihaela PRA Licensing Reviewer, DRA/APLA Brimfield, Terrence*

Reactor Systems Reviewer, DSS/SRXB Bucholtz, Kristy Technical Specifications Reviewer, DSS/STSB Curran, Gordon*

Balance of Plant Reviewer, DSS/SBPB de Messieres, Candace PRA Licensing Reviewer, DRA/APLA Dinsmore, Stephen*

PRA Licensing Reviewer, DRA/APLA Evans, Jonathan PRA Licensing Reviewer, DRA/APLA Matharu, Gurcharan Electrical Systems Reviewer, DE/EEOB Matthew, Roy Electrical Systems Reviewer, DE/EEOB Li, Ming I&C Technical Reviewer, DE/EICB Singh, Gursharan I&C Technical Reviewer, DE/EICB Suber, Gregory Deputy Division Director, DORL Tetter, Keith PRA Licensing Reviewer, DRA/APLB Tjader, Theodore Technical Specification Reviewer, DSS/STSB Vasavada, Shilp PRA Licensing Reviewer, DRA/APLB Wu, De PRA Licensing Reviewer, DRA/APLB Rosenberg, Stacey Branch Chief, DRA/APLA Sreenivas, V Project Manager, DORL Mehta, Shivani Project Manager, DRA/APLB Kodali, Hari Observer, DRA/APLA Joel Wiebe Senior Project Manager, DORL Smith, Cassandra Observer, DRA/APLA Pacific Northwest National Lab Team Coles, Garill PRA Reviewer Short, Steve PRA Reviewer

• Participated remotely via conference line.

Acronyms:

APLA - PRA Licensing Branch A; APLB - PRA Licensing Branch B; DE - Division of Engineering; DORL - Division of Operating Reactor Licensing; DRA - Division of Risk Assessment; DSS - Division of Safety Systems; EEOB - Electrical Engineering Operating Reactor Branch; EICB - Instrumentation and Controls Branch B; SBPB - Containment and Plant Systems Branch; SRXB - Reactor Systems Branch; STSB - Technical Specification Branch Licensee

Participants:

Exelon:

Jeffrey Stone Thomas Cole Shannon Rafferty-Czincila Giovanni (John) Panici Eugene Kelly Jonathan Cunzeman James Landale Terrence Myelle Philip Tarpinian Kevin Passmore Mark Gift Jimmy Boleware Gregory Curtin Tony Ziegelbauer Robert Mandik Edward Englert Lisa Simpson Burt Runde Philip Raush David Smith Darrel Riedinger Jensen Hughes:

Don Vanover Gregory Zucal Barry Sloane Jonathen Facemire Nick Sternowski Eric Thornsbury Vicki Warren Jeffery Schappaugh Brian Albinson Edward Parsley Michael Saunders Usama Farradj Arthur Holtz Andrew Nigh Leo Shanley 4.0 DOCUMENTS REVIEWED

1.

Procedures Common ER-AA-600-1014, R8 Risk Management Configuration Control ER-AA-600-1015, FPIE PRA Model Update ER-AA-600-1016, R12 Configuration Risk Model (PARAGON) Update ER-AA-600-1023, R9 PARAGON Model Capability ER-AA-600-1052, R0 Risk Management Support of RICT ER-AA-600-1053, R0 Calculation of RMAT and RICT ER-AA-600-1061, R5 Fire PRA Model Update and Control OP-AA-108-104, Rev 002, Technical Specification Compliance OP-AA-108-117, Rev 005, Protected Equipment Program OP-AA-108-118, R0 RICT Program OP-AA-201-012-1001, Rev 002, Operations On-lime Fire Risk Management WC-AA-101-1006, Rev 002, On-line Risk Management and Assessment

2.

PRA Documents LGS 1984 PRA (NUS-4507): Limerick Generating Station (LGS) - Ultimate Heat Sink Extreme Wind Hazard Analysis LG-LAR-009 - REV 001: RICT Estimates for TSTF-505 (RICT) Program license amendment request (LAR) Submittal LGS FPRA EPRI 1026511 Evaluation: Key Assumptions and Sources of Uncertainty (DRAFT)

RICT program Enclosure 9 Support Application DRAFT Rev 1: Assessment of Key Assumptions and Sources of Uncertainty for RICT Limerick PSA 1998 Peer Review Gap analysis that compared the LGS PRA to the requirements of the U.S.

Nuclear Regulatory Commission (NRC)-endorsed ASME PRA Standard, 2003 Limerick PRA model NRC RG 1.200 pilot assessment, July 2004 Limerick Generating Station PRA Peer Review Using ASME PRA Standard Requirements, November 2005 Limerick Generating Station Internal Flood PRA Peer Review Using ASME PRA Standard Requirements, August 2008 Peer review of Limerick Fire (FPRA) model, November 2011 Jensen Hughes Report 032156-RPT-00, Limerick Generating Station PRA Finding Level Fact and Observation Technical Review, August 2016 1BTI32299.005.044.100, Limerick Generating Station Fire PRA Focused Scope Peer Review Report: Use of THIEF, 2017 Limerick Generating Station, PRA Focused-Scope Peer Review & Finding Level Fact and Observation Independent Assessment, Revision 0, October 2018 B/B BWD Fire PRA Peer Review PWROG-15058-PBYR BWD F&O Closure Report_Rev2 Signed BYR BWD IE IF PRA Peer Review OG-13-449 Enclosure LTR-RAM-II-13-067 Rev 1 Byron Fire PRA Peer Review PWROG-15088-P

3.

