ML19269D126
| ML19269D126 | |
| Person / Time | |
|---|---|
| Site: | 05000484 |
| Issue date: | 02/09/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dienhart A NORTHERN STATES POWER CO. |
| References | |
| NUDOCS 7902270356 | |
| Download: ML19269D126 (1) | |
Text
p-UNITED STATES f.
4 NUC LE A R REGULATORY COMMISSION I J I
REGION lit
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799 RooSeVE LT RO AD s;. e, ote~ e e<v~. itti~o,S eoia7 FEB:
.379 Docket No. 50-484 Northern States Power Company ATTN:
Mr. A. V. Dienhart Vice President - Tyrone Energy Park 100 North Barstow Street Eau Claire, WI 54701 Gentlemen:
This Information Notice is provided as an early notification of a pcssibly significant matter.
It is expected that recipients will review the information for possible applicability to their facili-ties. No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding the matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely,
(/ James G. g k ~9.9 Ke p er Director
Enclosures:
1.
IE Information Notice No. 79-03 2.
List of IE Information Notices Issued in 1979 cc w/encls:
Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Regions I & IV 7 9 0 2 2 7 0.9ffo
A U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT RECION III February 9, 1979 IE Information Notice No. 79-03
'.IMITORQUE VALVE GEARED LIMIT SWITCH LUBRICANT Description of Circumstances:
At Co==onwealth Edison reactors excessive failure rates of the Limitorque valve geared limit switches were being experienced.
Investigation revealed that the failure mode was a drying out and hardening of the Beacon 325 lubricant. Once hardening takes place, the brass gears within the limit switch becoce immobile and destroy themselves when an attempt is made to operate the valve.
The Limitorque Corporation has recommended Mobilgrease 28 as a replacement grease for switch applications where the temperature exceeds 140 degrees Fahrenheit. Tests conducted by Mobil and Limitorque Corporation indicate that Mobilgrease 28, in addition to having a superior temperature rating, will satisfy the same environmental conditions and meet the same qualification parameters as Beacon 325.
All licensee and construction permit holders should consider conducting a review to deter =ine if Beacon 325 lubricant is being used in geared limit switches in environments conducive to drying out and subsequent hardening of the lubricant.
If conditions are found to be conducive to failures, consideration should be given to replacing the grease with a more suitable grease.
This information.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 evalua-tions so indicate, an IE-Circular.or Bulletin will be issued to recom-mend or request specific licensee actions. If you.have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Enclosure:
List of IE Information Notices Issued in 1979 yn 7902150358
IE Information Notice No. 79-03 February 9, 1979 LISTING OF IE INFORMATION NOTICES ISSUED IN 1979 Information Subject Date Issued To Notice No.
Issued 79-01 Bergen-Paterson Hydraulic 2/2/79 All power reactor Shock and Sway Arrestor facilities with an OL or a CP 79-02 Attempted Extortion -
2/2/79 All Fuel Fecilities Low Enriched Uranium e