Text

Forwards Deviation Investigation Repts Dir 06-01-90-021 & 022 Addressing Valid & Invalid Failures Experienced on Diesel Generator 1A,including Cracked Fuel Injection Pump Discharge Fittings & Spurious Overspeed Trip Signals
	ML20033G769
Person / Time
Site:	Byron
Issue date:	03/26/1990
From:	Pleniewicz R; COMMONWEALTH EDISON CO.
To:	Davis A; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
	BYRON-90-0322, BYRON-90-322, NUDOCS 9004120101
	Download: ML20033G769 (17)
	v • d • e

_

Commonwealth Edison D r:n Nuclear Sttion Afb 0 North German Church Road MI@IU E N Byron, Illinois 61010 FIrit 5 "JJL

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m Harch 26, 1990 LTR BYRON 90-0322 FILE:

2.07.0400 Mr. A. Dort Davis Regional Administrator Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinola 60137

Subject:

Dyron Unit 1 Operating License NPP-37, Docket No. 50-454, Reporting of Emergency Diesel Generator rallures Dear Mr. Davls This report is submitted in accordance with Byron Station Unit 1 Operating License NPr-37 Appendix A, Technical Specification 4.8.1.1.3, reporting of Dlesel Generator railures.

This report addresses two valid tests and failures and two invalid failures experienced on the 1A Diesel Generator (DG). The criteria to determine valid and nonvalid tests and failures is in accordance with Section C.2.e of Regulatory Guide 1.108.

Deviation Investigation Report DIR 06-01-90-021 is a summary of the two valid failures..The failures resulted from cracked fuel injection pump discharge fittings and the seizure of fuel injection pump internals. The failures occurred during surveillance testing following a scheduled teardown and inspection.

DIR 06-01-90-022 is a summary of invalid tests and failures resulting from spurious overspeed trip signals.

All of the trips occurred during maintenance and troubleshooting runs. The problem was corrected prior to declaring the Diesel Generator operable.

DIR 06-01-89-141 is a summary of invalid tests and failures resulting from spurious engine vibration trip signals.

The trips occurred after all testing requirements were met.

9004120101 900326 PDR ADOCK 05000454 S

PDC l l 1

(2455s/47z)

W 30 W M l

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. Byron 90-0322 page 2 The 1A DG was not required for operation at the time of the injection pump and overspeed failures, and operability was not affected by the vibration trips.

Therefore, the diesel generator was not considered to be unavailable at any time. The valid failures were the first and second fr.ilures within the previous twenty valid tests for the 1A DG.

Per Technical Specification Table 4.8-1, the 1A DG was placed on a weekly testing frequency.

Sincerely,

{

wad R. Plenlewicz Station Manager Dyron Nuclear Power $tation RP/TGD/bf Attachments cca Dyron Station NRC Senior Resident Inspector U.S. NRC Document Control Desk, Washington, D.C.

INPO Record Center CECO Distribution List i

(2455t/47z)

DEVIATION REPORT l

oVR M0.

6 1

90 - 021 iTA UNIT YEAR ND.

r m p,, p,,,

E,1_ l TITLE OF DEV!ATION 1A Diesel Generator failed fuel OCCURRED i

2 m

Injection Pumps Due to Overtorquing and Foreign Material

$YSTEN AFFECTED PLANT $TATU$ AT TIME OF EVENT TESTING 8

~ n0 l 20E &

POWER (%)

o WORK R

$7 NO.

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DESCRIPTION OF CVENT Event _It Between 1/25/90'and 1/31/90, during post maintenance testing and surveillances several injection pumps were found with cracked heads. The initial investipation into this problem indicates that the cause was a deficient installation procedure.

Event 23 On 2/17/90. during a maintenance test of the 1A Olesel Generator, it was noted that af ter loading the diesel to $500 kW that the 2R cylinder temperature was about 300*F instead of the normal 750-800'F. The 2R fuel injection pump was seized.

P0TENTIALLY $1GNIFICANT EVENT PER N50 DIRECTIVE A-07 YES NO g

g l, g 10CFR50.72 NRC RED PHONE l

l'

' ' '"8 NOTIFICAT!DN MADE l

l*

l x l" RE1poN1f El F SUPERVftot DATE TDE PART2l OPERATING ENGINEER'$ CO M NTS All pumps replaced.

M RE M TABLE M NT l x l NOTIFICATION 30 DAY REPORTA8LE/10CFR REGION !!!

