ML20128F266

Forwards Draft 137-0010-5 to GE-NE-523-172-1292, IWB-3640 Evaluation of Indication Detected at Recirculation Discharge Safe End D at Oyster Creek Station, for Review & Approval for 14R Augmented Insp for IGSCC

ML20128F266
Person / Time
Site:	Oyster Creek, 07201292
Issue date:	02/02/1993
From:	Keaten R GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20128F270	List: ML20128F266 ML20128F274
References
5000-93-0018, 5000-93-18, C321-93-2042, GL-88-01, GL-88-1, NUDOCS 9302110321
Download: ML20128F266 (2)

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- - - - GPU Nuclost Corporation Ono Upper Pond Road f.I.1

"' . UCae I M eers,nna,v.Ne ae,se,070s4 201 316-7000 TELEX 136 482 Wrilef 8 Direct Dial Number.

February 2, 1993 5000-93-0018 C321-93-2042 U. S. Regulatory Connission Attn Document Control Desk Washington, DC 20555 Gentlemen

Subject:

Oyster Creek Nuclear Generating Station (OCNGS)

Docket No. 50-219 Facility Operating License No. DPR-16 14R Augmented Inspections for IGSCC in accordance with Technical Specification 4.31., GP'JN is transmitting the flaw ovaluations for Recirculation System welds NG-D-18 and NG-D-23. NG-D-18 is a pipe to pipe wold and NG-D-23 is a safe end to nozzle weld.

GPUN's disposition of these wolds for continued service is delineated in Attachment 1. The IWB-3040 evaluation (GE-NE-523-172-1:92) for NG-D-23 is also included for your information.

In accordance with Generic letter 88-01 and our NRC approved inspection program (Topical Report TR-050, Rev. 3), wo are requesting yots' expedited review and

- ap )roval . If you have any questions or require further clarifications on this su)mittal, please contact Mr. Michael Laggart, Manager, Corporate Nuclear 1.icensing at (201) 316-7076.

Very truly yours, fR.W. Keaten Vice President and Director 10003"i Technical Functions DGJ/

cc: Administrator, Region I Senior Resident-Inspeccor 1 Oyster Creek NRC Project Manager Mft21g g "f$ g g 1 GNI Nuclear Corporahon is a subsidery of General rubhc Ut40s Corporato)

k Attachment 1  :

GPUN Disposition of Wold Flaws Epid NG-D-13 NG-D-18 is a of stress improvedidenti IHSI).

joint (fied IGSCC indication.The 14R inspection-report sho enlargement ' s previously '

Une indication, however, a circumferential flaw 0.3" long and 18% through-wall, is reported during 14R for the first time. This new indicatior, was previously i dispositioned as root geometry in 1986. This indication' is presently dispositioned as acc9ptable for continued service without repair by using the-acceptance criteria for stress improved joints in NUREG 0313. Rev. 2 (i.eK30% i through-wall and < 10% of circumference). This- indication satisfies this criteria and a crack growth analysis is not necessary. This joint is a Category - -,

F weldment, as per NUREG 0313 (Rev 2), because an oxial indication was previously identified after stress improvement.  ;

Ekld_ED-11 The joint between the "D" recirculation loop discharge . nozzle and the safe-end was inspected for the first time during the 14R outage out of a concern for possible IGSCC damage. The inspection identified a flaw contered about '1.9 inches from the weld, unusually far for IGSCCJ to occur. . Records from-construction described a weld repair of a boat sample at about the same location. ';

The initial inspection report was revisited with the boat sample repair being the.

possiblo reficctor. Additional investigation: using routine Section XI calibration and sizing methods resulted in an inspection report change characterizing the indications ..as geometric reflectors without surface-connections associated .with a weld repaired boat sample, r ASME Section XI, IWB-3640 analysis methods and acceptance criteria were used to disposition the indication, conservatively treated as linked together, as

' acceptable for continued service without repair. The disposition also included 1 the requirement to reinspect in ISR in crder..to verify both the analysis  ;

-assumption of- no surface connections and-the analysis result of . insignificant growth. ,

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