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Home NRC Library Document Collections Events, Reports Associated with Part 21 Reports 1997

Part 21 Report - 1997-170

 
 


ACCESSION #: 9702120176



Detroit

  Edison



Douglas R.  Gipson

Senior Vice President

Nuclear Generation



Fermi 2

6400 North Dixie Highway

Edison Newport, Michigan 48166

(313) 586-5249



                                             10CFR21.21



                                             February 6, 1997

                                             NRC-97-0005



U.  S.  Nuclear Regulatory Commission

Attn: Document Control Desk

Washington, D.  C.  20555



Reference:     Fermi 2

               NRC Docket No.  50-341

               NRC License No.  NPF-43



Subject:  10CFR21 Interim Report for Emergency Diesel Generator

          Automatic Voltage Regulator Printed Circuit Board



On November 13, 1996 at 0037 hours Emergency Diesel Generator (EDG)

number 11 failed surveillance test 24.307.01 (i.e., Technical

Specification 4.8.1.1.2) for Loss of Offsite Power coincident with Loss

of Coolant Accident (LOP/LOCA).  The electrical system voltage dropped to

approximately 50% when Residual Heat Removal (RHR) system pump A was auto

initiated.  Deviation Event Report (DER) 96-1655 was written to determine

a root cause and corrective actions for the problem.



Analysis of EDG number 11 components in the Automatic Voltage Regulator

(AVR) board revision B determined that the operational amplifier U8 chip

had failed.  Voltage regulator system testing was conducted.  The AVR was

again replaced with a revision B board and surveillance 24.307.01 run

with the same failure occurring.  AVR board revision B was replaced with

the earlier revision A board.  On November 26, 1996 surveillance

24.307.01 was performed successfully with the revision A board installed.



As part of the continuing investigation to determine the root cause, the

AVR board revision B was sent offsite to an independent engineering test

facility.  On December 9, 1996 Detroit Edison determined that a 10CFR21

reportability evaluation should be performed.  On January 30, 1997

Detroit Edison received a



USNRC

NRC-97-0005

Page 2



report from the testing facility on the U8 chip and the report is being

analyzed for its applicability to the AVR failure.



The AVR boards and U8 chips were supplied by Parsons Peebles as a safety

related component under 10CFR50 Appendix B requirements.  Parsons Peebles

is now Peebles Electric Inc.  and no longer supplies 10CFR50 Appendix B

components.  If the AVR board (revision B) or U8 chip is defective, it

would create a substantial safety hazard because the ability of the EDGs

to perform their safety function would be adversely affected.



Corrective actions include more analysis and testing of the AVR board and

operational amplifier U8 chips.  The 10CFR21 report should be completed

by June 30, 1997.



If you have any questions, please contact Joseph M.  Pendergast,

Licensing Engineer at (313) 586-1682.



                                   Sincerely,



cc:  A.  B.  Beach

     M.  J.  Jordan

     A.  J.  Kugler

     C.  F.  O'Keefe



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