ML081780213

Vermont Yankee - Request for Additional Information Regarding Technical Specification Change Relating to Degraded Grid Protection System Instrumentation (TAC No. MD8011)

ML081780213
Person / Time
Site:	Vermont Yankee
Issue date:	07/02/2008
From:	Kim J S NRC/NRR/ADRO/DORL/LPLI-1
To:	Entergy Nuclear Operations
kim J, NRR/ADRO/DORL, 415-4125
References
TAC MD8011
Download: ML081780213 (8)

Text

July 2, 2008

Vice President, Operations Entergy Nuclear Operations, Inc.

Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernon, VT 05354

SUBJECT:

VERMONT YANKEE - REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGE RELATING TO DEGRADED GRID PROTECTION SYSTEM INSTRUMENTATION (TAC NO. MD8011)

Dear Sir or Madam:

By letter dated February 12, 2008 (Agencywide Documents and Management System (ADAMS) Accession No. ML080660458), Entergy Nuclear Operations, Inc. (the licensee) requested changes to Vermont Yankee Nuclear Power Station (VY) Technical Specification (TS).

The Nuclear Regulatory Commission staff has been reviewing TS Sections 2.1, 3.1, and 3.2 relating to degraded grid protection system instrumentation and has determined that additional information is needed to complete its review. The specific questions are found in the enclosed request for additional information (RAI). A response to this RAI is requested to be provided within 30 days.

Sincerely, /RA/ James Kim, Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-271

Enclosure:

As stated cc w/encl: See next page

July 2, 2008 Vice President, Operations

ML081780213 OFFICE LPLI-1/PM LPLI-1/LA LPLI-1/BC NAME JKim SLittle MKowal DATE 6/27/08 7/02/08 7/02/08 VERMONT YANKEE - REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION CHANGE RELATING TO DEGRADED GRID PROTECTION SYSTEM INSTRUMENTATION

1. Confirm whether the Emergency Core Cooling Systems (ECCS) loads are started simultaneously or through a load sequencer on receiving a safety injection (SI) signal when there is no loss of offsite power. Provide a logic diagram or explain how the degraded voltage protection system interfaces with the starting of various ECCS loads on receipt of SI signal when the ECCS loads are fed from (a) offsite power, (b) emergency diesel generator (EDG).

2. When the 4160 V safety-related buses are powered from the offsite power source at the minimum grid voltage, confirm the following during the sequencing of ECCS loads (or block load if applicable):

(1) Minimum steady state voltage assumed at the switchyard (offsite source), and the basis for this minimum switchyard voltage; (2) Minimum steady state voltage at the 4160 V safety-related buses; (3) Minimum (worst case) transient voltage at the motor control center starter for the farthest load - whether adequate to pickup the starter/contactor; (4) Minimum (worst case) transient voltage at the starting motor (farthest load) - whether adequate to provide requisite torque to start the load; and (5) Minimum (worst case) transient voltage at the already running downstream Class 1E load terminals - whether adequate so that the load will not drop due to undervoltage at the downstream load.

3. In Section 8.5 of Final Safety Analysis Report (FSAR) of Vermont Yankee Nuclear Power Station (VYNPS), when the safety-loads are fed from the EDG, the licensee states that "a voltage drop limit of 40% is established as a maximum voltage variation to occur during the starting of any load group shown in the starting sequence of Tables 8.5-1A and 1B, 8.5.2A and 2B, and 8.5.3A and 3B."

NRC Safety Guide 9 and Regulatory Guide 1.9 recommend that: At no time during the loading sequence should the frequency and voltage decrease to less than 95 percent of nominal and 75 percent of nominal, respectively. During sequencing of the ECCS loads from the EDG at Vermont Yankee, confirm the following:

(1) Minimum (worst case) transient voltage profile at the 4160 V safety-related buses; (2) Minimum (worst case) transient voltage at the motor control center starter for the farthest load - whether adequate to pickup the starter/contactor; Enclosure (3) Minimum (worst case) transient voltage at the starting motor (farthest load) - whether adequate to start the load; and (4) Minimum (worst case) transient voltage at the already running downstream Class 1E load terminal - whether adequate so that the load will not drop due to undervoltage at the downstream load. 4. The proposed TS Table 3.2.8 ACTION Note 3 states in the end: If the action and associated completion time of Note 3.a or 3.b are not met, initiate increased voltage monitoring of the associated 4.16 kV emergency bus(es).

