ML17252A272

Dresden, Units 2 and 3, 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 1014121117171 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 lol3r 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