ML17252A272

Transmittal of Reportable Occurrence Report No. 50-249/1977-7

ML17252A272
Person / Time
Site:	Dresden
Issue date:	04/20/1977
From:	Stephenson B B Commonwealth Edison Co
To:	Keppler J G NRC/RGN-III
References
50-249/1977-7
Download: ML17252A272 (3)

See also: IR 05000249/2019077

Text

Commonwec9

Edison Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone

815/942-2920

BBS Ltr. # 333 April 20, Mr. James G. Keppler, Regional

Directorate

of Regulatory

Operation

-Region I I I U. s: "Nuclear Regulatory

Commission

799 Roosevelt

Road Glen Ellyn, 111 inois 60137 REGULATORY

DDCKEI RLE COPY Enclosed please find Reportable

Occurrence

50-249/1977-7.

This report is being submitted

to your office in accordance

with the bresden Nuc 1 ec;ir Power Station Techn i ca,1 Specif i cat..i ons,. Section 6. 6. B .. BBS: skm *Enclosure

cc: Director of Inspection

& Enforcement

Director of Management

& Program Control Fil e/NRC APR 2 5 1977

LICENSEE EVENT REPORT CONTROL BLOCK: Lj_** 1 L . , I . I c&sE PRINT ALL,REQUIRED

INFORMATION)

LICENSEE NAME *@El I I I LI DI RI s I 31 1 0*s 14 REPORT CATEGORY TYPE. 6 LICENSE NUMBER

15 25 REPORT SOURCE DOCKET NUMBER LICENSE . TYPE 41 1 p 11 11 I 26. . 3P EVENT DATE EVENT TYPE I o I 31 31 32 REPORT DATE @E]coN'.T

I I I LJ L':J I 01 51

12 14 19 I I o I 3 I 2 I .2 I 7 I 7 I 10141 2 1117171 7 . 8 57. 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION

ffilfil. I During testing of the Unit-3 d)esel generator

following

maintenance, the engine 7 8 9 lol 3 r I started,.but*the

generator

field failed to flash. The generator

field flashed 7 . 8 9 lol41'1 during a secon.d start-up of the diesel. The diesel was started a third time, 7 . 8**9 IPl51 J . and again the field did not flash. The Unit-3 diesel generator

was then shut 7 0*s lolsl I , down and dee 1 a red i noperab 1 e. A subsequent

attempt to start the Unit-2/3 diesel 1 *0 s .SYSTEM CAUSE PRIME

i nued) * COMPONENT

CoMPONENT

CODE . CODE COMPONENT

CODE SUPPUER MANUFACTURER

VDLATION [§E] IE IE I* w I El NI GI II NI El I WI 019 17 I * l!U 7 8 9 10 11 12 . : .* .*. 17 43 44 47 48 CAUSE DESCRIPTION . < I The failure was 'caused by an intermittent

capacitor

short in the generator

field 7 8 9 flashing circuitry.

The defective

capaci_tor'

was replaced, and the Unit-3 diesel 1* 0* 9 IT1§J I generator

was satisfact_orily

tested and returned to service. 7 8 9 FACIUTY STATUS Em L:J 7.; 8 .9 FORM OF ACTIVITY 'll. POWER I 01 913 10 CONTENT I 12 13 OTHER STATUS NA {continued)

DISCOVERY

DESCRIPTION

I 80 I 80 I 80 I 80 I 80 k 80 l eo I 80 80 rn RELEASED OF RELEASE AMOUNT OF ACTIVITY w LlJ : I . NA 11 LOCATION OF RELEASE .__------'---------.....JI

., 80 7 8 9 10 PERSONNEL

EXPOSURES . NUMBER TYPE. * DESCRIPTION

II§] J 0 I 0 I 0 I .. .__ __ NA __________

_;. ___ _;.__;. ______ __, 7 8 9 . 11* . 12 13 80 PERS'ONNEL

INJURIES . NUMBER 'DESCRIPTION

l1E1 I 0 I 0 I 0 I ':--__ N_A ___________

__ ""'=" 7 8 9* 11 12 80 * * OFFSITE .. CONSEQUENCES NA 7 8 9 LOSS OR DAMAGE . TO FACILITY TYPE [!El DESCRIPTION

NA 7 8 9 10 PUBLICITY

NA ADDITIONAL

FACTORS *Elfil I NA . 7 8 9 80 80 80

7 B. 9 &O J. B. Martin Ext. 265

....... -----------------------

PHONE:_.-...

_ _.._ __ _...;_ GPO 881*087

-. * EVENT DESCR1PTION (continued) -generator

was-;:::unsuccessful (R. 0. report no.

This event was of little safety significance, since the redundant

Unit-2/3 di ese 1 .generator

was demonstrated

to be operab 1 e short 1 y thereafter (within minutes), and off-site power remained available

this interval.

ihe -Unit-2 diesel generator

experienced

a similar

field flashing failure in April, 1975. (50-249/1977-7)

CAUSE DESCRIPTION (continued)

As a long-term

action, the

diesel generator

maintenance

procedure

will be revised to include a check of the generator

field flashing

capacitors.

The failed capacitot

is an 8-microfarad, 150-volt electrolytic

unit manufactured

by Aerovox: ; *--l : *4: -* ...... : ., ' ... , -. -... ,'J.,J ::::1