ML20043A673

LER 90-006-00:on 900416,containment Purge Isolation Signal & Control Room Ventilation Isolation Signal Occurred.Caused by Inadequate Procedures to Govern Deenergization of 120- Volt Ac Distribution Ctrs.Procedures revised.W/900516 Ltr

ML20043A673
Person / Time
Site:	Wolf Creek
Issue date:	05/16/1990
From:	Bailey J, Mike Williams WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-006, NO-90-0158, NUDOCS 9005220387
Download: ML20043A673 (6)

Text

-. . . . - ._- - - - - . . _ . . .. - - -

~!

l W4M.F CREEK NUCLEAR OPERATING CORPORATION ~ i L' John A. Belley Vlee Present Nucteer Operatione

{

i i

May 16,1990  :

N0 90-0158-

\

l

'U. S. Nuclear Regulatory Commission ATTN: Document Control Desk

, Mail Station F1-137 Washington, D. C. 20555 l

Subject:

Docket No. 50-482: Licensee Event: Report 90-006-00 1

Gentlemen:  !

The attached Licensee Event Report (LER) . is being submftted. pursuant to  ;

10 CFR 50.73 (a) (2) (i) concerning a Technical Specification violation', and pursuant to 10 CFR 50.73(a)(2)(iv) concerning acplanned' actuations of

, Engineered Safety Features.

Very truly youre,- l l

j V . A John A. Bailey

/

Vice~ President

, Nuclear Operations -l

-1 JAB /jra

. Attachment 1 j

cc R. D. Martin (HRC), w/a D. Persinko (NRC), w/a D. V. Pickett-(NRC), w/a '-

M. E. Skov (NRC), w/a .1 I

p Ov'5 E p.s }6 q Kif*S l c _ 'l F[lR H LIU LJ . ( F it it it 14 t ,_

y k'[li[

RO. Box 411/ Burlington, KS 66839 / Phone:(316) 364-8831 An Equal opportunity F.mployer MF/HCNET I i

e a.C perm 364 CSM U.5 NUCLEAR REOULa10AY COMMl5510N APPROVID OMS NO 3150 0104 I

LICENSEE EVENT REPORT (LER) '"at'"

7 ACILITY NAME (1) DOCKET NUMBE R (2) FAGE iY i Wolf Creek Generatin(StaLion o l5 l o j o l 0 l 418 l 2 1lOFl0l5 Engineered Safety Features Equipment Actuations and Technical Specification Violation Caused By Jnadequate Procedural Guidance i tVENT DATE (81 LER NUMetR ($1 REPORT DATE in OTMtR F ACILITit$ INVOtVED 10)

MONTH DAY YEAR Y&AR "*[ L" ' N,$ MONT H DAY YEAR F ACsLITv hauts DOCKET NUM8tRtSt ol5l0lolot l l l!6

~ ~

O!4 9 0 9l 0 0l 0! 6 0l 0 0l5 1 l6 9!0 oistoioici i i OPE R ATING THis REPORT is SUBMITTED PURSUANT TO TMt REO' UIREMEN1'8 GP 10 C7 R { (Chece one er enore of the tonovati(11)

MODE m b 20 402tti 20 400tel g 50.734sH2tlevi 73.71161 R to 406MH1Hil 50.36asHil 60.736aH2Hvl 73.71(el 0 01 l 10 20 40iH.Hiitin s0 misioi .0.73 H2H,u,

,_ _ __ guEgs7ggggg7;,

20 406teP.1Hl6H g to.73teH2HO 80.73teH2Het44HAl Js6AJ 30 40thH1Hivl 50.73teH2Hil) .

80,73teH2Hviultel to 406t.10 Hvt 50.73naH28tiiH 60.73taH3Hal  ?

LICENSEE CONT ACT FOR THl3 LER 112)

NAME TELEPHONE NUMBER ARE A COD 4 Merlin G. Williams - Manager Plant Support 3 l1 16 361 14 l- 1 8 l 8l3 l 1 COMPLETE ONE LINE FOR E ACH COMPONENT f AILURE OtSCRIBED IN THIS REPORT (13}

CAUSE 8v$'EM COMPONENT MA%AC.

HEP yO em S CAUSA sYsitM COMPONENT O' R ' ' '

O NPR

! 1 1 1 I I 1 '

I I i I I I i s .

