ML19325C487

LER 89-018-00:on 890829,both Trains of Control Area Ventilation (VC) & Chilled Water (Yc) Sys Declared Inoperable.Caused by Equipment/Failure Malfunction. Refrigerant Added to Vc/Yc chiller.W/890928 Ltr

ML19325C487
Person / Time
Site:	McGuire
Issue date:	09/28/1989
From:	Mcconnell T, Sipe A DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-018-02, LER-89-18-2, NUDOCS 8910160310
Download: ML19325C487 (7)

Text

- - -

y. - >

c ,:-

f e s

. Duke hwer Cornpany (704)FIHC00 McGuirr Nuclear Statson

~ ?O Box 488 Cornelius, N C 280314488 DUKEPOWER September 28, 1989 U.S. Nuclear Regulatory Commission e Document Control Desk Washington, D.C. . 20555

.~

Subject:

McGuire Nuclear Station Unit 1 and 2  ;

H Docket No. 50-369 Licensee Event Report 369/89-18 Gentlemen:-

l Pursuant to 10CFR 50.73 Sections (a)(1) and (d), attac.ed is Licensee Event Report 369/89-18 concerning botn trains of the Control Area Ventilation and Chilled Water  ;

system being inoperable because of equipment failure. This report is being C h 4t mitted in accordance with 10CFR 50.73(a)(2)(1)(B). This event is considered to be of no significance with respect to the health and safety of the public. ,

Very truly yours,

/ A dl .' '

7 T.L. McConnell DVE/ADJ/cb1  !

Attachment ,

xc: Mr. S.D. - Ebneter American Nuclear Insurers l Administrator, Region II c/o Dottie Sherman, ANI Library U.S. Nuclear Regulatory Commission The Exchange, Suit 245 101 Marietta St., NW, Suite 2900 270 Farmington Avenue Atlanta, GA 30323 Farmington, CT 06032 INPO Records Center Mr. Darl Hood Sc'te 1500 U.S. Nuclear Regulatory Conj 3sion 4 1100 Circle 75 Parkway Office of Nuclear Eractor Regulation Atlanta, GA 30339 Washington, D.C. 20555

l. M&M Nuclear Consultants Mr. P.K. Van Doorn L 1221 Avenue of the Americas NRC Resident Inspector '

l New York, NY 10020 McGuire Nuclear Station l

l i

.TM' \

t t 8910160310 890928 ADOCK 05000369 JDR cm _ _.

t 7, g o.

. - LER Cover latter y, Pdge 0, t

j .; .bxc: B.W. Bline

{ A.S. Daughtridge;

!' R.C. Futrell R.L. Gill R.M. Glover (CNS)

- T.D. Curtis (DNS)

-P.R. Herran S.S. Kilborn (W)

!' . S.E. LeRoy l R.E. Lopez-Ibanez

! J.J. Maher R.O. Sharpe (MNS)

G.B. Swindlehurst

'K.D. Thomas L.E. Weaver

'~

R.L. Weber J.D. Wylie (PSD)

J.W..Willis QA Tech. Services NRC Coordinator (EC 12/55)

MC-815-04 (20) l-i i

9 s

b i

!., .. l L .  !;

e u on... ....L. . v

• • ' amovee om i.e. eignini

l. 8"** r8t's LK;ENSEE EVENT hEPORT (LER) }

t ooCast umeen m -.m  :

T . Lee, m McGuire Nuclear Station, Unit 1 oIsIoloIo13g6 i9 S l0Flo I 5

"* '* Both Trains Of The Control Area Ventilation And Chilled Water System Were Declared i I

l fnnnerah:a Racanne Of Enufa= ant Failure otwin enciLives wvolvto ei l tvsNT oars e Lea asumosa ce, mePont oave tri