DATE TIME g

g ea n

1/90 12e 5 DAY REPORT PER 10CFR21 l

l N$O DATE TIME ANNUAL /$PECIAL REPORT REQUIRED g

g CEC 0 CORPORATE NOTIFICATION MADE IF A80VE NOT!FICATION !$ PER 10CFR21 A.I.R. #

TELECOPY g,g,g,,

CECD CORPGRATE OFFICER DATE TIME PRELININARY REPORT COMPLETED AM REVIEWE0 D. Brindle 1/31/90 GPERATING ENGINEER BA.TE i 2 W' C

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RESOLUTION APPROVED AND M

AUTHORIZED FOR O!$TRIBUTION k

(A _ _g

$TATIONNAN%R DATE 86-5176 (Form 15-52-1) 11-20-85

/

.UMENT 10 (0525R/0064R)

OtVIAf!0N IWt$f!GAf!0N REPORT (OtR)

I fJuy lltr_LO fac'itity Name Fact

,,ggren Nuclear Panar Station i 10Fl 0 1 4 fitle I A_Dianal Ganaratar Fallad Fuel Inf attian Punna Due in Overtarauf na and Feralen Material EVENT DATE Dit NUPSER REPORT DATE

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ffff ff st0VENTIAL ff Rty!$10N g

_ day gg, ifA UNIT YEAR

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NUMBER PONTH DAY YEAR 6

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010 01 2 21 8 91 0 l 10 fffk 0 l 21 1 11 21 $

91 0 01 6 01 1 91 0 CONTACT FOR THIS DIR NAMg TELEPHONE NUPSER ARCA CODE R. Flahlva. Technical Staf f lunarvisar Ent.

2 43 8l 1l5 2l3141 1B14l411 COMPLETE ONE LINE FOR rArN COMPONEN A f.URE DElftthED IN THit REPORT CAU$t

$Y$fCM COMP 0N(NT MANUFAC.

REPORTABLE CAU$E

$Y$ FEM COMPONENT MANVFAC.

R(PORTABLE TURER TO NPRDS TURER TO NrPDS x

[ lK l l IP Cl 61 31 4 Y

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l l l l SUPPLE 9ENfAL REPORf EKPECfED PONTH DAY 3AR_

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UI YE1 fif van..templeta EXPECTED stem 11110N DATE) l NO O $

Text Energy Industry Identification $ystem (E!!$) codes are identified in the text as (XX) t.

PLANT CONDITIONS PRIOR 70 EVENT!

Event Date/fime 1/21/90

/

Unit 1 MODE 6

Refuelina Outama Rx Power

,,,M,,,,

RC$ (AS) Temperature / Pressure 110*F/ 0 est Unit 2 MODE 1

Pawar Omaration Rx Power.,95,_,

RC$ (AS) Temperature / Pressure Narmal Omaratina B.

ESCRIPTION OF EVENT:

From January 25 through January 30, 1990, a total of ten fuel injection pumps (jerk pumps) on the 1A Olesel Generator (DG) (EK) cracked at the discharge fittings. The failures occurred as follows:

1/25/90 Cracked fitting at pump 4R 1/26/90 Cracked fitting at pump 10L 1/29/90 Cracked fitting at pump 4R 1/30/90 Cracked fittings at pumps 7L and 8L: Non Destructive Examination showed cracking at SL. 6L, 9L.

9Ri 3L fitting cracked during line reinstallation.

Also, two injection pumps failed as follows:

1/31/90 Injection pump 3L seized, preventing proper fuel flow to the affected cylinder.

2/17/90 Injection pump 2R seized, af ter having been replaced for minor leakage.

These f ailures occurred during various maintenance verification runs and surveillance testing following the scheduled five-year teardown and inspection of this Diesel Generator. The 1A Diesel Generator h d been taken Out-of-$ervice for the inspection and maintenance activities, and was not operable at the time of the failures. No safety system actuations occurred.

(0525R/0064R)

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1 t.

DCV!AT10sf INVE$T! GAT 10N RCPORT TEKT CONTINWAT10N g

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FACILITY NApg nia r e pact

$t00tNTIAL ttV!$104 STA tailf YEAa ta_ mat e NupSER 010 2

0F 0lJ[

Evran Nutlaar power Statinn 01 6 01 1 91 0 0l2l1 ftxi Energy industry Identification $ystem it!!$) codes are identified in the tout as (XX) j C.

