RC-99-0087, Part 21 Interim Rept (SSH 99-0001) Re 990218 Failure of Circuit Breaker Located in Cubicle 14 of XSW1DB to Close During Surveillance Testing.Caused by Positive Interlock Angle Was Incorrect.Breaker Was Returned to GE Factory

Part 21 Interim Rept (SSH 99-0001) Re 990218 Failure of Circuit Breaker Located in Cubicle 14 of XSW1DB to Close During Surveillance Testing.Caused by Positive Interlock Angle Was Incorrect.Breaker Was Returned to GE Factory

ML20205Q332
Person / Time
Site:	Summer
Issue date:	04/15/1999
From:	Gabe Taylor SOUTH CAROLINA ELECTRIC & GAS CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-99 RC-99-0087, RC-99-87, NUDOCS 9904210170
Download: ML20205Q332 (2)

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April 15,1999 XSCE&G_ A SCANA COMPANY RC-99-0087 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 Gentlemen:

Subject:

VIRGIL C. SUMMER NUCLEAR STATION DOCKET NO. 50/395 Guy f. Taylu OPERATING LICENSE NO. NPF-12 Vicc hesident ~

INTERIM REPORT PURSUANT TO 10 CFR PART 21 Abr omten5 (SSH 99-0001).

South Carolina Electric & Gas (SCE&G) submits this letter in accordance with the requirements of 10 CFR 21.21(a)(2) as an interim report of an identified defect potentially associated with a substantial safety hazard.

On February 18,1999, Nonconformance Notice (NCN) 99-0110 was initiated to address the failure to close during surveillance testing of the circuit breaker south Codina Elechic t ks(o located in cubicle 14 of XSW1DB. The breaker attempts to close, but as the vailc 5can Mer Station mechanism starts to move, it immediately collapses back to the open position. /

P.0 Nx 88 -

Jedicame. South tadna An on site inspection by SCE&G personnel and a GE field representative 29065 determined the following:

8 3 g 1. The positive interlock angle was incorrect 2.

weaacom The gap between the positive interlock plates and the upper link pin was incorrect.

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3. The gap in (2) above was inconsistent between the right and left sides.

4. The plates and the pin showed some evidence of contact.

During a conference call with the GE Magne-Blast engineer in Philadelphia and the Atlanta GE shop, it was unclear how this alignment problem could be present because the positive interlxk linkage is all drilled and pinned at the factory. The breaker was returned to the GE factory in Philadelphia, where it was determined found that one of the levers in the positive interlock linkage was flipped 180 degrees. The problem was corrected, however, the breaker still experienced the same problem of failing to latch closed.

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9904210170 990415 PDR ADOCK 05000395 S PDR NUCLEAR EXCELLENCE - A SUMMER TRADITION!

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Document Control Desk SSH 990001 RC-99-Od87

!. Page 2 of 2 Following further discussions with GE, the breaker was shipped to the Atlanta GE service shop for additional evaluation and root cause determination. As the root cause evaluation will not be completed within the 60 day reporting period, an interim report is being submitted to allow additional troubleshooting and cause determination by the vendor. The vendor anticipates that the problem with the breaker will be identified and a response should be provided to VCSNS by 8/13/99. A final report on the Part 21 evaluation will be submitted within thirty days of receipt of the vendor's information.

l l Should you have any questions, please call Mr. Jeffrey Pease at (803) 345-4124.

Very truly yours, l e Ga ir l

JWP/GJT/dr l c: J. L. Skolds

! W. F. Conway R. R. Mahan R. J. White L. A. Reyes i L. M. Padovan J. B. Knotts, Jr.

NRC Resident inspector M. N. Browne R. E. Slone INPO Records Center NSRC RTS (SSH 990001)

File (818.18)

DMS (RC-99-0087)

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