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 tfie 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 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. I0
IE Information Notice No.
February 9, 1979
LISTING OF IE INFORMATION NOTICES
ISSUED IN 1979
79-03 Information
Notice No.
Subject
Date
Issued
79-01
79-02 Bergen-Paterson Hydraulic
Shock and Sway Arrestor
Attempted Extortion -
Low Enriched Uranium
2/2/79
2/2/79 Issued To
All power reactor
facilities with an
OL or a CP
All Fuel Facilities
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| list | - Information Notice 1979-01, Bergen-Paterson Hydraulic Shock & Sway Arrestors (Hssa) (2 February 1979, Topic: Water hammer)
- Information Notice 1979-01, Bergen-Paterson Hydraulic Shock & Sway Arrestors (HSSA) (2 February 1979, Topic: Water hammer)
- Information Notice 1979-03, Limitorque Valve Geared Limit Switch Lubricant (9 February 1979)
- Information Notice 1979-04, Degradation of Engineered Safety Features (16 February 1979)
- Information Notice 1979-05, Use of Improper Materials in Safety-Related Components (21 March 1979)
- Information Notice 1979-06, Stress Analysis of Safety-Related Piping (23 March 1979, Topic: Earthquake)
- Information Notice 1979-07, Rupture of Radwaste Tanks (26 March 1979, Topic: Boric Acid)
- Information Notice 1979-08, Interconnection of Contaminated Systems with Service Air Systems Used as Source of Breathing Air (28 March 1979)
- Information Notice 1979-08, Interconnection of Contaminated Systems With Service Air Systems Used As Source of Breathing Air (28 March 1979)
- Information Notice 1979-09, Spill of Radioactively Contaminated Resin (30 March 1979, Topic: Hydrostatic)
- Information Notice 1979-19, Pipe Cracks in Stagnant Borated Water Systems at PWR Plants (17 July 1979, Topic: Boric Acid, Hydrostatic, Liquid penetrant)
- Information Notice 1979-20, NRC Enforcement Policy - NRC Licensed Individuals (7 September 1979, Topic: Overexposure)
- Information Notice 1979-21, Transportation & Commercial Burial of Radioactive Material (7 September 1979)
- Information Notice 1979-22, Qualification of Control Systems (14 September 1979)
- Information Notice 1979-24, Overpressurization of Containment of a PWR Plant After a Main Steam Line Break (1 October 1979)
- Information Notice 1979-25, Reactor Trips at Turkey Point Units 3 & 4 (1 October 1979, Topic: Loss of Offsite Power)
- Information Notice 1979-26, Breach of Containment Integrity (5 November 1979)
- Information Notice 1979-28, Overloading of Structural Elements Due to Pipe Support Loads (16 November 1979)
- Information Notice 1979-29, Loss of Nonsafety-Related Reactor Coolant System Instrumentation During Operation (16 November 1979)
- Information Notice 1979-30, Reporting of Defects & Noncompliances, 10 CFR Part 21 (6 December 1979, Topic: Basic Component)
- Information Notice 1979-31, Use of Incorrect Amplified Response Spectra (13 December 1979)
- Information Notice 1979-32, Separation of Electrical Cables for HPCI and ADS (21 December 1979, Topic: Fire Watch)
- Information Notice 1979-33, Improper Closure of Primary Containment Equipment Access Matches (21 December 1979, Topic: Local Leak Rate Testing)
- Information Notice 1979-34, Inadequate Design of Safety-Related Heat Exchangers (27 December 1979)
- Information Notice 1979-35, Control of Maintenance & Essential Equipment (31 December 1979, Topic: Notice of Violation, Loss of Offsite Power)
- Information Notice 1979-36, Computer Code Defect in Stress Analysis of Piping Elbow (31 December 1979)
- Information Notice 1979-37, Cracking in Low Pressure Turbine Discs (28 December 1979, Topic: Stress corrosion cracking, Turbine Missile)
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