ML20012D537

LER 90-002-01:on 900129,oil in Diesel Generator Governor 1A Found to Be Low & Could Not Be Seen in Sight Glass.Caused by Slow Leak from Compensation Needle Valve Plug.Proper Amount of Oil Added & Operability Test performed.W/900316 Ltr

ML20012D537
Person / Time
Site:	LaSalle
Issue date:	03/16/1990
From:	Diederich G, Sampson P COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-002, LER-90-2, NUDOCS 9003280023
Download: ML20012D537 (6)

Text

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! LtSa'le County Nuclear Stition

• ,4* Rural Route #1, Box 220 O CommonwoelthEdison Marseilles,lilinois 61341 Telephone B15/357-6761 March 16, 1990

. Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Station F1-137 Washington, D.C. 20555

Dear Sir:

Licensee Rvent Report #90-002-01, Docket 9050-373 is being submitted to your office in accordance with 10CFR50.73(a)(2)(vii) and supersedes previous submitted report.

This supplement is to correct a typographical error in the Licensee Rvent Report number found on the cover letter of the previously submitted report, dated February 28, 1990.

O O. J. Diederich

[StationManager LaSalle County Station GJD/PSS/kg i Enclosure xc: Nuclear Licensing Administrator NRC Resident Inspector NRC Region III Administrator INPO - Records Center 9003280023 900316 b

{DR ADOCK 05000373pnr 19

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LICENSEE EVENT REPORI (LER) form Rev 2.0 Facility 'Naus (1) Docket Wund>er (2) Pane (3)

LaSalle County Station Unit I _.

01 51 01 01 01 31 71 3 I of 0 5 iltle (4) 1A Diesel Generator Governor Low on Oil Due to Oil Leak on Campensation Needle Valve Cover Plug Caused by Procedural Inadequacy Event Date (5) LER Wadier (6) Report Date (7) Other facilities involved (8)

Month Day Year Year /// Sequential /// Revision Month Day Year fac,1]ityNames Docket Nwd>cr(s) fff j//ff

/// Wed>er / Ned>er _

LaSalle Unit 2 01.5101010131714

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01 1 21 9 91 0 91 0 01012 0l 1 0l3 Il 6 91.0 01 51 01 01 01 l l l lills REPORI is SUBMilll0 PURSUANI 10 lill RLQUIRLMLNIS OF 10CFR 8 I icheck one or more of the_ Lo]Iowl'gLij.lL__ a ._._ ..

I 20.402(b) __ 20.405(c) ,,,,_,, 50.73(a)(2)(lv) _ 73.71(b) g POWER __ 20.405(a)(l)(l) _ _ , 50.36(c)(1) ,_ 50.73(a)(2)(v) ,_, 73.71(c)

LEVEL i g _ 20.405(a)(1)(ll) _,, 50.36(c)(2) _ x__50.73(a)(2)(vil) _

Other (Specify (10) Il 01 0 _ 20.405(a)(1)(lit) _ 50.73(a)(2)(1) _ 50.73(a)(2)(vill)(A) in Abstract

/,//,/,/,/,//,/,/,/,/,/,/,/,/ /,/,/,/,/,/ /,/, /,/, _ 20.405(a)(1)(lv) _,, 50.73(a)(2)(ll) ,_ 50.73(a)(2)(vill)(B) below and in

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/// / // // / //

' '/' /' /' /' 7' /' ' ' /' )/' /' ' /' ' /' )/

_,, 20. 405 ( a ) ( 1 ) ( v ) _ 50.73(a)(2)(lii) _ 50.73(a)(2)(x) Text)

LICENSEE CONTACT IDR THIS LER (12)

Name IIttPHONE NUpWER ARLA CODE Paul SamDson. Technical Staff Engineer, extension 2704 8 l 1 15 315171-l6171611 COMPLETE ONE IINE fOR LAtll COMPON fAllURE_(LSCRIDED IN THl5 REPORI J13)

