ML19209B926
| ML19209B926 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/24/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 7910110155 | |
| Download: ML19209B926 (1) | |
Text
/Ec UNITED STATES
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NUCLEAR REGULATORY COMMISSION REGION IV 3',
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no 611 RYAN PLAZA DRIVE, SUITE 1000
. j ARLINGTON, TEX AS 76012
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September 24, 1979 In Reply Rr..fer To:
RIV Docket Nos. 50-498/IE Circular No. 79-20 50-499/IE Circular No. 79-20 Houston Lighting & Power Company ATTN:
Mr. E. A. Turner, Vice President Power Plant Construction and Technical Services Post Office Box 1700 Houston, Texas 77001 Gentlemen:
The enclosed IE Circular No. 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, i
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/[g Karl V.
frit Director j
Enclosures:
1.
IE Circular No. 79-20 2.
List of IE Circulars Issued in the Last 6 Months l'
1 137 9101 I ois s
Accession No.: 7908220118 SSINS No.: 6830 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT ] D"'
WASHINGTON, D. C.
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IE Circular No. 79-20 Date:
September 24, 1979 Page 1 of 1 FAILURE OF GTE SYLVANIA RELAY, TYPE PM BULLETIN 7305, CATALOG'5U12-11-AC WITH A 120V AC COIL Description of Circumstances:
During inspection of relays in the Engineered Safeguards Actuation System at Metropolitan Edison Three Mile Island Nuclear Station Unit #1, relay 62X2B/RCIA failed to drop out when the coil was de-energized. 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 Nuclear 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 war 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 from 0.001 to 0.003 inches deep.
Recommended 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 Circu'ar is required.
If you require additional information regarding this subject, contact the Director of the appropriate NRC Regional Office.
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IE L;.cular No. 79-20 September 24, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued To No.
Issue 79-06 Failure to Use Syringe 4/19/79 All Holders of Medical and Battle Shields in Licensees except Teletherapy Nuclear Medicine Licensees 79-07 Unexpected Speed Increase 5/2/79 All Holders of BWR Operating of Reactor Recirculation Licenses (CLs) or Construc-MG Set Resulted in Reactor tion Permits (cps)
Power Increase
' 79-08 Attempted Extortion - Low 5/18/79 All Fuel Facilities and Enriched Uranium Reactors Licensed by NRC 79-09 Occurrences of Split or 6/22/79 All Materials Priority I, Punctured Regulator Fuel Cycle and Operating Diaphragms in Certain Reactor Licenses (0L)
Self Contained Breathing Apparatus 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor Licensees from Unacceptable Material with a Construction Permit and/or Operating License (OL) 79-11 Design / Construction 6/27/79 All Holders of and Applicants Interface Problem for Power Reactor Construction Permits (CP) i 79-12 Potential Diesel Generator 6/28/79 All Power Reactor Licensee uith Turbocharger Problem a Construction Permit (CP) and/or Operating License (OL) 79-13 Replacement of Diesel 7/13/79 All Power Reactor Licensee Fire Pump Starting with a Construction Permit Contactors (CP) and/or Operating Licensee (OL)
Enclosure Page 1 of 2 l'
i 139
IE Circular No. 79-20 September 24, 1979 79-14 Unauthorized Procurement 7/13/79 All Medical Licensees and Distribution of Ey. cept Teletheraphy XE-133 Medical Licensees and to all Radiopharmaceutical Suppliers 79-15 Bursting of High Pressure 8/8/79 All Materials Priority I, Hose and Malfunction of Fuel Cycle and Operating Relief Valve "0" Ring in Power Reactor Licensees Certain Self-contained Breathing Apparatus 79-16 Excessive Radiation 8/16/79 All Radiography Exposures to Members Licensees of the General Public and a Radiographer 79-17 Contact Problem in SB-12 8/14/79 All Power Reactor Switches on General Licensees with a Electric Company Construction Permit Metalclad Circuit (CP) and/or Operating Breakers License (OL) 79-18 Proper Instaliation of 9/10/79 All Holders of a Target Rock Safety-Relief Power Reactor Operating Valves License (OL) or Construction Permit (CP) 79-19 Loose Locking Devices 9/13/79 All Power Reactor Ingersoll-Rand Pumps Licensees with a Construction Permit (CP) and/or Operating Licensee (OL)
Enclosure Page 2 of 2
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