CAust 0F EVilE i

It has been determined thet the cause of the cracking was overtorquing of the fuei itnes to the injection pumps. The root cause of the overtorquing was a procedural inadequacy. In 1969, as a result of previous overtorquing failures. Byron $tation implemented precedures for torgving fuel line fittings developed at an EPRI Otesel Generator Conference. The procedure. DNP 3106-11 Replacement of fuel Injection Pump (s) or l

Adjusting $ hiss to Meet Required Peak Firing pressures on Olesel Generator, directed the high pressure fuel line nuts to be torgued to 15 t 2 foot-pounds (f t-1bs), followed by an additional full turn for new nuts.

or an additional I/4 turn for existing nuts.

During the five year inspection, all twenty fuel injection pumps were replaced with new pumps. Maintenance personnel believed that, due to the installation of the new pumps, a full turn was required af ter the initial 15 ft-Ibs torque. Because the fuel lines were not replaced the actual requirement was only an additional 1/4 turn. five fuel leaks developed at different times due to the overterquing. Four pumps showed indications of cracking during non destructive emaninations (NDE). One pump fitting cracked during reassembly after the let.

Af ter consorsations with the Diesel Generator vendor and pump manufacturer, the most probable cause of the failure for the seized fuel pumps was the presence of foreign material in the pump. Tolerances are very tight in this type of pump, and even slight contamination can cause pump selaure. The fuel system lines are disassembled during the five year inspection. Although high standards of cleanliness are maintained.

It is possible that a small amount of contamination was introduced to the system.

The setted pumps were of similar serial numbers. (891217 and 891223), indicating that they were manufactured from the same lot. The failed pumps are being sent to the System Materials Analysis Department for a more detailed failure analysis. This report will be supplemented based on the results of the failure analysis. Because of the common mode f ailure implications, a potential part 21 Notification has been filed with Corporate Engineering for review of part 21 appitcability.

i D.

SAFETY ANALYSIS:

There were no safety consequences of this event. All of the failures occurred during a refueling outage.

In Modes 5 and 6. only one Emergency Diesel Generator is required per the plant's Technical Specifications. The 18 Diesel Generater was available and operable throughout the event. $1nce the failures can be attributed to activities during the refueling outage. the 1A Diesel Generator would have performed its intended safety function if required prior to the refueling outage. All of the failures were corrected prior to declaring the 1A Diesel Generator operable.

The injection pump selaures are attributed to problems encountered during installation and did not ef fect previous operability. The failures each occurred after only several hours of run time, approximately 10 hours1.157407e-4 days 0.00278 hours 1.653439e-5 weeks 3.805e-6 months and 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months respectively for the pumps. All other pumps installed on the 1A Diesel Generator have emperienced at least 40 hours4.62963e-4 days 0.0111 hours 6.613757e-5 weeks 1.522e-5 months of full load run time, and are not considered likely to f ail in a similar manner.

I (0525R/0064R)

l OtVIAI!ON llWE$7!$f!0N REPORT ftxt CONTINUAf!ON 5

Fem hav 2.0 !

4 I

FACILITY HAME D IR ** *"

PaGE

$t0VENTIAL REV!$10N

.1M, UNIT YEAR LARGER NUPGER i

A ran Nuclear Pasar Statian 01 6 01 1 91 0 01211 010 3

0F 0lJi TEXT

[nergy industry Identification System (t!!$) codes are identified in the tomt as (xx) i E.

CORRECTIVE ACTION $t i

All of the injection pump discharge fittings have been non destructively esamined by magnetic particle testing. All of the pumps which had either leakage er indications of cracking have been replsced. The maintenance precedures will be revised to readt a.

Tighten the nuts untti they are snug (metal to metal contact between the ferrule and seat).

E i'

b.

ilghten nuts approminately 1/4 turn more.

i The procedures will include a note which will allow the nuts to be tightened additionally if leahape esists l

during the maintenance run of the engine. AIR 454-225 90-04900 is tracking this procedure change.

The injection pumps which selsed have been replaced. The first replacement pump was subjected to a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months run after installation. The second pump to be replaced was subjected to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months of run time prior to being declared operable. All other spare injection pumps in storage at tyren Station with serial numbers similar to the failed pumps have been placed en held pending results from the failure analysis and potential part 21 Notification.

F.

RECURRING EVENTS SEARCH Aim AM&LY$1it a)

[y1l(T SEARCH (DIR. Ltal Q11L IIILE 06-01-84-032 18 Diesel Generator Fuel Oil teak 06-01-87-121 1A Diesel Generator Jerk Pump failure In addition, several fuel oil leak failures occurred on the 1A Diesel Generator during October of 1964 Braidwood DVR 20-2-89-044 documents a similar event.

b) 198U$TRY SEARCH (DPEX's NPRD11 i

A search through the Npil0$ Data tese revealed eleven reported failures of Cooper Bessemer Diesel

+

1 Generator fuel injection pumps, due to leakage at the pump discharges. Several of these included overtorquing as potential causes. The cerrective actions for these cases involved revising the installation procedures.

c)

M Five nuclear Work Roguests (NWRs) were identified for maintenance history on the Byron Station Diesel Generator fuel injection pumps.