CAUSE SYSTEM COMPONENT MANUFAC- REPORIABLE CAUSE SYSILM COMPONLNI MANUf AC- RLPORIABLE TURER 10 NPRDS 10RER TO NPRDS D El K _Ll L _LLL N I _LL L _L1 1 I I I_.1 LL1- _

i i i i _1 l L SUPPILMINI AL RIPORI LXPECILD (14) Expected Month l Day l Year Sutznission l ~ lyes (If yes. cunplete fxPECil0 SUHMIS$10N DATE) Yl _ NO l ll ll ABSTRACT (Limit to 1400 spaces, i.e, approxinutely fif teen single-space typewritten lines) (16) i On January 29, 1990 at approxinutely 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, with laSalle Unit I in Operational Condition 1 (Run) at approximately 100% power, and Unit 2 in Operational Condition I (Run) at approxinutely 98% power, an Equipment Operator (EO) noticed that the oil in the IA Olesel Generator (DG) Governor was low and could not be seen in the sight glass. At approximately 2230 hours0.0258 days <br />0.619 hours <br />0.00369 weeks <br />8.48515e-4 months <br /> on January 29, 1990, after filling the governor with Cll to the proper level, the lA DG was started, and proper operation of the governor was verlfled in l Ccc:rdance with LaSalle Operating Surveillance LOS-DG.M2, "lA (2A) Diesel Generator Operability S~rveillance." following the successful conpletion of LOS-DG-M2, the 1A DG was declared operable at approximately 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> on January 30, 1990.

The apparent cause of the governor being low on oil was a slow leak caning from the conpensation needle valve plug due to a used washer being replaced after the governor oil flush.

The safety consequences of this event were mininal. The nunufacturer of the governor (Woodward) _ stated that the main purpose of keeping the governor full of oil is for cooling. the quantity of oil that the governor i

was Clssing would not have prevented the governor frum performing its design f unction.

The proper amount of oil was added to the governor, and LOS DG M2 was performed to verify proper operation of the governor. Applicable procedures are being revised to prevent this type of leak from recurring, and to inc rporate increased monitoring of the DG governor oil levels.

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LLCEN5fE EVENT REPORT (t.ER) 1 EXT CONilNUAil0N form Rev 2.0 FACILITY NAME (1) DOCKEI NUMBER (2) _tM _NupeFR (6) Paee O) -

Year /// Sequential ff//j/ Revision fff

/// Nistier /// thster

• lle County Station Unit 1 0 1 5 1 0 1 0 l'0 l 31 71 3 910 - 01012 -

0I i 012 0F 01 5 TEXT Etwrgy Industry identification System (Ell 5) codes are identified in the text as [KX] ljl i

PLANT AND SYSTEM IDENilFICA110N j

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.. General Electric - Bolling leater Reactor  !

Energy Industry identification System (Ell 5) codes are identified in the text as [KKJ.

J A. CON 0lil0N PRIOR 10 EVENT j Unit (s): t/2 Event Date: J s0 Event ilme: 20I5 Hours _ i

Reactor Mode (s): 1/1 Mode (s) Nue: Run/Run Power Level (s): 100E/98%

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B. DESCRIP110N OF EVENT On January 29, 1990 at approximately 20l5 hours, with LaSalle Unit I in Operational Condition l-(Run) at. ,

approximately 100% power, and Unit 2 In Operational Condition I (Run) at approximately 98% power, an Equipment Operator (EO) noticed that the oil in the 1A Diesel Generator (DG) ((K) governor was low and 4 could not be seen in the sight glass. The [0 also noticed that the governor sight glass vented plug was alssing. The [0 lunediately notified the Shif t foreman and Electrical Maintenance f oreman, to determine ,

the type of oil used in the governor. The 1A DG was declared Inoperable due to not being able to determine the oil level in the governor. The E0 stated that af ter adding approximately 4 to 5 ounces of - 1 oil, the oli level could be seen in the sight glass. Approximately 5 to 10 more ounces of oll were added to fill the governor to the upper sight glass line (Marinusn iIll Line). 1he missing sight glass vent plug was found on a DG skid support adjacent to the governor and was subsequently replaced.

At the time of the event, the Unit 2 "B" Residual Heat Removal (RilR) [B0] system was Inoperable for ,

preventive maintenance (valve inspections which included having Icad shielding on RilR piping, relay ,

calibrations, and cleaning of the *B" RHR punp seal cooler). Due to the "B" RHR system being Inoperable, the' Unit 2 Hydrogen Recentainer (HG) [BB] had also been declared inoperable for Unit 2 since -  !

the HG cooling water is supplied from the Unit 2 *B RitR system when the Unit 2 HG system is used for i Unit 2. (The Unit 2 HG system is also used to support Unit 1, however the source of cooling water is Unit 1 RHR which was available.) Since the 1A DG is the emergency power supply for Unit i HG, and the >

Unit 2 HG was already lnopereble, lechnical Specification Action 3.0.3 was entered for Unit 2.

