United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: ILLINOIS POWER CO.                 

SITE: CLINTON 1                             EN NUMBER:32648

DOCKET: 05000461                         EVENT DATE: 07-18-97

RX TYPE: BWR                             EVENT TIME: 12:00

VENDORS: GE-6                           NOTIFY DATE: 07-18-97

EMERGENCY CLASS: N/A  REGION: 3 STATE: IL      TIME: 16:55

OPS OFFICER: DICK JOLLIFFE            

10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH

UNIT  SCRAM   RX   INIT  INITIAL MODE     CURR   CURRENT MODE

      CODE   CRIT  PWR                    PWR

 1    N       N      0   COLD SHUTDOWN      0   COLD SHUTDOWN  



-POSSIBLE 10CFR21 REPORTABLE CONDITION RE POTENTIAL DEGRADATION  

OF RPS UPS-                                                      

                                                                 

GENERAL ELECTRIC SPECIFICATION #22A3153, REVISION 5, PARAGRAPH   

4.3.5.6.3 REQUIRES THAT POWER BEING SUPPLIED BY REACTOR          

PROTECTION SYSTEM (RPS) UNINTERRUPTIBLE POWER SUPPLY (UPS)       

#103-1-189 BE DISCONNECTED IF AN ABNORMAL VOLTAGE OR FREQUENCY   

CONDITION EXISTS FOR A DURATION OF 4 SECONDS OR MORE.            

                                                                 

AN ENGINEERING INVESTIGATION CONDUCTED BY ELGAR CORPORATION, SAN 

DIEGO, CA, AT CLINTON'S REQUEST, DETERMINED THAT WHILE THE       

UNDER/OVER-FREQUENCY CIRCUIT CAN BE CALIBRATED TO MEET THE 4     

SECOND DELAY THRESHOLD, THE UNDER/OVER-VOLTAGE DETECTION CIRCUIT 

CANNOT MEET THIS SPECIFICATION DUE TO THE R-C TIME CONSTANT OF   

THE OVER-VOLTAGE CIRCUIT INPUT FILTER COMPONENTS, WHICH BY       

THEMSELVES, EXCEED THE 4 SECOND THRESHOLD AT CLINTON.            

                                                                 

ELGAR CORPORATION RECOMMENDS THAT CLINTON EVALUATE THE TIMING    

DELAY REQUIREMENTS APPLICABLE TO THE REACTOR PROTECTION SYSTEM TO

DETERMINE IF ACTUAL PERFORMANCE IS DEGRADED AND THAT CLINTON TAKE

ACTION AS APPROPRIATE. ELGAR CORPORATION IS PREPARED TO ASSIST IN

THIS EFFORT AT CLINTON'S REQUEST.                                



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