)

M Bd9354 09-25-87 Replaced jerk pump due to fuel oli leak B55313 05-25-88 Replaced jerk pump due to fuel oil leak B55314 05-25-88 Replaced jerk pump due to fuel oil leak I

861445 10-19 48 replaced jerk pump and injection line D63773 02-10 89 Replaced jerk pump (0525R/0064R)

OtVIAi10N ! tnt 57IGAi1081 RtPORf fLXf CONTINuAi10N f arm Rev 2.0 s,

FACILITY N4pg bla = - a pagg

$tgutNTIAt

tV!$!0*f ETA tailf YEAR gamera pagett

-l Svran Nutlaar Pasar SLglign el 6 01 1 91 0 010 4 IDF 014 j 0l2l 1 ftXT Energy Industry identification System (t!!5) codes are identified in the tout as (xx)

F.

RECURRING [yENTS 11AACH Als ANALY11$2 (Continued) i d) 6MALY$11 7he.e,. hisi.,, as revie.ed and n. c on mode fenvre

. idenufied.

G.

COMPONENT FAlLUBE DATA:

MANUFACfutER Mg MDEL lANGER MFG PART NUfGER 8endia Corp. (0tM)

Type FOX-22 Inj Pump 10 73422-57 Cooper-Sessemer($PLR)

Fuel Injection Pump 2-50F-030-001 I

I H.

OTHER RELATED 00CLNENf t None.

EFFECTIVEM11 REVIEW t

1 Not required.

J.

ADDITIONAL DATA:

4 a)

Affected Technical Specification: 3/4.8.1.1.2 b)

Procedures DNP 3108-11 Replacement of Fuel Injection Pump (s) or Adjusting Shims to Meet kettvired i

Peak Firing Pressures on Olesel Generator c)

Cause Code: 013MM, XP9918 4

d)

Equipment Involved: 10001MA t

e)

Other: Fuel Injection Pump 4

(0525R/0064R)

e DEVIATION REPORT s

DYR NO.

90 - 022 01 06 STA UNIT YEAR ND-Form Pev 2J ;

PART1l TITLE OF DEVIATION 1A Diesel Generator Overspeed Trips DCCURRtD

,,pg,,,,,D Due to a Misaligned Butterfly Valve um a

$YSTEM AFFECTED PLANT $TATU$ AT TIME OF EVENT TE$ TING lY$

g gNo DG MODE 6

POWER (f.)

0 WORK REQUEST NO.

l X DE$CRIPTION OF EVENT During post maintenance testing the 1A OG tripped on overspeed several times. $1nce the DG was connected to the grid at the time, and no actual overspeed is possible, these trips were classified as spurious. The cause has been determined to be air flow over the butterfly valve causing it to move, and inistating a trip signal.

r POTENTIALLY $1GNIFICANT EVENT PER NSD DIRECTIVE A-07 YES NO g

g gy g 10EFR50.72 NRC RED PHONE l_

l NOTIFICATION MADE l

l l X l TIK RESPON$1BLE SUPERVISOR DATE PART2l OPERATING ENGINEER'S COMMENTS None.

NON REPORTABLE EVENT l X l NOTIFICATION 30 DAY REPORTABLE /10CFR.

REGION !!!

DATE TIME g

g 0We M L Malman 1/mo 12 @

5 DAY REPORT PER 10CFR21 l

l NSD DATE TIME ANNUAL /$PECIAL REPORT REQUIRED g

g IF AB0VE NOTIFICATION !$ PER 10CFR21 A.I.R. #

TELECOPY

.E.R.

CECO CORPORATE OFFICER DATE TIME PRELIMINARY REPORT COMPLETED AND REVIEWED D. Brindle 1/31/90 OPERATING ENGINEER DATE INVESTIGATION REPORT & RESOLUTION ACCEPTED BY STATION REVIEW

/

A7-f*

h,b I / 10 K

3=9 M RESOLUTION APPROVED AND I'

AUfHORI2ED FOR DISTRIBUTION A A 2 4 N_)

STATION MANAG DATE 86-5176 (Form 15-52-1) 11-20-85 DOCUMENT ID (0532R/0066R)

