ML19209C210
| ML19209C210 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/24/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 7910120207 | |
| Download: ML19209C210 (1) | |
Text
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P!ALNUT CRE E K. CALIFORNI A 94595 September 24, 1979 Docket No. 50-312 Sacraraento f4unicipal Utility District P. O. Box 15830 Sacramento, California 95813 Attention:
14r. John J. Mattimoe Assistant General Manager Gentlemen:
The enclosed IE Circular t!o. 79-20 is forwarded to you for information.
No written response is required.
Should you have any questions related to your understanding of this matter, please contact this office.
Sincerely, fbi $ng.(L.
R. S. Engelken Director
Enclosures:
1.
IE Circular flo. 79-20 2.
List of IE Circulars Issued in the Last Six Months cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD 1144 077 7910120 M' Q
y p
p 6 W Ll d:a A ) U E L Accession flo.: 7908220118 SSINS ?!o.: 6830 UNITED STATES NUCLEAR REGULATORY COMMISS10fl 0FFICE OF INSPECTI0tl AND Et!FORCEMENT WASHINGTON, D. C.
20555 September 24, 1979 IE Circular No. 79-20 FAILURE OF GTE SYLVAtlIA RELAY. TYPE PM BULLETIN 7305, CATALOG 5U12-11-AC WITH A 120V AC C0ll Description of Circ;nstances:
During inspection of relays in the Engineered Safeguards Actuation System at f4etropolitan Edison Three Mile Island fluclear Station Unit #1, relay 62X2B/RCIA failed to drop out when the coil was deenergized. The failed relay would not prevent component starting but would have reduced the 2 of 3 coincidence logic to 2 of 2, affecting Decay Heat Closed Cooling Pump A and fluclear Services Closed Cooling Pump A or B.
The cause for failure was attributed to a notch in the armature operating rod. The notch occurs where the rod vibrates against the magnet assembly due to coil hum. A review of the history of this component indicates that similar relays failed during 1977 through 1979 at least one of which was attributed to notching. An inspection of forty-eight (48) relays by this licensee indicated that twenty-five (25) of the relays had detectable notches ranging fron 0.001 to 0.003 inches deep.
Recomended Actions for Licensees' Consideration:
1.
Ensure that all GTE Sylvania Relays Type PM Bulletin 7305, with a 120V AC Coil used in or affecting the operation of safety-related equipment are examined to ensure that the armature operating rod is not notched and is operating freely.
2.
Relays found with detectable notches on the operating rod should be corrected.
If correction cannot be accomplished then administrative controls should be initiated to assure demonstrated operation until the relay condition is corrected.
No written response to this Circular is required.
If you require additional information regarding this subject, contact the Director of the appropriate f!RC Regional Office.
1144 078
IE Circular No. 79-20 Enclosure September 24, 1979 Page 1 of 2 LISTING 0F IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued to No.
Issue 79-03 Inadequate Guard Training-2/23/79 All Holders of Qualification and Falsified and applicants Trair.ir.g Raccrds for Special Nuclear Material Licenses in Safeguards Group I 79-04 Loose Locking Nut On 3/16/79 All Holders of Linitorque Valve Reactor OLs or cps Operators 79-05 Moisture Leakage In 3/20/79 All Holders of Stranded Wire Conductors Reactor OLs or cps 79-06 Failure to Use Syringe 4/19/79 All Holders of and Bottle Shields in Medical Licensees Nuclear Medicine except teletherapy licensees 79-07 Unexpected Speed Increase 5/2/79 All Holders of of Reactor Recirculation BWR OL's or CP's MG Set Resulted in Reactor Power Increase 79-08 Attempted Extortion - Low 5/18/79 All Fuel Facilities Enriched Uranium Licensed by NRC 79-09 Occurrences of Split or 6/22/79 All Materials Punctured Regulator Diaphragms Priority I, Fuel In Certain Self Contained Cycle and Operating Breathing Apparatus Reactor Licensees 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor from Unacceptable Material Licensees with a CP and/or OL 79-11 Design / Construction 6/27/79 All Applicants Interface Problem for, and Holders of Power Reactor cps 1i44 079
- IE Circular No. 79-20 Enclosure September 24, 1979 Page 2 of 2 LISTING 0F IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued to No.
Issued 79-12 Potential Diesel Generator 6/28/79 All Power Reactors orchler Ocerating Facilities Torbe:F:rger and all Utilities having a CP 79-13 Replacement of Diesel 7/10/79 All Power Reactor Fire Pump Starting Operating Facilities Contactors and all Utilities having a CP 79-14 Unauthorized Proc"rement and 7/13/79 All Medical Licensees Distribution of XE-133 except Teletheraphy Medical Licensees and to all Radiopharmaceu-tical Suppliers 79-15 Bursting of High Pressure Hose 8/8/79 All Materials Priority I, and Malfunction of Relief Fuel Cycle and Operating Valve "0" Ring in Certain Self-Power Reactor Licensees Contained Breathing Apparatus 79-16 Excessive Radiation Excosures 8/16/79 All Radiography To Members Of The General Public Licensees And A Radiographer 79-17 Contact Problem in SB-12 8/14/79 All Power Reactor Switches on General Electric Licensees with a CP Company Metalclad Circuit and/or OL Breakers 79-18 Proper Installation of 9/10/79 All Holders of a Target Rock Safety-Relief Power Reactor OL Valves or CP 79-19 Loose Locking Devices on 9/13/79 All Power Reactor Ingersoll-Rand Pumps Operating facilities and all utilities having a CP Ii44 0580
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