ML20206E864

Forwards SER Concluding That Flaw Evaluation Meets Rules of ASME Code Concerning Util 990329 Request to Extend Reinspection Period for Jet Pump Riser Circumferential Weld Flaws Discovered During 1998 Refueling Outage

ML20206E864
Person / Time
Site:	Vermont Yankee
Issue date:	04/29/1999
From:	Croteau R NRC (Affiliation Not Assigned)
To:	Maret G VERMONT YANKEE NUCLEAR POWER CORP.
Shared Package
ML20206E868	List: ML20206E864 ML20206E874
References
TAC-MA5109, NUDOCS 9905050268
Download: ML20206E864 (3)

Text

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%ril 29,1999

' Mr. Gregory A. Maret Director of Operations Vermont Yankee Nuclear Power Corporation 185 Old Ferry Road Brattleboro, VT 05301

SUBJECT:

JET PUMP RISER CIRCUMFERENTIAL WELD INSPECTIONS AT VERMONT YANKEE NUCLEAR POWER STATION (TAC NO. MA5109) i

Dear Mr. Maret:

i By letter dated March 29,1999, you requested to extend the reinspection period for the jet pump riser circumferential weld flaws discovered during the 1998 refueling outage from one q cycle to two cycles. We had previously reviewed the weld information and concluded that the i flaw evaluation met the rules of the American Society of Mechanical Engineers (ASME) Code regarding extending reinspection for one cycle as documented in our October 26,1998, letter.

Ultrasonic inspections identified a flaw indication in four of the RS-1 (thermal sleeve to riser elbow) welds and your latest evaluation concluded that jet pump riser in!.agrity and performance are not compromised for at least the next two operating cycles.

We have completed our review of the weld inspection information that you provided associated with extending reinspection for two cycles and concluded that the flaw evaluation meets the rules of the ASME Code. Since the predicted flaw size at the end of two fuel cycles is less than the critical flaw size with an adequate margin, we agree with your assessment that Vermont Yankee can be operated without repair for two fuel cycles. We understand that you plan to reinspect these flaws during the 2001 refueling outage and to further evaluate the flaws at that time.-

Our safety evaluation is enclosed. This completes our effort for TAC No. MA5109.

Sincerely, ,

Original signed by:

Richard P. Croteau, Project Manager, Section 2 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271 /

Enclosure:

Safety Evaluation I

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PUBLIC A. Lee T. Clark /

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,,,g # April 29,1999 i Mr. Gregory A. Maret Director of Operations l Vermont Yankee Nuclear Power Corporation 185 Old Ferry Road -

Brattleboro, VT 05301

SUBJECT:

JET PUMP RISER CIRCUMFERENTIAL WELD INSPECTIONS AT VERMONT YANKEE NUCLEAR POWER STATION (TAC NO. MA5109)

Dear Mr. Maret:

By letter dated March 29,1999, you requested to extend the reinspection period for the jet pump riser circumferential weld flaws discovered during the 1998 refueling outage from one cycle to two cycles. We had previously rev; awed the weld information and concluded that the flaw evaluation met the rules of the American Society of Mechanical Engineers (ASME) Code regarding extending reinspection for one cycle as documented in our October 26,1998, letter.

Ultrasonic inspections identified a flaw indication in four of the RS-1 (thermal sleeve to riser elbow) welds and your latest evaluation concluded that jet pump riser integrity and performance are not compromised for at least the next two operating cycles.

We have completed our review of the weld inspection information that you provided associated with extending reinspection for two cycles and concluded that the flaw evaluation meets the 4 rules of the ASME Code. Since the predicted flaw size at the end of two fuel cycles is less than the critical flaw size with an adequate margin, we agree with your assessment that Vermont Yankee can be operated without repair for two fuel cycles. We understand that you plan to reinspect these flaws during the 2001 refueling outage and to further evaluate the flaws at that time.

~ Our safety evaluation is enclosed. This completes our effort for TAC No. MA5109.

' Sincerel ,

) 'f ' k Richard P. Croteau, Project Manager, Section 2 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-271 '

Enclosure:

Safety Evaluation cc w/ encl: See next page

.A

i Vermont Yankee Nuclear Power Station cc:

- Regional Administrator, Region I l U. S. Nuclear Regulatory Commission Mr. Raymond N. McCandless 475 Allendale Road Vermont Division of Occupational  !

King of Prussia, PA 19400 and Radiological Health Administration Building Mr. David R. Lewis Montpelier, VT 05602 Shaw, Pittman, Potts a Trowbridge I

2300 N Street, N.W. Mr. Gautam Sen Washington, DC 20037-1128 Licensing Manager {

Velmont Yankee Nuclear Power '

Mr. Richard P. Sedano, Commissioner Corporation Vermont Department of Public Service 185 Old Ferry Road 120 State Street,3rd Floor Brattleboro, VT 05301 Montpelier, VT 05602 Resident inspector Public Service Board Vermont Yankee Nuclear Power Station i State of Vermont U. S. Nuclear Regulatory Commission 120 State Street P.O. Box 176 Montpelier, VT 05602 Vernon, VT 05354 Chairman, Board of Selectmen Mr. Peter Laoorte, Director Town of Vernon ATTN: James Muckerheide P.O. Box 116 Massachusetts Emergency Management

- Vernon, VT 05354-0116 Agency 400 Worcester Rd.

Mr. Richard E. McCullough P.G. Box 1496 Operating Experience Coordinator Framingham, MA 01701-0317 Vermont Yankee Nuclear Power Station P.O. Box 157 Jonathan M. Block, Esq.

Governor Hunt Road Main Street Vernon, VT 05354 P. O. Box 566 Putney, VT 05346-0566 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. Deborah B. Katz Box 83 Shelburne Falls, MA 01370