Part 21 Report - 1997-190

LICENSEE: INDIANA & MICHIGAN ELECTRIC CO. SITE: COOK 1 2 EN NUMBER:31922 DOCKET: 05000315 05000316 EVENT DATE: 03-10-97 RX TYPE: PWR PWR EVENT TIME: 00:00 VENDORS: W-4-LP W-4-LP NOTIFY DATE: 03-10-97 EMERGENCY CLASS: N/A REGION: 3 STATE: MI TIME: 11:25 OPS OFFICER: JOHN MacKINNON 10 CFR SECTION: CDEG 21.21(c)(3)(i) DEFECTS/NONCOMPLIANCE UNIT SCRAM RX INIT INITIAL MODE CURR CURRENT MODE CODE CRIT PWR PWR 1 N N 0 REFUELING 0 REFUELING 2 N Y 100 POWER OPERATION 100 POWER OPERATION DC COOK DETERMINED THAT THE STANDARD SMB-00 LIMITORQUE TORQUE SWITCH ASSEMBLIES REMAINING IN STOCK WERE ALL MISSING A SPACER. ON JANUARY 8, 1997, WHILE INSTALLING A NEW TORQUE SWITCH ASSEMBLY FOR MOTOR OPERATED VALVE 2-MMO-421, IT WAS NOTED THAT A SPACER APPEARED TO BE MISSING FROM THE TORQUE SWITCH. AN INSPECTION OF ALL THE STANDARD SMB-00 TORQUE SWITCH ASSEMBLIES REMAINING IN STOCK DETERMINED THAT THEY WERE ALL MISSING A SPACER. THESE TORQUE SWITCH ASSEMBLIES WERE PART OF A GROUP OF 7 RECEIVED FROM LIMITORQUE FOR GENERAL USE AT DC COOK UNDER ASP 18787. A CONDITION REPORT WAS WRITTEN TO INVESTIGATE IF THIS WAS A NEW DESIGN. THE DEFECTIVE LOT OF 7 RECEIVED FROM LIMITORQUE APPARENTLY RESULTED FROM A MANUFACTURING ASSEMBLY ERROR AT THE LIMITORQUE FACILITY. THE DOUBLE POLE TORQUE SWITCH IS A STANDARD CONFIGURATION FOR AMERICAN ELECTRIC POWER AND IS USED EXTENSIVELY AT THE DC COOK PLANT IN SMB-00 ACTUATORS. THE 7 ASSEMBLIES SUPPLIED UNDER ASP 18787 WERE PLACED IN OPEN STOCK FOR USE IN THE NEXT VALVE REQUIRING ONE. THEREFORE, THE 3 TORQUE SWITCH ASSEMBLIES IN OPEN STOCK COULD HAVE BEEN USED IN ANY NUMBER OF SAFETY RELATED APPLICATIONS WITH UNKNOWN RESULTS. THE FAILURES IN THE 4 VALVES IN WHICH THEY WERE INSTALLED DID NOT RESULT IN ANY SAFETY IMPACT, HOWEVER, THIS COULD NOT BE GUARANTEED FOR ALL OTHER SMB-00 VALVE ACTUATORS IN THE PLANT DUE TO THE LARGE VARIETY OF APPLICATIONS FOR THE ASSEMBLY. SINCE IT IS NOT POSSIBLE TO DEFINITIVELY EVALUATE ALL POSSIBLE APPLICATIONS FOR SIGNIFICANT SAFETY HAZARD, IT WAS CONSERVATIVELY DECIDED TO SUBMIT THIS EVENT AS A PART 21. ALL 4 OF THE DEFECTIVE ASSEMBLIES WHICH WERE INSTALLED HAVE BEEN EITHER REPLACED, OR REPAIRED BY ADDITION OF A SPACER. ALL 7 ASSEMBLIES WERE RETURNED TO LIMITORQUE FOR EVALUATION ON MARCH 10, 1997. LIMITORQUE HAS NOT BEEN ABLE TO PREDICT WHEN THEIR EVALUATION MIGHT BE COMPLETE. COPY OF PART 21 SENT TO VERN HODGE.

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