ML19246B306
| ML19246B306 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/25/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Hines E DETROIT EDISON CO. |
| References | |
| NUDOCS 7907130119 | |
| Download: ML19246B306 (1) | |
Text
cM" W4, UNITED ST ATES Tic NUCLEAR REGULATORY COMMISSION g ig];,g" f,j
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R E GION 131 f
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%,,,,4 June 25, 1979 Docket No. 50-341 The Detroit Edison Company ATTN:
Mr. Edward Hines, Assistant Vice President and Manager Quality Assurance 2000 Second Avenue Detroit, MI 48226 Gentlemen:
The enclosed lE Bulletin No. 79-13 is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincer.'ly, w
tJames G. Keppler Director
Enclosures:
- 1. lE Bulletin No. 79-13
- 2. Listing of IE Bulletins Issued in Last 12 Months cc w/encls:
Central Files Director, NRR/ DPM Director, NRR/ DOR PDR
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Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Eugene B. Thomas, Jr.,
Attorney t> ~9(v1 04 0
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U.S. NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT REGION 111 June 25, 1979 IE Bulletin No. 79-13 CRACKING IN FEEDWATER SYSTEM PIPING Description of Circumstances:
On May 20, 1979, Indiana and Michigan Power Company notified the NRC of cracking in two feedwater lines at their D. C. Cook Unit 2 facility. The cracking was discovered following a shutdown on May 19 to investigate leakage inside containment. Leaking circumferential cracks were identified in the 16-inch feedwater elbows adjacent to two steam generator nozzle elbow welds.
Subsequent radiographic examination revealed crack indications in all eight steam generator feedwater lines at this location on both Units 1 and 2.
On May 25, 1979, a letter was sent to all PWR licensees by the Office of Nuclear Reactor Regulation which informed licensees of the D. C. Cook failures and requested specific information on feedwater system design, fabrication, inspection and operating histories. To further explore the generic nature of the cracking problem, the Office of Inspection and Enforcement requested licensees of PWR plants in current outages to immediately conduct volumetric examination of certain feedwater piping wcids.
As a result of these actions, several other licensees with Westinghouse steam generators reported crack indications. Southern California Edison reported on June 5, 1979, that radiographic examination revealed indications of cracking in feedwater nozzle-to-piping welds on two of three steam generators of San Onofre Unit 1.
On June 15, 1979, Carolina Power and Light reported that radiography showed crack indications in similar locations at their H. B. Robinson Unit 2.
Duquesne Power and Light confirmed on June 18, 1979, that radiography has shown cracking ia their Beaver Valley Unit 1 feedwater piping to vessel nozzle weld. Publir. Service Electric and Gas Company report,ed on June 20, 1979 that Salem Unit 1 also has crack indications. Wisconsin Public Service company decided on June 20, 1979 to cut out a feedwater nozzle-to-pipe weld which contained questionable indication, for metallurgical examination. As of June 22, 1979 and since May 25, 1979 seven other PWR facilities have inspected the feedvater nozzle-to-pipe welds without finding cracking indications.
The feedwater nozzle-to-pipe configurations for D.C. Cook and for San Onofre are shown on the attached figures 1 and 2.
A typical feedwater pipe-to-nozzle weld jointdetailshowingtheprincipalcracklocationsforD.C.CookandSanOp"o5g4.m are shown on the attached figure 3.
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On March 17, 1977, during heat-up for h-DUPLICATE DOCUMENT Unit 1, a leak was discovered in the ve the 16-inch diameter feedwater piping t Entire document previously entered nondestructive examination of all nozzl into system under:
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