ML19246B307
| ML19246B307 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 06/25/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Gerstner W ILLINOIS POWER CO. |
| References | |
| NUDOCS 7907130125 | |
| Download: ML19246B307 (1) | |
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W UNITED STATES 4,
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G LE N E L L Y N. lL U NOis 6013 7 June 25, 1979 Docket No. 50 +bl Docket No. 50-462 Illinois Power Company ATTN:
Mr. W. C. Gerstner Executive Vice President 500 South 27th Street Decatur, IL 62525 Centlemen:
The enclosed IE Bulletin No. 79-13 is forwarded to you for information.
No written response is required.
If you desire this matter, please contact this additional information regardit 3 office.
Sincercly, 0.W/
- w g/ames G. Keppler/'
Director
Enclosures:
- 2. Listing of IE Bulletins Issued in Last 12 Months cc w/ encls:
Central Files Director, NRR/ DPM j
Director, NRR/ D0R PDR Local PDR NSIC TIC Mr. Dean Hansell, Office of Assistant Attorney General oid g. Lab
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U.S. NUCLEAR REGULATORY C0te!ISSION 0FFICE OF INSPECTION AND ENFORCEMENT REGION III June 25, 1979 IE Bulletin No. 79-13 CRACKING IN FEEDWATER SYSTEM PIPING Description of Circumstances:
On May 20, 1979, Indiana and 111chigan Power Company notified the NRC of cracking in two feedwater lines at their D. C. Cook Unit ? 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 specliic 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 reported on June 5, 1979, that radiographic examination revealed indications of cracking in feedwater nozzle-to piping welds or two of three steam generators of San Onofre Unit 1.
On June 15,197, 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 report,ed 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 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 and 2.
A typical feedwater pipe-to-nozzle weld joint detail showing the principal crack locations for D.C. Cook and San Onofre are shown on the attached figure 3.
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w On March 17, 1977, during heat-up for 1 QUPLICATE DOCUMENT C ?yA O Unit 1, a leak was discovered in the v.
the 16-inch diameter feedwater piping Entire document nondestructive examination of all nozz Into system under:previousl entered
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