United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: ILLINOIS POWER CO.                 

SITE: CLINTON 1                             EN NUMBER:33819

DOCKET: 05000461                         EVENT DATE: 03-02-98

RX TYPE: BWR                             EVENT TIME: 14:25

VENDORS: GE-6                           NOTIFY DATE: 03-02-98

EMERGENCY CLASS: N/A  REGION: 3 STATE: IL      TIME: 14:25

OPS OFFICER: JOHN MacKINNON           

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  



INCORRECT CALCULATION IN DIESEL GENERATOR CONTROL CIRCUITRY      

RESULTS IN INSUFFICIENT VOLTAGE AND INOPERABILITY OF THE DIVISION

1 DIESEL GENERATOR.                                              

                                                                 

A DISCREPANCY IN A DIRECT CURRENT VOLTAGE CALCULATION FOR THE    

DIVISION 1 DIESEL GENERATOR CONTROL CIRCUITRY WAS DISCOVERED. THE

CALCULATION DID NOT INCLUDE THE EXISTENCE OF TWO CABLES THAT ARE 

RUN TO THE REMOTE SHUTDOWN PANEL AND THEIR EFFECT ON THE VOLTAGE 

DROP TO THE DIESEL GENERATOR CONTROL PANEL. PRELIMINARY          

EVALUATION OF THE IMPACT OF THIS ERROR INDICATED THAT THERE HAS  

NOT BEEN SUFFICIENT VOLTAGE TO THE CONTROL PANEL FOR ALL OF ITS  

CONNECTED EQUIPMENT. THE CAUSE OF THIS EVENT IS AN ERRONEOUS     

CALCULATION PROVIDED BY SARGENT AND LUNDY DESIGN ENGINEERS. THE  

ENGINEER FAILED TO INCLUDE THE CABLE LENGTHS FROM AND TO THE     

REMOTE SHUTDOWN PANEL IN THE VOLTAGE DROP CALCULATION FOR THE    

DIESEL GENERATOR CONTROL PANEL. THIS ERROR WAS OVERLOOKED IN     

SEVERAL SUBSEQUENT REVISIONS. THE CORRECTIVE ACTIONS FOR THIS    

EVENT ARE TO RESTORE THE DIESEL GENERATOR CONTROL PANEL VOLTAGE  

TO AN ACCEPTABLE LEVEL, TO REVIEW OTHER VOLTAGE  CALCULATIONS TO 

ENSURE NO OTHER CIRCUITS OMITTED CABLING, TO REVIEW THE CONTROL  

CIRCUITS THAT PASS THROUGH THE REMOTE SHUTDOWN PANEL AND TO BRIEF

ENGINEERING PERSONNEL ON LESSONS LEARNED FROM THIS EVENT.  LER   

WAS SUBMITTED BY THE LICENSEE.                                   





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