ML19246B310
| ML19246B310 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/25/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Bryan J UNION ELECTRIC CO. |
| References | |
| NUDOCS 7907130155 | |
| Download: ML19246B310 (1) | |
Text
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4, UNITED STATES
.t NUCLEAR REGULATORY COMMISSION f_l /,', [
REGION 111
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799 ROOSE V E LT RO AD GLE N ELLYN IL LINOIS 60137
%...*~p June 25, 1979 Docket No. 50-483 Docket No. 50-486 Union Electric Company ATTN:
Mr. John K. Bryan Vice President - Nuclear P. O. Box 149 St. Louis, MO 63166 Gentlemen:
The enclosed IE 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.
Sincerely,
\\'
!U-9 em
' James G. Kepple Director
Enclosures:
- 2. Listing of IE Bulletins Issued in Last 12 Months cc w/encls:
Mr. W. H. Webr.r, Manager, Nuclear Construction Central Files s'
Director, NRR/ DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Region I & IV Ms. K. Drey Hon. C. J. Frass, Chairman Missouri Public Service Commission 426 121
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7 9 0'T 13 0 t c, 5 1
U.S. NUCLEAR REGULAT0nY C0!CilSSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III 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 linen at their D. C. Cook Unit 2 facility. The cracking was discovered follawing a shutdown on May 19 to investigate leakage inside containment.
Leak Mg circumferential cracks were identified in the 16-inch feedvater elbows adjacent to two steam generator nozzle elbow welds.
Subsequent radiographie examination revealed crack indications in all eight steam generator feedvater 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 regt.ested specific information on feedwater system design, f abrication, inspection and operating histories. To further explore the generic nature of the cra ming problem, the Office of Inspection and Enforcement r_ quested licensees of PWR plants in current outages to immediately conduct 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 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 report,ed on June 20, 1979 that Salem Unit 1 also has crack indic'tions. Wisconsin Putlic 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 're shown on the attached figures 1 and 2. y ' " el feedwater pipe-to-nozzle weld joint detail showing the principal crac ;jDUptrbAT D
are shown on the attached figure 3.
-l
~w C'ument previous 1 On March 17, 1977, during heat-up for w
t 3 em Unit 1, a leak was discovered in the v under:
Y entered the 16-inch diameter feedwater piping ANO h
d3 nondestructive examination of all n'z:
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