United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9809300278


POWER REACTOR EVENT NUMBER: 34836
FACILITY: INDIAN POINT REGION: 1 NOTIFICATION DATE: 09/25/98
UNIT: [2] [ ] [ ] STATE: NY NOTIFICATION TIME: 16:19 [ET]
RX TYPE: [2] W-4-LP, [3] W-4-LP EVENT DATE: 09/25/98
EVENT TIME: 00:00 [EDT]
LAST UPDATE DATE: 09/25/98
NRC NOTIFIED BY: SANTINI
HQ OPS OFFICER: BOB STRANSKY
EMERGENCY CLASS: NOT APPLICABLE NOTIFICATIONS
MOHAMED SHANBAKY RDO
10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH VERN HODGE (VIA FAX) NRR


UNIT SCRAM CODE RX CRIT INIT PWR INIT RX MODE CURR PWR CURR RX MODE
2 N Y 100 POWER OPERATION 100 POWER OPERATION

EVENT TEXT

10 CFR PART 21 REPORT REGARDING WESTINGHOUSE DB-75 CIRCUIT BREAKERS THE FOLLOWING IS TEXT OF A FACSIMILE SUBMITTED BY THE LICENSEE:

"ON 07/21/98, DURING THE PERFORMANCE OF THE EMERGENCY DIESEL GENERATOR (EDG) LOAD TEST, THE WESTINGHOUSE MODEL DB-75 OUTPUT BREAKER EDG-2053-005 (SERIAL #880.715-3), WHICH CONNECTS THE EDG TO ITS 480 VAC BUS, WOULD NOT CLOSE. A SECOND ATTEMPT WAS MADE TO CLOSE THE BREAKER, AND AGAIN THE BREAKER DID NOT CLOSE. THE BREAKER WAS REMOVED AND THEREAFTER EXAMINED USING HIGH-SPEED PHOTOGRAPHY. IT WAS OBSERVED THAT THE TRIP BAR OPERATION WAS HANGING UP. THE EXACT CAUSE OF THE TRIP BAR MALFUNCTION WAS NOT INITIALLY IDENTIFIED SO THE MECHANISM WAS REMOVED. DURING FURTHER INVESTIGATION, THE TRIP BAR LATCH AND TRIGGER WERE FOUND TO BIND ON OCCASION DUE TO ROUGH EDGES ON THE FACES. COMPARISONS WERE MADE TO OTHER BREAKER MECHANISMS, AND THESE MECHANISMS COULD NOT BE MADE TO HANG UP IN THIS AREA."

"DURING THE INSPECTIONS OF THE REMAINING DB-75 BREAKERS, ONE ADDITIONAL BREAKER WAS FOUND TO EXHIBIT THE SAME BINDING PROBLEM. THIS WAS EDG BREAKER 2053-006 (SERIAL #880.715-1). THIS BREAKER WAS OF THE SAME SERIES AS THE OTHER BREAKER, WHICH MAY INDICATE A MANUFACTURER'S DEFECT. ANOTHER BREAKER IN THE SAME SERIES WAS EXAMINED BUT DID NOT EXHIBIT THE SAME PROBLEM."


Attachment "CRS - Condition Detail Report"


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