ML19332B215
| ML19332B215 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 08/07/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | William Jones OMAHA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 8009260283 | |
| Download: ML19332B215 (1) | |
Text
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UNITED STATES PDR:HQ
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NUCLEAR REGULATORY COMMISSION LPDR JP REGloN IV g
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611 RY AN PLAZA DRIVE. SulTE 1000
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'T-A.,,.J f August 7, 1980 Docket No.
50-285 Omaha Public Power District ATIN:
W. C. Jones, Division Manager -
Production Operations 1623 Harney Street Omaha, Nebraska 68102 Gentlemen:
This IE Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an II Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely,,
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m p,l / bly KarlV.Seyfrit.;/
Director
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Enclosures:
1.
IE Information Notice No. 80-29 2.
List of Recently Issued IE Information Notices cc:
S. C. Stevens, Ewager Fort Calhoun Station Post Office Box 98 Fort Calhoun, Nebraska 68102 8009260 2 3 )
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SSINS No.: 6835
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UNITED STATES 8006190028 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Information Notice No. 80-29 Date:
August 7, 1980 Page 1 of 1 BROKEN STUDS ON TERRY TURBINE STEAM INLET FLANGE When removing the governor and stop valve on the Unit 1 steam driven emergency feedwater pump at Arkansas Nuclear One for repair of a steam leak at the steam inlet flange, Arkansas Power and Light discovered that five of the eight studs securing the flange were broken.
The cause of the stud failure is unknown at this time.
Metallurgical evalua-tion of the failed bolting will be performed to identify the mode of failure.
The failed studs are 3/4 inch diameter by 3-1/2 inch long and are thought to be of ASTM-193 grade B7 steel.
The turbine flange bolting is generally covered with insulation and not visible for inspection.
From the information available, the bolting has not been removed or inspected since installation seven to eight years ago.
The steam driven emergency feedwater pump turbine at ANO-1 is a type G turbine manufactured by the Terry Steam Turbine Company of Hartford, Connecticut.
The turbine is rated at 680 BHP and 3560 RPM. The turbine operates at a reduced steam pressure of 270 psig and temperature of 400 F and has previously experienced overspeed trips and vibrations whlch may have been caused by slugs of water from the piping.
Licensees are encouraged to carefully examine insulation in the flange to turbine casing region for evidence of leakage and consider inspection of the turbine steam inlet flange bolting.
Further, during surveillance testing, care should be taken to observe if abnormal vibration or other transients occur which could promote loss of bolting integrity.
This Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
It is expected that recipients will review the information for possible applicability to their facility.
No specific action or response is requested at this time.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
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IE Information No. 80-29 August 7, 1980 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-23 Loss of Suction to 5/29/80 All power reactor to Emergency Feedwater facilities with an Pumps Operating License (OL) or Construction Permit (CP) 80-24 Low Level-Radioactive 5/30/80 All NRC and Agreer.ent Waste Burial Criteria State Licensees 80-25 Transportation of 5/30/80 Material Licensee Pyrophoric Uranium in Priority / Categories II-A, II-D, III-I and IV-DI; Agreement State Licensees in equivalent categories l
80-26 Evaluation of Contractor 6/10/80 All Part 50 Licensees QA Programs 80-27 Degradation of Reactor 6/11/80 All Pressurized Water Coolant Pump Studs Reactor Facilities holding power reactor Operating License (OL) or Construction Permits (cps) 80-28 Prompt Reporting Of 6/13/80 All applicants for and Required Information holders of nuclear power to NRC reactor construction permits l
l Supp. to Notification of 7/29/80 All holders of Reactor 80-06 Significant Events at Operating Licenses (OLs) l l
Operating Power Reactor and to near term Facilities operating license applicants Enclosure r
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