ML20024G680

LER 91-010-00:on 910322,unit 1 Operated Outside Tech Spec Due to Auxiliary Feedwater Sys Test Line Isolation Valve Not Closed.Root Cause Not Determined.Providing Addl Guidance to Operators & Operators Monitoring valves.W/910422 Ltr

ML20024G680
Person / Time
Site:	Comanche Peak
Issue date:	04/22/1991
From:	William Cahill, Hope T TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-91-010, LER-91-10, TXX-91143, NUDOCS 9104240049
Download: ML20024G680 (7)

Text

- - - - - - - - -

9..--....._-... . . . , , , , .. . . . .

Z C Log i TXX-91143 71/ELEC7RlC File # 10200 Ref. # 50.73

% !!!iarn J. Cahlit. Jr. 50.73(a)(2)(i)

I:sn utnt h e htmknl April 22, 1991 U. S. Nuclear Regulatory Comission Attnt Document Control Desk Washington, D. C. 20555 SUBJECTS CONANCHEPEAKSTEAMELECTRICSTATION(CPSES)

DOCKET NO. 50-445 CONDITION PROHIBITED BY THE PLANT'S TECHNICAL SPECIFICATIONS LICENSEE EVENT REPORT 91-010 00 Gentlemen:

Enclosed is Licensee Event Report 91-010-00 for Comanche Peak Steam Electric Station Unit 1. " Unit 1 Operated Outside Technical Specifications Due to Auxiliary Feedwater System Test Line Isolation Valve not Fully closed."

Sincerely, W. J. Cahill Jr.

Bys ..f<l6 /A//  !

W'. G. 6~uldemond_ /

Manager, Site Licensing JAA/bm c - Mr. R. D. Martin, Region IV Resident Inspcctors CPSES (3) 400 North Olise Street Lil 81 Dallas,1exai 75201 9104240049 910422 PDR ADOCK 05000445 / l 6 PDR

. Enclosuro to TXX 91143 Nis SOHW ase' V 6 NuctLAR HLOAAIOHV (OWWif 60N APPROW D OUD NO. 31201D4

. LKPIR[& 4'092 ESTNATLD BURDCN PER RE $PONSE TO COMPLY WITH THIS INFORMAIlJN COLitCTON REQUEST: 600 HRS, FORWA*O COWWINTS REGAr.Otw I

' " " ' " " ' " ' ' ' ' ' "' "5 "'**"'"""'""'"'

LICENSEE EVENT REPORT (LER) 6 RANCH (P 630h U.S. NUCL( AR Rt OJL A1OHY COMW bSSON, WASHINGTON.

3C. 70666. AND 10 THE PAP (RWORK REDUCTON PROJECT ($tS0104) 0FFICE OF uANAGEWLNT AC 9UDGEt. WASHINGTON DC.#0601 l

1

,,~.m a., ~-.na r o, i COMANCHE PEAK - UNIT 1 0l51010101414l5 1 I or 10i6 UNIT 1 OPERATED OUTSIDE TECHNICAL SPECIFICATIONS DUE TO AUXILIARY FEEDWATER SYSTEM TEST LINE ISOLATION VAL VE NOT FULLY CLOSED ,

t ,- 0,.. n. - - . - n... m ow .- ~, o.,

%* *yg**

uw o., v, o.,

v., t'r,' uo,iin v. ,

jlb31010l l I l 013 212 91 911 01110 -

Olo 014 212 9 11 N/A 0151010101 1 I

%,.,,, 1, ... .. ~ . i.~ . ..ioa y oc m . oio uou m ' 5 _ nan _ n<w _ Er*nm _ nism .

Fo 90.36(c)(1) 60.7ha)(atv) 7171(c)

_ 20 406(.)(1H4) _

)

hY 01010 -

" '0*x'HS 20.406(.)(1Hid) 3 E73t.MaM 57***#

E7%.)(2(veMA)

• • 48'**',******"d*'"'-

NHC Fo m MA) m 9 %, . 20 40bxiHiv) _ E73(a)(FH4 _

60,7haXa(v4(9) enm.m m trem &n rh.m.)

Lkone Cont.d Fe, The. LE R (12)

N.,,,. r u-.,

T. A_ HOPE COMPLIANCE SUPERVISOR C ,  % t .., c a, c F.$, o-,~, .,1, 8I1 I7 8 I 917 l- l 6131710 R. n 3, c sni com u.,,s ,

,a gg 3 s c sn*,, com- u.,s a*gg m>

i  ; j i l l l gap l l l ;  ;; ; ly 4 i l l l l l l "WK l l l l l l l V5<

s, n , c. .w.) t ~,, tw v.-

s- .

