ML20011F555

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LER 90-002-00:on 900129,after Filling Diesel Generator 1A Governor W/Oil,Generator Started & Declared Inoperable. Caused by Slow Leak Coming from Compensation Needle Valve Plug.Oil Added & Plug Washer replaced.W/900228 Ltr
ML20011F555
Person / Time
Site: LaSalle Constellation icon.png
Issue date: 02/28/1990
From: Diederich G, Sampson P
COMMONWEALTH EDISON CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-002-04, LER-90-2-4, NUDOCS 9003060256
Download: ML20011F555 (6)
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. Comm:n :Ocith Edison [

LaSailo County Nuclear Station Rural Route #1, Box 220  ;

Marseilles, Illinois 61341 N ,

Telephone 815/357 6761--

February 28, 1990

'f Director of Nuclear Reactor Regulation.

U.S. Nuclear Regulatory Comunission Mail Station Pl-131 l Washington, D.C. 20555

Dear Sir:

i Licensee Event Report #89-002-00; Docket #050-373-is being submitted to your office in accordance with

'10CFR50.73(a)(2)(vii).

Yd '

O. J. Dieder ch ';

Station Manager LaSalle County Station GJD/PSS/kg g Enclosure-l xc: Nuclear Licensing Administrator NRC Resident Inspector NRC Region III Administrator

(; INPO - Records Center i

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. <; ADOCK05000373 h '\

PDC lj i

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LICENSEE EVENT REPORT (LER)

F LO Facility Name (1) Docket Neber (2) Pace (3)

LaSalle County Station ~0 nit 1 Ol5101010131713 1lofl0l5 Title (4) 1A Diesel Generator Governor Low on Oil Due to Oil Leak on f e nsation Needle Valve Cover Plue Caused by Procedural Inadecuacy Event Date (5) LER Weber (6) i Report Date (7) Other Facilities involved (8)

Month Day Year Year // Sequential // Revision Month Day Year Facility Names Docket Neber(s)

/j/jj

// Weber g/// Weber LaSalle Unit 2 0151010l0131714

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01 1 21 9 91 0 91 0 010l2 01 0 012 21 8 91 0 01 51 01 01 01 l l THIS REPORT.15 SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10CFR OP'MNG (Check one or more of the followine) (11)

MDDE W 1 20.402(b) _

20.405(c) _ 50.73(a)(2)(iv) _ 73.71(b)

POWER _ 20.405(a)(1)(l) _ 50.36(c)(1) _ 50.73(a)(2)(v) _ 73.7)(c)

LEVEL 20.405(a)(1)(ll) 50.36(c)(2) ,J_ 50.73(a)(2)(vil) _

Other (Specify 1l 0l 0 (10) _ 20.405(a)(1)(lii) _ 50.73(a)(2)(i) _ 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

/ /, r/' / /

/'j///j// 'j//jfj/j'j'/jj//j////j / _ 20.405(a)(1)(v) _ 50.73(a)(2)(lii) _ 50.73(a)(2)(x) Text)

LICENSEE CONTACT FOR THIS LER (12)

Name TELEPHONE NUftlER AREA CODE Paul Sampson. Technical Staff Enaineer, extension 2704 8 I I 15 315171-l6171611 COMPLETE ONE LlWE FOR EACH CO W ONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT MANUFAC- REPORTABLE TURER TO WPRDS TURER TO NPRDS D El K l l l l l l N 1- I l l l l l l l l l l l l l 1 l l l l l SUPPLEMENTAL REPORT EXPECTED (14) Expected Month i Day l Year Submission

~

lyes (if ves, complete EXPECTED SUBMISSION DATE) YlNO "

l lil A8STRACT (Limit to 1400 spaces, i.e, approximately fifteen single-space typewritten lines) (16)

-On January 29, 1990 at approximately 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, with LaSalle Unit 1 in Operational Condition 1 (Run) at approximately 1005 power, and Unit 2 in Operational Condition 1 (Run) at approximately 98% power, an Equipment operator (EO) noticed that the oil in the 1A Diesel 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 oil to the proper level, the lA DG was started, and proper operation of the governor was verified in accordance with LaSalle Operating Surveillance LOS-0G-M2, "1A (2A) Diesel Generator Operability Surveillance." Following the successful completion of LOS-0G-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 coming from the compensation needle valve plug due to a used washer being replaced after the governor oil flush.

The safety conseqrences of this event were minimal. The manufacturer of the governor (Woodward) stated that

) the main purpose of keeping the governor full of oli is for cooling. The quantity of oli that the governor was missing would not have prevented the governor from perfonning its design function.

The proper amount of oil was added to the governor, and LOS-0G-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 incorporate increased monitoring of the DG governor oil levels.

