ML17252A272

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

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

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 Directo~

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 rep~rt nu~ber 50-249/1977-7.

This report is being submitted to your office in accordance with the bresden Nuc 1ec;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 lnf~rmation & Program Control Fil e/NRC APR 2 5 1977

LICENSEE EVENT REPORT CONTROL BLOCK:

LICENSEE Lj_**

1 L ., I . I 6

c&sE PRINT ALL,REQUIRED INFORMATION)

LICENSE EVENT NAME LICENSE NUMBER . TYPE TYPE

• @El I I I LI DI RI sI 31 1°1°1~1°1°1°1°1°1-1°1°1 ~ 41 1 p 11 11 I I o I 31 1 0*s 14 15 25 26. . 3P 31 32 REPORT REPORT CATEGORY TYPE. SOURCE DOCKET NUMBER EVENT DATE REPORT DATE

@E]coN'.T I I I LJ L':J I 01 51 01~10 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 I lol 3 r I started,.but*the generator field failed to flash. The generator field flashed 7 8 9 80 7 . 8 9 I

80 lol41'1 during a secon.d start-up of the diesel. The diesel was started a third time, I 7 . 8**9 80 IPl51 J . and again the field did not flash. The Unit-3 diesel generator was then shut I 7 0*s 80 lolsl I , down and dee 1a red i noperab 1e. A subsequent attempt to start the Unit-2/3 diesel I

1 *0 s PRIME ~foont i nued)

• 80

.SYSTEM CAUSE COMPONENT CoMPONENT

[§E] IE IE I*

7 8 9 10 CODE w

. CODE 11 I El COMPONENT CODE NI GI 12 . : .* .*.

II NI El 17 SUPPUER

~

43 I

44 MANUFACTURER WI 019 17 I 47 VDLATION

• l!U 48 CAUSE DESCRIPTION . <

~ I The failure was 'caused by an intermittent capacitor short in the generator field k

7 8 9 The defective capaci_tor' was replaced, and the Unit-3 diesel 80

~ll flashing circuitry.

l IT1§J0* 9I 1*

generator was satisfact_orily tested and returned to service. eo I

7 8 9 80 FACIUTY {continued)

STATUS 'll. POWER OTHER STATUS DISCOVERY DESCRIPTION Em8 7.;

L:J I 01 913 I NA

.9 10 12 13 80 FORM OF ACTIVITY CONTENT AMOUNT OF ACTIVITY LOCATION OF RELEASE rn w RELEASED OF RELEASE 7 8 9 LlJ 10

11I . NA

.__------'---------.....JI 80

.,

PERSONNEL EXPOSURES

. NUMBER TYPE.

• DESCRIPTION II§] J 0 I 0 I 0I .~ . .____NA_ _ _ _ _ _ _ _ _ __;.____;.__;._ _ _ _ _ ___,

7 8 9 . 11* . 12 13 80 PERS'ONNEL INJURIES

. NUMBER 'DESCRIPTION l1E1 I 0 I 0 I 0I ':--__N_A_ _ _ _ _ _ _ _ _ _ _.......:..---...~....-...__;..-__;..__;.._;._ _""'="

7 8 9* 11 12 80

• • OFFSITE .. CONSEQUENCES

~. NA 7 8 9 80 LOSS OR DAMAGE . TO FACILITY TYPE DESCRIPTION

[!El ~J NA 80 7 8 9 10 PUBLICITY NA ADDITIONAL FACTORS

. 7

• Elfil8 9I NA 80

~.L-~~--------------------~--'-~--------~~

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

~E:= .......- - - - - - - - - - - - - - - - - - - - - - - PHONE:_.-..._ _..__ __...;_

GPO 881*087

-.

EVENT DESCR1PTION (continued)

-generator was-;:::unsuccessful (R. 0. report no. 50~237/1977-11).

This event was of little safety significance, since the redundant Unit-2/3 di ese 1 .generator was demonstrated to be operab 1e short 1y thereafter (within

~5 minutes), and off-site power remained available durin~ this interval. ihe

- Unit-2 diesel generator experienced a similar gen~rator field flashing failure in April, 1975.

(50-249/1977-7)

CAUSE DESCRIPTION (continued)

As a long-term corr~ctive action, the annu~l diesel generator maintenance procedure will be revised to include a check of the generator field flashing circ~it capacitors. The failed capacitot is an 8-microfarad, 150-volt electrolytic unit manufactured by Aerovox:

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