Technical Specification 3.0.5 was the appropriate specification for this condition, however entry into 3.0.3 was conservative.

Durlng the first hour of Technical Specification 3.0.3, preparations were begun to conmence a Unit 2 reactor shutdown by reviewing proper procedures and verifying offslic power lineup.

t i tCtWSIE EVINI RfPORT (LER) TEXLCONilWUAll0N form Rev 2.0  ;

FACILIT' NAME il)

Y DOCKti NumLR (2) _ttR WustR (6) Pane (3)

Year /// Sequential /j/j/ Revision f

/j/j/ Wisd>cr j/// Wisdier LaSalle county station Unit 1 0 l 5 l O_10 1 O _1 3LIL3 JLLO_ _ -_ _0_ l O_LL ._

0I i 01 3 Or 01 s l, TEXT Energy Industry identification $ystem (LIIS) codes are identified in the text as [XXJ

8. DESCRIPTION OF EYLNI (Continued) t 1he Station Operation Duty Officer ($D0) directed the shift Engineer (licensed Senior Reactor Operator) I to pursue getting the 28 RilR system back in service by clearing the out of services and removing the ,

lead shielding. Upon conpletion of an operability survelliance, the 2B RilR system ar.d the Unit 2 IIG l reconbiner was declared operable and Technical Specification 3.0.3 was exited at 2140 hours0.0248 days <br />0.594 hours <br />0.00354 weeks <br />8.1427e-4 months <br /> on January ,

'29, 1990. No load reduction was performed.

At approximately 2230 hours0.0258 days <br />0.619 hours <br />0.00369 weeks <br />8.48515e-4 months <br /> on January 29, 1990, after filling the governor with oil to the proper level, the lA DG was started, and proper operation of the governor was verlfled by disturbing the engine h fuel rack, and verifying that the governor returned the engine to normal speed without excessive oscillations (hunting). 1he 1A DG was subsequently loaded for one hour in accordance with LaSalle ,

Operating Surveillance LOS-DG M, "lA (2A) Diesel Generator Operability surveillance." following the '

successful completion of LOS-DG-M2, the 1A DG was declared operable at approxinutely 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> on January 30, 1990. 1he lA DG was inoperable for approxinately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 45 minutes.

C. APPARENT CAUSE OF EVENI L

1he ipparent cause of the governor being low on oil was a slow leak coming from the convensation needle l valve plug. This plug, along with a copper washer, is used to prevent the oli that nuy leak past the  !

! needle valve threads from leaking out of the governor. Approximately a month and a half prior to this event, LaSalle Electrical Procedure LEP-DG-103, " Diesel Generator Governor Ilush and Convensation Procedure," was performed on the 1A DG governor, f ollowing the conpletion of the conpensation adjustment,theneedlevalveplugandtheoriginalwasherwerereinstalled. After discussion with the .

governor nanufacturer (Woodward), they stated that it is not required, but it is a good practice to replace the copper washer every time this plug is removed and reinstalled. This particular style of l washer creates a seal when it is crushed by the plug. Once it has been crushed, it can be reused, however it may not seal as well. In this particular event, the used washer did not seal correctly, and ,

the vented sight glass plug being removed probably increased the rate at which the oil leaked out. 1he

, small vent hole'In the sight glass plug is the only vent port on the governor. The purpose of this vent l hole is to allow the sight glass to indicate the proper oil level in the governor. '

Presently, DG governor oil level is checked, but not docunented, prior to the monthly operability surveillances. It is also occasionally checked during the Equipnent Operator rounds, but it is not included in the rounds package.

t D. SAFE 1Y ANALYSIS OF EVENT l 1he safety consequences of this event were mininal due to the diesel generators capability to perform its design function was still available. 1he nunufacturer of the governor (Woodward) stated that the l main purpose of keeping the governor full of oil is for cooling. 1he quantity of oil that the governor l was missing, would not have prevented the governor from performing its design function. The UG-8 t

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l'CtWSIE EVINT kiPORT (LER) 1 EXT CONilWuAlinN_ form Rev 2.0 FACilliY NRME (I) DOCKET WumLR (2) ,_LER NU4tR (6) Pane (3)

