Part 21 Report - 1998-106

LICENSEE: CONSOLIDATED EDISON CO. OF N.Y./NEW SITE: INDIAN POINT 2 EN NUMBER:34713 DOCKET: 05000247 EVENT DATE: 08-29-98 RX TYPE: PWR EVENT TIME: 00:00 VENDORS: W-4-LP NOTIFY DATE: 08-29-98 EMERGENCY CLASS: N/A REGION: 1 STATE: NY TIME: 17:12 OPS OFFICER: BOB STRANSKY 10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH UNIT SCRAM RX INIT INITIAL MODE CURR CURRENT MODE CODE CRIT PWR PWR 2 N N 0 HOT SHUTDOWN 0 HOT SHUTDOWN 10 CFR PART 21 REPORT REGARDING BINDING OF WESTINGHOUSE DB-50 CIRCUIT BREAKERS "AFTER COMPLETION OF SURVEILLANCE TEST PMT-170 AUXILIARY FEEDWATER PUMP (AFWP) ACTUATION FUNCTIONAL TEST, OPERATIONS MADE AN ATTEMPT TO START 21 AFWP FROM CCR CONTROL SWITCH. THE BREAKER DID NOT CLOSE. "DURING STEP BY STEP INVESTIGATION AND INSPECTION, IT WAS DETERMINED THAT: (1) THE INERTIA LATCH FAILED TO RESET TO ITS NORMAL POSITION TO ENABLE THE OPERATING MECHANISM CLOSING THE BREAKER. (THE VISUAL INSPECTION FOUND THE INERTIA LATCH TO BE IN A POSITION TO PRECLUDE THE OPERATING MECHANISM FROM CLOSING THE BREAKER.) (2) THE INERTIA LATCH INITIALLY WAS BINDING SEVERELY. AFTER MANIPULATION OF THE LATCH THE FRICTION DECREASED TO A POINT WHERE THE MOVEMENT WAS NORMAL. WHEN THE LATCH WAS MOVED AXIALLY TOWARD THE SNAP RING IT WOULD BIND AT THAT POINT. (3) THE CAUSE OF THE FAILURE WAS SPALLING OR BREAKING-AWAY OF SURFACE COATING ON THE PIVOT PIN AND POSSIBLY THE BUSHING (PIVOT PIN HOLE) OF THE INERTIA LATCH. THE FRAGMENTS OF THE COATING ACCUMULATED ON THE SURFACES OF THE PIN AND THE BUSHING IN DISCREET LOCATIONS, REDUCED THE CLEARANCE BETWEEN THE PIVOT PIN AND THE BUSHING. THE REDUCTION IN CLEARANCE RESULTED IN BINDING OF THE INERTIA LATCH. THE INERTIA LATCH BINDING PREVENTED THE LATCH TO RESET IN ITS NORMAL POSITION AND PREVENTED THE BREAKER FROM CLOSING. THE DIMENSIONS OF THE 21 AUXILIARY FEED PUMP BREAKER INERTIA LATCH PIN AND PIVOT PIN HOLE [BUSHING] WERE FOUND TO BE NOMINAL 0.375" AND 0.376" RESPECTIVELY.) "THE EXAMINATION OF THE COATING ON THE SHAFT PIN CLEARLY SHOWED THAT THE COATING WAS BREAKING AWAY FROM THE SURFACE. THE DAMAGE MAY HAVE BEEN INITIATED DURING TREATMENT WITH THE EMERY CLOTH AS PART OF THE CUSTOM FITTING PROCESS. HOWEVER IT APPEARS, THAT DURING SERVICE, MATERIAL WAS DISLODGED FROM THE SURFACES. THE VISUAL EXAMINATION INDICATES THAT THE QUALITY OF BONDING OF THE COATING ON THE SHAFT WAS INADEQUATE." THE NRC RESIDENT INSPECTOR WILL BE INFORMED BY THE LICENSEE.

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