ML20085N740
| ML20085N740 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/23/1995 |
| From: | Stetz J CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20085N744 | List: |
| References | |
| 2304, GL-95-03, GL-95-3, NUDOCS 9506300304 | |
| Download: ML20085N740 (4) | |
Text
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300 Madison Avenue John P. Stetr Toledo, OH 436524001 Vice President Nuclear 419-249-2300 Ms-h i
Docket Number 50-346 License Number NPF-3
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Serial Number 2304 June 23, 1995 United States Nuclear Regulatory Commission l
Document Control Desk Vashington, D. C. 20555-0001 Subj ect : Toledo Edison Response to Generic Letter 95-03, Circumferential Cracking of Steam Generator Tubes i
Ladies and Gentlemen:
Nuclear Regulatory Commission (NRC) Generic Letter (GL) 95-03 (Toledo Edison Log Number 4529), dated April 28, 1995, (1) provided notification about the recent steam generator tube inspection findings at the Haine Yankee Atomic Power Station and the safety significance of those findings, (2) requested that Toledo Edison (TE) implement certain actions as describ-ed within the generic letter for its Davis-Besse Nuclear Power Station (DBNPS), and (3) required that TE submit to the NRC, a written response regarding implementation of the requested actions. Additionally, the i
generic letter advised TE of the importance of performing comprehensive examinations of steam generator tubes using techniques and equipment capable of reliably detecting steam generator tube degradation.
t Generic Letter 95-03 encouraged licensees to develop generic safety assess-ments and inspection plans for logical groupings of plants where possible.
Toledo Edison has worked closely with the Babcock & Vilcox Owners Group (BV0G) Steam Generator Committee in developing a generic response that is applicable to TE's DBNPS.
Toledo Edison endorses the enclosed generic
,l response developed by the BV0G Steam Generator Committee and vill take the j
actions specified in the generic response at the DBNPS's next refueling outage.
Toledo Edison personnel assigned to monitor the steam generators, are aware of ongoing industry issues to ensure that the latest and most effective eddy current techniques are used where appropriate. An example of this is Operating Companies:
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that an optimized rotating cross wound probe was used to perform eddy current inspections during the last refueling outage. These personnel are responsible for safe and proper operation of the B&W once-through steam generators (OTSGs) installed at the DBNPS.
Section I of the BV0G generic response provides background information and discusses the applicability to B&V OTSG type steam generators.
Section I.3.2 addresses tube roller expansion transitions and discusses that some steam generator tubes were cold work roller expanded subsequent to the furnace stress relief process and did not receive the post-roll stress relief. The DBNPS has eight tubes in this category. There are four per steam generator; seven in the upper tube sheet and one in the lower tube sheet.
Section II of the BV0G generic response provides a justification for continued operation. The BV0G OTSG plants have not identified any service-induced circumferential cracking in tubes or sleeves other than fatigue-induced circumferential cracks in the upper span of the lane /vedge region.
At the DBNPS, no circumferential cracking has ever been identified in the steam generators.
Based upon the demonstrated success of the industry preventive sleeving program for the upper span of the lane vedge region used at the DBNPS, and the lack of observed failures in other areas believed to be most suscepti-ble to circumferential cracking, TE has determined that the DBNPS is safe for continued operation.
Section III of the BV0G generic response provides the plans and scope for inspection of OTSG tubes during the next scheduled inspection. The DBNPS's next refueling outage is scheduled to begin in April of 1996. Toledo Edison vill perform tube inspections as described in the BV0G generic response during this scheduled refueling outage.
Should you have any questions or require additional information, please contact Mr. Villiam T. O'Connor, Manager - Regulatory Affairs, at (419) 249-2366.
Very truly yours, FVK/laj enclosures cc:
L. L. Gundrum, DB-1 NRC/NRR Project Manager J. B. Martin, Regional Administrator, NRC Region III S. Stasek, DB-1 NRC Senior Resident Inspector Utility Radiological Safety Board
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Dockat Nu;b2r 50-346
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RESPONSE TO GENERIC LETTER 95-03' FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NUMBER 1-.
This letter (Serial Number 2304) is in response to NRC Generic Letter 95-03, "Circumferential Cracking of Steam Generator Tubes." - It is submitted pursuant to 10 CFR 50.54(f).
For:
J. P. Stetz, Vice' President - Nuclear By:
S.~C. Jain, Director - Efgineering and Services Sworn and Subscribed before me this 23rd day of June, 1995.
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