ML20038B835
| ML20038B835 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Cooper, Arkansas Nuclear, River Bend, Waterford, South Texas, Comanche Peak, Fort Calhoun, Fort Saint Vrain  |
| Issue date: | 12/02/1981 |
| From: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | ARKANSAS POWER & LIGHT CO., GULF STATES UTILITIES CO., HOUSTON LIGHTING & POWER CO., KANSAS GAS & ELECTRIC CO., NEBRASKA PUBLIC POWER DISTRICT, OMAHA PUBLIC POWER DISTRICT, PUBLIC SERVICE CO. OF COLORADO, TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| References | |
| NUDOCS 8112090142 | |
| Download: ML20038B835 (2) | |
Text
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UNITED STATES 3+
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NUCLEAR REGULATORY COf/1 MISSION g
REGION IV
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/,p 611 RYAN PLAZA DRIVE. SUITE 1000 ARUNGTON. TEXAS 76011 December 2, 1981 Gentlemen:
The enclosed NRC Information Notice provides early notification of an event that may have safety significance.
It is expected that recipients will review the infomation notice for possible applicability to their facilities.
If you have any questions regarding this matter, please contact this office.
Sincerely, kg/ h6w
- dohnT. Collins Regional Administrator
Enclosures:
1.
NRC Infonnation Notice No. 81-35 2.
Listing of Recently Issued NRC Infomation Notices
/E 3j 8112090142 811202' PDR ADOCK 05000267 3
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IE INFORMATION NOTICE N0. 81-35: CHECK VALVE FAILURES Licensee Facility / Docket Number Arkansas Power and Light.Conpany Arkansas Nuclear One,' Unit 1 & 2
" Little Rock, Arkansas 50-313r50-368 v
Nebraska Public Power District Cooper Nuclear Station
- olumbus, Nebraska 50-298 C
Omaha Public Power District Fort Calhoun Station
- Omaha, Nebraska j50-285 Public Service Company of Colorado Fort St. Vrain Generating Station Denver, Colorado v50-267 Gulf States Utilities River Bend Beaumont, Texas40-458;40-459
_ Houston Lighting & Power Company South Texas Project Houston, Texas M O-498;56-499
, Kansas Gas & Electric Company Wolf Creek Wichita, Kansas s STN 50-482 s Louisiana Power & Light Company Waterford-3 New Orleans, Louisiana "50-382
,. Texas Utilities Generating Company Comanche Peak Steam Electric Station Dall s, Texas40-445; 60-446
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SSINS No.:
6835 Accession No.:
8107230041 IN 81-35 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON,.0.C.
20555 December 2, 1981 NRC INFORMATION NOTICE N0. 81-35:
CHECK VALVE FAILURES Description of Circumstances:
After undertaking a program at Three Mile Island Nuclear Station Unit 1 (TMI-1) to follow the recommendations in IE Circular 78-15, " Tilting Disk Check Valves Fail to Close With Gravity in Vertical Position," Metropolitan Edison Company (Met-Ed) reported (LER 80-003/01T and supplement) loose valve internals in the high pressure injection pump discharge check valves.
The valves are Crane three-inch 1500# tilting disk check valves.
The initial cause of the loose valve internals was traced to the corrosion of the seat holddown device.s of the valves.
As a result of these findings. Met-Ed developed and implemented a continuing inspection program for TMI-7.
A design study of the tilting disk check valves was also conducted.
Further inspection led to the discovery that some valves could not prevent back flow due to the failure of the hinge pin and seat ring retention devices.
A hinge pin was found to have fallen off, and tack welds on the hinge pin retaining screws were either cracked, weak, or nonexistent.
In the seat ring retention device, one lock plate assembly was missing and the seat ring retention device became loose because washers were not installed.
Met-Ed also found many fabrication inconsistencies that may nave initiated and/
or contributed to these failures.
These inconsistencies ranged from the use of materials, other than those specified in procurement documents, to poo" workman-ship, particularly in the case of welds.
For instance, where tack weids were t
called for on the hinge pin retaining screws, the screws were peened.
There l
were also instances where flat washers were installed in the valves instead of spring washers, and nickel plated carbon steel washers were used when precipi-tation hardened stainless steel washers were specified.
Additional problems with disk retaining pins in Crane check valves were reported by Florida Power Corporation (LERs 80-017/03L-0 and 80-021/03L-0) at Crystal River Unit 3 and by Virginia Electric and Power Company (LER 80-023/01T-0) at Surry Unit 1.
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IN 81-35 December 2, 1981 Page 2 of 2 The failure of the hinge lugs on a Mission Manufacturing Company check valve at Fort Calhoun Station was reported by Omaha Public Power District (LER 78-036/
03L-0).
The failure of the hinge lugs allowed the disk plate to migrate to the steam generator.
No damage was observed in the steam generator when the disk plate was removed.
The valve is a Mission Type 3"-C308, Style "B" Duo Check, Series 900 check valve.
The discovery of internal damage to two Anchor Darling check valves at Arkansas Nuclear One Unit 2 was reported by Arkansas Power and Light Company (LER 81-034/
99X-0). When the first valve was opened to repair a leak, it was discovered that the disk pin was broken from the disk and the disk pin, pin nut, and washer were missing.
The equivalent valve in the redundant train was then opened and a disk pin nut and washer were found missing.
Both failures were attributed to the valve being manufactured with wire used as the locking device rather than the pin shown on the design drawing.
Both valves are Anchor Darling four-inch swing check valves, drawing number 3102-3.
Thus, the check valve failures can be attributed to two main causes: (1) poor retaining device design, and (2) poor quality control on the assembly of the valve internals.
Similar problems with check valves from another manufacturer are described in IE Ir. formation Notices No. 80-41, " Failure of Swing Check Valve in the Decay Heat Removal System at Davis-Besse Unit No. 1," and 81-30, "Velan Swing Check Valves."
This information is provided as notification of a potentially 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 you have questions regarding this matter, please contact the Regional Administrator of the appropriate NRC Regional Office.
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NRC Informati.on Notice No. 81-35 December 2,1981 LISTING OF RECENTLY ISSUED NRC INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 81-27 Flammable Gas Mixtures 9/3/81 All power reactor facilities in the Waste Gas Decay with an Operating License Tanks in PWR Plants (0L) or Construction Pennit (CP) 81-28 Failure of Rockwell-Edward 9/3/81 All power reactor facilities Main Steam Isolation Valves with an Operating License (0L) or Construction Permit (CP) 81-29 Equipment Qualification 9/24/81 All power reactor facilities with an Operating License (0L) or Construction Permit
(.CP )
81-30 Velan Swing Check Valves 9/28/81 All power reactor facilities with an Operating License (0L) or Construction Permit (CP) 81-31 Failure of Safety Injection 10/8/81 All power reactor facilities Valves to Operate Against with an Operating License Differential Pressure (0L) or Construction Permit (CP) 81-32 Transfer and/or Disposal of 10/23/81 All medical licensees Spent Generators 81-33 Locking Devices Inadequately 11/9/81 All power reactor facilities Installed on Main Steam with an Operating License Isolation Valves (0L) or Construction Permit (CP) 81-34 Accidental Actuation of Prompt 11/16/81 All power reactor facilities Public Notification System with an Operating License (OL) or Construction Permit (CP)
Enclosure