ML071080205

Response to Generic Letter 2006-02 Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power

ML071080205
Person / Time
Site:	Sequoyah
Issue date:	05/03/2007
From:	Moroney B NRC/NRR/ADRO/DORL/LPLII-2
To:	Swafford P Tennessee Valley Authority
Moroney B, NRR/DORL, 415-3974
References
GL-06-002, RG-1.155, TAC MD1033, TAC MD1034
Download: ML071080205 (4)

Text

May 3, 2007 Mr. Preston D. Swafford Interim Chief Nuclear Officer Nuclear Support Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 - RESPONSE TO GENERIC LETTER 2006-02 GRID RELIABILITY AND THE IMPACT ON PLANT RISK AND THE OPERABILITY OF OFFSITE POWER (TAC NOS. MD1033 AND MD1034)

Dear Mr. Swafford:

On February 1, 2006, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2006-02, Grid Reliability and the Impact on Plant Risk and the Operability of Offsite Power (Agencywide Document Access and Management System (ADAMS) Accession No. ML060180352) to all holders of operating licenses for nuclear power reactors except those who have permanently ceased operation and have certified that fuel has been removed from the reactor vessel.

GL 2006-02 notified licensees of the NRC staffs need for information in four areas, as follows:

(1) use of protocols between the nuclear power plant (NPP) and the transmission system operator (TSO), independent system operator (ISO), or reliability coordinator/authority (RC/RA) and the use of transmission load flow analysis tools (analysis tools) by TSOs to assist NPPs in monitoring grid conditions to determine the operability of offsite power systems under plant technical specifications (TSs). (The TSO, ISO, or RA/RC is responsible for preserving the reliability of the local transmission system. In this GL the term TSO is used to denote these entities);

(2) use of NPP/TSO protocols and analysis tools by TSOs to assist NPPs in monitoring grid conditions for consideration in maintenance risk assessments; (3) offsite power restoration procedures in accordance with Section 2 of NRC Regulatory Guide (RG) 1.155, Station Blackout; and (4) losses of offsite power caused by grid failures at a frequency equal to or greater than once in 20 site-years in accordance with RG 1.155.

Subsequent to the GL, the NRC issued a Request For Additional Information (RAI) (ADAMS Accession No. ML063380308) regarding the resolution of GL 2006-02 to 63 of 65 holders of operating licenses for nuclear power reactors. The RAI requested licensees respond to questions in the following areas:

P. Swafford (1) Switchyard Minimum Voltage; (2) Loss of Real-Time Contingency Analysis (RTCA) Capability; (3) Verification of RTCA Predicted Post-Trip Voltage; (4) Identification of Applicable Single Contingencies; (5) Seasonal Variation in Grid Stress (reliability and Loss-of-offsite power (LOOP) Probability; (6) Interface With Transmission System Operator During Extended Plant Maintenance.

By letters dated April 3, 2006 (ADAMS Accession No. ML060950306), and January 31, 2007 (ADAMS Accession No. ML070330051), the Tennessee Valley Authority (TVA) responded to the information request of GL 2006-02 and the subsequent RAI, respectively. Based on the information provided, the staff has concluded that compliance is being maintained with NRC regulatory requirements governing electric power sources and associated personnel training and considers TVAs response to GL 2006-02 complete for the Sequoyah Nuclear Plant, Units 1 and 2.

If you have any questions, please contact me 301-415-3974.

Sincerely,

/RA/

Brendan T. Moroney, Project Manager Plant Licensing Branch II-2 Division of Operating Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: See next page

ML060950306), and January 31, 2007 (ADAMS Accession No. ML070330051), the Tennessee Valley Authority (TVA) responded to the information request of GL 2006-02 and the subsequent RAI, respectively. Based on the information provided, the staff has concluded that compliance is being maintained with NRC regulatory requirements governing electric power sources and associated personnel training and considers TVAs response to GL 2006-02 complete for the Sequoyah Nuclear Plant, Units 1 and 2.

If you have any questions, please contact me 301-415-3974.

Sincerely,

/RA/

Brendan T. Moroney, Project Manager Plant Licensing Branch II-2 Division of Operating Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 cc: See next page Distribution:

PUBLIC LPL2-2 r/f RidsNrrLACSola RidsNrrPMBMoroney RidsNrrDorlLpl2-2 RidsOgcRp RidsAcrsAcnwMailCenter RidsRgn2MailCenter RidsNrrDeEeeb SCampbell, EDO, Region II JRobinson, NRR ADAMS ACCESSION NUMBER: ML071080205 OFFICE LPL2-2/PM LPL2-2/LA EEEB/BC LPL2-2/BC NAME BMoroney RSola GWilson TBoyce DATE 4/19/07 4/20/07 4/20/07 5/3/07 Mr. Preston D. Swafford SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. Ashok S. Bhatnagar, Senior Vice President Mr. Glenn W. Morris, Manager Nuclear Operations Licensing and Industry Affairs Tennessee Valley Authority Sequoyah Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Soddy Daisy, TN 37384-2000 Mr. Larry S. Bryant, Vice President Mr. David A. Kulisek, Plant Manager Nuclear Engineering & Technical Services Sequoyah Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000 1101 Market Street Soddy Daisy, TN 37384-2000 Chattanooga, TN 37402-2801 Senior Resident Inspector General Counsel Sequoyah Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatory Commission 6A West Tower 2600 Igou Ferry Road 400 West Summit Hill Drive Soddy Daisy, TN 37379 Knoxville, TN 37902 Mr. Lawrence E. Nanney, Director Mr. John C. Fornicola, Manager Division of Radiological Health Nuclear Assurance Dept. of Environment & Conservation Tennessee Valley Authority Third Floor, L and C Annex 6A Lookout Place 401 Church Street 1101 Market Street Nashville, TN 37243-1532 Chattanooga, TN 37402-2801 County Mayor Ms. Beth A. Wetzel, Manager Hamilton County Courthouse Corporate Nuclear Licensing and Chattanooga, TN 37402-2801 Industry Affairs Tennessee Valley Authority Ms. Ann P. Harris 4X Blue Ridge 341 Swing Loop Road 1101 Market Street Rockwood, TN 37854 Chattanooga, TN 37402-2801 Mr. Robert H. Bryan, Jr., General Manager Licensing and Industry Affairs Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Randy Douet, Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000