ML19263C617

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Forwards IE Info Notice 79-03, Limitorque Valve Geared Limit Switch Lubricant
ML19263C617
Person / Time
Site: Arkansas Nuclear  Entergy icon.png
Issue date: 02/09/1979
From: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To: Cavanaugh W
ARKANSAS POWER & LIGHT CO.
References
NUDOCS 7902280016
Download: ML19263C617 (1)


Text

CENTRAL FILES e Rico UNITED STATES PDR:HQ NUCLEAR REGULATORY COMMISSION o

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February 9,1979 Docket fios. 50-368 50-313 Arkansas Power and Light Company ATTN:

Mr. William Cavanaugh III Executive Director of Generation and Construction Post Office Box 551 Little Rock, Arkansas 72203 Gentlemen:

This Information flotice fio. 79-03 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 the Director of the appropriate NRC Regional Office.

Sincerely, f

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Karl V. Seyfrit Director

Enclosures:

1.

IE Information Notice No. 79-03 2.

List of IE Information Notices Issued in 1979 790228cC4

UNITED STATES NUCLEAR REGULATORY COMMISSION 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.

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 Corporation has recommended Mobilgrease 28 as a replace-ment 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.

Enclosure:

List of IE Information Notices Issued in 1979 DuPd 790 2150358

IE Information Notice fio. 79-03 February 9,1979 LISTIfiG OF IE INFORMATION fl0TICES ISSUED IN 1979 Information Subject Date Issued To flotice flo.

Issued 79-01 Bergen-Paterson Hydraulic 2/2/79 All power reactor Shock and Sway Arrestor facilities with an Operating Licenses (OL) or a Construc-tion Permits (CP) 79-02 Attempted Extortion -

2/2/79 All Fuel Facilities Low Enriched Uranium e