ML19254E189
| ML19254E189 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 10/17/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 7910310274 | |
| Download: ML19254E189 (1) | |
Text
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UNITED STATES o
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".,,g NUCLEAR REGULATORY COMMISSION g
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- E REGION V 0,
1990 N. CALIFORNI A BOULEVARD I
% * *, e *,e SUITE 202, WALNUT CREEK PLAZA WALNUT CREEK, CALIFORNIA 94S96 October 17, 1979 Docket flo. 50-312 Sacramento Municipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention: Mr. John J. Mattimoe Assistant General Manager Gentlemen:
Enclosed is IE Bulletin No. 79-13, Revision 2 which requires action by you with regard to your power reactor facility (ies).
Should you have any questions regarding this Bulletin or the actions re-quired by you, please contact this office.
Sincerely, b~4b' R. H. Engelken Director
Enclosures:
1.
IE Bulletin No. 79-13, Revision 2 2.
List of IE Bulletins Issued in the Last Six Months cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD
\\1 1248 02j2 m
7910310 1
SSINS:
6830 Accession No.:
7908220135 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AllD ErlFORCEMENT WASHINGTON, D.C.
20555 October 16, 1979 IE Bulletin No. 79-13 Revision 2 CRACKil1G IN FEEDWATER SYSTEM PIPING Description of Circumstances:
This revision to IE Bulletin No. 79-13 is based on the results of the radio-t graphic examinations and ongoing investigation of the subject problem to date j
since the initial Bulletin was issued.
The revision reduces in scope the R2 number and extent of the piping system welds required to be examined. The requirements for reporting and action time frame remain unchanged.
l 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 stear 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 fluclear Reactor Regulation which infcrmed 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 Enforcenent requested licensees of PWR plants in current outages to immediately conduct volumetric examination of certain feedwater piping weld-as a result af 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-pipe welds on two of three steam generators of San Onofre Unit 1.
On June 15, 1979, Carolina Power and 1.ight 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 1 feedwater piping-to-vessel nozzle weld.
Public Service Electric and Gas Company reported on June 20, 1979 that Salem Uni t 1 al so ha- ~'
4"i-'"me u<ernne<n onu i r Service company decided on June 20, 197 weld which contained questionable indic As of June 22, 1979 and since May 25, 1 DUPLICATE DOCUMENT inspected the feedwater nozzle-to-pipe Entire document previously entered into system under:
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