O v- * < . w r a.a.d - ,0.i.i CD a. 1 I I A,. it- u00. - t... - ,.l., , , ,, ..,o.,>n.)

On March 22,1991, an Auxiliary Operator discovered the Train B Motor Driven Auxiliary

' Feedwater Pump Recirculation Test Line Isolation Valve one_ quarter turn open. _The valve was last operated on March 13,1991, during an Auxiliary Feedwater operability test With the valve one quarter turn open, auxiliary feedwater flow is 8 gallons per minute less than assumed in the safety analysis; therefore, Train B Auxiliary Feedwater was inoperable from March 13 until the valve was closed on March 22. This exceeded the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Technical Specification Action Statement for one auxiliary feedwater pump or associated flow path inoperable.

-The root cause for why the valve was not fully closed could not be determined. Possibilities include the Operator falling to fully close the valve when restoring from the test, the valve being disturbed after it was closed on March 13, or vibration causing the valve to slightly back off its seat. Corrective actions include providing additional guidance to Operators on ensuring these type of valves are closed, having Operators monitor these type of valves during the next pump runs, and having Engineering take vibration readings on the valve.

- . - - - _ _ - . - _ _ _ . - - _ - . - - . - - _ ~

. Encio.sure to TXX 91143 hua ,ong yd u 6. evdat An htuJL A10HY umWibbevN Appio g a3 p 181%IAft D DJ4DE N PE R RE SHONSE 10 COMPLY WITH TH15 PF04:dATION LICENSEE EVENT REPORT (LER) MC"U,'g *,'; yy *,"* ', g,'"3 gg',33, TEXT CONTINUATlON Sg*gf 73,"o ,"f*g,","Z'gflg,"l,'Oc*'g%

sset or uav.mut=1 Awa Dutm. nasumica te nos 6 aces; M as p) ;hAas Wnte A tt 4 Anne ,o f's.o (m m' Wi? t.:

COMANCHE PEAK - cUNIT 1_0151010101414 l 5 911 -

0l110 -

010 012 OF 016 i ..u. ~. . - . ~ .m a

1. DESCRIPTION OF THE REPORTABLE EVENT A. REPORTABLE EVENT CLASSIFICATION Any operation or condition prohibited by the plant's Technical Specifications.

B. PLANT OPERATING CONDITIONS PRIOR TO THE EVENT On March 22,1991, Comanche Peak Steam Electric Station Unit 1 was in Mode 5, Cold Shutdown, with reactor coolant temperature at 135 degrees Farenheit and pressure at 325 pounds per square inch gage. Steam Generator 04 (Ells:(SG)(SB))

was being filled with the Train B Motor Driven Auxiliary Feedwater Pump (MDAFW)

(Ells:(P)(BA)).

C. STATUS OF STRUCTURES, SYSTEMS, OR COMPONENTS THAT WERE INOPERABLE AT THE START OF THE EVENT AND THAT CONTRIBUTED TO THE EVENT There were no inoperable structures, systems or components that contributed to the event.

D. NARRATIVE

SUMMARY

OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES At 0145, March 22,1991, while filling Steam Generator 04, the Auxiliary Operator (AO)(utility, non licensed) heard an unusual noise in the vicinity of the Train 8 MDAFW Pump. Investigation determined that 1 AF-0055, Train B MDAFW Pump Recirculation Test Line Isolation Valve (Ells:(ISV)(BA)), was one quarter turn open.

The valve was closed and the noise stopped.

1 AF 0055 was last opened during an Auxiliary Feedwater operability test on March 13,1991. The valve was opened, closed and independently verified closed at the conclusion of the test. There have been no work clearances or tests performed

. between March 13,1991, and March 22,1991, that would require 1 AF 0055 to be operated.

l

'r Enclosuro to TXX 91143 h4CfOttWSo6A U.6 NJut Alt entnA.AIOHV Glasvit.6uh APP 8 M D W h M $ @ W (BilMATE D BJ80f N Pf R 84 h bt T C W8*LY Wif H THit IN80flWATON LICENSEE EVENT REPORT (LER) gj,C'g,a',y

, 8'; ,","$$c j, n",*,','S Q'j,"j';'l'(,',

TEXT CONTINUATlON i O,%',g',",'"g4',L'C*L'Oc*$7%

O'%'

35 81CE OF WANAQtWLNT AND DJDGEt WARHINoinst to 30!Ko eecsay Name 0 Jun.i Nene (b L4 R N n Fap M COMANCHE PEAK - UNIT 1 0l51010l0l414l5 9l1

. . ~. .,~. w oa .m r, 0l1l0 -

0:0 013 OF 0l8 i..n.

