BVY 06-033, Cycle 24 10 CFR 50.59 Report

Cycle 24 10 CFR 50.59 Report

ML061170443
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	04/24/2006
From:	Devincentis J Entergy Nuclear Northeast, Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 06-033
Download: ML061170443 (4)

Text

Entergy Nuclear Northeast Entergy Nuclear Operaticns, Inc.

Vermont Yankee P.O. Box 0500 c- Entergy 185 Old Ferry Road Brattleboro, VT 05302-0500 Tel 802 257 5271 April 24, 2006 BVY 06-033 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockvil e, MD 20852-2738

Subject:

Vermont Yankee Nuclear Power Station Docket No. 50-271, License No. DPR-28 Cycle 24 10 CFR 50.59 Report

References:

(1) Letter, USNRC to VYNPC, 'TMI Action Plan Item II.K.3.3, Reporting o: Relief Valve and Safety Valve Failures and Challenges," NVY 82-44, dated March 30,1982 In acco dance with 10 CFR 50.59, attached is a copy of the Vermont Yankee (VY) Cycle 24 10 CFR 50.59 Report. This report contains a brief description of the 50.59 evaluations that supported changes, tests and experiments between May 4, 2004 and November 11, 2005.

Additionally, in accordance with Reference 1, VY reports that there were no Relief Valve o.' Safety Valve failures or challenges during this period.

Should you have any questions or require additional information, please contact me at (802) 258-4236.

There are no new commitments being made in this submittal.

Sincerely,

('James M. DeVincentis Manager, Licensing Vermont Yankee Nuclear Power Station

Attachment:

Vermont Yankee Cycle 24 10 CFR 50.59 Report cjSe q

VY 06-033 / Page 2 of 2 cc:

Mr. Samuel J. Collins (w/o attachment)

Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mr. James J. Shea, Project Manager Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-G9A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road P.O. Box 157 Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street, Drawer 20 Montpelier, Vermont 05620-2601

BVY 06-033 Docket No. 50-271 Attachment Vermont Yankee Nuclear Power Station Vermont Yankee Cycle 24 10 CFR 50.59 Report

Attachment to BVY 06.033 Docket No. 50-271 Page 1 of 1 Vermont Yankee Cycle 24 10 CFR 50.59 Report Between May 4, 2004 and November 11, 2005, Vermont Yankee (VY) implemented one change requiring evaluation in accordance with 10 CFR 50.59. This report includes the 10 CFR 50.59 Evaluation Summary for that Vermont Yankee Engineering Request.

The following change did not require prior Nuclear Regulatory Commission approval. It was reviewed by the On-Site Safety Review Committee (OSRC) and approved by the OSRC Chairman.

10 CFR 50.59 Evaluation Number: 2005-01 Revision Number: 0 Engineering Request 04-1337. "24V DC Power Distribution ImDrovements" This change involved modifying selected components and installing Appendix R blocking diodes in the output circuitry of the 24V DC ECCS Power Supplies. The component modifications included the internal power supply mounting, the ground fault monitor mounting, and replacing the power supply incandescent bulb with an LED. The blocking diodes eliminate the need for an operator to manually transfer power supplied to Appendix R equipment, thus improving Appendix R response times.

50.59 Evaluation Summary This change did not result in more than a minimal increase in the frequency of occurrence of any prlviously analyzed accident because the 24V DC ECCS Power Supplies cannot malfunction in a manner that would initiate an accident. This change did not result in more than a minimal increase in the likelihood of occurrence of a malfunction of equipment important to safety because the modifications have been designed, installed and tested to ensure that they will not negatively affect the seismic or environmental qualifications of the power supplies. This change did not result in more than a minimal increase in the consequences of any previously analyzed accident or malfunction because the modifications have been designed, installed and tested b ensure that they will not negatively affect the seismic or environmental qualifications of the power supplies or their ability to perform their function in the mitigation of a previously analyzed accident or malfunction. This change did not create the possibility for an accident or malfunction of a different type than previously analyzed because no new failure modes are being introduced. This change did not result in a design basis limit for a fission product barrier being eKceeded or altered because the response of ECCS instrumentation is unaffected. This change did not result in a departure from an existing method of evaluation because this was a physical modification and did not involve an evaluation methodology.