BVY 07-066, License Renewal Application, Amendment 31

License Renewal Application, Amendment 31

ML072670135
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	09/17/2007
From:	Ted Sullivan Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 07-066, TAC MC9668
Download: ML072670135 (5)

Text

- Entergy Entergy Nuclear Operations, Inc.

Vermont Yankee P 0. Box 0500 185 Old Ferry Road Brattleboro, VT 05302-0500 Tel 802 257 5271 September 17, 2007 Docket No. 50-271 BVY 07-066 TAC No. MC 9668 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Letter, Entergy to USNRC, "Vermont Yankee Nuclear Power Station, License No.

DPR-28, License Renewal Application," BVY 06-009, dated January 25, 2006.

Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

License Renewal Application. Amendment 31

Dear Sir or Madam,

On January 25, 2006, Entergy Nuclear Operations, Inc. and Entergy Nuclear Vermont Yankee, LLC (Entergy) submitted the License Renewal Application (LRA) for the Vermont Yankee Nuclear Power Station (VYNPS) as indicated by Reference 1. This letter provides clarification for commitments made to the NRC regarding Environmentally Assisted Fatigue.

Should you have any questions concerning this letter, please contact Mr. Dave Mannai at (802) 258-5422.

I declare under penalty of perjury that the foregoing is true and correct, executed on September 17, 2007.

Sincerely, sit,ý,i~ce President Vermont Yankee Nuclear Power Station cc: See next page enc: Attachment 1

"-1/7

BVY 07-066 Docket No. 50-271 cc:

Mr. James Dyer, Director U.S. Nuclear Regulatory Commission Office 05E7 Washington, DC 20555-00001 Mr. Samuel J. Collins, Regional Administrator U.S. Nuclear Regulatory Commission, Region 1 475 Allendale Road King of Prussia, PA 19406-1415 Mr. Jack Strosnider, Director U.S. Nuclear Regulatory Commission Office T8A23 Washington, DC 20555-00001 Mr. Jonathan Rowley, Senior Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike MS-C-1 1 F1 Rockville, MD 20853 Mr. Mike Modes USNRC RI 475 Allendale Rd, King of Prussia, PA 19406 Mr. James S. Kim, Project Manager U.S. Nuclear Regulatory Commission Mail Stop 0 8 C2A Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC P.O. Box 157 (for mail delivery)

Vernon, Vermont 05354 Mr. David O'Brien, Commissioner VT Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601 Diane Curran, Esq.

Harmon, Curran, Spielberg & Eisenberg, LLP 1726 M Street, N.W., Suite 600 Washington, D.C. 20036

BVY 07-066 Docket No. 50-271 Vermont Yankee Nuclear Power Station License Renewal Application Amendment 31

VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT 1 Supplemental Information for Environmentally Assisted Fatigue Vermont Yankee Nuclear Power Station (VYNPS) provides the following information in response to license renewal Commitment 27. The commitment specified addressing environmentally assisted fatigue by refining fatigue analyses to include the effects of reactor water environment to verify that the cumulative usage factors (CUFs) are less than 1. Entergy has completed refinement of the fatigue analyses as specified in Commitment 27 in accordance with the clarifying details provided in the letter of July 30, 2007. The results indicate that the CUFs of the most fatigue sensitive locations will be less than 1.0 through the period of extended operation, considering both mechanical and environmental effects.

The following results of the refined fatigue analyses are the environmentally adjusted CUF values for 60 years of operation for the locations specified in NUREG/CR-6260.

VYNPS Cumulative Usage Factors for NUREG/CR-6260 Limiting Locations Material Overall*

Environmental Environmentally NUREG-6260 Location Multiplier (Fen)

Adjusted CUF I

RPV vessel shell/ bottom head Low alloy steel 9.51 0.08 2

RPV shell at shroud support Low alloy steel 9.51 0.74 3

Feedwater nozzle forging blend radius Low alloy steel 10.05 0.64 4

RR Class 1 piping (return tee)

Stainless steel 12.62 0.74 5

RR inlet nozzle forging Low alloy steel 7.74 0.50 6

RR inlet nozzle safe end Stainless steel 11.64 0.02 7

RR outlet nozzle forging Low alloy steel 7.74 0.08 8

Core spray nozzle forging blend radius Low alloy steel 10.05 0.04 9

Feedwater piping riser to RPV nozzle Carbon steel 1.74 0.29

• Effective multiplier for past and projected operating history, power level, and water chemistry.

The Fatigue Monitoring Program (FMP) tracks actual plant transients and evaluates these against the design transients. Per license renewal Commitment 5, the FMP will ensure that the numbers of transient cycles experienced by the plant remain within the analyzed numbers of cycles and hence, the component CUFs remain below the values calculated in the fatigue evaluations. The LRA and subsequent amendments treated the actions specified under license renewal Commitment 27 as separate from the VYNPS FMP and took exception to the consideration of reactor water environment in the program. The transients assumed in the refined fatigue analyses will be added to the FMP and tracked to ensure ongoing validity of the inputs to the refined analyses.

Consequently, the FMP will include assessment of the impact of reactor water environment on critical components. The program will also include periodic review of accumulated transient cycles and associated updates of fatigue usage calculations, if necessary. Therefore, the exceptions identified in the LRA for the FMP are no longer appropriate. Removal of these exceptions makes the FMP, upon implementation of the enhancements identified in the LRA, consistent with the program described in NUREG-1801 Section X.M1, Metal Fatigue of Reactor Coolant Pressure Boundary. By tracking the number of cycles analyzed in the refined fatigue analyses, the Fatigue Monitoring BVY 07-066 Docket 50-271

VERMONT YANKEE NUCLEAR POWER STATION LICENSE RENEWAL APPLICATION SUPPLEMENT ATTACHMENT 1 Program will manage the effects of environmentally assisted fatigue on reactor coolant system components through the period of extended operation in accordance with 10 CFR 54.21 (c)(1)(iii).

LRA Section A.2.2.2.3 revisions (strikeouts=deletions, underline=additions)

The effects of reactor water environment on fatigue were evaluated for license renewal.

Projected cumulative usage factors (CUFs) were calculated for the limiting locations identified in NUREG/CR-6260 with no.SeveFal locations miay exceeding a CUF of 1.0 with consideration of environmental effects during the period of extended operation. F the**e*' ation",

prFie to the period of exto'ndo"d operation, VYNPS Will (1) rofino the fatigue aRalysih to lower the prodirctd CUE to less, than 1.0; (2) mnago fatigue at the af~fecGtled locations-with an inspection progra~m that hass boon rviow and approvod by the NRCG (e.g., perio~dic non dostructiVo examination-of the affected locations at inspection intervals to be determined by a method acceptable to the NRC); or()rpi or replac-e the affecGted locations-.

BVY 07-066 Docket 50-271