ML17290A381

Forwards GE Rept R-R8-111 Re Flaw in Reactor Bldg Piping. Review of Program Output for Fatigue Analysis & IGSCC Fracture Mechanics Showed Current Crack Size Well within Limit of Util Evaluation.Indication Will Be Monitored

ML17290A381
Person / Time
Site:	Columbia
Issue date:	05/21/1993
From:	Parrish J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17290A382	List: ML17290A381 ML17290A383
References
GO2-93-119, TAC-M80358, NUDOCS 9306040268
Download: ML17290A381 (6)

Text

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ACCESSION NBR:9306040268 DOC.DATE: 93/05/21 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION PARRISH,J.V. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Forwards GE Rept R-R8-ill re flaw in reactor bldg piping.

Review of program output for fatigue analysis & IGSCC fracture mechanics showed current crack size well within limit of util evaluation. Indication will be monitored.

DISTRIBUTION CODE: A001D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: OR Submittal: General. Distribution NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PDV LA 1 1 PDV PD 1 1 CLIFFORD,J 2 2 INTERNAL: ACRS 6 6 NRR/DE/EELB 1 1 NRR/DORS/OTSB 1 1 NRR/DRCH/HICB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 OC ~EMB 1 0 OGC/HDS1 1 0 G FILE 01 1 1 EXTERNAL: NRC PDR 1 1 NSIC 1 1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTEl CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEEDl TOTAL NUMBER OF COPIES REQUIRED: LTTR 21 ENCL 19

0 0 WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Wasbtngton Way ~ Rtcbtand, Wasbtngton 99352496'8 ~ (509) 372-5000 May 21, 1993 G02-93-119 Docket No. 50-397 U.S Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 REPORT ON FLAW IN REACTOR RECIRCULATION PIPING

References:

1) Letter, G02-92-123, dated May 14, 1992, GC Sorensen (SS) to NRC, "Report on Flaw in Reactor Recirculation Piping (TAC No. 80358)"

2) Letter dated June 25, 1992, RR Assa (NRC) to GC Sorensen (SS),

"Review of Updated Report on Reactor Recirculation Piping Flaw at Washington Public Power Supply System (WPPSS) Nuclear Reactor Number 2 (TAC No. M83721)"

The indication in ISI weld 20RRC(6)-8, as discussed in Reference 1, was reexamined, for the second successive time May 12, 1993, to determine any size change. No significant changes in the indication depth nor signal characteristics were noted. The flaw depth was found to be 0.175 inch (0.17 inch at R-7) The slight difference in depth is attributed to the minor

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differences in calibration and data point locations along the indication length. The length, now reported as 3.6 inches is based on the EPRI NDE practice for IGSCC detection of length based on reference gain. The length previously reported (4.5 inches) was based on 12db over reference to determine initial length of flaw based on CE-2 signal disappearing into baseline.

Both lengths were reported in the R7 NDE data report 1RRU-166 enclosed with Reference 1.

The length of the flaw remains unchanged. The indication does not exhibit the UT signals characteristic of IGSCC.

The initial fracture mechanics analysis was reviewed using the current indication depth of 0. 175 and length of 3.62 inches. The analysis predicts a crack depth of 0.38 inches after 740 days from the initial examination in May of 1991, if the IGSCC mechanism is active. The analysis also predicts that the depth would exceed the maximum allowable depth of 0.62 inches after 4 additional years. The current flaw depth is 0.175 inches. This depth is approximately 10.8%

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Page Two REPORT ON FLAW IN REACTOR RECIRCULATION PIPING of the predicted growth as determined by analysis. Review of the program output for both the fatigue analysis and the IGSCC fracture mechanics analysis showed the current crack size is well within the limits of our evaluation that was previously performed. Therefore, based on the analysis and the examination results, the indication is determined to be acceptable for continued operation without repair until the next examination.

The Supply System will continue to monitor this indication. At refueling outage R-9, Spring 1994, the indication will be resized. If it still does not show any signs of significant growth, it willbe reanalyzed to justify changing the examination frequency. This weld is still classified as an IGSCC, Category "F" weld.

The results of this reexamination and evaluation are submitted for your review and approval for plant restart scheduled for Sunday June 13, 1993, (Reference 2).

Sincerely

. V. Parrish (Mail Drop 1023)

Assistant Managing Director, Operations DPR/bk

Enclosure:

NDE Report No. R-R8-111 CC: JB Martin - NRC RV NS Reynolds - Winston Ec Strawn JW Clifford - NRC DL Williams - BPA/399 NRC Site Inspector - 901A

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