ML19224D524
| ML19224D524 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/25/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Woolever E DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 7907120489 | |
| Download: ML19224D524 (1) | |
Text
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UNITED STATES
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- ' 't, NUCLEAR REGULATORY COMMISSION 3 k[,C "f
REGION I
$ 7ef,;, hrj G31 PARK AVENUE f
KING OF PRUSSt A, PENNSYLVANI A 1940G June 25, 1979 Docket No. 50-412 Duquesra Light Company ATTN:
Mr. E. J. Woolever Vice President 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Gentlemen:
Tne cnclosed Bulletin 79-13 is forwarded to you for information. No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerel<,
cxMf. 6IfStn oyce H. Grier y % irector
Enclosures:
1.
IE Bulletin No. 79-13 w/ Attachments 2.
List of IE Bulletins Issued in Last 12 Months cc w/encls:
R. J. Washabaugh, Quality Assurance Manager a
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v Too71gg,gg 348 097
ENCLOSURE 1 UNITED STATES NUCLEAR REGULATORY C0f! MISSION OFFICE OF INSPECTION AND ENFORCEf!ENT WASHINGTON, D.C.
20555 IE Bulletin No. 79-13 Date: June 25, 1979 Page 1 of 4 CRACKING IM FEEDWATER SYSTEM PIPING Description of Circumstances:
On flay 20, 1979, indiana and flichigan Power Company notified the NRC of cracking in two n
" lines at their D. C. Cook Unit 2 facility.
The cracking was discoverw 1ollowing a shutdown on flay 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 PUR 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 reauested licensees of PWR plants in current outages to immediately conduct volumetric examination of certain feedwater piping welds.
As a resu't of these actions, several other licensees with Hestinghouse 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 recorted 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.
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 15, 1979 seven other PWP. ft ilities 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 and 2.
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weld joint detail showing the principal cract are shown on the attached figure 3.
DUPLICATE DOCUMENT Entire document previously entered On ?! arch 17, 1977, Unit 1, a leak was discovered in the vessel rduring heat-up for hot fug}
into system under:
the 16-inch diameter feedwater piping to ste-nondestructive examination of all nozzle welc ANO No. of pages:
34d U10
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