I I I I I I I I I I I I I I SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YFAR SU8 MIS $10N YtS ill yen. cameter. tx9ECTf0 5V06t!SSION CA TEI No l l l 1.. T R ACT a- . ,m c.u . . w ,,N ,, ,s.,wc, ,,-., ,,,,,,, n.>

On April 16,1990, at 0819 CDT, a Containment Purge Isolation Signal and a Control Rom Ventilation Isolation Signal (CRVIS) occurred when power es renoved fran Containment Purge Radiation Monitor GP RE-33. As a result of this event it me discovered that the 'B' train Control Room Pressurization Fan OGK04B had not been restored to service prior to declaring the 'B' train Control Rom Emergency Ventilation Systen operable, resulting in a violation of Technical Specification 3.7.6. CGK04B was restored to service at approximately 0847 CDT. At 2140 CDP, another CRVIS occurred when signal power ws renoved fran Control Rom Air Intake Chlorine Monitor, GK AIT-2.

All required equipnent responded properly.

These Engineered Safety Features equipnent actuations occurred when the associated 120 volt A.C. distribution center a s de-energized for Refueling activities without placing all affected instruments in the bypass position.

'lhe root cause of these events es inadequate pro :iures to govern de-energization of individual 120 volt A.C. distribution centers. Appus-iate procedures are being developed. OGK04B had not been restored to service

~

following the electrical bus maintenance because of procedural ambiguity. A s ucelure change has been initiated to clarify this procedure.

N C Poem 306 q

_ _ _ _ _ )

)

NRC POAW 3e6A U.S. ICUCL4A2 A53ULATU.sY Coeduiss10N EXPIRts 473oM2 UCENSEE EVENT REPORT (LER) f,Ns'd',%',f"80,'C4",o"'AIS*f,2 ,,o* 'l'TA' !R,l'd's .,

TEXT CONTINUATlON Su "",f."/o'#%%"d5,'UW'C0'*/l#l,"'"'8 "f!  !

E PAPE WO RG U T ON 3 04 i 07 MANAGEMENT ANL18UDGET, WASHINGTON,DC 20503.

pJ.CitiTV NAM 6 IH DOCKET NUMBER ul LtR NUMSER 16) PA05 13) vsAa -

" M7,', P $*O Wolf Creek Generating Station o l5 l0 l0 l0 l4 l 8l2 9l0 -

0lOl6 -

ol 0 012 U 015 - 1 I

TEXT (# ruere spece a ,evosett, use : MAC form Jests / 07) i e i On April 16,1990, at 0819 CDP, a Containment Purge Isolation Signal (CPIS) }

and a Control Room Ventilation Isolation Signal (CRVIS) occurred when povar }

was removed from Contalment Purge Radiation Monitor GT RE-33 [IIrle). As a result of this event, it was discovered that the 'B' train Control Rom 4 Pressurization Fan CGK04B [VI-FAN]- had' not been restored to service prior to .i declaring the 'B' train Control Roan Bnergency Ventilation Syistem oper.able,

'resulting in a violation of 'Dochnical Specification 3.7.6. At 2140 C M ,- .

another CRVIS occurred when signal power.was removed from Control Rean Air Intake Chlorine Monitor, GK AIT-2 [VI-AIT). 'Ihis report is being robnitted pursuant to 10 CFR 50.73(a)(2)(iv) concerning unplanned actuatione.of Engineered Safety Features (ESF) [JE] equipnent, and pursuant to 10 CFR 50.73(a)(2)(1) concerning a condition prohibited-by Technical:

Specifications.

DIEKRIPTIGT T EVEBRS At the time of these events, the plant was in Mode 6, Refueling, with the #

Reactor Coolant System [AB) average t=am m ture at 82 degrees. Fahrenheit. ,

Ta'annmry power was being supplied to the 120 volt A.C. Class 1E '

distribution centers. On the norning of April 16, propmtions were in i g upass to restore the 120 volt A.C. Class 1E distribution centers to their normal power supply following maintenance activities. In preparation for removal of tangnmry power to the distribution centers, several instruments required placement in the bypass position to prevent unnamaaey actuations of ESF equipnent when power was renoved. . At 0740 CDT on April- 16, the .

Control Roan Air Intake Radiation Monitor GK RE-04 [IIeM21], the Contalment Atmosphere Radiation Monitor GT RE-31 [IL-lG), the Fuel Building Exhaust.

