ML20090E464

AO 50-237/75-44:on 750923,diesel Generator Failed to Start.Caused by Operator Failure to Follow Monthly Insp Procedure & QC Procedure for safety-related Component Replacement.Air Start Sys Inspected & Seal Ring Replaced

ML20090E464
Person / Time
Site:	Dresden
Issue date:	10/02/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20090E462	List: ML20090E458 ML20090E464
References
655-75, AO-50-237-75-44, RO-50-237-75-44, NUDOCS 8303310653
Download: ML20090E464 (2)

Text

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.aonal Ptrza. Chicagy, tihnoni Address fPpty 11: P;st Offica Box 767 is Chicago. Ilhnois 60690 BBS Ltr. f655-75 Dresden Nuclear Power Station R. R. #1 Morris, Illinois 604504 y ' ~~

October 2,.1975 pJ.L ~ .

en!@~h; Mr. James .G. Keppler, Regional Director 2 OQQ )

Directorate of Tcegulatory Operation-Recion III 2 e, p IM8 2. L U. S. Nuclear Ecipalagory Cer=tission k; W ;r

c4 ., t 799 Roosevelt Road Glen Ellyn, Illinois 60137

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SUBJECT:

REPOR? 0F A? :0RM.AL OCCURREICE PER SECTION 6.6.A 0F THE TECEI SP:.CIFICATICi3 U;11T-2 DIE.5EL GDIDIATOR FAILURE TO ST13T

References:

1) Regulatory Guide 1.16 Rev. 1 Appendix A.

2) Notification of Region III of U. S. uclear Regulatory Commission Telephone: P. Johncon,1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on 'Septe=bw '23,1975 Telegram: J. Keppler, 1505 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.726525e-4 months <br /> on September 23, 1975

3) Drawing Number M173 Report Number: 50-237/75 A4

. Report Date: October 2, 1975 '

Occurrence Date: September 23, 1975 Facility: Dresden Nuclear Power Station, V. orris, Illinois IDDTPIFICA? ION OF OCCURRE:CE The Unit-2 diesel centerator failed to start. -

CO::DITIONS PRICR TO OCCURRENCE -

Unit-2 was in a steady-state condition at a power level of 1576 Ist and 490 ice. The Unit-2 diesel generator was being tested to demonstrate operability for a Unit 2/3 diesel generator outage.

DE."fRIPTION OF OCCURR3!CE At approximately 0230 hours0.00266 days <br />0.0639 hours <br />3.80291e-4 weeks <br />8.7515e-5 months <br /> on September 23, 1975, the Unit-2 diesel generator failed to turn over during starting. The pinion gears of the air starting motors engaged properly, but the main air relay valve failed to open, blocking the driving air pressure from the starting motors. '

8303310653 751217 '

PDR ADOCK 05000237 ' 7-' ' D' S PDR

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Mr. Jam;c G. Kspplev/

Cetober 2, 1975 Immediately following the initial attempt, the diesel generator was successibily started three consecutive times.

DESIGNATICM OF APPAREIT CAUSE OF OCCURRENCE (Operator Error) .

The apparent cause of the occurrence was the failure to follow the monthly diesel generator inspection procedure and quality control procedures for replacement of, safety related co::ponents. The valve was disassembled during a routine conthly inspection rather than during the extensive annual inspection.

Tne seal ring was replaced with a ring that was not specifically a replacceent part. The improper seal ring was responsible for the sluggish operation.of the valve.

ANALYSIS OF OCCURRECE This occurrence did not threaten public health and safety. Had en accident condition developed, off-site pcwer as well as the Unit 2/3 diesel generator would have been available to supply necessary emergency equip::ent.

• CORRETIVE ACTION The diesel generator was removed from service, and the entire air start system was inspected for obstructicns._ The air relay valve was subsequently dismantled, and the sticking seal ring was replaced with the proper component.

Upon reassembly, the valve was operated satisfactorily several times. The diesel generator has been started at least three times since the valve was, re-installed. No starting difficulties have been noted.

The importance of adhering to the monthly diesel-generator inspection procedure end quality control procedures will be reemphasized ,to the maintenanco depart-ment. In addition, storcroom control of the proper replacement seal will be established to prevent a similar occurrence.

/ u,um: .

. . Stefp'honcon

' Superintendent ,

.EBS:JEM:smp File /NRC F

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