The valvo is operated by a floor stand with a 24 inch diameter handwheel. There are three drive shafts connecting four gear boxes from the hand wheel to the valve. The handwheel is required to be tumed counterclockwise to close the valve and this is clearly labeled. Also, due to the diameter of the handwheel and the gear reduction, the use of a leverage device is not permitted. The valve was opened and closed for this evaluation by the AO (utility, non licensed) that operated the valve during the March 13 test. The valve stroked without the need of a second person or leverage device. The closing feel was

• spongy" due to the extensive linkage, but there did not appear to be any binding or extraordinary effort required to close the valve.

An engineering evaluation determined that with 1 AF 0055 one quarter turn open, flow from Train B MDAFW Pump would be 8 gallons per minute less than assumed in the safety analysis; therefore, Train B Auxiliary Feedwater was inoperable from March 13 to March 22, when 1 AF 0055 was closed. CPSES Unit 1 Technical Specifications require three independent steam generator auxiliary feedwater pumps and associated flow paths be operable during modes 1,2, or 3. Unit 1 was in modes 1,2, or 3 from March 13 to March 20; therefore, the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Action Statement for one auxillary feedwater pump or associated flow path inoperable was exceeded.

E. THE METHOD OF DISCOVERY OF EACH COMPONENT OR SYSTEM FAILURE OR PROCEDURAL ERROR The AO heard an unusual noise in the vicinity of the Train B MDAFW Pump.

Investigation determined that 1 AF 0055 was one quarter turn open.

II. COMPONENT OR SYSTEM FAILURES A. . FAILURE MODE, MECHANISM, AND EFFECT OF EACH FAILED COMPONENT No failed components contributed to this event.

B. CAUSE OF EACH COMPONENT OR SYSTEM FAILURE No failed components contributed to this event.

4 F.nclosure to TXX.91143 woonu 3.u u uu Aa nic.a.aioam=w$sou ,,, n c., ,o ,, m, t StIMAYL D DJH:( h PL R ht & SL 10 MMV Wf H THis INI04WA?UN LICENSEE EVENT REPORT (LER) $. jfy'7",,"2'l$'; ,7 "'l$

, c gy% ?l@' / ,gl$,j, TEXT CONTINUATlON Q^%f O L',!l P ,.c" "Z'.,'W ASHINGtON.

J fICf OF WANAQtWLNT ANDILKiGEY CC Ritc3L*,

..,,,.n, - .. . m an~~ r. a

- tw g COMANCHE PEAK UNIT 1 01510101014I4l5 911 -

0I110 -

010 014 OF 016

..n. ~. . . . .. . - w .oa ., o n C. SYSTEMS OR SECONDARY FUNCTIONS THAT WERE AFFECTED BY FAILURE OF COMPONENTS WITH MULTIPLE FUNCTIONS No failed components contributed to this event.

D. FAILED COMPONENT INFORMATION No failed components contributed to this event.

111. ANALYSIS OF THE EVENT A. SAFETY SYSTEM RESPONSES THAT OCCURRED There were no safety system actuations associated with this event.

B. DURATION OF SAFETY SYSTEM TR AIN INOPERADILITY Train B MDAFW Pump was inoperable from March 13 through March 22.

C. SAFETY CONSEQUENCES AND IMPLICATIONS OF THE EVENT The Auxiliary Feedwater System (Ells:(BA))is designed to provide a supply of high-pressure feedwater to the secondary side of the steam generators for reactor coolant heat removal following a loss of normal foodwater. After a loss of the main feedwater system (Ells:(SJ)), either the two motor driven auxiliary feedwater pumps together, the turbine driven pump alone, or any combination are capable of providing sufficient flow to the steam generators to allow the plant to be taken to a safe shutdown condition.

