ML20112E737
| 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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s Wh camamon ENERGY 300 Mod 6 eon Annue John P. sest qpfpfg Vice President. Nuclear foiedo, OH 43652 0001 419-249-2300 m. gene, i
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1 Docket Number 50-346 License Number NPF-3 i
Serial Number 2378 United States Nuclear Regulatory Commission 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
I data supports the field procedure in that the deeper rolls were not used on these eight tubes. Toledo Edison now believes that there are no non-stressed relieved roll transitions in the DBNPS' OTSGs.
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OperatinD Companies:
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Toledo Edison
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Docket Number 50-346 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.
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
,