C'b DOCkt T NU#DtN8' f MONTM Day Vlam vtan  %$j',4 7,% MONYM Det vlAR McGuire , 'TUnit 2 v hawl8 o is,o g o g o ,3,7 i0 0 l0 0l9 2l8 8l9 o,g,o,o,o, 0l 8 2l9 89 8l9 0 l1l8 twe me. car e eveWirtIo Punova=, eo eat niovineutiers o, i C,a e ,C ., . ., ea, e.u. ,, iiii "o**

• I nw n .nw nonwans _

nnw n ewmm unem wni.nsim nmm go.,

m towmm n=wm

.a ni.nsn.c gagsy,gg,, , ,

i i _ _ _

ma,

, m mwmie 1 wnwmm _

mnwmi unai n wnns _

anem. _

.ni.imi nei f M .mlenilm 90 7Seeutnull M 73ien2Hal LICGNSit CONT ACT 908 TMit Lth (12)

YtLtPMONE NUW9tM NAMS a+taCoot Alan Sipe, Chairman, McGuire Safety Review Group 7,04 i 8,7 i Si4 i i 1,8 i3 COMPLtit ONE LING POR SACM C0 asp 0estNT f AILuht Ditcm4tD IN THet herom? 1131 MA C. m Rf08,f,'jg t CAvst sv8ttu Cout0NENT 0,m tpaI' '

Cault Sysitu COMPONENT Wa% AC.

I I I i i 1 l l t i I I I I I l l i 1 I l l 1 I i i l i I MONTH D&v Yt&R SipPLSM4NTAL htPont tutCTOD lie vtS H ves ..mpo.e. tJrPICitO 8veutS$tonr OATil f No,o.,

l l l

- - . ,, .y , - .N - ,...,

,..C,a .. . . e...

On August 29, 1989 at 0930, Operations personnel secured Train A of the Control Area Ventilation (VC) and Chilled Water (YC) system because the current for the Train A VC Chiller was fluctuating due to improper refrigerant level. At 0930, r Operations personnel started Train B of the VC/YC system and the Train B VC/YC Chiller tripped on a Lo Flow Alarm. Operations attempted to start Train B of VC/YC a second time and it would not start. At 1000, after Mechanical Maintenance personnel added refrigerant to the Train A VC/YC Chiller, Operations personnel declared Train A of VC/YC operable. At 1004, Operations personnel failed open the Nuclear Service Water Supply valve to Train B VC/YC Chill.er and successfully ,

started Train B of the VC/YC system. Unit I was in Mode 1, Power Operation at 48 percent power, and Unit 2 was in Mode 5, Cold Shutdown, at the time this event was discovered. This event is assigned a cause of Equipment Failure because.the Nuclear Service Water Supply valve failed to open as required on a start of Train B VC/YC system Chiller. Mechanical Maintenance personnel repaired a guide vane seal leak on the Train A VC/YC Chiller. Operations personnel will make appropriate procedure changes concerning the operation of the VC/YC Chillers.

t 4

us uca na neou utomv on  !

me asia . .o=

UCENSEE EVENT REPORT MR) TEXT C^NTINUATION maovio ow o mo-m. ,

weni o w s paceUTv asaast m oocett, seuesten m g ,gy,,,,,g, vs.m 68 Q[,*4 .Q4g,4 McGuire Nuclear Station, Unit 1 o lslololol3l 6l9 8l 9 -

0l 1l 8 Og 0 0l2 or 0 l5 vsc - w. a .ww. .mm me e amm nn L f EVALUATION:

Background

The Control Area Ventilation (VC) (EIIS:VI) and Chilled Water (YC) [EIIS:KM] system is designed to maintain the environment in the Control Room [EIIS:NA), Control Room Area and Switchgear Room, within acceptable limits for safe occupancy of the Control Room during plant operations and following post accident shutdown. Based on these criteria, the system is designed as an Engineered Safety Features (ESF) system with absolute and carbon filtration in the outside air intakes and with l

equipment redundancies for use as conditions require.

