ML19224D525
| ML19224D525 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/25/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 7907120491 | |
| Download: ML19224D525 (1) | |
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72 UNITED STATES
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NUCLEAR REGULATORY COMMISSION 3 ' 7W(( [s REGION I C,'**
631 PARK AVENUE O
KING OF PRUSSIA, PENNSYLVANIA 19406 g
June 25, 1979 Docket No. 50-334 Duquesne Light Company ATTN:
Mr. C. N. Dunn Vice President Operations Divisi.a 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Gentlemen:
Enclosed is IE Bulletin No. 79-13 which requires action by you with regard to your power reactor facility (ies) with an operating license.
Should you have any questions regarding this 'aulletin or the actions rec iired by you, please contact this office.
Sincerely,
?
Boyce H. Grier Director
Enclosures:
1.
IE Bulletin Wo. 79-13 w/ Attachments 2.
List of IE Bulletins Issued in Last Twelve Months cc w/encis:
F. Bissert, Technical Assistant Nuclear R. Washabaugh, QA Manager J. Werling, Station Superintendent G. Moore, General Superintendent, Power Stations Department J. J. Carey, Nuclear Technical Assistant n(u p
Y9071 2o 348*039
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATOPY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-13 Date: June 25, 1979 Page 1 of 4 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 lines at their D. C. Cook Unit 2 facility.
The cracking was discovered following a shutdown on "ay 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 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 Hestinghouse steam generators reported crack indications.
Southern California cdison 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 reported on June 20, 1979 that Salem Unit 1 also has crack indications. Misconsin Public Service company decided on June 20, 1979 to cut out a feedwater nozzle-to-pipe weld which contained questionable indication, for netallurgical examination.
As of June 22, 1979 and since May 15, 1979 seven othe* PWR facilities have inspected the feedwater nozzle-to-pipe welds without fin, ng cracking indications.
Thefeedwaternozzle-to-pipeconfiguratif
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shown on the attached figures 1 and 2.
weld joint detail showing the principal UPLICATE DOC I
are shown on the attached figure 3.
Entire document into system under:Prenously entered S-On March 17, 1977, during heat-up for h Unit 1, a leak was discovered in the ve the 16-inch diameter feedwater piping t ANO 7 hdQgg
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