IR 05000424/2019012

Reissue Vogtle Electric Generating Plant, Units 1 & 2 - NRC Temporary Instruction 2515/194 Inspection Report 05000424/2019012 and 05000425/2019012

ML20122A261
Person / Time
Site:	Vogtle
Issue date:	05/01/2020
From:	Bradley Davis NRC/RGN-II/DCI/CIB2
To:	Gayheart C Southern Nuclear Operating Co
References
IR 2019012
Download: ML20122A261 (11)

Text

May 1, 2020 Ms. Cheryl A. Gayheart Regulatory Affairs Director Southern Nuclear Operating Co. Inc.

3535 Colonnade Parkway Birmingham, AL 35243 SUBJECT: REISSUE - VOGTLE ELECTRIC GENERATING PLANT UNITS 1 & 2 - NRC TEMPORARY INSTRUCTION 2515/194 INSPECTION OF THE LICENSEE'S IMPLEMENTATION OF INDUSTRY INITIATIVE ASSOCIATED WITH THE OPEN PHASE CONDITION DESIGN VULNERABILITIES IN ELECTRIC POWER SYSTEMS (NRC BULLETIN 2012-01) REPORT 05000424/2019012 AND 05000425/2019012 Dear Ms. Gayheart On September 25, 2019, the US Nuclear Regulatory Commission (NRC) issued the Temporary Instruction 2515/194 - Inspection of the Licensees Implementation of Industry Initiative Associated with the Open Phase Condition Design Vulnerabilities in Electric Power Systems Report, ADAMS Accession Number ML19268A063. In reviewing this report, we identified two areas that required two editorial changes to the Inspection Results.

Specifically, that The inspectors also determined that the Technical Specification Bases was not affected by this VII. was added to statement 4 of Observation: Detection, Alarms, and General Criteria - TI 2515/194-03.01 - VII (Part 1,) and that statement 2 of Observation:

Detection, Alarms, and General Criteria Exceptions - TI 2515/194-03.01 - VII (Part 1) was removed entirely. We request that the cover letter and report be replaced with the Enclosures and to this letter.

In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390 Public inspection, exemptions, requests for withholding of the NRCs Agency Rules of Practice and Procedure, a copy of this letter will be available electronically for public inspection in the NRC Public Document Room, of the Publicly Available Records (PARS) component of NRCs ADAMS; accessible from the NRC Website at https://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

C. Gayheart 2 Please contact me at 404-997-4519 with any questions you have regarding this letter

Sincerely,

/RA/

Bradley J. Davis, Chief Construction Inspection Branch 2 Division of Construction Oversight Docket Nos. 05000424 and 05000425 License Nos. NPF-68 and NPF-81

Enclosure:

1. Reissued Vogtle Cover Letter 2. Reissued Inspection Report 05000424/2019012 and 05000425/2019012

Inspection Report

Docket Numbers: 05000424 and 05000425 License Numbers: NPF-68 and NPF-81 Report Numbers: 05000424/2019012 and 05000425/2019012 Enterprise Identifier: I-2019-012-0016 Licensee: Southern Nuclear Operating Co., Inc.

Facility: Vogtle Electric Generating Plant Units 1 & 2 Location: Waynesboro, GA Inspection Dates: August 12, 2019 to August 16, 2019 Inspectors: J. Kent, Construction Inspector Approved By: Christopher J. Even, Chief Construction Inspection Branch 2 Division of Construction Oversight Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a NRC TEMPORARY INSTRUCTION 2515/194 INSPECTION OF THE LICENSEE'S IMPLEMENTATION OF INDUSTRY INITIATIVE ASSOCIATED WITH THE OPEN PHASE CONDITION DESIGN VULNERABILITIES IN ELECTRIC POWER SYSTEMS (NRC BULLETIN 2012-01) at Vogtle Electric Generating Plant Units 1 & 2 in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

No findings or violations of more than minor significance were identified.

Additional Tracking Items

None.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL 2515/194 - Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities In Electric Power Systems (NRC Bulletin 2012-01)

This inspection was conducted using Temporary Instruction 2515/194 (ADAMS Accession No.