Describe in detail what is meant by increased voltage monitoring (i.e., logging requirements and time intervals).

Vermont Yankee Nuclear Power Station cc:

Regional Administrator, Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415

Mr. David R. Lewis Pillsbury, Winthrop, Shaw, Pittman, LLP 2300 N Street, N.W. Washington, DC 20037-1128 Mr. David O

=Brien, Commissioner Vermont Department of Public Service 112 State Street Montpelier, VT 05620-2601 Mr. James Volz, Chairman Public Service Board State of Vermont 112 State Street Montpelier, VT 05620-2701 Chairman, Board of Selectmen Town of Vernon P.O. Box 116 Vernon, VT 05354-0116

Operating Experience Coordinator Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernon, VT 05354 G. Dana Bisbee, Esq. Deputy Attorney General 33 Capitol Street Concord, NH 03301-6937 Chief, Safety Unit Office of the Attorney General One Ashburton Place, 19th Floor Boston, MA 02108

Ms. Carla A. White, RRPT, CHP Radiological Health Vermont Department of Health P.O. Box 70, Drawer #43 108 Cherry Street Burlington, VT 05402-0070 Ms. Charlene D. Faison Manager, Licensing Entery Nuclear Operations 440 Hamilton Avenue White Plains, NY 10601 Resident Inspector Vermont Yankee Nuclear Power Station U. S. Nuclear Regulatory Commission P.O. Box 176 Vernon, VT 05354 Massachusetts Emergency Management Agency ATTN: John Giarrusso, Nuclear Preparedness Manager 400 Worcester Rd. Framingham, MA 01702-5399

Jonathan M. Block, Esq. Main Street P.O. Box 566 Putney, VT 05346-0566

Vermont Yankee Nuclear Power Station cc: Senior Vice President Entergy Nuclear Operations, Inc.

P.O. Box 31955 Jackson, MS 39286-1995 Mr. Oscar Limpias Vice President, Engineering Entergy Nuclear Operations P.O. Box 31955 Jackson, MS 39286-1995 Mr. John A. Ventosa GM, Engineering Entergy Nuclear Operations 440 Hamilton Avenue White Plains, NY 10601 Mr. Joseph P. DeRoy VP, Operations Support Entergy Nuclear Operations, Inc. P.O. Box 31955 Jackson, MS 39286-1995 Mr. John R. Dreyfuss Director, NSA Entergy Nuclear Operations Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernon, VT 05354 Manager, Licensing Entergy Nuclear Operations, Inc. Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernon, VT 05354

Vice President Oversight Entergy Nuclear Operations, Inc.

P.O. Box 31955 Jackson, MS 39268-1995 Senior Manager, Nuclear Safety & Licensing Entergy Nuclear Operations, Inc. P.O. Box 31953 Jackson, MS 39286-1995 Senior Vice President and COO Entergy Nuclear Operations, Inc. 440 Hamilton Avenue White Plains, NY 10601 Assistant General Counsel Entergy Nuclear Operations, Inc. 440 Hamilton Avenue White Plains, NY 10601 Vice President, Operations Entergy Nuclear Operations, Inc. Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernon, VT 05354 Mr. James H. Sniezek 5486 Nithsdale Drive Salisbury, MD 21801 Mr. Garrett D. Edwards 814 Waverly Road Kennett Square, PA 19348

Vermont Yankee Nuclear Power Station cc: Ms. Stacey M. Lousteau Treasury Department Entergy Services, Inc. 639 Loyola Avenue New Orleans, LA 70113 Mr. Norman L. Rademacher Director, NSA Vermont Yankee Nuclear Power Station P.O. Box 250 Governor Hunt Road Vernont, VT 05354 Mr. Raymond Shadis New England Coalition Post Office Box 98 Edgecomb, ME 04556 Mr. James P. Matteau Executive Director Windham Regional Commission 139 Main Street, Suite 505 Brattleboro, VT 05301

Uldis Vanags State Nuclear Engineer Vermont Department of Public Service 112 State Street Montpelier, VT 05620-2601

Mr. Michael D. Lyster 5931 Barclay Lane Naples, FL 34110-7306