ML19207C198
| ML19207C198 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 08/30/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 7909100249 | |
| Download: ML19207C198 (1) | |
Text
CENTRat
[(p'#*%,y,i UM:TED STATES PDR S
% v, NUCLEAR REGULATORY CO2,1TAISSION ippq 7,iM,7,hM(%'
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AR LINGTON. T EX AS 7 G012 August 30, 1979 Docket No. 50-267 Public Service Company of Colorado ATTN:
Mr. C. K. Millen Senior Vice President P. O. Box 840 Denver, Colorado 80201 Gentlecen:
IE Bulletin 79-13 was originally sent to you for a: tion on June 27, IT/9.
The enclosed IE Bunctin 79-13, Revision 1 is formrded to you for inf r ition.
No written response is required. This Revision is being dispatched for action to the additional Utilities, listed in Enclosur2 3, who are appUcants for operating licenses.
If you desire additional information regardin; this natter, please contact this office.
Sincerely, (i
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Karl V. Sevfrit Director
Enclosures:
1.
IE Bulletin No. 79-13, Revision 1 0
0 t) k j JS 2.
List of IE Bulletins t
Issued in Last Six g r-gItmg Months J
i 3.
Designated Applicants for kj;.jb j(CJJJU Jd b Operating Licenses cc:
D. W. Warenbourg, Nuclear Production Manager Fort St. Vrain Nuclear Station P. O. Box 368 Platteville, Colorado 80651 L. Brey, Manager, Quality Assurance D.y ru,.lO 7900100297
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
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IE Bulletin No. 79-13 Revision 1 Date: August 30, 1979 Page 1 of 4 CRACEING IN FEEDWATER SYSTEM PIPING Desc.iption of Circumstances:
,0n 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 shutdown on May 19 to investigate leakage inside containment. Leaking circumfereitial cracks were identified in the 16-inch feedwater elbows adjacent to two steam generator nozzle elbow welds.
Subsequent radiographic examination revealed crack indict.tions 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 repor*ed on June 5, 1979, tbat radiographic examination revealed indications of cracking in feedvater nozzie-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 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 configurations for D. C. Cook and for San Onofre are shown on the attached Figures 1 an E
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