ML21225A553

August 13,2021, Public Meeting Summary with Southern Nuclear Operating Regarding Proposed LAR to Revise Technical Specifications Related to Reactor Trip System & Engineered Safety Feature Actuation System Instrumentation for Vogtle 1&2 (L-2

ML21225A553
Person / Time
Site:	Vogtle
Issue date:	08/31/2021
From:	John Lamb Plant Licensing Branch II
To:	Gayheart C Southern Nuclear Operating Co
Lamb, J.
Shared Package
ML21225A622	List: ML21225A553
References
EPID L-2021-LRM-0073
Download: ML21225A553 (8)

Text

August 31, 2021 LICENSEE: Southern Nuclear Operating Company, Inc.

FACILITY: Vogtle Electric Generating Plant, Units 1 and 2

SUMMARY

OF AUGUST 13, 2021, PUBLIC PRE-SUBMITTAL MEETING WITH SOUTHERN NUCLEAR OPERATING COMPANY, INC., REGARDING A PROPOSED LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATIONS RELATED TO REACTOR TRIP SYSTEM AND ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION FOR VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 (EPID L-2021-LRM-0073)

On August 13, 2021, an Observation Public Meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Southern Nuclear Operating Company, Inc. (SNC, the licensee). The purpose of the pre-submittal meeting was for SNC to describe its plan to submit a license amendment request (LAR) to revise Technical Specification (TS) 3.3.1, Reactor Trip System (RTS) Instrumentation, and TS 3.3.2, Engineered Safety Feature Actuation System (ESFAS) Instrumentation, for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2.

A list of attendees is provided as an Enclosure.

On July 23, 2021 (Agencywide Document and Access Management System (ADAMS)

Accession No. ML21204A005), the meeting was noticed on the NRC public webpage.

The SNC presented slides contained in ADAMS Accession No. ML21197A003.

Introduction The NRC staff opened the meeting with introductory remarks and introduction of the attendees.

The SNC personnel discussed the following topics: (1) background, (2) proposed LAR, and (3) milestones.

Background

SNC requested this pre-submittal meeting to communicate to the NRC staff that SNC intends to submit a LAR to revise TS 3.3.1 and TS 3.3.2 at Vogtle, Units 1 and 2.

SNC stated that the instrument uncertainty calculations for the Vogtle, Units 1 and 2, RTS and ESFAS trip functions have been updated. The licensee said that the calculation inputs have been updated to account for component/equipment, replacement, operating experience (OE),

and vendor communications.

SNC said that there has been no change to the nominal trip setpoints (NTS) and there is no impact to the safety analyses of record (AOR) or safety analysis limits (SALs).

The licensee stated that the updated uncertainty calculations for the RTS and ESFAS would result in changes to the Allowable Values (AVs) contained in Technical Specifications (TS)

Tables 3.3.1-1 and 3.3.2-1.

SNC said that the uncertainties used in the Revised Thermal Design Procedure (RTDP) analyses were re-calculated based on the updated inputs used in the RTS and ESFAS trip function uncertainty calculations. The licensee stated that the changed parameters are pressurizer pressure, primary coolant temperature (Tavg), reactor power, and Reactor Coolant System (RCS) flow. SNC stated that the proposed changes are either consistent with or more conservative than the revised RTDP analyses uncertainty values in the AOR. SNC said that the updated RTDP uncertainty values will be implemented under Title 10 of the Code of Federal Regulations (10 CFR), Section 50.59, Changes, tests, and experiments, as a change to the Updated Final Safety Analysis Report (UFSAR).

The licensee stated that the NTS in conjunction with the use of as-found and as-left tolerances, together with the requirements of the AV ensure that safety limits (SLs) are not violated during Anticipated Operational Occurrences (AOOs) and that the consequences of Design Basis Accidents (DBAs) will be acceptable. SNC said that the NTS are determined from the Analytical Limits (ALs) in UFSAR Chapters 6 and 15. The licensee said that the NTS separation from the AL is based on a combination of all errors. SNC stated that Reactor Protection and Engineered Safety Feature (ESF) actuation function AV provided in TS are limiting values that allow for deviation of the as found setting from the NTS during calibration. The licensee stated that the updated AVs have been calculated using previously NRC-approved setpoint methodology for Vogtle, Units 1 and 2. SNC said that the AVs serve as the as-found TS OPERABILITY limit for the purpose of the Channel Operational Test (COT). SNC showed the NTS and AV relationship graphically on slide 7.

