ML17286A840

Informs of Reasonable Assurance That Structural Integrity of Piping Will Be Maintained & Util May Restart Unit W/ Identified Crack & Operate Through Cycle 7 Until Next Refueling Outage

ML17286A840
Person / Time
Site:	Columbia
Issue date:	05/23/1991
From:	Eng P Office of Nuclear Reactor Regulation
To:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
References
TAC-80358, NUDOCS 9106040093
Download: ML17286A840 (5)

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Docket No. 50-397 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 ViAY 2 3 199,'r.

G.

C. Sorensen, Manager Regulatory Programs Washington Public Power Supply System 3000 George Washington Way P.O.

Box 968 Richland, Washington 99352

SUBJECT:

FLAW IN REACTOR RECIRCULATION PIPING AT WNP-2 (TAC NO. 80358)

By letter dated May 10, 1991 (G02-91-096), you informed us of a linear indication found during the inservice inspection of the 20 inch shutdowh cooling suction line of the reactor recirculation system.

The indication was detected by personnel using procedures qualified for the detection and sizing of Intergranular Stress Corrosion Cracking (IGSCC) in stainless steel piping systems.

The indication was found on a weld designated as Category B

as defined in Generic Letter 88-01, "NRC Position on IGSCC in BWR Austenitic Stainless Steel Piping."

You stated that your inspection sample size was expanded to examine additional welds, and you forwarded your evaluations of the indication to us for review.

We understand that you are assuming that the flaw is due to IGSCC even though this weld was treated with the Induction Heating Stress Improvement process prior to service.

We also understand that this weld wi 11 be reexamined during the next refueling outage scheduled for April 1992, to determine crack growth rate.

The NRC staff has reviewed your May 10, 1991, submittal and concluded that there is reasonable assurance that structural integrity of the piping will be maintained and that the Washington Public Power Supply System Nuclear Project No.

2 (WNP-2) may restart the unit with the identified crack and operate through Cycle 7 until the next refueling outage which is scheduled for April 1992.

Furthermore WNP-2 has committed to reexamine the weld, evaluate crack growth and to determine whether IGSCC is the cause of the flaw.

The results of the next examination and evaluation are to be submitted to the NRC for review and approval prior to resumption of reactor operation following the next refueling outage.

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The Safety Evaluation which provides the basis for the above conclusion will be transmitted to you at a later date.

The reporting requirements contained in this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.

If you have any questions regarding this issue, please contact me.

Sincerely, ORIGINAL'IGNED BY Patricia L. Eng Project Directorate V

Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation n,

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Mr. G. C. Sorensen Washington Public Power Supply System I

WPPSS Nuclear Project No.

2 (WNP-2)

CC:

Mr. J.

W. Baker WNP-2 Plant Manager Washington Public Power Supply System P.O.

Box 968, MD 927M Richland, Washington 99352 G. E.

C. Doupe, Esq.

Washington Public Power Supply System 3000 George Washington Way P. 0.

Box 968 Richland, Washington 99532 Mr. R.

G. Waldo, Chairman Energy Facility Site Evaluation Council Mail Stop PY-ll Olympia, Washington 98504 Mr. Alan G. Hosier, Licensing Manager Washington Public Power Supply System P. 0.

Box 968, MD 956B

Richland, Washington 99352 Mr. A. Lee Oxsen, Acting Managing Director for Operations Washington Public Power Supply System P.

0.

Box 968, MD 1023

Richland, Washington 99352 Mr. Gary D. Bouchey, Director Licensing and Assurance Washington Public Power Supply System P.

0.

Box 968, MD 280

Richland, Washington 99352 Regional Administrator, Region V

U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Chairman Benton County Board of Commissioners P. 0.

Box 190

Prosser, Washington 99350-0190 Mr.

R.

C. Sorensen U. S. Nuclear Regulatory Commission P. 0.

Box 69

Richland, Washington 99352 Nicholas S. Reynolds, Esq.

Winston E Strawn 1400 L Street, N.W.

Washington, D.C.

20005-3502

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