ML17137A416), dated October 31, 2017. The inspectors reviewed the licensees implementation of Nuclear Energy Institute (NEI) voluntary industry initiative (VII) in compliance with regulatory requirements and current licensing bases. The inspectors discussed the licensees OPC system design and ongoing implementation plans with plant staff. The inspectors reviewed licensee documentation, vendor documentation, and performed system walkdowns to verify that the installed equipment was supported by the design documentation. The inspectors verified that the licensee had completed the installation and testing of equipment, installed and tested alarming circuits both local and in the control rooms, and analyzed potential impacts associated with the design implementation on the current licensing basis.

Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities In Electric Power Systems (NRC Bulletin 2012-01) (1 Sample)

(1) Temporary Instruction 2515/194 - Inspection of the Licensees Implementation of Industry Initiative Associated With the Open Phase Condition Design Vulnerabilities In Electric Power Systems (NRC Bulletin 2012-01)

The objective of Temporary Instruction 2515/194 is to verify that licensees have appropriately implemented the NEI VII (ADAMS Accession No. ML15075A454), dated March 16, 2015, including updating their licensing basis to reflect the need to protect against OPCs.

Temporary Instruction 2515/194-03.01 - VII (Part 1)

Vogtle Electric Generating Plant selected the open phase detection system designed and manufactured by Power System Sentinel Technologies, LLC. At the end of this inspection the system remained in the monitoring mode of operation to facilitate continued data gathering of the system for evaluation of alarm and trip setpoints. The equipment was installed on the Reserve Auxiliary Transformers (RAT) 1NXRA, 2NXRA, 1NXRB, and 2NXRB and the swing Standby Auxiliary Transformer (SAT)

ANXRA. Vogtle Electric Generating Plant currently is scheduled to transition the open phase detection system to full implementation (tripping functions enabled) by December 31,

INSPECTION RESULTS

Observation: Detection, Alarms, and General Criteria; TI 2515/194-03.01 - VII 2515/194 (Part 1)1. OPCs will be detected and alarmed in the control room on the common annunciator panel.

2. Detection circuits will be sensitive enough to identify an OPC for all credited loading conditions for installed equipment.

3. No Class-1E circuits were being replaced with non-Class 1E circuits in the design.

4. The UFSAR has been updated to discuss the design features and analyses related to the effects of, and protection for, any OPC design vulnerability. The inspectors also determined that the Technical Specification Bases was not affected by this VII.

No findings were identified.

Observation: Protective Actions Criteria; TI 2515/194-03.01 - VII (Part 1) 2515/194 5. Five transformers were susceptible to an OPC as identified in this VII during all modes of operation. The licensee installed detection and mitigating equipment for these affected transformers.

6. With an OPC present and with or without an accident condition signal, the open phase design would not adversely affect the function of important-to-safety systems, structures, or components. The licensees OPC design solution added Power System Sentinel Technologies, LLC systems on the Reserve Auxiliary Transformers (RAT)1NXRA, 2NXRA, 1NXRB, and 2NXRB and the swing Standby Auxiliary Transformer (SAT) ANXRA. The tripping function, when enabled, will provide an additional input to the associated transformer lockout relays. The credited plant response is not negatively affected and will be the same regardless of the conditions that generated the lockout of the transformer.

No findings were identified.

Observation: Detection, Alarms, and General Criteria Exceptions; TI 2515/194- 2515/194 03.01 - VII (Part 1)

The inspectors identified the following minor exceptions to the Temporary Instruction criteria resulting from the operating status of the design modification. The licensees design was operating in the monitoring mode with already established setpoints and gathering data to verify the OPC design and protective schemes would minimize mis-operation, or spurious actions in the range of voltage unbalance normally experienced in the transmission system.

The licensee developed engineering calculations to demonstrate coordination of the OPC detection and tripping setpoints for the actuation circuit that does not result in lower overall plant operation reliability. This calculation was presented in X3CA53, Vogtle Nuclear Power Plant Open Phase Detection System Setpoint Calculation, Version 3.0.

Observation: Protective Actions Criteria Exceptions; TI 2515/194-03.01 - VII 2515/194 (Part 1)

The inspectors identified the following minor exceptions to the Temporary Instruction criteria resulting from the operating status of the design modification.

(1) The licensees OPC design solution uses Power System Sentinel Technologies, LLC to detect, alarm, and provide an input to the associated transformer lockout relays. Upon an initiation of the transformer lockout relays, the associated transformer train that is affected is tripped and isolated.

