ML14118A201
| ML14118A201 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 05/29/2014 |
| From: | Justin Poole Watts Bar Special Projects Branch |
| To: | Tennessee Valley Authority |
| Dion J | |
| Shared Package | |
| ML14132A270 | List: |
| References | |
| Download: ML14118A201 (5) | |
Text
LICENSEE:
Tennessee Valley Authority FACILITY:
Watts Bar Nuclear Plant, Unit 2
SUBJECT:
SUMMARY
OF APRIL 24, 2014, MEETING WITH TENNESSEE VALLEY AUTHORITY REGARDING WATTS BAR NUCLEAR PLANT, UNIT 2, OPEN ITEMS FOR LICENSING On April 24, 2014, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) staff and representatives of the Tennessee Valley Authority (TVA) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of this meeting was for TVA to discuss with NRC outstanding electrical engineering open items related to the licensing effort for the Watts Bar Nuclear Plant (WBN), Unit 2. Attendees for this meeting are listed in Enclosure 1.
The NRC staff is currently in the process of completing a technical review of TVA's Final Safety Analysis Report for WBN Unit 2. Protecting Class 1 E safety systems from degraded voltage conditions in offsite power systems (grid) is a generic industry concern, commonly referred to as the degraded voltage relay (DVR) issue. NRC guidance and background information on this issue is available in Regulatory Information Summary 2011-12, "Adequacy of Station Electric Distribution System Voltages," which is available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML113050583. An open item for licensing WBN Unit 2 is to resolve the degraded voltage issue that is documented as Open Item No. 30 in Section 8.3.1.2, "Low and Degraded Voltage Conditions," published in Supplement 22 of NUREG-0847 "Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant, Unit 2" (ADAMS Accession No. ML110390197).
Open Item No. 30 states:
TVA should confirm that all safety-related equipment (in addition to the Class 1 E motors) will have adequate starting and running voltage at the most limiting safety-related components (such as motor-operated valves (MOVs), contactors, solenoid valves or relays) at the DVR setpoint dropout setting. TVA should also confirm that (1) the motor starting transient studies are based on the dropout voltage value of DVR and time delay,(2) the steady-state voltage drop studies are carried out by maximizing running loads on the Class 1 E distribution system (bounding combination of safety systems loads), with the voltage at 6.9-kV [kilovolt] Class IE buses (monitored by the DVRs) at or just above the DVR dropout setting, and (3) the DVR settings do not credit any equipment operation (such as LTC [load tap changer] transformers) upstream of the 6.9-kV Class 1 E buses. TVA should also confirm that the final technical specifications (TSs) are properly derived from these analytical values for the degraded voltage settings.
TV A gave a presentation, slides are available in ADAMS at Accession No. ML14118A195, outlining their approach to resolve the degraded voltage issue. A brief history of the degraded voltage issue was presented along with a summary of the existing regulatory guidance on the issue. TVA reviewed the past industry events and corresponding regulatory information available on the topic. The methodology for deriving the DVR set point was explained. TVA then reviewed information previously submitted to the NRC in 2012, documenting a degraded voltage study at WBN Unit 2 (ADAMS Accession No. ML12160A350). NRC staff asked several clarifying questions regarding the presented scenarios and case studies analyzed by TVA.
In 2011, the NRC issued a non-cited violation for WBN Unit 1 failing to use the DVR setpoint values as specified in the technical specifications. Inspection Report 05000390/2010005 (ADAMS Accession No. ML110280456) documents the finding which prompted the technical reviewers to document licensing Open Item No. 30 in the licensing review of WBN Unit 2. For WBN Unit 1, the licensee will address the deficiency as part of the corrective action program.
TVA explained how degraded voltage protective measures are implemented for Class 1 E systems at Unit 1 of the WBN site and how the proposed changes will resolve the open item.
TVA stated that the same protective measures will be implemented for Unit 2. TVA and NRC staff agreed that the preferred regulatory vehicle to address the matter for Unit 2 is through closure of Open Item No. 30 with a possible related confirmatory item to be closed through onsite inspection.
