ML19254F169
| ML19254F169 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 10/17/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7911070238 | |
| Download: ML19254F169 (1) | |
Text
-
CENTRAL FILES UNITED STATES M:HQ f(tr a "Ecoq'o NUCLEAR REGULATORY COMMISSION R
J. *D R EGloN IV o
611 RY AN PLAZA DRtVE SUITE 1000 pg{g
$j 2
g
- . :, y ARLINGTON, TEXAS 76012
..w u, 1
,%,,',~ j j o
,8 October 17, 1979 Docket No.
50-298 Nebraska Public Power District ATTN:
J. M. Pilant, Director Licensing & Quality Assurance Post Office Box 499 Columbus, Nebraska 68601 Gentlemen:
The enclosed IE Bulletin 79-13, Revision 2 is forwarded to you for information. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely,.
ll
~/
-O /
' S e - i j,/ 23 Karl V. Seyfrit. '
Director
Enclosures:
1.
IE Bulletin No. 79-13, Revision 2 2.
List of IE Bulletins Issued in the Last Six Months cc:
L. C. Lessor, Sunerintendent Cooper Nuclear Station Post Office Box 98 Brownville, Nebraska 68321 e
1290 00!
S 7911070
SSINS:
6830 Accession No.:
7908220135 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-13 Revision 2 October 16, 1979 Page 1 't 5 CRACKING IN FEEDWATER SYSTEM PIPING Description of Circumstances:
This revision to IE Bulletin No. 79-13 is based on the results of the radio-graphie examinations and ongoing investigation of the subject problem to date 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.
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 containceat.
Leaking circumferential 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 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 reqaested 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.
A2 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 pipe 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 the to-vessel nozzle weld. Public Servic NOTE: R1 and R2 indicates lines re-i DUPLICATE DOCUbH:NT Entire document previously entered into system under:
ANO N o.
of pages:
. _.