The tripping function input to the transformer lockout relays remained deactivated during the onsite system implementation inspection and was not able to be demonstrated to perform the designed function. The licensee did perform commission testing to demonstrate Main Control Room (MCR) annunciator panel illumination and tripping function signal was present at the local transformer lockout relay. The licensee is currently tracking the tripping function initiation under Technical Evaluation (TE) 1049641. Once enabled, the OPP system will have the ability to isolate an affected RAT or the SAT with an OPC detected on the high voltage side of the transformer at any operating condition when the transformers are energized.

Due to the configuration of Vogtle Electric Generating Plant electrical distribution system while at low power, a loss of phase on one transformer would only affect one train of equipment, and loads required to mitigate postulated accidents would be available on the non-affected train. At normal power, a loss of phase on one transformer would not affect the associated train of equipment as the emergency diesel generators would pick up all loads. This configuration would ensure that safety functions are preserved as required by the current licensing bases.

Periodic tests, calibrations, setpoint verifications or inspections (as applicable) have been established for any new protective features. The surveillance requirements have been maintained for the plant Technical Specifications (TSs) in compliance with the provisions of 10 CFR 50.36. Existing plant equipment will continue to be maintained according to the licensees current preventative maintenance program.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On August 15, 2019, the inspectors presented the NRC TEMPORARY INSTRUCTION 2515/194 INSPECTION OF THE LICENSEE'S IMPLEMENTATION OF INDUSTRY INITIATIVE ASSOCIATED WITH THE OPEN PHASE CONDITION DESIGN VULNERABILITIES IN ELECTRIC POWER SYSTEMS (NRC BULLETIN 2012-01)results to Mr. Jesse Thomas and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision

Procedure or Date

2515/194 Calculations X3CA53 Vogtle Nuclear Power Plant Open Phase Detection System Setpoint 3.0

Calculation

Drawings 02-1560 1/C 350KCM XLPE/XLPO 2000V Cable Cut Sheet

AXJD-AA-AOJA VOGTLE - WILSON MASTER ONE LINE DIAGRAM 20

SNC676475E001 THREE-LINE DIAGRAM STANDBY AUXILIARY TRANSFORMER 1

ANXRA

SNC680113E111 OPEN PHASE PROTECTION (OPP) SYSTEM, ELECTRICAL 1

DRAWINGS, CHANNEL 1 & CHANNEL 2

SNC680114E003 THREE LINE DIAGRAM UNIT 2 RESERVE AUX. TRANSFORMERS 1

2NXRA & 2NXRB

SNC847051E016 CONNECTION DIAGRAM OPEN PHASE PROTECTION (OPP) PANEL 1

1NCPORA

SNC872975E007 WIRING DIAGRAM OPEN PHASE PROTECTOIN (OPP) PANEL 1

ANCPORA

Engineering SNC676474 Unit 2 RAT A Open Phase Detection Design 3.0

Changes SNC676475 Common SAT Open Phase Detection 2.0

SNC676476 Unit 1 RAT A Open Phase Protection 3.0

Engineering TE 1049641

Evaluations

Miscellaneous SNC872971 RAT/SAT Open Phase Protection Trip Implementation 1.0

Procedures 13415-1 Reserve Auxiliary Transformers 20

13418A-1 Standby Auxiliary Transformer Unit One Train A Operations 5.2

17032-1 ANNUNCIATOR RESPONSE PROCEDURES FOR ALB 32 ON EAB 29

PANEL

25912-C Open Phase Protection Maintenance 1.01.0

Work Orders SNC833646 OPP-OUTAGE-ONLINE COMMISSIONING TEST FOR OPP (2NCPORB) 11/8/2018

SNC797503 NON-OUTAGE SAT Testing for 1NCPORB Open Phase Protection 9/28/2017

SNC804598 OUTAGE- Online Commissioning Test for 1NCPORA 10/9/2018

SNC832552 PERFORM FUNCTIONAL-COMMISSIONING TEST FOR ANCPORA 11/7/2018

SNC833626 OPP-NON- OUTAGE- SAT TESTING FOR 2NCPORA OPEN PHASE 9/28/2017

PROTECTION

6