ML20084E043

AO 50-237/75-23:on 750511,diesel Generator Overheated After Inadvertent Fast Start & ECCS Inadvertently Initiated. Overheating Caused by Loss of Cooling Water Pump Suction. ECCS Initiation Caused by Valving Out Flow Check Valve

ML20084E043
Person / Time
Site:	Dresden
Issue date:	05/21/1975
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
320-75, 5758, AO-50-237-75-23, NUDOCS 8304130539
Download: ML20084E043 (3)

Text

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h/Qf*g, Ccmmsnwealth Oo. f ir ,1 NF Ediscn llierio S  ;

H to. Post Othee llos 7G7

((X.j, '/ Address (,)at Ptil,. Chie'MO Ch cago. Imnom 60690 i

EBG Ltr. 8320-75 Dresden !!ucicar Power Station R. R. J1 I*orric, Illinois ,

May 21, 1975 60h50[e'~~~

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.. / fi;uLii LU cg Mr. Jcnes G. Keppler, Regional Director p,[g'(p,71976 p- Z I Directorate of Reculatory Operation-Region III . ,.,,.,,,,,., ff- l U. S. :uclear Reculatory Ccrciccion ,6,\ wnw A I 799 Roocevelt Road ' A.,

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Glen Ellyn, Illinoic 60137

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SUDJECT: REFC*iT OF Arr*':*.tL CCCURRZ:CE PIB SECTICM 6.6. A OF Ti!E T.~JiOIICf.U~

SI EC:FIC1.0IC'.!3 1*:IIT-2 DI:CLL GE*D.tTCR OVECJ14TED

References:

1) Regulatory Guide 1.16 Rev. 1 Appendix A

2) !!otification of Region III of U. S. Muelear Regulatory Cor.icolon Telephone: P. Johnson,1510 hours0.0175 days <br />0.419 hours <br />0.0025 weeks <br />5.74555e-4 months <br /> on I~ay 11, 1975 Telegram: J. Keppler, 1405 hours0.0163 days <br />0.39 hours <br />0.00232 weeks <br />5.346025e-4 months <br /> on leay 12, 1975

3) Drawing "unter M173 Report !! umber: 50-237/1975-23 Report Date: I*.ny 21, 1975 Occurrence Date: May 11, 1975 Facility: Dresden Nuclear Power Station, Morris, Illinois 60450

_IDZ:TIFICATIC:I 0F CCCURRE!CE The Unit-2 dieccl generator overheated after an inadvertent fact start. The rcmoval of a Ri'S/ECCS instru.T.ent line check valve upset level instruments initiating ECCS. The diocel generator failure could have prevented the intended function of an engineered cafety feature systcm.

CONDITIC::S FP.IOR TO CCCUR:C:CE Unit-2 was in the cold shutdown Ir. ode during an extended refueling outage.

DESCRIIIC: CP C-CCIT.lRZ:'":

At ap;?roxir ately 0645 heura on May 11, 1975, an instrument flow check valve was diamantled, causing the loan of one leg of a Yarway level indicator. Thic.

8304130539 750521 ra qg PDR ADDCK 05000237 PDR u v S

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Pr. Mr.edsG. heppler f'j May 21, 197'; l l

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deficiency initiated th. U:.it-2 F wrconcy Core Ocelin.rSystem. The Unit-2 diciel (:enerator started Lut everhcnted due to lack ci cooling water, i

'I Dr.Z C"'c'IU: C c' ."'Pl.i.".~.' C1"r Cy CCJ"REE (Cperator/ Equip. ent) II l'

t; The innd'ic rt crt initiatic" of *l.c F^".S occurred becauce the effect of valving i out ficw cierch valve T-Zuf-?-15A had not been adequately investigated.

i The diecel ,enerator overheated beca.cc its cooling water pumpo 1 cat cuetien.

Trarelir cereu. , C and D i ere out, of cervice for cn electrical centrol I r.odification and cencequently were blocked. A differential preccure instru~.en*.

on the traveling cerecro u;c inoperable, preventing the high differential preccure alarm fre. actuating.

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Js". n' '. ,T. '; T .*4 c'.'C~".'"..'.'.*.",~t' Thic occurrcnec in no way jr'opardized the health and safety of t,he ;ublic.

Unit-2 van :n cold chutdcun e.nd no work wac being dcne that potentially endangered care rcactor ecclont levcl.

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I The diccel generator uns irrodiately taken out of service and inspected for dar. age . '.!crk was alto initiated to correct the problema with the traveling cercenc and differential precoure switch.

The station is revic.dn; irorovements in the crib hcuse operator roundo to help detect problc.n uith the travelin' cerecns and their controls. This review is scheduled for ccmpletion by June 15, 1975 ,

FAILURE DATA Failure of the dienel i;cnerator due to this particular cequence of evento has never occurred before.

Sincerely, s

1)s % y (e D. B. Stephencon Superintendent E"S:JE4:n p PileA.~iC

-T-J W. MPPLU, K8810nal N rT_ tor:co cf Re c ry Operctions hiecopid Dan F ' /5)- D -

ion III '"

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.>a Nuclo r Regul ry Commaiccion #'"""" 8 v 7F9 Roosevelt Road M -

Glen E11p, II, 60137- g j/

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Bernard C. Rusche, Director Directorate of Licensing 148. Nuclear Regulatory Commission Washington, D.C. 20555 gUBJECT: DPR= /@ , Dresden Nuclear Power Statica, Unit 2 This. will confinn s conversation with ///2 /J'AJSOA/ of

// M a y your office at 4570 hrs chie f ee concerning rew Op th r 2 WL SGA t'7f/'270A? . . Gwe,eg r5$sy.as g,,ggyjg. 7,&ncusz:.y s,uut.g.

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h Call. B. B. StePhenson, Superintendent GE ~ 5-858-2660x16 (auto) " * * " "

DC 1-301-492-7617 (aut.o) '

• 6 Curaonwea;;.. dison.Crepany W. - 815-942-4449/4321 R.L #1 Station.Dist: Originator (copy)

Horria, J.L . 60450 i

Incident File (copy) + ,

! Telegram File (origwn '

, ,,pho e: 815-942-2920/2921x212' L (telecopy x262)

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