ML19208D298
| ML19208D298 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle  |
| Issue date: | 09/24/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | John Miller GEORGIA POWER CO. |
| References | |
| NUDOCS 7909280209 | |
| Download: ML19208D298 (2) | |
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
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REGION il o
101 MARIETTA ST N.W., SUITE 31M ATLANTA, GEoRQtA 30303 SEP 2 41979 ram &
In Reply Refer To:
RII:JPO 50-321.90-366
@ 24, 50-42 D Georgia Power Company Attn:
J. H. Miller, Jr.
Executive Vice President 270 Peachtree Street, N.W.
Atlanta, Georgia 30303 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 underscanding of this matter, please contact this office.
Sincerely, James P. O'Reilly Director
Enclosures:
1.
IE Circular No. 79-20 2.
List of IE Circulars Issued in tha last six months t
1052 008 1%8 7909 280
SEP 2 41979 Georgia Power Company.
cc w/ encl:
M. Manry, Plant Manager Post Office Box 442 Baxley, Georgia 31513 C. E. Belflower Site QA Supervisor Post Otfice Box 442 Baxley, Georgia 31513 K. M. Gillespie Construction Project Manager Post Office Box 282 Waynesboro, Georgia 30830 E. D. Groover QA Site Supervisor Post Office Box 282 Waynesboro, caorgia 30830
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e Accession No.: 7908220118 SSINS No.: 6830 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPEC' ION A'io ENFORCEMENT WASHINGTON, D. C.
20555 September 24, 1979 IE Circular No. 79-20 FAILURE OF GTE SYLVANIA REIAf, TYPE PM BULLETIN 7305, CATALOG 5U12-12-\\C 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 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 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 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 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 'C Coil used in or affecting the operation of safety-related equipment art 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 administratise controls should be initiated to assure demonstrated operation until the relay condition is corrected.
No written response to this Circular is requiredl If you require additional information regarding this subject, contact the Director of the appropriate NRC Regional Office.
DUPLICATE DOCUMENT Entire document previously entered into system under:
Ano 790M;20// 7 3
1052 010 uo. of gases:
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