The Train A MDAFW Pump and the Turbine Driven Auxiliary Foodwater Pump (TDAFW) (Ells:(P)(BA)) were operable during the time that the Train B MDAFW Pump was inoperable; therefore, the Auxiliary Feedwater System could perform its intended safety function. At no time did a condition exist that required the operation of the Auxiliary Feedwater System to mitigate the event. At no time during this period did an actual condition exist that threatened the health or safety of the public.

l

. Enclosure to TXX 91143  ;

N6C 90HW stud W & MCLLA84 64UUL ATOHV OUWW4hlON APPROW D OMB W 3%W (KPl8CS 47A1Rt

($1sAtt0 DURD( N PC A lit $PONSE f 0 .10MPLY wif M tHis INr onuAioN LICENSEE EVENT REPORT (LER) *',*y,",',T*,';

o, gf'foo',o,*,'ggjffy, a

TEXT CONTINUATION

• • • ""*'"'**""'""'""','"'c*****""'"'"-

1 20665. AND TO THE PAP (RWORK RCDUCTON PROJECT ($@pnq 35 FCE Or MAN 40t utN1 AND BJurt WASHINGIUN, DC.#0603

. .., N,. o , - .m a a .., i., P.,,. a

~  %~2 mm:

COMANCHE PEAK - UNIT 1 1..n ~. ... ~,.. -,..N<,5- w .,on 0151010101414l5 911 -

0l110 -

010 015 OF 018 l

IV. CAUSE OF THE EVENT 1

( ROOT CAUSE 1

l The investigation could not determine how the valve became one quarter turn open; however, three possibilities are:

1. The AO and independent verifier failed to fully close the valve when restoring from the test on March 13,1991.

2. The valve was disturbed after it was closed on March 13,1991.

3. Vibration caused the valve to slightly back off its seat.

V. CORRECTIVE ACTIONS

CORRECTIVE ACTIONS TO PREVENT RECURRENCE

. ROOT CAUSE (POTENTIAL)

1. The AO and the independent verifier (utility, non licensed) failed to fully close the valve when restoring from the test on March 13,1991.

CORRECTIVE ACTION A Lesson's Learned memo has been issued to Shift Operations personnel describing the problem as well as additionalinstruction to ensure that the auxiliary feedwater pump recirculation test line isolation valves are closed.

2. The valve was disturbed after it was closed on March 13,1991.

l

,_ ,__._ ___. , - , _ _ _ , . , . . - _ _ , . _ _ _ . , . . . . - - . . . _ . . . - , . . - _ . ~ . , . ~ - . . . - _ . _ _ _ _ _ . , - . _ _ _ . _ _ _ . , . . . - , , , . _ .

Enclosure to TXX 91143 NHg iO6ty ;nA U S NJud Alt itt OJLA10HY (4WWibbE)N ggg,I M D(WB O W W L $1IWATL D DVQ N PE A RE b N501 ( Wl'LY WlTH THIS PdOF4WA10N LICENSEE EVENT REPORT (LER)  ;%, 'n',C",,"j";',",';

, ,$'",',*co'ng'*3 Tl@,1(jfs,

'""**""^*""'*"'*

TEXT CONTINUATION 30. 20666. AND 10 THE PAPI RWOilK

""'" " '" ' "" " '" "'"".ft[ DJCT ON P ROJL C J f CE (# WANAGEWEN" AND SJDQL1 W ASHINGf ON, DC Mc3 i . u, N. . oi w N-. g, a a Nm. i., r. os

'e= W;f 1 M:

COMANCHE PEAK tJNIT 1 0l5101010l414l5 9l1 -

Ol110 -

0IO Ol6-OF 0I6 i..n. ~. . . . .- . .~. N.c 5.,- ., o n CORRECTIVE ACTION No additional corrective actions can be added to the above actions. The Lesson's Learned memo will make operators more sensitive to these valves.

3. Vibration caused the valve to back slightly off its seat.

CORRECTIVE ACTION Auxiliary Operators will check 1 AF 0055 the next two times the Train B MDAFW Pump is run with 1 AF 0055 closed to determine the possibility of a vibration problem. This check will also include 1 AF 0042, Train A MDAFW Pump Recirculation Test Line Isolation Valve and 1 AF 0069, TDAFW Pump Recirculation Test Line isolation Valve.

A Lesson's Learned memo has been issued to alert Shift Operations personnel of the possibility of auxiliary feedwater pump recirculation test line isolation valves vibrating open. It also alerts Operators of ways the test valves can be monitored to be closed and to be aware of the sounds in the auxiliary feedwater pump rooms.

Engineering will take vibration readings on 1 AF 0055 during the next Train B MDAFW Pump run test. If vibration is determined to cause valve movement, then additional corrective actions will be taken to secure the valves.

VI. PREVIOUS SIMILAR EVENTS There have been no previous similar events reported pursuant to 10CFR50.73.

Vll. ADDITIONAL INFORMATION The times listed in the report are approximate and Central Standard Time.

._ - ____-__ _