Proposed LAR SNC stated that it proposes to change the TSs to revise specified AVs contained in TS Tables 3.3.1-1 and 3.3.2-1. The revised AV were determined from the NTS method. SNC stated that the revised AVs would move closer to the NTS values and that the WCAP-11269, Westinghouse Setpoint Methodology for Protection Systems Vogtle Station, would be replaced by WCAP-16969, Westinghouse Setpoint Methodology for Protection Systems Vogtle Electric Generating Plant - Units 1 and 2.

SNC provided proposed changes in slides 10 - 22.

Milestones SNC said that it plans to submit the proposed LAR for Vogtle, Units 1 and 2, in the third quarter of 2021 (July - September 2021). SNC stated that it expects to request the NRC staff complete its review of the proposed LAR within 12 months with implementation within 3 months of NRC approval of the proposed LAR.

NRC Questions to SNC The NRC staff asked SNC questions regarding the methodology used to calculate the proposed AVs, uncertainty calculations for the RTS and ESFAS that results in changes to the AVs, and results of as-found and as-left tolerance limits of the NTS calibrations associated with the proposed AVs, and the current ALs. SNC representatives acknowledged that it understood the information context and NRC review expectations for the proposed LAR. has more detail on the information that the NRC staff would need in the proposed LAR.

The NRC asked if SNC considered Revision 4 instead of Regulatory Guidance (RG) 1.105, Revision 3, Setpoints for Safety-Related Instrumentation, December 1999 (ADAMS Accession No. ML993560062). SNC stated that Vogtle is licensed to Revision 3 of RG 1.105, so the proposed LAR will follow RG 1.105, Revision 3 and not Revision 4.

SNC said that it would submit a proprietary and non-proprietary version of WCAP-16969, Westinghouse Setpoint Methodology for Protection Systems Vogtle Electric Generating Plant -

Units 1 and 2, when it submits the proposed LAR. SNC stated that WCAP-16969 is a Vogtle-specific WCAP.

The NRC staff asked about the Rack Calibration Accuracy [RCA] = 0.5% span of the example Pressurizer Pressure P-11 Permissive AV. The NRC staff questioned would the licensee provide the summary of the calculation of the RCA?. SNC said that it did not have the RCAs calculation, but it would provide the manufacturers sources of the RCA.

Public Questions to NRC There were no questions from the public. There were no members of the public in attendance.

Closing The NRC staff made no regulatory decisions during the meeting.

Once received, the NRC staff will perform a thorough review of the proposed LAR and make any regulatory decisions in writing in a timely manner.

Public Meeting Feedback forms were available, but no comments were received.

The meeting adjourned at 10:27 am (Eastern time).

Please direct any inquiries to me at 301-415-3100.

/RA/

John G. Lamb, Senior Project Manager Plant Licensing Branch, II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosures:

1. List of Attendees

2. NRC Staff Notes cc w/encls: Distribution via Listserv

LIST OF ATTENDEES AUGUST 13, 2021, PUBLIC MEETING WITH SOUTHERN NUCLEAR COMPANY REGARDING A PROPOSED LICENSE AMENDMENT REQUEST VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 ATTENDEE REPRESENTING John G. Lamb U.S. Nuclear Regulatory Commission (NRC)

Mike Markley NRC Sheila Ray NRC Matt Hamm NRC Tarico Sweat NRC Hang Vu NRC Ken Lowery Southern Nuclear Operating Company (SNC)

Jamie Coleman SNC Ryan Joyce SNC Cheryl Gayheart SNC Randle Johnson SNC Wes Sparkman SNC John Moorehead Westinghouse Daniel Spaulding Westinghouse Enclosure 1

NRC STAFF NOTES FOR VOGTLE PRE-SUBMITTAL MEETING TO REVISE TECHNICAL SPECIFICATIONS 3.3.1 and 3.3.2 ALLOWABLE VALUES AUGUST 13, 2021 The U.S. Nuclear Regulatory Commission (NRC) staff expects the following information to be included in the licensees application:

Summary of the licensees methodology using to calculate the proposed Allowable Values (AVs).