DEVIATION INVESTIGATION REPORT (DIR) s Fore Rev 2.0 i

facility Name Pg[

Jmjiggjaar Pasar Statlan 1 0F 0 4

Title ll 1A Diesel Generatar Oversaand Trias Due in a Mitalinned Rutterf1v Valva d

EVENT DATE DIR NUPSER REPORT DATE q

$EQUENTIAL REVl$10N i

MONTH DAY YEAR

$fA UNIT YEAR NUpBER pluPSER MONTH DAY--

YEAR 6

POWER 010 01 3 11 2 91 0 l 10 01212 0 11 2 15 9 lo 0l6 0 11 9 10

~

CONTACT FOR THIS DIR NAng TELEPHONE NUPSER AREA CODE P. O'Neill. Antistant Technical Staf f sunarvisar Ext. 2244 8l1 15 2l3l4l.151414l1 COMPLETE ONE LINE FOR EACH COMPONEN A URE DESCRIBED IN THIS REPORT CAU$E SYSTEM COMPONENT MANUFAC.

REPORTA8tE CAU$E SYSTEM COMPONENT MANUFAC.

REPORTABtt

_ TURER 70 NPRD1 TURER TO NPRD$

x EIK I si el y cis 13 14 Y

l l l l l l l l

1 1 I I I I I

I I I I SUPPLEENTAL REPORT EXPECTED PONTH DAY

((ML p

$UBMIS$10N

.71YESfifvu_ggeeleteEXPECTED$UBMIS$10NDATE) l NO l

i l

TEXT Energy Industry Identification System (E!!$) codes are identified in the text as (XX)

A.

PLANT C0peITIONS PRIOR 70 EVENT Event Date/ Time 1/25/90

/

Unit 1 MODE 6 Refuelina Rx Power _01 _

RC5 (A8] Temperature / pressure 120'f/Atmonebarie Unit 2 MODE 1

. _ Power Omaration Rx Power _981 _

RCS (AB) Temperature / Pressure Normal Omaratino B.

DESCRIPfl0N OF EVENT:

from January 25 through January 27,1990, the 1A Diesel Generator (DG) (EK) experienced two independent problems with the engine overspeed trip system. These problems were discovered during maintenance or troubleshooting runs of the Diesel Generator following a scheduled five year teerdown and inspection.

Following the five year inspection, the 1A Olesel Generator tripped 5 times due to spurious engine overspeed trip signals. Four of the trips occurred during maintenance or troubleshooting runs. One trip occurred during surveillance testing, af ter all testing requirements had been met. In all cases, the DG was synchronized with offsite power at the time of the trip signals. In a synchronized condition, an actual engine overspeed is not possible, and did not occur. The engine speed sensing circuitry did not show any unusual transients, It was determined that the cause of the spurious overspeed trip signals was movement of the turbocharger inlet butterfly valve away from its normally open position. This movement was in the direction of further opening the valve. The movement caused the valve's position sensing limit switches to actuate. The engine trip circuitry sensed this actuation as an engine overspeed trip.

The butterfly valve normally closes automatically when the engine experiences an actual overspeed trip.

The limit switches cause a redundant electronic engine.overspeed trip signal when the butterfly valve moves away from its normally open position.

(0532R/0066R)

i s

DEVIATION INVE$f!GATION REPORT TEXT CONTINUATION Form Rev 2.0 FAC[t!TY NAME DIR MUMBER PAGE j

5000ENTIAL REV!510N

..$1A

. UNIT YEAR _

NLNe[R

,389UL, 0 10 2

0F 0ld Jy.fon Nuclear power __11111on 01 6 01 1. 91 0 01212 itxt Energy Industry Identification System ([115) codes are identified in the text as (XX) l 8.

DERIEll0N OF EVENT: (Continued)

Af ter the spurious trip signal problem was resolved, an actual overspeed trip test was performed. During this test the engine tripped at the correct speed, however, the inlet butterfly valve did not auto-close as designed. The fuel supply to the engine isolated as destyned, causing the engine to shutdown. The cause of the failure was determined to be binding between the butterfly valve shaft and the remote reset mechanism. The problem was corrected, and the overspeed trip was satisfactorily retested.

The 1A Diesel Generator had not yet been declared operable following the five year teardown and inspection. The Unit remained stable throughout this event. No safety system actuations occurred.

Operator actions did not impact this event.

i C.

tAust or EVENT:

j The cause of the spurious engine overspeed trip signals was movement of the inlet butterfly valve away from its normally open position. The butterfly valve is normally in a horisental position. When the engine overspeed governor is actuated, the valve latching nochenism is released and a spring closes the valve.

