ML20112E737

Submits Rev of Response to GL 95-03, Circumferential Cracking of Steam Generator Tubes

ML20112E737
Person / Time
Site:	Davis Besse
Issue date:	06/03/1996
From:	Stetz J CENTERIOR ENERGY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2378, GL-95-03, GL-95-3, TAC-M92238, NUDOCS 9606070060
Download: ML20112E737 (3)

Text

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Wh camamon ENERGY 300 Mod 6 eon Annue John P. sest ,

foiedo, OH 43652 0001 419-249-2300 qpfpfg Vice President . Nuclear m . gene, l

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l t 1 Docket Number 50-346 License Number NPF-3 i

Serial Number 2378 I

United States Nuclear Regulatory Commission I Document Control Desk Washington, D. C. 20555 l

Subject:

Revision of Toledo Edison's Responses to Generic Letter 95-03, "Cir-cumferential Cracking of Steam Generator Tubes" (TAC No. M92238)

Ladies and Gentlemen:

Toledo Edison (TE) responded to NRC Generic Letter 95-03 by TE Serial Letter L Number 2304, dated June 23, 1995, for the Davis-Besse Nuclear Power Station I

(DBNPS). In the June 23 letter, an attached Babcock and Wilcox generic response i discussed non-stress relieved, roller-expanded tube transitions within the l' tubesheet region of the once-through steam generators (OTSGs). In response to a NRC request for additional information on the non-stress relieved transitions, TE provided additional information in TE Serial Letter Number 2354, dated February 1, 1996. In the February 1 letter, TE stated there were eight non-stress relieved, cold-worked, roller-expanded tube transitions within the tubesheet region of the DBNPS once-through steam generators (OTSGs).

! A re-review of Babcock and Wilcox's original records for the OTSGs as part of the DBNPS Tenth Refueling Outage eddy current testing indicates that these eight roller-expanded transitions were stress relieved. The Babcock and Wilcox records indicate that the procedure used for the DBNPS OTSGs had been modified to eliminate the use of deeper roller-expansion as a temporary seal until leaking seal welds could be repaired. Accordingly, seal weld repair on these eight tubes was re-performed without re-expanding the tubes deeper in the l

tubesheet. No new transition was made and the original transition was stress relieved. The Bobbin and Motorized Rotating Pancake Coil probe eddy current i data supports the field procedure in that the deeper rolls were not used on I these eight tubes. Toledo Edison now believes that there are no non-stressed relieved roll transitions in the DBNPS' OTSGs.

9606070060 960607 PDR ADOCK 05000346 g P PDR 'p ; ,

OperatinD Companies:

Cleveland Electnc illuminat:ng i \ h l Toledo Edison

l Docket Number 50-346 l

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.. License Number NPF-3 '

Sirial Number 2378 Page 2 i

Should you have any questions or require additional information, please )

contact Mr. James L Freels, Manager - Regulatory Affairs, at  !

(419) 321-8466.  !

l Very truly yours, )

FWK/laj cc: L. L. Gundrum, DB-1 NRC/NRR Project Manager  !

H. J. Miller, Regional Administrator, NRC Region III S. Stasek, DB-1 NRC Senior Resident Inspector Utility Radiological Safety Board i

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