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O LirzucEE EVENT REPORT (LER) TEXT CONTINUATION Fors Rev 2.0 f FACILITY NRME (1) DOCKET NumER (2)' _ LER NUMER (6) Pane (3) q Sequential , Revision Year - // //

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// Neber - // Number i J

t 0 l 5101010 l 31713 910 l'

  • 11e County Station Unit 1 - 010l'2 - 01 0 0l2 '0F 01 5 TEXT- . Energy industry identification System (Ells) codes are identified in the text as [XX]

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PLANT AND SYSTEM IDENTIFICATION

'1 General Electric - Bolling Water Reactor

- EnergyIndustryIdentificationSystem(Ells)codesareidentifiedinthetext.as[XX].

A. CONDITION PRIOR TO EVENT

~ Unit (s): 1/2 . Event Date: 1/29/90 Event Time: 2015 Hours Reactor Mode (s): 1/1 Mode (s) Name: Run/Run Power Leve1(s): 100W985 h

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8. DESCRIPTION OF EVENT '

L On .lanuary 29, 1990 at approximately 2015 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.667075e-4 months <br />, with LaSalle Unit 1 in Operational Condition 1 (Run) at

. approxima tle y -1005 power, and Unit 2 in Operational Condition ~1 (Run) at approximately 905 power, an--

Equipment Operator (EO) noticed that the oil in the 1A Diesel Generator (DG) [EK] governor was low and.

p . could not be seen in the sight glass. The E0 also noticed that the governor sight glass vented plug was missing. The E0. lsmediately notified the Shift Foreman and Electrical Maintenance Foreman, to determine . *

- the type of. oil used in the governor. The 1A DG was declared inoperable due to not being able to. 4 determine the oil level in the governor. The E0 stated that after. adding approximately 4 to 5 ounces of- ,

oil,.the oil level could be seen in the sight glass. Approximately 5 to 10 more ounces of oil were  ;

added to fill the governor to the upper sight glass line (Maximisa Fill Line). The missing sight glass ,

ventplugwasfoundonaDGskidsupportadjacenttothegovernorandwassubsequentlyreplaced.-

At the time of the event, the Unit 2 "B" Residual-Heat Removal (RHR) [80] system was inoperable for -

preventive maintenance.(valve inspections which included having lead shleiding on RHR piping . relay

' calibrations, and cleaning of the "B" RHR pa p seal cooler). 'Due to the "B" RHR system being

- Inoperable, the Unit 2 Hydrogen Recombiner (HG) [8B] had also been declared inoperable for Unit 2'since -

the HG cooling water is supplied from the Unit 2 "B RHR system when the Unit 2 HG system is used for Unit 2. (The Unit 2 HG system is also used to support Unit 1,.however the source of coollng watercis Unit 1 RHR which was available.) Since the 1A DG is the emergency power supply for Unit 1 HG, and the t Unit 2'HG was already inoperable, Technical Specification Action 3.0.3 was entered for Unit 2. t Technical Specification 3.0.5 was the appropriate specification for this condition, however entry into ~

3.0.3 was' conservative.

During the first hour of Technical Specification 3.0.3, preparations were begun to commence a Unit 2 '

reactor shutdown by reviewing proper procedures and verifying offsite power lineup.

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$ ... I L1?EAKEE EVENT REPORT (LER)~ TEXT CONTINUATION Form Rev 2.0 FACILITY NAPE (1) 00LKET GENBER (2) LER NUPSER (6) Pace (3)

Year /y/j/ Sequential j Revision T// Numer /f/j/

n Number leS411e County Station Unit 1 0 1 5 1 0 1 0 1 0 1 31 71 3 910 - 010l2 - 01 0 01 3 0F 01 5 TEXT Energy Industry identification System (Ells) codes are identified in the text as [XX]

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B. DESCRIPTION OF EVENT (Continued)

The Station operation Duty Officer (500) directed the Shift Engineer (lleensed Senior Reactor Operator) to pursue getting the 2B RHR systen back in service by clearing the out of services and removing the  ;

lead shleiding. Upon completion of an operability surveillance, the 28 RHR system and the Unit 2 HG -

recombiner was declared operable aed k chalcal 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 pwf0fand.