Systems LGS 4.16 KV AC Distribution Familiarization Rev000 (Extracts)

Emergency Service Water System Rev002 (Extracts)

Residual Heat Removal Service Water System (RHRSW) Rev 002 (Extracts)

Secondary Containment heating, ventilation, and air conditioning 076-01 Rev 003 SIM-M-0012, Sheet 0001, Rev 013, Emergency Service Water RHR Service Water Overview

4.

Instrumentation LGS Revised Instrumentation TS Markups

5.

References LGS UFSAR Revision 19, September 2018 Limerick Vacuum Breakers Amendment Nos. 46 and 9 (ML011550302)

B/B BB TSTF-505 LAR Supplement with Attachments (2-14-19)

BB UFSAR Rev 17 Dec 2018 Correction to NRC SE dated 4-9 Associated with TSTF-418 NRC SE dated 1-29 TSTF-411 and TSTF-418 NRC SE dated 3-30 Revision to 3.3.1 and 3.3.2 Associated with TSTF-418

6.

Drawings LGS E-0001, Sheet 0001, Rev 031, Single Line Diagram Station E-0015, Sheet 0001, Rev 030, Single Line Meter and Relay Diagram 4KV Safeguard Power Systems E-0016, Sheet 0001, Rev 026, Single Line Meter and Relay Diagram 4KV Safeguard Power Systems M-0011, Sheet 0001, Rev 088, P&ID Emergency Service Water M-0012, Sheet 0001, Rev 092, P&ID Residual Heat Removal Service Water -

SGST 076-01 Rev 003 SIM-E-0001, Sheet 0001, Rev 003, Simplified Single Line Diagram 66KV, 220KV and 500KV Subs SIM-M-0012, Sheet 0001, Rev 013, Emergency Service Water Residual Heat Removal (RHR) Service Water Overview Instrumentation Drawings (35 drawings)

5.0 REFERENCES

1.

Letter from James Barstow, Director, Licensing and Regulatory Affairs, Exelon Generation Company, LLC, to U.S. Nuclear Regulatory Commission, Limerick Generating Station Units 1 and 2, License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505 Revision 2, Provide Risk-Informed Extended Completion Times -RITSTF Initiative 4b, dated December 13, 2018 (ADAMS Accession No. ML18347B366).

2.

Letter from David M. Gullott, Director, Licensing and Regulatory Affairs, Exelon Generation Company, LLC, to U.S. Nuclear Regulatory Commission, Application to Revise Braidwood Station and Byron Station Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505 Revision 2, Provide Risk-Informed Extended Completion Times -RITSTF Initiative 4b, dated December 13, 2018 (ADAMS Accession No. ML18352B063).

3.

Letter from David P. Helker, Manager, Licensing and Regulatory Affairs, Exelon Generation Company, LLC, to U.S. Nuclear Regulatory Commission, Supplement to License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, dated February 14, 2019 (ADAMS Accession No. ML19045A011).

4.

Letter from Patrick R. Simpson, Manager, Licensing and Regulatory Affairs, Exelon Generation Company, LLC, to U.S. Nuclear Regulatory Commission, Supplement to Application to Revise Braidwood Station and Byron Station Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b, dated February 14, 2019 (ADAMS Accession No. ML19050A399).

5.

Comments on Draft Safety Evaluation for Technical Specifications Task Force (TSTF)

Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times -

RITSTF Initiative 4b, dated July 2, 2018 (ADAMS Accession No. ML18183A493).

6.

Letter from U.S. Nuclear Regulatory Commission to Technical Specifications Task Force, Final Revised Model Safety Evaluation of Traveler TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4B, dated November 21, 2018 (ADAMS Package Accession No. ML18269A041).

7.

U.S. Nuclear Regulatory Commission, NRR Office Instruction, LIC-101, Revision 4, License Amendment Review Procedures, dated May 22, 2012 (ADAMS Accession No. ML113200053).

8.

U.S. Nuclear Regulatory Commission, NRR Office Instruction, LIC-111, Regulatory Audits, effective date December 29, 2008 (ADAMS Accession No. ML082900195).

9.

Nuclear Energy Institute, NEI 06-09, Revision 0-A, Risk-Informed Technical Specification Initiative 4b Risk-Managed Technical Specification Guidelines, dated November 2006 (ADAMS Accession No. ML12286A322).

10.

U.S. Nuclear Regulatory Commission, Final Safety Evaluation for Nuclear Energy Institute Topical Report 06-09, Risk-Informed Technical Specification Initiative 4b Risk-Managed Technical Specification Guidelines, Revision 0, dated May 17, 2007 (ADAMS Accession No. ML071200238).

11.

U.S. Nuclear Regulatory Commission, Regulatory Guide 1.200, Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, dated March 2009 (ADAMS Accession No. ML090410014).

12.

U.S. Nuclear Regulatory Commisison, Regulatory Guide 1.174, Revision 3, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, dated January 2018 (ADAMS Accession No. ML17317A256).

13.

U.S. Nuclear Regulatory Commission, Regulatory Guide 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decision-Making: Technical Specifications, dated May 2011 (ADAMS Accession No. ML100910008).

ML19253A963

• concurrence by e-mail OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL3/PM* NRR/DORL/LPL1/LA* NRR/DRA/APLA/BC NAME VSreenivas JWiebe CSmith SRosenberg DATE 09 /06 / 2019 09 / 10 / 2019 09 /30 / 2019 08 / 23 / 2019 OFFICE NRR/DORL/LPL1/BC NRR/DORL/LPL3/BC NRR/DORL/LPL1/PM NAME JDanna LRegner VSreenivas DATE 09 / 30 / 2019 09 /12 / 2019 09/ 30 / 2019