CNS-17-027, Submittal of 2015/2016 10 CFR 50.59 Evaluation Summary Report

Submittal of 2015/2016 10 CFR 50.59 Evaluation Summary Report

ML17135A291
Person / Time
Site:	Catawba
Issue date:	05/10/2017
From:	Simril T Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNS-17-027
Download: ML17135A291 (6)

Text

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'? ENERGYco Tom Simril Vice President Catawba Nuclear Station Duke Energy CN01 VP I 4800 Concord Road York, SC 29745 o: 803.701.3340 f: 803.701.3221 CNS-17-027 10 CFR 50.59 10 CFR 50.4 May 10, 2017 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555-0001 Duke Energy Carolinas, LLC (Duke Energy)

Catawba Nuclear Station, Units 1 and 2 Docket Nos.50-413 and 50-414 Renewed License Nos.NPF-35 and NPF-52

Subject:

2015/2016 10 CFR 50.59 Evaluation Summary Report Attached please find the 2015/2016 10 CFR 50.59 Evaluation Summary Report. The report contains a brief description of changes, tests, and experiments, including a summary of the safety evaluations for Catawba Nuclear Station, Units 1 and 2. This report is submitted pursuant to the provisions of 10 CFR 50.59(d)(2) and 10 CFR 50.4.

If there are any questions regarding this submittal, please contact Tolani E. Owusu at (803) 701-5385.

Sincerely, Tom Simril Vice President, Catawba Nuclear Station :eE1:~

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Attachment Catawba Nuclear Station, Units 1 and 2 2015/2016 10 CFR 50.59 Evaluation Summary Report www.duke-energy.com

I U.S. Nuclear Regulatory Commission CNS-17-027 May 10, 2017 Page 2 cc: Attachment C. Haney, Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 J. D. Austin, Senior Resident Inspector U.S. Nuclear Regulatory Commission Catawba Nuclear Station M. Mahoney, NRC Project Manager (Catawba)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mailstop 0-8H4A Rockville, MD 20852-2738 S. E. Jenkins Manager Radioactive & Infectious Waste Management Division of Waste Management South Carolina Department of Health and Environmental Control 260 Bull St.

Columbia, SC 29201

U.S. Nuclear Regulatory Commission CNS-17-027 May 10, 2017 Attachment Catawba Nuclear Station, Units 1 and 2 2015/2016 10 CFR 50.59 Evaluation Summary Report CNS-17-027 May 10, 2017 Page 1of3 Action Request 01351537 EC105813 - Upgrade Unit 1 Main Feedwater Control and Bypass Valve Positioners The present pneumatic valve positioners for the Main Feedwater Control Valves (MFCVs) and Bypass Feedwater Control Valves (BFCVs) are obsolete and present other maintenance and reliability challenges such as susceptibility to drift and absence of ability to communicate with the Distributed Control System (DCS) without additional hardware. Also, single point vulnerabilities exist with the single MFCV pneumatic positioners such that the failure of a single positioner could lead to a unit trip.

To address the obsolescence, maintenance, and reliability concerns the feedwater control system will be upgraded under EC 105813 to replace the pneumatic positioners with digital positioners, provide redundant positioners for the MFCVs, provide capability to switch between the primary and backup MFCV positioners, and replace existing safety-related solenoid valves, including removal of the Wabco quick release valves for the BFCVs.

The revised system will continue to perform the same basic function of using a control air signal to modulate control valve position in order to maintain proper steam generator water levels with respect to reactor power output and turbine steam requirements.

There is no impact on the Technical Specifications.

The proposed change has been evaluated relative to each of the eight (8) evaluation questions in 10CFRS0.59 and the supplemental questions for digital upgrades from NEI 01-01 Appendix A. Considering the probability and consequences of the various hardware and software failure modes of the proposed changes, the evaluation concluded that this change can be implemented without prior NRC approval.

,:,I Attachment 1 CNS-17-027 May 10, 2017 Page 2 of 3 Action Request 01962944 Revision to Methodology Report DPC-NE-2009-P-A to implement Revision 1-A to WCAP-8963-P-A Addendum 1-A, Safety Analysis for the Revised Fuel Rod Internal Pressure Design Basis (Departure from Nucleate Boiling Mechanistic Propagation Methodology)

The proposed activity being evaluated is a revision to the fuel rod analysis methodology (Section 4.0) in the Westinghouse Fuel Transition methodology report (DPC-NE-2009-P-A). The proposed activity adds a mechanistically based DNB propagation methodology to DPC-NE-2009-P-A. Specifically, methodology report DPC-NE-2009-P-A Revision 3a is being revised to implement Revision 1-A to WCAP-8963-P-A Addendum 1-A, Safety Analysis for the Revised Fuel Rod Internal Pressure Design Basis (Departure from Nucleate Boiling Mechanistic Propagation Methodology),

which has been previously approved by the NRC. DPC-NE-2009 methods are considered part of the Updated Final Safety Analysis Report (UFSAR, Reference 3) via reference, and as such, are considered "as described in the UFSAR." This 10 CFR 50.59 evaluation is performed in accordance with guidance in Revision 1 of NEI 96-07 endorsed by the NRC via Regulatory Guide 1.187. It was concluded that the proposed activity is not a departure from a method of evaluation described in the UFSAR, and thus does not require NRC review and approval.

/'

r Attachment 1 CNS-17-027 May 10, 2017 Page 3 of 3 Action Request 01992138 EC105814/000 - Upgrade Unit 2 Main Feedwater Control and Bypass Valve Positioners The present pneumatic valve positioners for the Main Feedwater Control Valves (MFCVs) and Bypass Feedwater Control Valves (BFCVs) are obsolete and present other maintenance and reliability challenges such as susceptibility to drift and absence of ability to communicate with the Distributed Control System (DCS) without additional hardware. Also, single point vulnerabilities exist with the single MFCV pneumatic positioners such that the failure of a, single positioner could lead to a unit trip.

To address the obsolescence, maintenance, and reliability concerns the feedwater control system will be upgraded under EC 105814 to replace the pneumatic positioners with digital positioners, provide redundant positioners for the MFCVs, provide capability to switch between the primary and backup MFCV positioners, and replace existing safety-related solenoid valves, including removal of the Wabco quick release valves for the BFCVs.

The revised system will continue to perform the same basic function of using a control air signal to modulate control valve position in order to maintain proper steam generator water levels with respect to reactor power output and turbine steam requirements. There is no impact on the Technical Specifications.

The proposed change has been evaluated relative to each of the eight (8) evaluation questions in 10CFR50.59 and the supplemental questions for digital upgrades from NEI 01-01 Appendix A. Considering the probability and consequences of the various hardware and software failure modes of the proposed changes, the evaluation concluded that this change can be implemented without prior NRC approval.