Two 100 percent redundant air handling systems are provided for the Control Room, Switchgear rooms, and the Control Room area (equipment rocms, cable room, battery room, etc.). The air handling units [EIIS:ANU) are provided with chilled water

, f.om the YC system. Two Control Room pressurization fans (EIIS: FAN] and filter '

l -[EIIS:FLT] trains are provided for pressurization of the Control Room, to prevent entry of dust, dirt, smoke, radioactivity, etc., originating outside the Control Room. Air filtration is provided by prefilters on all air handling units.

Instruments are provided for temperature control and indication, and to indicate radioactivity levels. Smoke alarms [EIIS: ALM] are also provided.

Technical Specification (TS) 3/4.7.6 includes requirements that in Mode 1, Mode 2, Startup, Mode 3, Hot Standby, and Mode 4 Hot Shutdown, with one train of the VC/YC system inoperable, the inoperable train must be restored to operable status within seven days or be in at least Hot Standby within the next six hours, and in Cold Shutdown within the next thirty hours. With both trains of VC/YC inoperable with the unit in Mode 1 the specified action is to comply with TS 3.0.3. TS 3.0.3 requires that within I hour the unit must be placed in a mode in which the TS does j not apply. TS 3.7.6 applies to both Unit 1 and Unit 2 because the VC/YC system is l shared by both units.

Description of Event On August 29, 1989 at approximately 0900, Operations Control Room personnel noticed the Train A VC/YC Chiller [EIIS:CHL] current fluctuating. Mechanical Maintenance ,

(MM) HVAC personnel were contacted to investigate and determine the reason the current was fluctuating. At approximately 0920, MM HVAC personnel determined that -

H Train A VC/YC Chiller had improper refrigerant level and would need to be removed from service so that refrigerant could be added to the Chiller. The MM HVAC Supervisor informed the Operations Shift Supervisor that Train A VC/YC Chiller could be damaged if it continued to run. At 0928, Operations personnel removed the Train A VC/YC Chiller from service, declared it inoperable, and attempt'ed to swap to Train B of the VC/YC system. After Operations personnel started Train B VC/YC Chiller, it ran for approximately 2 minutes and tripped on a Lo Flow Alarm.

Operations personnel attempted to restart the Train B VC/YC Chiller but it would not start because of the Lo Flow Alarm. At 0930, Unit 1 entered TS 3.0.3 because both trains of VC/YC were inoperable. At 0930, Operations personnel implemented procedure AP/0/A/5500/39, Control Room Hi Temperature, when both trainr. of VC/YC became inoperable.

w... no, m , e m mow

g ,ow m.

k, .

.m. a uc u ...u m . ,i

• • " **eaonoom =o mo-om UCENSEE EVENT REPORT (LER) TEXT CONTINUATION EAPtMES. $'31/5 F40648YY .sa t tte Dockii souheth set L84 8vM94R * **04 m

"*a "buh" 57.1T0 McGuire Nuclear Station, Unit I r;l6 j o l 0 j o l 3 l 6l 9 8j 9 _

0l 1l8 _.

0 l 0 0 l3 or 0 l5 mru- . w. mesm.mm At 1000, the MM HVAC Supervisor informed Operations personnel that refrigerant had been added to the Train A VC/YC Chiller and it was now operable. At 1000, Unit I exited TS 3.0.3 because Train A of VC/YC was declared operable.

Further investigation by Operations and MM HVAC personnel determined that valve

[EIIStV) 1RN-460, Train B VC/YC Chiller Nuclear Service Water [EIIS:BL) (RN) supply, had failed to open causing the low flow alarm. Operations personnel failed valve 1RN-460 to the fully open position.

At 1004, Operations personnel started Train B of VC/YC successfully. MM HVAC personnel informed Operations personnel that with valve IRN-460 failed open Train B of VC/YC was operable. Operations personnel declared Train B of VC/YC operable at 2004. At 1100, Operations personnel exited from the Control Room Hi Temperature procedure because both trains of VC/YC were operable.