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 1A DG was s' tarted, and proper operation of the governor was verified by disturbing the engine '

fuel rack, and verifying that the governor returned the engine to norinal speed without excessive >

l oscillations (hunting). The 1A DG was subsequently loaded for one hour in accordance with LaSalle Operating Surveillance LOS-0G-M2, "1A (2A) Diesel Generator Operability Surveillance." Following the f successful completion of LDS-0G-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 IA DG was inoperable for approximately'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 EVENT ~

, The apparent cause of the governor being low on oil was a slow leak coming from the compensation needle - ,

valve plug. This plug, along with a copper washer, is used to prevent the oil that may 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-0G-103, " Diesel Generator Governor Flush and Compensation Procedure," was perforined on the 1A DG governor. Following the completion of the compensation adjustment,theneedle.valveplugandtheoriginalwasherwerereinstalled. After discussion with the governor manufacturer (Woodward), they stated that it is not required,' but it is a good practice to replace the copper washer every time this plug is renoved and reinstalled. This particular style of washer creates a seal when it is crushed by the plug.c 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 s l; the vented sight glass plug being removed probably increased the rate at which the oil leaked out. The r l small vent' hole in the sight glass plug is the only vent port on the governor. The purpose of.this vent i hole is to allow the sight glass to indicate the proper o!) level in the governor. l Presently, DG governor oil level is checked, but not documented, prior to the monthly operability-surveillances. It is also occasionally checked during the Equipment Operator rounds, but it is not included in the rounds package.

l' O. SAFETY ANALYSIS OF EVENT The safety consequences of this event were minimal due to the diesel generators capability to perform its design function was still available. The manufacturer of the governor (Woodward) stated that the  !

main purpose of keeping the governor full of oil is for cooling. The quantity of oli that the governor was missing, would not have prevented the governor from perforlaing its design function. The UG-8 l:

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'Lic M EE EVENT REPORT (LER) TEXT CONTINUATION Fom Rev 2.0

'FACIL11Y NAME (1) DOCKET NUSER (2) LER NU SER (6) Pace (3) ,

Year / Sequential // Rwvision

/g/j/

/ Nueer j//j/j/ Nueer la lie County Station Unit 1 015101010 l 31713 910 - 0_1 0 ' 2 - 01 0 01 4 0F 01 5 TEXT. Energy Industry identification System (Ells) codes are identified L the text as (XX)

L l D. SAFETY ANALYSIS OF EVENT (Continued) governor used on LaSalle's diesels holds about one and a half quarts of all. If filled to the upper mark on the sight glass. The oli level is supposed to be maintained between the upper.and lower marks on the t 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 conces to fill to the upper sight glass mark, the governor was low by a maximum

' of 15 ounces of oil. This amount of oli missing would not have prevented the governor from perfoming as designed. In addition, the internal hydraulic pups' the power piston, the pilot valve, the pressure-regulating accumulators, and compensation pistons are all located at the very bottom of tle governor.

-These are the components that control the operation of the governor. Therefore, not taking into l- consideration the cooling function of the oil, the oil would have to be about one quart low to affect ,

the operation of these components. 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 time 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 ls-  !

running through the oil fill cap.

E. CORRECTIVE ACTIONS During the first hour of Technical Specification 3.0.3, preparations were begun to commence a Unit 2

' reactor shutdown by reviewing proper procedures and verifying off site power lineups.

The 005 directed ~ the Shift Engineer to pursue getting the 28 RHR system back in service by clearing the .1 out of services and removing the lead shleiding. Upon completion of an operability surveillance, the 28 ,

RHR system and the Unit 2 HG reccabiner 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.

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l. The proper amount of oil was added to the governor, and LOS-DG-M2, "1A (2A) Diesel Generator Operability Test," was perfomed 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 IA DG governor oil level until the compensation needle valve plug washer was replaced. The 1A DG needle valve plug washer was replaced and other DG governors inspected for leaks.

!' The Equipment Operators were canvassed to see if they have been ransving the governor's sight glass plug to check oil level to determine the reason for it being removed. No reason could be detemined on why the sight glass plug was removed.

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L:CENSEE EVENT REPORT (LER) TEXT CONTINUATION Fom Rev 2.0 FACILITY NAE (1) DOCKET NumER (2) LER NUMER (6) Pace (3)

Year Sequential /// -Revision

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/// lhsiber fff

/// Number LaSalle County Station Unit 1 0 l 5 1 0 1 0 1 0 1 31 71 3 910 - 010l2 - 01 0 01 5 OF ' 01 5 TEXT Energy Industry Identification System (Ells) codes are identified in the text as (XX]

E. -CORRECT!YE ACTIONS (Continued)

To prevent the same type of leak from reoccurring, LaSalle Electrical Procedure LEP-0G-lG3, "Olesel Generator Governor Flush and Compensation Procedure," is being revised to incorporate installing a new copper washer when replacing the compensation needle valve plug. Action item Record (AIR) 373-200-90-01801 has been initiated to track the completion of this procedure revision.

The Equipment Operator rounds packages have been revised to incorporate monitoring the DG governor oli levels daily. The DG monthly surveillance will be reviewed to detemine if a revision is appropriate.

AIR 373-200-90-01802 has been initiated to track the completion of this action.

F. PREVIOUS EVENTS None.

G. COMPONENT FAILURE DATA None.

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