Summary of the Updated uncertainty calculations for the Reactor Trip System (RTS) and Engineered Safety Feature Actuation System (ESFAS) result in changes to the AVs contained in Technical Specifications (TSs) Tables 3.3.1-1 and 3.3.2-1.

Summary of calibration or test results of the as-found and as-left tolerance limits of the Nominal Trip Setpoint (NTS) calibrations associated with the proposed AVs.

The current analytical limits (ALs) in Chapter 6 and Chapter 15 of the Updated Final Safety Analysis Report (UFSAR).

The basis for the expected information is listed below.

Regulatory Guidance (RG) 1.105, Revision 3, Setpoints for Safety-Related Instrumentation, dated December 1999 (ADAMS Accession No. ML993560062), describes a method acceptable to the NRC staff for complying with the NRCs regulations for ensuring that setpoints for safety-related instrumentation are initially within and remain within the TS limits. The RG 1.105 endorses Part I of Instrument Society of America1 (ISA) Standard 67.04-1994, Setpoints for Nuclear Safety Related Instrumentation. On Page 7 of RG 1.105, this document stated:

Part II, "Methodologies for the Determination of Setpoints for the Nuclear Safety-Related Instrumentation," of ISA-S67.04-1994 is not addressed by this regulatory guide. The NRC staff will use this guide to establish the adequacy of the licensees setpoint calculation methodologies and the related plant surveillance procedures.

Regulatory Information Summary (RIS) 2011-12, Revision 1, Adequacy of Station Electric Distribution System Voltages, dated December 29, 2011 (ADAMS Accession No. ML113050583), clarifies voltage studies necessary for Degraded Voltage Relay (DVR)

(second level undervoltage protection) setting bases and Transmission Network/Offsite/Station electric power system design bases for meeting the regulatory requirements specified in General Design Criterion (GDC) 17, Electric Power Systems, to Title 10 of the Code of Federal Regulations (10 CFR) Part 50 Appendix A. The RIS states, in part:

Licensee voltage calculations should provide the basis for their DVR settings, ensuring safety-related equipment is supplied with adequate voltage (dependent on equipment manufacturers design requirements),

based on bounding conditions for the most limiting safety-related load (in terms of voltage) in the plant.

1 In 2008, the name of this organization was changed to International Society of Automation.

Enclosure 2

RIS 2006-17, NRC Staff Position on the Requirements of 10 CFR 50.36, Technical Specifications, Regarding Limiting Safety System Settings, During Periodic Testing and Calibration of Instrument Channels, dated August 24, 2006 (ADAMS Accession No. ML051810077), discusses issues that could occur during testing of limiting safety system settings (LSSSs) and which, therefore, may have an adverse effect on equipment operability.

The RIS also represents an approach that is acceptable to the NRC staff for addressing these issues for use in licensing actions. The RIS states, in part:

As one measure of instrument operability, the NRC staff expects licensees to verify during testing or calibration that the change in the measured [trip setpoint] TSP since the last test or calibration is within predefined limits (double-sided acceptance criteria band) and to take appropriate actions if the change is outside these limits. The acceptance criteria band should be derived from the licensees setpoint methodology, including use of generic or plant-specific data.

It is NRC staffs position that verifying that the as-found TSP is within the acceptance band limits during test or calibration is part of the determination that an instrument is functioning as required.

Package, ML21225A622 Meeting Notice, ML21204A005 Meeting Summary, ML21225A553 Slides, ML21197A003 OFFICE DORL/LPL2-1/PM DORL/LPL2-1/LA DEX/EICB/BC DORL/LPL2-1/BC DORL/LPL2-1/PM NAME JLamb KGoldstein MWaters MMarkley JLamb DATE 8/13/2021 8/18/2021 8/25/2021 8/30/2021 8/31/2021