ML20247E536
| ML20247E536 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 04/30/1998 |
| From: | Geoffrey Edwards PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9805180373 | |
| Download: ML20247E536 (1) | |
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l tti.tlon Support Department
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PECO NUCLEAR nco se c-9r>s chestorbrook Boulevard A Unit of PECO Energy Wayne PA 19067-5691 l
April 30,1998 Docket No. 50-278 i
License No. DPR-56 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
SUBJECT:
Peach Bottom Atomic Power Station, Unit 3 Jet Pump Riser Piping
REFERENCES:
(1) Letter from G. A. Hunger, Jr. to U. S. Nuclear Regulatory Commission, dated December 22,1997 (2) Letter from T. A. Mitchell, to U. S. Nuclear Regulatory Commission, dated November 19,1997
Dear Sir / Madam:
Reference letter (1) committed PECO Energy Company to provide information describing the actual operating history and the crack growth for this operating period following the repair outage. Unit 3 was operated a total of 3187 hours0.0369 days <br />0.885 hours <br />0.00527 weeks <br />0.00121 months <br /> between its last refueling outage and the repair outage in March. Of the total,2592 hours0.03 days <br />0.72 hours <br />0.00429 weeks <br />9.86256e-4 months <br /> were with nominal recirculation drive flow at 80% or less, and 595 hours0.00689 days <br />0.165 hours <br />9.837963e-4 weeks <br />2.263975e-4 months <br /> were with nominal recirculation drive flow greater than 80% (considered to be 91% for analysis purposes).
The total hours of operation represent an additional 163 hours0.00189 days <br />0.0453 hours <br />2.695106e-4 weeks <br />6.20215e-5 months <br /> over the total hours assumed in the original operating strategy which was transmitted by reference letter (2). The 163 hours0.00189 days <br />0.0453 hours <br />2.695106e-4 weeks <br />6.20215e-5 months <br />, from an additional week of operation, did not impact the original analysis margin because of lower than expected operation at 91% nominal recirculation drive flow. The original operating strategy conservatively assumed the hours at 91% nominal drive flow at the beginning of the cycle while the actual hours at 91% nominal recirculation drive flow occurred predominantly near the end of the cycle.
The same type of UT examination was performed of the cracked riser piping, prior to repairs, as was performed in October 1997. There was no change in crack length at either repair location over this operating period as measured by UT examination.
If you have any questions, please do not hesitate to contact us.
Very truly yours, b_-
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Garrett D. Edwards Director-Licensing g
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cc:
H. J. Miller, Administrator, Region I, USNRC p
l A. C. McMurtray, USNRC Senior Resident inspector, PBAPS 3
l 9805190373 990430 PDR ADOCK 05000278 p
PDR i
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