ML19224D567
| ML19224D567 | |
| 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 7907120624 | |
| Download: ML19224D567 (1) | |
Text
g.< ri cg hk 7>g UNITED STATES
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- W NUCLE AR REGULATORY COMMISSION
$,[.gh', /', of REGloN V t Nu O r g 1930 fJ. Calif ORNI A BOULEVARD
' 4 d' SUIT E 202, WALNUT CRE E K PL AZA WALNL.' f CREE K, C ALIF ORNI A 94596 y
TESb. j June 25, 1979 Docket i'o. 50-206 Southern California Edison Company P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Attention: Mr. J. B. Moore Vice President Gentl emen:
Enclosed is IE Bulletin 79-13 which requires action by you with regard to your power reactor facility (ies) with an operating license.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sin
- ely, kii~2,.,,( C _.
s R. H. Engelken Director
Enclosures:
1.
IE Bulletin flo. 79-13 2.
List of IE Bulletins Issued in Last 12 Months cc w/ enclosures:
J. M. Curran, SCE J. T. Head, SCE
- 355, fej 7 90712 0 w/
.~
UNITED STATES fiUCLEAR REGULATORY COMMISSI0ii 0FFICE OF INSPECTION AND EllFORCEMEliT WASHI!;GTON, D.C.
20555 June 25, 1979 IE Bulletin fio. 79-13 CRACKI!u 4 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 circunferential 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 gcnerator feedwater lir,es at this location on both Units 1 cind 2.
On May 25, 1979, a letter was sent to all PMR licensees by the Office of fluclear Reactor Regulation which inforned licensees of the D. C. Cook failures and requested specific informat;on on feedwater system design, fabrication, inspection and operating histories. To further explore the ceneric 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.
Souths a 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 Licht confirr.ed on June 18, 1979, that radiography has shown cracking in their Beaver Valley Unit 1 feedwater pipirg to vessel nozzle weld.
Public Service Electric and Gas Company reported on June 20, 1979 thet Salem Unit 1 also has crack indications. Wisconsin Public Service conpany 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 flay 25, 1979 seven other PMR 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
.hcyn on the attached figures 1 and 2.
A typical feedwater pipe-to-nozzle we]d jcint detail showing the principal crack locations. for.'1 Cd'* <'
P C
~
are shown on the attached figure 3 g~
LLICATE DOCUMENT D
On March 17, 1977, during heat-up f d
r?itire document previously entere Unit 1, a leak was discovered in th the 16-inch diareter feedwater pipi into System under:
y nondestructive examination of all n
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