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.
Page Last Reviewed/Updated Wednesday, March 24, 2021