ML18102A676
| ML18102A676 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/12/1996 |
| From: | Naidu K NRC (Affiliation Not Assigned) |
| To: | Cwalina G NRC (Affiliation Not Assigned) |
| References | |
| 31391, NUDOCS 9612230025 | |
| Download: ML18102A676 (2) | |
Text
MEMORANDUM TO:
FROM:
SUBJECT:
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555--0001 December 12, 1996 Gregory C. Cwalina, Section Chief Vendor Inspection Section Special Inspection Branch Division of Inspection Jnd Supper~ Programs Office of Nucle~r Re~tor *~egulation Kamal akar R.. Naidu ~i~
Vendor Inspection Section Special Inspection Branch Division of Inspection and Support Programs Office of Nuclear Reactor Regulation FOLLOW UP ON EVENT No~ 31391 AT SALEM 4.16 KV BREAKER*
FAILURE-HMA RELAYS On December 1, 1996, during surveillance testing of a vital bus, Public Service Electric Company reported that a 4.16-kV GE Magne-Blast circuit breaker (23 CSD) failed to close on demand at its Salem station. The licensee found that a GE HMA type anti-pump relay had caused the failure.
The licensee took the failed relay to GE Power Management (GE PM), Malvern, Pennsylvania.
GE PM disassembled the failed relay and found that the armature was binding in the closed position. After a similar situation occurred in 1982, GE PM issued Service Advice Letter (SAL) 721-PSM No. 171.1, "HMA Relay Armature Binding,"
on December 17, 1982, to all customers stating that HMA relays manufactured in 1974 or before may have insufficient clearance between the armature tail piece and molded posts on either side of the tail piece. If this condition exists, twisting of the armature may cause binding of the armature tailpiece when the armature is energized and prevent the opening of the armature when it is deenergized.
In the SAL, GE PM recommended that its customers deenergize the relay and measure the gap between the armature tail piece and the posts by inserting a 0.005-inch feeler gauge (without using force).
If the gap was less than 0.005 inches, GE PM recommended that the gap be increased by removing material from the posts.
On December 10, 1996, Dave Skeen and I talked with Mr. Jim Teague of GE PM regarding the failure of the subject HMA relay.
He stated that it is the policy to ship relays (commercial-grade) with the proper adjustment.
We requested and he agreed to provide clarification to SAL 721 as to how to adjust the gap to prevent binding.
We propose to use the information he provides to draft an IN if required.
We also contacted Ken Staring at Salem station to determine if GE NE Apparatus Service Shop (GE ASS) dedicated the relay which was manuactured in 1995.
According to his review of the quality assurance records of refurbishment of the breaker, GE ASS replaced the HMA relay on this breaker.
However, he could not fiund any information on the relay dedication to 230005 r~9-6-12_2_,3c-=o-=02=5 961212 PDR ADOCK 05000272 S
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G. determine if the gap was verified to be acceptable.
Ken Staring informed us that Salem technicians checked and found the gaps to be acceptable on four HMA type anti-pump relays that had been recently replaced.
Ken Staring was aware of similar occurrence at Millstone recently with a relay manufactured in 1993.
In our discussions with GE PM's Jim Teague we determined that he was not aware of this failure.
Distribution:
PSIB R/F Central Files/Docket Files/PUBLIC A. E. Chaffee R.L. Denning D. L. Skeen DOCUMENT NAME: G:\\NAIDU\\HMA the box: "C" = Copy without enclosures "E" = Copy with enclosures "N" = No copy I
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OFFICE PSIB:DI II-NAME DATE OFFICIAL RECORD COPY I
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