Valve limit switches detect valve movement, and give the engine a redundant trip signal. For the spurious trips experienced, air flow over the valve disk caused it to move slightly in the direction opposite of normal closure. This movement was enough to release the valve limit switches, giving the engine an electronic trip signal. All of the trips occurred when the engine was at full load, when the intake air flow is maximited.

Prior to these occurrences, the valve did not experience this problem. Work performed during the five year teerdown and inspection may have affected either the air flew rate at the turbocharger inlet, or the inlet butterfly valve's orientation and linkage, although an exact cause cannot be positively identified.

The failure of the inlet butterfly valve to close during actual engine overspeed testing was caused by mechanical binding between the valvv shaf t and the remote reset mechanism. The remote reset mechanism consists of a pneumatic cylinder and linkage connected to the valve shaft. The linkage normally slides in a slot to reposition the valve af ter an autoclosure. This slotted connection had bound, preventing movement of the valve in the closed direction. :t cannot be determined if this condition existed prior to the engine teardown, or was the result of maintenance activities during the teerdown. The remote reset mechanism is not normally used at Syron Station.

O.

SAFETY ANALYSIS:

There were no safety consequences resulting from the spurious engine trips or the f ailure of the inlet butterfly valve to close on a actual engine overspeed. The redundant electronic engine trip resulting from the butterfly valve limit switches is bypassed when the Diesel Generator is operating in emergency mode.

The butterfly valve was not moving enough from its normal position to affect air intake flow beyond the engine's intake requirements.

The f ailure of the butterfly valve to close on an actual overspeed condition did not prevent the engine from tripping when required. The overspeed governor actuates both an isolation of fuel and intake air to the engine. In case of failure of the butterfly valve actuation, the isolation of the fuel supply is sufficient to shutdown the engine. There is a possibility that the eigine would continue to run on a mixture of lube oil and air. In this case, the air intake butterfly valve could be manually tripped closed.

Because the events occurred during maintenance and troubleshooting runs of the Diesel Generator, these are considered to be invalid f ailures per Regulatory Guide 1.108.

(0532R/0066R)

i DCV!ATION lWVt$T! GAT 10N REPORT TEXT CONTINUATION Fem Rev 2.0 FACit!TY NAME DIR NUMBER PAGE SEQUENT!At REVISION STA UNIT YEAR NL#efa NUpeER

_IE0n Nutlaar Power Station 01 6 01 1 91 0 012l2 010 3

0F 014 1[xi Energy Industry Identification System ([!!$) codes are identified in the tout as (KK)

[.

CORRECTIVE ACTIONS:

t to correct the problem of butterfly valve disk movement caused by air flow, the valve disk was rotated on its shaf t until the disk was tilted 3' of f horizontal towards the closed direction when the valve is latched in its normally open position. This is in accordance with Installation Instructions provided on the vendor assembly drawing for the valve. This prevents the valve from being forced off of its limit switches under high air flow conditions. This condition has not been experienced on the other Diesel Generators.

To correct and prevent recurrence of the mechanical binding of the reset mechanism, the linkage connecting the pneumatic cylinder to the valve shaft was removed under Minor Change M6-1-90-616. The linkage has also been removed on the IB Diesel Generator. Action Item Record 455-225-90-0047 tracks the removal of the linkape on the Unit 2 Diesel Generators.

F.

RECURRING EVENTS SEARCH AE ANALY115:

a)

EVENT SEARCH IDIR. LER)

No previous DVRs have been written due to problems with the Diesel Generator overspeed trip systems.

b)

INDUSTRY SEARCH (OPEX's NPRDS)

No similar failures were identified in the NPR05 search, a

c)

IfB

$1milar problems occurred with the 1A DG overspeed reset linkage in 1985 and 1988. At those times, the reset linkage was cleaned lubricated and adjusted to eliminate the binding. Previous Nuclear Work Request (NWR). numbers are B24330, 861411 and 961519.

d)

ANALYSIS No adverse trend identified.

G.

COMPONENT FAILURE. DATA:

MANUFACTURER NDPENCLATURE MDDEL NUISER MFG PART NUPSER Cooper-Bessemer Overspeed Butterfly Viv K5V-72-10 H.

OTHER ftELATED DOCUPENTS:

None.

(0532R/0066R)

r-DEVIATION INVEST!GAYl0N REPORT TEXT CONilNUAi!0N I

fore Rev 2 2.

FACILITY NAME D1R WuMBEA FAGE

$EQUENTIAL REVl$10N

$TA UNIT YEAR NUPSER NUPSER 012l2 010 4

0F 014

,8vron Nuclear Power Station 016 0 11 9 l.0 TExf Energy Industry Identification System (ElI$) codes are identified in the text as (xx) 1.

