ML19246B225
| ML19246B225 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 06/25/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dewitt R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 7907120700 | |
| Download: ML19246B225 (1) | |
Text
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pa atog UNITED STATES
/
NUOLEAR REGULATORY CCMMISSION e'
)) r REGloN til f
E GLE N E LLYN. ILLINOIS 60137 s
June 25, 1979 Docket No. 50-155 Cansumers Power Company ATTN:
Mr. R.
B. DeWitt Manager of Nuclear Plant Operations 212 West Michigan Avenue Jackson, MI 49201 Gentlemen:
The er;losed IE Bulletin No. 79-13 is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matte-please contact this office.
Sincerely, r
James G. Keppler b Director
Enclosures:
- 2. Listing of IE Bulletins Issued in Last 12 Months cc w/ encl:
Mr. C. J. Ha r t ma n,
Plant Superintendent Central Files Director, NRR/ DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Anthony Roisman, Esq.,
Attorney a
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U.S. NUCLEAR REGLLATonY COM'11SSION OFFICE OF INSPECTION AND ENFORCEMENT REGION III June 25: 1979 IE Bulletin No. 79-13 CRACKING IN FEEDWATER SYSIEM PlPING 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 May 19 to investigate leakage inside containment. Leaking circunferential 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 31censees of PWR plants in current outages to icmediately 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 2dison 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 veld. Public Service Electric and Gas Company report,ed 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 fsedwater 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 crackina, indications.
The feedwater nozzle-to pipe configurations for D.C. Cook and for San Oncfre are shown on the attached figures 1 and 2.
A typical feedwater pipe-to-nozzle weld joint detail showing the principal crack locations for D.C. Cook and San Onofre are shoun on the attached figure 3.
F " 72 7 !
- 7 DUPLICATE DOCUMENT On March 17, 1977, during heat-up for hot b^
p Unit 1, a leak was discovered in the vesse Entire document Pr V the 16-inch diameter feedwater piping to s into System under usly entered nondestructive examination of all nozzle w f 0 (p Q [ Q p f
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