Year /// 5equential /// Revision ffj fff

/// Nunber /// Nunber LaSalle County Station Unit 1 0.1 5 1 0 1 0 1 0 1 31 71 3 910 - 0l0l2 - 0l 1 01 4 0F 01 5 l TEXT Energy Industry identification Systm (LilS) codes are identified in the text as [XXJ 0, SAFETY ANALYSl$ OF LYLNI (Continued) governor used on LaSalle's diesels holds about one and a half quarts of oil if filled to the upper mark on the sight glass. The oil level is supposed to be maintained between the upper and lower marks on the sight glass. There is approximately 5 ounces of oil between the upper and lower sight glass marks.

Based on the operator's estimate of adding 4 to 5 ounces of oil to obtain a reading in the sight glass, and adding 5 to 10 more ounces to fill to the upper sight glass mark, the governor was low by a maximum of 15 ounces of 011. This ancunt of oil missing would not have prevented the governor from performing as designed. In addition, the Internal hydraulle punps, the power piston, the pilot valve, the pressure regulating acewaulators, and cepensation pistons are all located at the very bottom of the governor.

1hese are the conponents that control the operation of the governor. 1herefore, not taking into consideration the cooling function of the oil, the oil would have to be about one quart low to affect the operation of these conponents. The removal of the vented sight glass plug also does not affect the operation of the governor.

The consequences of this event could have been significant if the DG would have started on an auto start signal, and ran for an extended period of Line without anyone noticing that the oil was low, in this case, the governor can be damaged from over heating. Oil can be added to the governor while the DG is running through the oil fill cap.

E. CORRECilVE Aci10N5 During the first hour of lechnical Specification 3.0.3, preparations were begun to connence a Unit 2 reactor shutdown by reviewing proper procedures and verifying of f site power lineups.

lhe 005 directed the $hif t Engineer to pursue getting the 2B RHR system back In service by clearing the out of services and rmoving the lead shleiding. Upon cunpletion of an operability surveillance, the 28 RHR system and the Unit 2 HG reconbiner were declared operable and Technical Specification 3.0.3 was exited at 2140 hours0.0248 days <br />0.594 hours <br />0.00354 weeks <br />8.1427e-4 months <br /> on January 29, 1990.

The proper amount of oil was added to the governor, and LOS4Ki-M2, "lA (2A) Ulcsel Generator Operability l

Test," was performed satisfactorily to verify proper operation of the governor. The 1A DG was declared operable at 0100 on January 30, 1990. An Operating Special Log was also initiated to monitor the lA DG l governor oil level until the conpensation needle valve plug washer was replaced. 1he lA DG needle valve l plug washer was replaced and other DG governors inspected for leaks.

The Equipnent Operators were canvassed to see if they have been removing the governor's sight glass plug -

to check oil level to determine the rearon for it being removed. No reason could be determined on why the sight glass plug was rmoved.

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-tUCENSIE EVENT REPORT (LER) TEXT CONilNUAil0W Fore Rev 2.0 i FACIL11Y IpsE (1) DDCKE1 NumER (2) LER NUSER (6) Pane (3) l Year /// Sequential //j/ Revision }

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ff Ne$er ff

/// Ns6er j usalle Countv 5tation unit 1 01.5 I o I o 1.0131113 910 - oIol2 - oI 1 ol 5 or 01 5 TEXT Energy Industry Identification Systm (Ell 5) codes are identified in the text as (XX] l:i ,

1 I

- E. CORRECilVE AC11DNS (Continued) lo prevent the same type of leak from reoccurring, LaSalle Electrical Procedure LEP-DG-103, " Diesel Generator Governor Flush and Convensation Procedure," is being revised to incorporate Installing a new '

copper washer when replacing the conpensation needle valve plug. Action item Rec.ard (AIR) l 373-200-90-01901 has been initiated to track the conpletion of this procedure revision.

The EquipmDnt Operator rounds packages have been revised to incorporate monitoring the DG governor oil (

levels dally. The DG monthly surveillance will be reviewed to detennine if a revision is appropriate.  !

AIR 373-200-90-01802 has been initiated to track the conpletion of this action. l F. PREVIOUS EYLNIS l None.

G. COMPONENT FAILURE DATA N0ne.

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