ML19284A493
| ML19284A493 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 02/09/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Tallman W PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 7903060625 | |
| Download: ML19284A493 (1) | |
Text
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9[g NUCLEAR REGULATORY COMMISSION y
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/f 631 PARK AVENUE g *, ;i,4 j Kina or caussia.ecunsvevania is4os February 9, 1979 Docket Nos. 50-443 50-444 Public Service Company of New Hampshire ATTN: Mr. W. C. Tallman President 1000 Elm Street Manchester, New Hampshire 03105 Gentlemen:
This 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 IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding the matter, please contact this office.
Sincerely, M
dn i
hBoyceH.Grier Director
Enclosures:
1.
IE Information Notice No. 79-03 2.
List of IE Information Notices Issued in 1979 cc w/encls:
John D. Haseltine, Project Manager 79030606R5
UNITED STATES NUCLEAR REGULATORY COMiISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Information Notice No. 79-03 Date:
February 9, 1979 Page 1 of 1 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.
Investiaation revealed that the failure mode was a drying out and hardaning 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 Corporation has recommended Mobilgrease 28 as a replacement grease for switch applications where the temperature exceeds 140 degrees Fanrenheit. 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 licensea 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 spe_ific 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 re-garding this matter, please contact the Director of the appropriate NRC Regional Office.
Enclosure:
List of IE Information Notices Issued in 1979 Dufb 7902150 35 8
IE Information Notice No. 79-03 Date:
February 9, 1979 Page 1 of 1 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 Operating License (0L) or a Construction Permit (CP) 79-02 Attempted Extortion -
2/2/79 All Fuel Facilities low Enriched Uranium