[FFECTIVENESS REVIEW:

None required.

J.

ADDITIDNAL_DA1A:

a)

Affected Technical $pecification: 3/4.8.1.2 b)

Procedures: None, c)

Cause Code: XCMUK, XCMM9 d)

Equipment involved: 10G01KA e)

Other: Overspeed Trip l

(0532R/0066R) l

r DEV!AT10N REPORT OVR NO.

01 89 - 141 06 STA UNIT YEAR 98. I Fern Rev 2.0

ARL,1_l TITLE OF DEVIATION OCCD.FD 11/9/a9 1814

.,_11'URIQU$ VIBRAf tDN TRIP OF 1 A DIEEEL GENERATOR DATE.

TIE

^

$YSTEM AFFECTED PLANT STATU$ AT TIME OF EVENT TE$ TING B71327 lYES

]NO M00E 1

POWER (1) 100 WORK REQUEST NO.

l X DG

~

DESCRIPTION OF EVENT The 1A D/G tripped following complotton of monthly DOS while unloading the generator. The unit tripped from approximately 2000 KW.

Tech $taf f is present to investigate the probles.

POTENTIALLY $1GNIFICANT EVENT PER NSD DIRECTIVE A-07 YES N0 g

g g,

10CFR50.72 NRC RED PHONE l

l NOTIFICATION MADE l

l l X l TIE RESPONRIALE SUPERVISOR DATE PART2l OPERATING ENGINEER'S COMTS NON REPORTA8LE EVENT

[

~, g NOTIFICATION 30 DAY REPORTABLE /10CFR REGION I!!

DATE TIME g

g 0

ma H 1 /89 0830

$ DAY REPORT PER 10CIR21 l

l NSD DATE TIME ANNUAL /SPECIAL REPORT REQUIRED g

g CECO CORPORATE NOTIFICATION MADE g

I A.I.R. #

TELECOPY L.E.R. #

Ceco CORPORATE OFFICER DATE TIM PRELIMINARY REPORT COMPLETED AND REVIEWED R. Henkins 11/13/89 OPERATING ENGINEER DAIE e 1

INVESTIGATION REPORT & RESOLUTION

//, 98 ACCEPTED BY STATION REVIEW

/ 2 v.f"- 81 g,

.., v SR TION M 9 STATION MANAGE DATE /

-5176 (Form 15-52-1) 11-20-85 DOCUMENT 10 (0477R/0060R)

. _ =.

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SUPPLEMENT TO DVR DVR NO.

D. 06 - 01

- 89 141

$TA UNIT YEAR NO.

PART 1 TITLE OF EVQ[1 OCCURRED

$purious Vibration Trip of IA Diesel Generator 11/09/89 1814 Due to raulty Vibration Trip $ witch DATE T!HE REASON FOR SUPPLEMENTAL REPORI Rarist saustal_erant and sataty analysis.

4 i

A N -

om oe se/s SUPPLEMENTAL REPORT APPROVED T

N

/

cSf'2Df?5

~

smlomNrcy om (0540R/0067R)

O OEy!ATION INy[$TIGATION REPORT (DIR)

Form Rev 2.0

4 facilft'y Name PAGE

_IyIAQ.Mttlt4I_fkEst_51319n 1 IQIJ_DM Title

_RV!Ll0VLYllMllDN TRIP OLjipl[KLGLil[Mt0R DUE TO _ FAULTY V1BRAfl0W TRIP $ WITCH EVENT DATE DIR NUPSER

. REPORT DATE

// $[QUENTIAL

// REVI$10N t1Q!(Iti. PAL ICAIL

_51A.Vtill IIAR_h

_ NUPEER h

NUteER MONTH DAY YEAR 1

POWER Il1 QJLjj9_9J6. 011 2 19 1 14 l 1 0l1 01 3 21 0 91 0 11010 CQt(IACT FOR THIS DIR NAME TELEPHONE NUMER AREA CODE L Schrock. Degratino Encinger Ext. 2216 8l 1l5 2l3l4l-l5l414l1 COMPLETE ONE LINE FOR EACH COMPONEN URE DESCRIBED IN THl$ REPORT CAU$[

$Y$ TEM COMPONENT P%NUFAC-REPORTABLE CAU$E SYSTEM COMPONENT MANUFAC-REPORTABLE TURER TO NPRDS.____

TURER TO NPRDS l

l l l_

l I l l

1 I l I l I I

I I I I I I l

I l I l SUPPLEMENTAL REPORT EXPECTED ti0 LIli ' AL1LA&~

EXPECTED

$UBMIS$10N DATE I

l l

l YES (if vin. complete EXPECTED $UBMIS$10N DATE)

X l N0 I

i i

TEXT Energy Industry identification System (E!!$) codes are identified in the text as (XX)

A.

