ML15152A505

Summary of May 20, 2015, Meeting with Exelon Generation Company, LLC, on Digital Upgrade of Non-Safety Control Systems

ML15152A505
Person / Time
Site:	Byron, Braidwood
Issue date:	08/17/2015
From:	Joel Wiebe Plant Licensing Branch III
To:
Joel Wiebe,NRR/DORL
References
TAC MF5819, TAC MF5820, TAC MF5821, TAC MF5822
Download: ML15152A505 (4)

Text

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• • • • ~ August 17, 2015 LICENSEE: Exelon Generation Company, LLC FACILITY: Braidwood Nuclear Station, Units 1 and 2, and Byron Nuclear Station, Unit Nos. 1and2

SUMMARY

OF MAY 20, 2015, MEETING WITH EXELON GENERATION COMPANY, LLC, ON DIGITAL UPGRADE OF NONSAFETY-RELATED CONTROL SYSTEMS (TAC NOS. MF5819, MF5820, MF5821, AND MF5822)

On May 20, 2015, a Category I public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Exelon Generation Company, LLC (Exelon; the licensee) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss Exelon's plans for upgrading the nonsafety-related (NSR) control systems at Braidwood Nuclear Station, Units 1 and 2 (Braidwood), and Byron Nuclear Station, Units No. 1 and 2 (Byron). The meeting notice and agenda, dated March 18, 2015, is available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML15138A055. A list of attendees is provided as Enclosure 1.

The licensee stated that:

• The NSR control systems at Byron and Braidwood are the original construction and have been in service for more than 30 years.

• With planned License Extensions, the systems will need to remain in service and reliable for up to 33 additional years.

• The primary project objective is to improve equipment reliability and reduce exposure to plant transients and initiating events thereby improving margins of safety.

The licensee described Exelon and industry perspective regarding digital upgrades, the project scope, and the licensee's modernization strategy, as detailed in their presentation (see ADAMS Accession No. ML15133A473).

The NRC staff asked clarifying questions regarding the presented material.

The NRC staff made no decisions regarding the licensee's plans but made the following observations:

• Communications between licensees and the NRC staff prior to actual implementation of 10 CFR 50.59 design changes such as this one are very helpful.

• The terminology used is causing some confusion. The definitions should be clarified.

• The NRC staff will need further interaction with industry to evaluate the acceptability of the bounding of a Common Cause Failure, as a result of a design defect.

• The project design principles should consider Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix A, General Design Criteria 1 and Generic Letter 84-01, "NRC use of the Terms, "Important to Safety" and Safety Related""

(ADAMS Accession No. ML031150515), especially the second half of the second paragraph.

• The licensee should keep Region Ill and the NRR Project Manager informed of the status of the project.

• The project should identify standards to be used for digital NSR systems.

• The licensee stated that, while interface protocols exist for vetting safety-related digital modifications (i.e., ISG-06), there is no published corollary process for NSR digital modifications conducted under the 10 CFR 50.59 process. The NRC staff notes that 10 CFR 50.59 applies to NSR systems, as well as safety-related systems and the Standard Review Plan, Section 7.7 (ADAMS Accession No. ML070670042), applies to NSR systems, as well as safety-related systems.

• Common Cause Failure considerations should include Human Factors involvement regarding operator errors.

• The 10 CFR 50.59 evaluation must consider and be consistent with the Updated Final Safety Evaluation wording.

One member of the public was in attendance by phone. Public Meeting Feedback forms were not received.

Please direct any inquiries to me at 301-415-6606, or Joel.Wiebe@nrc.gov.

oel S. Wiebe, Senior Project Manager Plant Licensing 111-2 and Planning and Analysis Branch Office of Nuclear Reactor Regulation Docket Nos. 50-454, 50-455, 50-456 and 50-457

Enclosure:

List of Attendees cc w/encls: Distribution via Listserv

LIST OF ATTENDEES MAY 20. 2015. MEETING EXELON GENERATION COMPANY. LLC DIGITAL UPGRADE OF NON-SAFETY CONTROL SYSTEMS NRC Staff Norbert Carte Office of Nuclear Reactor Regulation (NRR)

Bernard Dittman Office of Nuclear Regulatory Research David Rahn NRR David Beaulieu NRR Joel Wiebe NRR Steven Arndt NRR Richard Stattel NRR Exelon Generation Company, LLC and Support Personnel Joseph Bauer Exelon Generation Company, LLC (Exelon)

Gordon Clefton Nuclear Energy Institute (NEI)

Panfilo Federico Westinghouse Steven Hutchins NEI Bruce Geddes Southern Energy Services John Connelly Exelon Jason Remer NEI Paul Hunton Duke Jim Andrachek Westinghouse Kati Austgen NEI Jonathan Williams Exelon Richard Johnston Exelon Public Joseph Fougere MPR Associates Enclosure

ML031150515), especially the second half of the second paragraph.

• The licensee should keep Region Ill and the NRR Project Manager informed of the status of the project.

• The project should identify standards to be used for digital NSR systems.

• The licensee stated that, while interface protocols exist for vetting safety-related digital modifications (i.e., ISG-06), there is no published corollary process for NSR digital modifications conducted under the 10 CFR 50.59 process. The NRC staff notes that 10 CFR 50.59 applies to NSR systems, as well as safety-related systems and the Standard Review Plan, Section 7.7 (ADAMS Accession No. ML070670042), applies to NSR systems, as well as safety-related systems.

• Common Cause Failure considerations should include Human Factors involvement regarding operator errors.

• The 10 CFR 50.59 evaluation must consider and be consistent with the Updated Final Safety Evaluation wording.

One member of the public was in attendance by phone. Public Meeting Feedback forms were not received.

Please direct any inquiries to me at 301-415-6606, or Joel.Wiebe@nrc.gov.

IRA!

Joel S. Wiebe, Senior Project Manager Plant Licensing 111-2 and Planning and Analysis Branch Office of Nuclear Reactor Regulation Docket Nos. 50-454, 50-455, 50-456 and 50-457

Enclosure:

List of Attendees cc w/encls: Distribution via Listserv DISTRIBUTION:

PUBLIC RidsAcrsAcnw_MailCTR Resource TWertz, NRR LPLlll-2 R/F RidsNrrDorllpl3-2 Resource NCarte, NRR RidsNrrPMByron Resource RidsNrrLASRohrer Resource RDaley, Rill RidsRgn3MailCenter Resource BDittman, RES DRahn, NRR DBeaulieu, NRR KMorganButler, EDO Region Ill SArndt,NRR RStattel, NRR Accession Number: ML15152A505 OFFICE DORL/LPL3-2/PM DORL/LPL3-2/LA NRR/DE NRR/DE/EICB DORL/LPL3-2/BC DORL/LPL3-2/PM NAME JWiebe SRohrer (SF /fl) SArndt DRahn(A) TT ate JWiebe (w/comments)

DATE 8/12/16 8/12 /15 7/16/15 7/28/15 8/14/15 8117/15