On February 27, 2014, the NRC staff issued requests for additional information (RAis) addressing Open Item No. 30 for WBN Unit 2, which are available in ADAMS at Accession No. ML14059A158. TVA stated that they will respond to these RAis based on the clarification discussed with the technical staff during the meeting. TVA said they will expeditiously prepare the package for submittal to the NRC and will ask for coordination of clarification calls with NRC staff to avoid future iterations of submitted information.
No regulatory decisions were made at the meeting. Two members of the public participated in the meeting. No members of the public had any questions.
Please direct any inquiries to me at 301-415-2048 or viae--~--
Docket No. 50-391
Enclosure:
List of Attendees cc w/encl: Distribution via Listserv Justin C. Poole, Senior Project Manager Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
MEETING ATTENDANCE LIST Licensee: Tennessee Valley Authority
Subject:
Electrical Open Items for Watts Bar Unit 2 Location: U.S. Nuclear Regulatory Commission Headquarters, Room 0-7B4 NAME TITLE Michele Evans Division Director Patrick Hiland Division Director John Menninger Deputy Division Director Jessie Quichocho Branch Chief Justin Poole Sr. Project Manager Jeanne Dian Project Manager Jake Zimmerman Chief, Electrical Engineering Branch Gurcharan Matharu Senior Electrical Engineer Roy Mathew Team Leader Plant: Watts Bar Nuclear Plant, Unit 2 Date: April 24, 2014 Time: 8:30p.m.- 11:00 a.m.
ORGANIZATION NRC/NRR/DORL NRC/NRR/DE NRC/NRRIDORL NRC/NRRIDORUPiant Licensing Branch 11-2 NRC/N RR/DORUPiant Licensing Branch 11-2 NRC/NRRIDORUPiant Licensing Branch 11-2 NRC/NRR/DE/EEEB NRC/NRR/DE/EEEB NRC/NRR/DE/EEEB
NAME TITLE ORGANIZATION Chris Even*
Project Engineer NRC/RII Mark Bowman TVA Joe Shea TVA Gordon Arent TVA Director, WBN Licensing TVA Ruth Thomas*
Member of Public Jack Roe Member of Public
- participated via teleconference
ML12160A350). NRC staff asked several clarifying questions regarding the presented scenarios and case studies analyzed by TVA.
In 2011, the NRC issued a non-cited violation for WBN Unit 1 failing to use the DVR setpoint values as specified in the technical specifications. Inspection Report 05000390/2010005 (ADAMS Accession No. ML110280456) documents the finding which prompted the technical reviewers to document licensing Open Item No. 30 in the licensing review of WBN Unit 2. For WBN Unit 1, the licensee will address the deficiency as part of the corrective action program.
TVA explained how degraded voltage protective measures are implemented for Class 1 E systems at Unit 1 of the WBN site and how the proposed changes will resolve the open item.
TVA stated that the same protective measures will be implemented for Unit 2. TVA and NRC staff agreed that the preferred regulatory vehicle to address the matter for Unit 2 is through closure of Open Item No. 30 with a possible related confirmatory item to be closed through onsite inspection.
On February 27, 2014, the NRC staff issued requests for additional information (RAis) addressing Open Item No. 30 for WBN Unit 2, which are available in ADAMS at Accession No. ML14059A158. TV A stated that they will respond to these RAis based on the clarification discussed with the technical staff during the meeting. TVA said they will expeditiously prepare the package for submittal to the NRC and will ask for coordination of clarification calls with NRC staff to avoid future iterations of submitted information.
No regulatory decisions were made at the meeting. Two members of the public participated in the meeting. No members of the public had any questions.
Please direct any inquiries to me at 301-415-2048 or via e-mail at Justin.Poole@nrc.gov.
Docket No. 50-391
Enclosure:
List of Attendees cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC LPL 2-2 Reading RidsAcrsAcnw_MaiiCTR Resource RidsNrrDoriLp_Wb Resource RidsNrrDE Resource RidsNrrDeEeeb Resource ADAMS Accession No. PKG ML14132A270 IRA/
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DORULPWB/LA DE/EEEB/BC DORULPWB/BC DORULPWB/PM NAME JDion JPoole BCiayton JZimmerman JQuichocho JPoole DATE 5/19/14 5/24/14 5/19/14 5/20/14 5/27/14 5/29/14