ML19207C197
| ML19207C197 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 08/30/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Short T OMAHA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7909100244 | |
| Download: ML19207C197 (1) | |
Text
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UNITED STATES PDR:HQ g%
NUCLEAR REGULATORY COMMISSION (proj L i 3 gf( g 9
REGION IV
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ARUNGToN, TEX AS 7G012 w
August 30, 1979 Docket No.
50-285 Omaha Public Power District ATTN:
T. E. Short, Assistant General Manager 1623 Harney Street Omaha, Nebraska 68102 Gentlemen:
IE Bulletin 79-13 was originally sent to you for action on June 27, 197.1 The enclosed IE Bulletin 79-13, Revision 1 is for;;arded to you for info.ation.
No written response is required. This Revision is bein3 dispatched for actica to the additional Utilities, listed in Enclosure 3, who are applicants for operating licenses.
If you desire additicnal information regarding this catter, please contact this office.
Sincerely,f u-j' $
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' Karl V. Seyf ri't
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Director
Enclosures:
1.
IE Bulletin No. 79-13, Revision 1 2.
List of IE Bulletins Issued in Last Six Months 3.
Designated Applicants for Operating Licenses cc:
R. L. Andrews, Manager Fort Calhoun Station Post Office Box 93 Fort Calhoun, Nebraska 68102 OUI.O(!b 70001002f72
UNITED STATES NUCLEAR REGULATORY COMMISSItN OFFICE OF INSPECTION AND ENFORCEMENT VASIrlGTON, D.C.
2G555 IE Bulletin No. 79-13 Revision 1 Date:
August 30, 1979 Page 1 of 4 LRACKING IN FEEDWATER SYSTEM PIPING Descriptio of Circumstances:
On May 20, 1979, Indiar i 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 steam generator nozzle elbow welds.
Subsequent radiographic examinatica 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 informed 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 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, +. hat 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 Poacr 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 reported on June 20, 1979, that Salem Unit I 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 cracking indications.
The feedwater nozzle-to pipe configuin_-
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rooA a,n g og San Onofre are shown on the attached Figures 1
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- g er weld joint detail showing the princi; DUPLICATE DOCUMENT onofre are shown on the attached Figt yd[I,'bf p ;
s previously entered into sy e
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