ML19256B516
| ML19256B516 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 06/25/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 7907240258 | |
| Download: ML19256B516 (1) | |
Text
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UNITED STATES R
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NUCLEAR REGULATORY COMMISSION 4
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REGION IV NSIC
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611 RYAN PLAZA DRIVE. SUITE 1000 O. A _
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June 25, 1979 Docket No. 50-298 Nebraska Public Power District ATTN:
Mr. J. M. Pilant, Licensing &
Quality Assurance Manager Post Office Box 499 Columbus, Nebraska 68601 Gentlemen:
Enclosed is IE Bulletin 79-13 which requires action by you with regard to your power reactor facility with an operating license.
Should you have any questions regarding this Bulletin or the actions required by you, please contact this office.
Sincerely, e
Karl V. Seyfrit Director
Enclosures:
1.
List of IE Bulletins Issued in Last 12 Honths cc:
L. C. Lessor, Superintendent Cooper Nuclear Station Post Office Box 98 Brownville, Nebraska 68321
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMEN"1 WASHINGTON, D.C.
20555 IE Bulletin No, 79-13 Date: June 25, 1979 Page 1 of 4 CRACKING IN FEEDWATER SYSTEM PIPING De;cription of Circumstances:
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 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 requested specific information on feedwater system design, fabrication, inspection and operating histories. To further explore the generic nature of the cracking problemi 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, 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 I feedwater piping to vessel nozzle weld.
Public Service Electric and Gas Company reported on June 20, 1979 that Salem Unit 1 also has crack ir.dications. Wisconsin Public Service Company decided on June 20, 1979 to cut out a feedwater nozzle-to pipe weld which contained a questionable indication, for metallurgical examiation. 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 configura
_Onofre are shown on the attached Figures 1 and 2.
joint detail showing the principal cra are shown on the attached Figure 3.
E DUPLICATE DOCUMENT On March 17, 1977, during heat-up for Entire document previously Unit 1, a leak was discovered in the v entered into system under:
the 16-inch diameter feedwater piping nondestructiveexaminationofallnozzg ANO 7 9gJp Jt/ g N o.
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