ML19269D151
| ML19269D151 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/09/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Johari Moore SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 7902270390 | |
| Download: ML19269D151 (1) | |
Text
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UNITED STATES c
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t NUCLEAR REGULATORY COMMIS$10N
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WALNUT CREEK, C ALIFORNI A 94596 February 9,1979 Docket Nos. 50-206 50-361 50-362 Southern California Edison Company P. O. Box 800 2244 Walnut Grove Avenue Rosemead, California 91770 Attention: Mr. Jack B. Moore Vice President Gentlemen:
This Infomation Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the infonnation for possible applicability to their facil-ities.
No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding the matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely,
{$W4All--
R. H. Engelken Director
Enclosures:
1.
IE Infomation Notice No. 79-03 2.
List of IE Information Notices Issued in 1979 cc w/ encl:
J. M. Curran, SCE J. T. Head, SCE J. H. Drake, SCE 7902270340
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 February 9, 1979 IE Information Notice No. 79-03 LIMITORQUE VALVE GEARED LIMIT SWITCH LUBRICANT Description of Circumstances:
At Commonwealth 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 become immobile and destroy themselves when an attempt is made to operate the valve.
The Limitorque Corperation 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 determine 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.
b Page 1 of 1 7902150358
IE Information Notice No. 79 n3 February 9, 1979 LISTING 0F IE INFORMATION NOTICES ISSUED IN 1979 Information Subject Date Issued To Notice No.
Iscued 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 Facilities Low Enriched Uranium
.