On September 6, 1989, Instrumentation and Electrical (IAE) personnel using Work Request (WR) 139609 investigated the reason that valve IRN-460 did not open on a start of Train B VC/YC Chiller. IAE personnel along with Onerations Control Room and MM HVAC personnel secured the Train A VC/YC Chiller and started Train B VC/YC Chiller with valve IRN-460 working off the controller. Valve 1RN-460 opened as required when Train B VC/YC Chiller was started. No problems were identified and WR 139609 was signed as completed on September 7, 1989. Operations personnel restored valve 1RN-460 to the normal operating condition on September 10, 1989.

Conclusion This event is assigned a cause of Equipment Failure / Malfunction because valve 1RN-460 failed to open as required to supply RN system water to the Train S VC/YC Chiller. The cause of the failure could not be determined during this investigation. WR 139609 was written ta determine the cause of the failure of valve 1RN-460 to open on a start of Train B VC/YC Chiller. IAE, MM HVAC, rnd Operations personnel secured the Train A VC/YC Chiller and started Train B Chiller.

Valve 1RN-460 opened as required. IAE personnel verified that the controller for valve IRN-460 operated properly. IAE personnel ensured that all the circuitry for valve IRN-460 was working as required on a start of Train B of VC/YC. Valve 1RN-460 has not been the cause of any Train B VC/YC failures in the past.

Train A of VC/YC was shutdown because of improper refrigerant level causing a fluctuation in current. A guide vane seal (EIIS: SEAL] leak was causing the loss of refrigerant level. MM HVAC personnel repaired the guide vane seal leak and added refrigerant to Train B VC/YC Chiller. MM HVAC personnel stated that they could not recall having any previ>us problems with refrigerant lesks caused by guide vane seal leaks. The guide vane seals are checked as part of the Preventat!.ve Maintenance for the VC/YC system chillers.

On August 29, 1989 at approximately 0400, Operations personnel began the alignment for the portion of procedure PT/2/A/4200/09A, ESF Actuation Periodic Test that aligned the VC/YC system chillerr, in series. Nor.nally the VC/YC Chillers are operated in parallel. The VC/YC system operated in the series mode until the decision was made to shutdown Train A of VC/YC and start Train B of VC/YC. Train b u cre e -e

.eccoa. m .

1 eut emai nen u s mucLam t:vu. tony commission' LICENSEE EVENT REPORT (LER) TEXT CCNTINUATION mmovio ow. =o meio. I EXPimfS l'at/m )

Facttsty hanet m DOCtli NVIG4R m ggg ggyjgg ggg pggg ggy j

"*a " t'?.h" W.?: I McGuire Nuclear Station, Unit 1 o l5 l 0 l 0 l o l 3 l 6l 9 8g9 __ 0l1j8 Og0 0l4 C' 0 l5 fint a . = w e =ac e am m m VC/YC Chiller also had an indication of high bearing temperature. The series mode l operation of the chillers is a possible cause of the high bearing temperature.

Operations personnel do not operate the VC/YC system with the Chillers in series  ;

except to align the system for ESF testing. During normal or accident conditions, the VC/YC Chillers are operated in the parallel mode. However, during ESF testing Performance personnel are required to test the VC/YC system with the VC/YC Chillers aligned in series because Operations procedures allow the VC/YC system Chillers to be operated in series. Performance personnel are required to test the VC/YC system in all configurations the system may be operated. Operations personnel will change procedure OP/0/A/6450/11, VC/YC System, to delete operation of the VC/YC system Chillers in series. Operations personnel will review all other applicable Operation procedures to ensure that no other procedure allows series operation of the VC/YC system Chillers. Performance personnel will request that Design Engineeritig personnel determine if any design basis requirements would be affected by deletion of series operation of the VC/YC chillers. After the determination by

