ML081780213

Request for Additional Information Regarding Technical Specification Change Relating to Degraded Grid Protection System Instrumentation

ML081780213
Person / Time
Site:	Vermont Yankee
Issue date:	07/02/2008
From:	James Kim 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 Ms. Carla A. White, RRPT, CHP U. S. Nuclear Regulatory Commission Radiological Health 475 Allendale Road Vermont Department of Health King of Prussia, PA 19406-1415 P.O. Box 70, Drawer #43 108 Cherry Street Mr. David R. Lewis Burlington, VT 05402-0070 Pillsbury, Winthrop, Shaw, Pittman, LLP 2300 N Street, N.W. Ms. Charlene D. Faison Washington, DC 20037-1128 Manager, Licensing Entery Nuclear Operations Mr. David O=Brien, Commissioner 440 Hamilton Avenue Vermont Department of Public Service White Plains, NY 10601 112 State Street Montpelier, VT 05620-2601 Resident Inspector Vermont Yankee Nuclear Power Station Mr. James Volz, Chairman U. S. Nuclear Regulatory Commission Public Service Board P.O. Box 176 State of Vermont Vernon, VT 05354 112 State Street Montpelier, VT 05620-2701 Massachusetts Emergency Management Agency Chairman, Board of Selectmen ATTN: John Giarrusso, Town of Vernon Nuclear Preparedness Manager P.O. Box 116 400 Worcester Rd.

Vernon, VT 05354-0116 Framingham, MA 01702-5399 Operating Experience Coordinator Jonathan M. Block, Esq.

Vermont Yankee Nuclear Power Station Main Street P.O. Box 250 P.O. Box 566 Governor Hunt Road Putney, VT 05346-0566 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

Vermont Yankee Nuclear Power Station cc:

Senior Vice President Vice President Oversight Entergy Nuclear Operations, Inc. Entergy Nuclear Operations, Inc.

P.O. Box 31955 P.O. Box 31955 Jackson, MS 39286-1995 Jackson, MS 39268-1995 Mr. Oscar Limpias Senior Manager, Nuclear Safety &

Vice President, Engineering Licensing Entergy Nuclear Operations Entergy Nuclear Operations, Inc.

P.O. Box 31955 P.O. Box 31953 Jackson, MS 39286-1995 Jackson, MS 39286-1995 Mr. John A. Ventosa Senior Vice President and COO GM, Engineering Entergy Nuclear Operations, Inc.

Entergy Nuclear Operations 440 Hamilton Avenue 440 Hamilton Avenue White Plains, NY 10601 White Plains, NY 10601 Assistant General Counsel Mr. Joseph P. DeRoy Entergy Nuclear Operations, Inc.

VP, Operations Support 440 Hamilton Avenue Entergy Nuclear Operations, Inc. White Plains, NY 10601 P.O. Box 31955 Jackson, MS 39286-1995 Vice President, Operations Entergy Nuclear Operations, Inc.

Mr. John R. Dreyfuss Vermont Yankee Nuclear Power Station Director, NSA P.O. Box 250 Entergy Nuclear Operations Governor Hunt Road Vermont Yankee Nuclear Power Station Vernon, VT 05354 P.O. Box 250 Governor Hunt Road Mr. James H. Sniezek Vernon, VT 05354 5486 Nithsdale Drive Salisbury, MD 21801 Manager, Licensing Entergy Nuclear Operations, Inc. Mr. Garrett D. Edwards Vermont Yankee Nuclear Power Station 814 Waverly Road P.O. Box 250 Kennett Square, PA 19348 Governor Hunt Road Vernon, VT 05354

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