United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9507170398

                                             Illinois Power Company
                                             Clinton Power Station
                                             P.O. Box 678
                                             Clinton, IL 61727
                                             Tel 217 935-5623
                                             Fax 217 935-4632

                                             John G. Cook
                                             Vice President
  POWER                                           U-602466
                                                  L16-95( 07-12 )LP
                                                  July 12, 1995

Docket No. 50-461                                 10CFR21.21

Document Control Desk
Nuclear Regulatory Commission
Washington, D.C.  20555

Subject:       Follow-Up to 10CFR21 interim Report 21-95-010:
               Elgar Inverter PWM Drive Logic Card (J4) Failure

Dear Sir:

     On May 22, 1995, Illinois Power (IP) issued 10CFR21 Interim Report
21-95-010: Elgar Inverter PWM Drive Logic Card (J4) Failure, (IP letter
U-602446), to notify the NRC that an evaluation was being performed of
the logic card failures in accordance with the provisions of 10CFR21. 
The interim report stated that the evaluation of the issue was expected
to be completed by June 30, 1995.  The evaluation completion date was
based on the expectation that returning the deficient cards to Elgar
Corporation for failure analysis would lead to identification of the
cause of the logic card failures.  Elgar has performed several functional
tests on the cards and has found no logic card deficiencies.  However,
since the logic cards did fail in the Clinton Power Station (CPS)
inverter, Elgar has employed an independent consultant to assist in the
failure analysis.  Elgar has performed additional testing of the cards on
site (at CPS) and is developing a schedule for evaluating the test
results; however, no completion date has been provided to IP.  IP will
provide an update on the status of the evaluation of this issue by
September 27, 1995.

                                        Sincerely yours,

                                        J. G. Cook
                                        Vice President


cc:  NRC Clinton Licensing Project Manager
     NRC Resident Office, V-690
     Regional Administrator, Region III, USNRC 
     INPO Records Center
     Illinois Department of Nuclear Safety
     Elgar Corporation

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