ML19224D568
| ML19224D568 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/25/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Johari Moore SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 7907120625 | |
| Download: ML19224D568 (1) | |
Text
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June 25, 1979 Docket flos. 50-361 50-362 Southera California Edison Company P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Attention:
Mr. J. B. Moore Vice Pre'.ident Gentlemen:
The enclosed IE Bulletin No. 79-13 is forwarded to you for information.
ilo written response is required.
If you desire additional information regardir' this matter, please contact this office.
Sincerely,
( O l ').
C L d
R. H. Engelken Director
Enclosures:
1.
Listing of IE Bulletins Issued in Last 12 Months cc w/ enclosures:
J. H. Drake, SCE 70071eoUz6
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UtlITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND EllFORCEMENT UASHINGTON, D.C.
20555 June 25, 1979 IE Bulletin flo. 79-13 CRACKING IN FEEDWATER SYSTEM PIPING Description of Circumstances:
On May 20, 1979, Indiana ed 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 feedwater elbows adjacent to two steam generator nozzle elt'ow 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 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 Enforcement requested licensees of PWR plants in current outages to immediately conduct volurretric 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 similar locations at their H. B. Robinson Unit 2.
Duquesne Power and Light confirmed on June 18, 1979, that radiography has shown cracking in their Beaver Valley Unit I 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. Wis ansin 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 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 joint detail showing the principal crack locations for D.C. Cook and San Onofre are shown on the attached figure 3' w:
On March 17, 1977, during heat-up fl DUPLICATE DOCUMENT Unit 1 a leak was discovered in t the16inchdiameterfeedwaterpi'Mg Entire document previously entered I
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