PLANT CONDITIONS PRIOR TO EVENT:

Event Date/ Time 11/9/89

/ 1814 Unit 1 MODE 1 Power Operation Rx Power 100%

RCS [AB) Temperature / Pressure Normal Op.etatina Unit 2 MODE 1 Power Operation Rx Power 100%

RCS (AB) Temperature / Pressure Normal Ooeratino B.

DESCRIPfl0N OF EVEt(1:

On 9/13/89, while unloading the IA Diesel Generator (DG) (EK) following completion of the Monthly OperabIllty Surveillance (IBOS 8.1.1.2.a-1), the engine tripped from approximately 2300 kW.

The cause of the trip was a spurious actuation of the engine high vibration switch. The engine was restarted, fully loaded, and then unloaded. No vibration problems were observed. The following day, the engine vibration trip switch was recalibrated, and the Operability Surveillance was reperformed. A vibration analyzer was attached next to the trip switch, and the analysis showed no indication of a vibration problem at full load, during unloading, or during engine cooldewn.

On 10/12/89, with the engine running unloaded during the cooldown cycle following the Monthly Operability Surveillance, the 1A DG tripped due to another spurious actuation of the engine vibration switch. The following day, ancther vibration analysis was performed. The engine once again tripped due to the vibration trip switch, although no vibration problem was indicated.

On 11/9/89, prior to the Monthly Operability Surveillance, the vibration trip switch was recalibrated to a slightly lower sensitivity. While unloading the 1A DG following completion of the Monthly Operability Surveillance, the engine once again tripped f rom approximately 2000 kW, due to the vibration trip switch.

Since no actual vibration problem existed, and the engine vibration trip is bypassed during emergency mode operations, the lA DG was ceclared operable per On Site Review 0$R 89-256. The engine vibration trip switch was then adjusted to its lowest sensitivity. Another vibration analysis was performed.

No components were inoperable prior to the engine trips, and no Safety System Actuations occurred.

(0540R/0067R)

i DEVIATION INVESTIGATION REPORT TEXT CONTINUAfl0N o

F o rm Rty_Lp.

FACI (ITVNAME DIR__Ny!g[R PAGE

$[QUENTIAL REVl$10N STA

.11tf1T_

YEAR

_ NuteER

_NyrgL 0l1 2

pf 013 1l4l1

.9stofLHuiltAr fDFtE_litt10n Q_jl 01 1 81 9 TEXT Energy Industry Identification System ([!!$) codes are identified in the text as [XX)

C.

CAUSE OF EVIgI:

The cause of the engine trips was a faulty vibration trip switch. Enemination of the failed switch showed no visible abnormalities. The switch could not, however, be calibrated with repeatable results. The root cause of the switch failure remains indeterwinste.

D.

SAFETY A % Qil$t There were no safety consequences resulting from the engine trip, or f rom the f ailure of the engine vibration trip switch. There was no vibration problem with the Diesel Generator. The vibration trip is bypassed during emergency mode operations, and does not affect Diesel Generator operability or reliability. This is considered an invalid f ailure, per Regulatory Guide 1.108.

l E.

LORRECTIVE ACT10E$:

The engine vibration trip switch for the 1A Diesel Generator will be replaced and properly adjusted under NWR B71327. Action Item Record (AIR) 454-225-89-30200 will track the completion of the switch replacement. Based on the Diesel Generator manufacturer, the engine vibration trip is designed for catastrophic failures. As such, the vibration switch sensitivity may be decreased further if the problem persists.

F.

RECURRING EVENTS SEARCH AND ANALY1H; l

a)

EVENT 1EARCH (DIR. LER) l l

DVR 6-2-87-114 2A Diesel Generator failed Due tJ High Vibration Alarm DVR 6-1-88-160 1B Diesel Generator Trip on Spurious Actuation of Vibration Instrumentation There have been other spurious actuations of the DG engine vibration trip switches, which did not result in testing failures.

b)

INDUSTRY SEARCH (OPEX's NPRDS)

Four similar occurrences were found in the NPRDS search, c) tDfR 4

Due to previous problems with the vibration trip sensitivity. the switches had been disabled from j

1984 to 1988. Work history shows a number of calibrations for these switches, d)

ANALY$U Trend 89-015 was initiated on 10/16/89.

H.

ML20033G769

Text

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