ML20108D606
| ML20108D606 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/01/1996 |
| From: | Jain S DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9605080195 | |
| Download: ML20108D606 (2) | |
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ve Vaney Power Station Shipp6ngport, PA 15077-0004 May 1,1996 SUSHIL C.JAIN g a33,3333, DMsion Vice President Fax H12) 643-8069 Nuclear Services Nuclear Power Divison U. S. Nuclear Regulatory Commission Attention: Document Control Desk l
Washington, DC 20555-0001 i
1
Subject:
Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Analysis of Flaw Indications: Follow-up Submittal The purpose of this letter is to submit follow-up information regarding the Duquesne Light Company (DLC) evaluation of an indication identified during non-l destructive examinations (NDE) of Class 1 austenitic piping. On April 23,1996, DLC submitted a letter report summarizing a bounding analysis demonstrating that the assumed flaw indication in the reactor coolant system (RCS) "C" loop cold leg is l
acceptable for continued service until the end of service lifetime. It was also stated that a follow-up to the April letter would be submitted by May 1,1996, docketing the DLC weld disposition. This subn ittal provides information docketing the current status as of l
May 1,1996.
l l
The indication in shop weld DLW-LOOP 3-7-S-02 is still being evaluated relative to its classification under IWB-3514.5 as potentially a metallurgical reflector. Additional i
fabrication information was received on April 30,1996, which identifies weld repairs l
made to the ends of the subject cast piping during manufacture.
The location and l
applicability of these repairs to our situation has not yet been fully established. We l
expect this evaluation to be completed in the near future.
Additionally, the results of the video and eddy current examinations of the inner diameter (ID) surface have been reviewed and evaluated.
The results of these examinations verified that there are no surface breaking indications or geometric irregularities on the ID surface. The lack of any ID surface breaking indication provides assurance that there is no inservice failure mechanism to be addressed. This lack of an ID surface indication coupled with the evidence of weld repairs at the pipe ends during manufacture suggests that the ultrasonic indication recorded is likely associated with either the metallurgical interface of the repair weld or a manufacturing repair anomaly in c,,
DEllVERING 080033 ouatiiY E II E R G Y 9605080195 960501 i
PDR ADOCK 05000334 p
PDR sf 8
Beav&r Valley Power Station, Unit No.1 Analysis of Flaw Indications: Follow-up Submittal Page 2 the repair weld. This is consistent with industry inspection experience and mechanistic failure studies of cast austenitic piping completed by the Westinghouse Electric Corporation.
Pending further evaluation, DLC is continuing to conservatively treat the indication as a flaw. Therefore, the request for NRC evaluation as submitted on April 23, 1996, remains necessary to support plant restart from the current eleventh refueling outage and entry into Mode 4.
It is suggested that upon completion of the ongoing evaluation, a meeting be scheduled with members of the NRC staff to present the DLC conclusions. If you have any questions regarding this submittal, please contact Mr. Roy K. Brosi at (412) 393-5210.
i Sincerely, Sushil C. Jain c:
Mr. L. W. Rossbach, Sr. Resident Inspector Mr. T. T. Martin, NRC Region I Administrator Mr. D. S. Brinkman, Sr. Project Manager i
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