ML20070M021
| ML20070M021 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Summer, Surry, North Anna  |
| Issue date: | 03/09/2020 |
| From: | Mark D. Sartain Dominion Energy Virginia |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 20-055 | |
| Download: ML20070M021 (5) | |
Text
Dominion Energy Services, Inc.
5000 Dominion Boulevard, Glen Allen, VA 23060 Dominion Energy.com March 9, 2020 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555
Dominion
- --' Energy Serial No.:
20-055 NRA/GDM R2 Docket Nos.:
50-336/423 50-338/339 50-280/281 50-395 License Nos.: DPR-65 NPF-49 NPF-4/7 DPR-32/37 NPF-12 DOMINION ENERGY NUCLEAR CONNECTICUT, INC (DENG)
VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION ENERGY VIRGINIA)
DOMINION ENERGY SOUTH CAROLINA, INC (DESC)
MILLSTONE POWER STATION (MPS) UNITS 2 AND 3 NORTH ANNA POWER STATION (NAPS) UNITS 1 AND 2 SURRY POWER STATION (SPS) UNITS 1 AND 2 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 NRC BULLETIN 2012-01 DESIGN VULNERABILITY IN ELECTRIC POWER SYSTEM REGULATORY COMMITMENT CHANGE TO REMAIN IN MONITORING VS.
PROTECTION MODE By letter dated December 19, 2018 [ADAMS Accession No. ML18361A573], Dominion Energy Virginia and DENC committed to enabling the trip function for the Open Phase Isolation Systems (OPIS) at NAPS and SPS Units 1 and 2, and MPS Units 2 and 3, respectively, by December 31, 2020. By letter dated May 2, 2019 [ADAMS Accession No. ML19122A517], DESC committed to enabling the OPIS trip function at VCSNS Unit 1 by October 31, 2020.
On June 6, 2019, the Nuclear Energy Institute (NEI) issued Revision 3 of the voluntary industry initiative (VII), Open Phase Condition Initiative, which incorporated a Risk Informed Evaluation Method that could be used to demonstrate that operator manual actions would be sufficient to mitigate the impact of an open phase condition (OPC). NEI also issued Technical Report NEI 19-02, Guidance for Assessing Open Phase Condition Implementation Using Risk Insights, as a means of performing the risk evaluation allowed by Revision 3 of the VII. NEI 19-02 provides guidance for the performance of a risk assessment to inform the decision of whether to implement the OPIS automatic trip function or to implement the OPIS to provide alarm and indication to the control room operator and rely on operator action to diagnose and respond to the presence of an OPC.
Serial No.20-055 Docket Nos. 50-336/423/338/339/280/281 /395 Commitment Change - NRCB 2012-01 Page 2 of 5 After reviewing these two documents, Dominion Energy Virginia, DENC, and DESC (collectively, Dominion Energy) performed risk evaluations for NAPS and SPS Units 1 and 2, MPS Units 2 and 3, and VCSNS Unit 1, respectively, in accordance with the NEI 19-02 guidance. The risk evaluations were performed to determine whether the units met the risk acceptance criteria for maintaining their OPIS in detection (i.e., monitoring and control room indication) mode, with associated manual operator actions, to address an OPC, as opposed to enabling the automatic trip protection function.
The risk evaluation performed for each station evaluated the risk of OPCs that could potentially impact various switchyard transformers and determined the risk benefit, if any, of operating the OPIS in protection (trip) mode versus detection (monitoring) mode. The completed risk evaluations for the Dominion Energy plants determined that the benefit of operating the OPIS in automatic (protection) mode is considered "very small" in accordance with Regulatory Guide 1.17 4. Therefore, operation of the OPIS in detection mode with alarmed operator response to an OPC is considered sufficient to mitigate the impact of an OPC.
Based on the completed risk evaluations discussed above, Dominion Energy is hereby revising its fleet NRC Bulletin 2012-01 commitments to place the respective plants' non safety-related OPIS in detection and indication mode as opposed to automatic trip mode.
NAPS and SPS Units 1 and 2 have both non-safety-related and safety-related OPIS installed.
Their safety-related OPIS will remain in automatic trip mode at this time; however, this decision may be reevaluated in the future regarding the use of a detection and indication solution. License amendment requests would be required should NAPS and/or SPS elect to remove the automatic trip function for their safety-related OPIS. The revised station commitments are summarized in the table below. Note that the previously provided OPIS completion commitment dates have not changed and are provided in the table below for completeness.
REVISED NRC BULLETIN 2012-01 COMMITMENTS Automatic Trip Detection and Alarm Only Plant Mode Mode Completion Date (Yes/No)
(Yes/No)
MPS Units 2 No Yes December 31, 2020 and 3 NAPS Units 1 Yes - Safety-Yes - Non-safety -
December 31, 2020 and 2 related OPIS related OPIS SPS Units 1 Yes - Safety-Yes - Non-safety -
December 31, 2020 and 2 related OPIS related OPIS VCSNS Unit 1 No Yes October 31, 2020
Serial No.20-055 Docket Nos. 50-336/423/338/339/280/281 /395 Commitment Change - NRCB 2012-01 Page 3 of 5 If you have any questions or require additional information, please contact Mr. Gary D.
Miller at (804) 273-2771.
Sincerely, Mark D. Sartain Vice President - Nuclear Engineering and Fleet Support Commitments made in this letter: See Commitment Table above.
COMMONWEAL TH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain, who is the Vice President - Nuclear Engineering & Fleet Support of Virginia Electric and Power Company and Dominion Energy Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of those Companies, and that the statements in the document are true to the best of his knowledge and belief.
Acknowledged before me this+/- day of J+ja..,J,,
, 2020.
My Commission Expires: Jr}a.v-.31, 1tJZ.. Z, DIANE E. AITKEN NOTARY PUBLIC REG. #7763114 COMMONWEAL TH OF VIROlfM MV COMMISSION EXPIRES MARCH 31, 2022 Notary Public
cc: Regional Administrator, Region I U. S. Nuclear Regulatory Commission 2100 Renaissance Blvd., Suite 100 King of Prussia, PA 19406-2713 Regional Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower Serial No.20-055 Docket Nos. 50-336/423/338/339/280/281 /395 Commitment Change - NRCB 2012-01 Page 4 of 5 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, Georgia 30303-1257 Mr. Richard V. Guzman Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08 C-2 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Vaughn Thomas NRC Project Manager - Surry U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 04 F-12 11555 Rockville Pike Rockville, MD 20852-2738 Mr. G. Edward Miller NRC Senior Project Manager - North Anna U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738 Mr. Shawn A. Williams NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08 B1-A 11555 Rockville Pike Rockville, Maryland 20852-2738
Mr. Marcus Harris Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd. Suite 300 Glen Allen, Virginia 23060 NRC Senior Resident Inspector North Anna Power Station NRC Senior Resident Inspector Surry Power Station NRC Senior Resident Inspector Millstone Power Station NRC Senior Resident Inspector V C Summer Power Station Serial No.20-055 Docket Nos. 50-336/423/338/339/280/281 /395 Commitment Change - NRCB 2012-01 Page 5 of 5