• Design Engineering personnel, Performance personnel will delete the series ESF l actuation requirement from the ESF Actuation Periodic Test procedure. There are no l

Technical Specification or Final Safety Analysis Report requirements that specify operation of the VC/YC Chillers in the series mode.

i During the time the Control Room was without either train of the VC/YC system, valve ICF-32, Steam Generator 1A Feedwater Control, closed because of Channel 1 l Steam Flow failing low. Operations personnel placed valve ICF-32 in manual to l control Steam Generator level. Operations personnel swapped to Channel 2 and placed valve ICF-32 back on auto. This was the only equipment malfunction during l this time that was thought to be caused by the Control Room High Temperature.

I Control Room temperature never exceeded approximately 82 degrees-F.

A review of McGuire Licensee Event Reports (LERs) for the past 12 months did not reveal any TS violations caused by equipment failure with an unknown cause.

Therefore this event is not considered recurring.

l This event is not Nuclear Plant Reliability Data System (NPRDS) reportable.

l There were no personnel injuries, radiation overexposures, or releases of radioactive material as a result of this event.

CORRECTIVE ACTIONS:

Immediate: 1) MM HVAC personnel added refrigerant to the Train A VC/YC Chiller, and Operations personnel declared Train A of VC/YC operable.

2) Operations personnel implemented procedure OP/0/A/5500/39, Control Room Hi Temperature.

3) Operations personnel failed valve IRN-460 open and started Train B VC/YC Chiller and declared Train B of VC/YC operable.

NIC pgnu seca Gros 1998 520 " ' l'00'O

- . _- _'U.S.

O' 4 <

g'o mia vs muc6saa neou6atonycommenion l UCENSEE EVENT REPORT (LERI TEXT CONTINUATION *+aone oue no. ns.oios

6 emes. swa F=50UTV seAAAB H) DeCatt eeuesta 43) LOR auaEDSA W) pass (3 vtan l

[ McGuire Nuclear Station,11ait 1 o ls j o j o l o l 3 l 6l 9 8l9 0l1l8 0l0 0l5 0F 0l5 i renva . .mmm macw anewci7i l

Subsequent: IAE, MM HVAC, and Operations personnel investigated the reason that  !

valve IRN-460 would not open.

Planned: 1) Operations personnel will change procedure OP/0/A/6450/11, VC/YC system to delete operation of the VC/YC system in the series mode and will review all applicable Operations procedures to ensure that no other procedure allows operation  :

of the VC/YC Chillers in the series mode.  ;

Performance personnel will request that Design Engineering 2) personnel approve the deletion of series operation of the VC/YC ,

Chillers and delete the requirement to test the VC/YC system Chillers in series mode from procedure PT/1 and 2/4200/09A, ESF Actuation Periodic Test, based upon approval by Design Engineering personnel. '

SAFETY ANALYSIS:

s The VC/YC system is designed to maintain proper temperature, cleanlinesa, and  !

pressurization in the Control Room during plant operation, shutdown, post accident i conditions, and in all feasible weather conditions.

During the event when both trains of VC/YC were declared inoperable, OPS implemented the Control Room Hi Temperature Abnormal Procedure which ensured Control Room temperature did not exceed 120 degrees-F as specified in TS 3/4.7.6.

During the event the temperature did not exceed approximately 82 degrees-F.

During'the event there were no accidents that would have required operation of the

! VC/YC system to maintain habitability of the Control Room. If an accident had l occurred during the 30 minutes the cooling portion of the VC/YC system was inoperable, the VC/YC system air handling filtration units would have been opened to maintain the habitability of the Control Room. In addition to these considerations, respirators with air supplied from a cascade system of breathing air bottles are provided in the Control Room.

This event did not affect the health and safety of the public.

I

'V. 8, CNi 1986-Ur SPS rN 4 FO.M 3e66