ML19224D561
| ML19224D561 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 06/25/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| NUDOCS 7907120615 | |
| Download: ML19224D561 (1) | |
Text
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UNITED STATES
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4' E G.., E 'n NUCLEAR REGULATORY COMMISSION
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1990 fJ. CAllF ORNIA DOULEVARD
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SUITE 202, WA LNUT CH F E K PL AZ A
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.,s WALNUT CREEK, CALIFORNI A 9450G 1I June 25,1979 Docket flos. 50-528 50-529 50-530 Arizona Public Ser/ ice Company P. O. Box 21666 Phoenix, Arizona 83036 Attention:
Mr. E. E. Van Brunt, Jr.
Vice President, Construction Projects Centlemen:
The enclosed IE Bulletin i!o. 79-13 is forwaraed to you for information. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,
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.Cl.
R. H. Engelken Director
Enclosures:
1.
Listing of IE Bulletins Issued in Last 12 Months cc w/ enclosures:
F. W. Hartley, APS M/
IOOY 0 (o tf
UtilTED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 June 25, 1979 IE Bulletin No. 79-13 CRACKING IN FEEDWATER SYSTEM PIPING Description of Circumstances:
On May 20, 1979, Indiana and Michigan Power Conpany 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 containnent.
Leaking circumferential cracks were identified in the 16-inch 'eMwater elbows adjacent to two steam generator nozzle elbow welds.
Subsequent radiographic exanination 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 PKP licensees by the Office of Nuclear Reactor Regulation which infomed 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 Enforcerent requested licensees of PWR plants in current outages to immediately ccnduct volumetric examination of certain feedwater piping welds.
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 sinilar locations at their H. B. Robinson Unit 2.
Duquesne Power and Light confirr.ed on June 18, 1979, that radiography has shown cracking in their Beaver Valley Unit 1 feedwater piping to vessel nozzle weld.
Public Service Electric and Gas Company reported 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 feedwater nozzle-to-pipe welds without finding c.Acking 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 joint detail showing the principal crack locctions for D.C. Cook and San Onofre are shown on the attached figure 3.
On March 17, 1977, during heat-t IjDbPLICATE DOCUMENT Unit 1, a leak was discovered it 1
the 16-inch diameter feedwater I jEntire document previously entered nondestructive examination of al 4into system under:
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