Radiation Monitor GG RE-28 [IIrMJN), and GK. AIT-2.were placed in the bypass position. Entry was made into the app usiate Technical Specification-Action Statements. At 0819 CDP, a CPIS and a CRVIS occurred as a result of loss of power to GT RE-33 when .the tenporary power was renoved. GT RE-33 had not been placed in bypass along with the other affected instruments, and upon loss of power, an actuation signal was generated as required by the design of the monitor.

1

.s s'

NRC Fasm 386A 1649)

. . . .- - . . . , . - . - . . - - . - a .]

suA v.s. wucttaa asov6arouv co= Mission ,,,,,v,, ,,, ,,,,,,,,,,,

g:,c eo.

. x,,. . . .o.

LICENSEE EVENT REPORT (LER) '$"n^'!,D o *M80e"o"'jEn,T JMV

,"o'" %'j ,

TEXT CONTINUATlON Su ""n'",'o'n% o^,",MM',"on'C7^,'!M"' OE RA ,

t P API WO Rt UCTIO R O 04 0 i OF MANAGEMENT AND BUDO.NT, W A$HINGTON. OC 20603.

PAcetlTV NAME(U DOCKET NUMSER GI gg, Ngugg, qq) PAGE Q) ma "W'?Jn .

3*J:

Wolf Creek Generating Station o l5 io lo j o l4 l 8l2 9] O -

0l 0l 6 -

0l0 013 0F 0 l5 i ssx,w n . m m ecr mx.mn 1 1

At 0840 CDT, nozmal power ma restored to the affected instruments, and at approxinately 0847 CDP, restoration of the Control Roczn Ventilation System i (VI) to nonnal configuration began. During this s ucess, it e s discovered that the 'B' train Control Room Pressurization Fan OGK04B (VI-FAN) had not 3 started because its handswitch a s in pull-to-lock. Following this l discovery, CGK04B es restored to q=mble status. . All other required i equipnent responded sply to the actuation signals. At 0910 CDT, restoration fram the actuation signals ma ccmpleted.

Subsequent investigation revealed that the handswitch for CGK04B had been placed in pull-to-lock on April 7, 1990, as part of the 'B' train Class lE electrical bus outage, rendering the 'B' train Control Room Bnergency Ventilation Systen inoperable. Technical Specification 3.7.6 requires that with one train of the control Rom Emergency Ventilation System inoperable, to restore it to operable status within.7 days or to initiate and maintain 1 operation of the reaining train in.the recirculation node. Between April 7, 1990 and April 16,1990 at 0300 CDP, this Action Statement was satisfied. On April 16,1990, at 0300 CDP, Control Rom operators -realigned the Control Rom Dnergency Ventilation System frm.the recirculation mode to the normal configuration upon restoration of the 'B' train. Control Rom Air Conditioning Unit [VI-ACU) to service. The Action Statement of Technical Specification 3.7.6 m s exited at that time. It me not recognized that .

OGK04B should also be returned to service as required for q=mhility of the

'B' train Control Room Emergency Ventilation System. At the time, the "

Control Rom operators did not recognize that a non-14ance with Technical' Specifications had occurred.

At 2140 CUT on April 16, 1990, 120 volt A.C. Class 1E Distribution Center NN04 [EF-BUS) was Imoved frun service for cleaning. When NN04 was de-energized, a CRVIS occurred because of a loss of signal power to GK AIT-2.

When the signal power es lost, the monitor failed low and initiated an ESF actuation as required by the design of the nonitor. All equipment responded properly to the CRVIS. At approximately 2145 CDP, GK AIT-2 m s placed in the bypass position. At 2207 CDP, the Control Rom Ventilation Systen was restored to normal configuration. NN04 was re-energized at 0244' CDP on April 17, 1990, and GK AIT-2 was restored to service at 0248 CDP.

N3C Penn 3e6A (&801

_ . . _ . . __ ___ _ __ __ __ - ,..__-- _ - , - , - a

- 1 u.s. Nuctaaa assu6avoav coMuissioN gcpu seeA g g ]

w,,,s .mm .

1 f=

I LICENSEE EVENT REPORT (LER). 58'l%^4'so'M8Rd',"oa 'gN, vo TO C l,nH Hl$ /

R""N,%'N i MS AMMnM"e'#^.'!R'"/Of"n TEXT CONTINUATION

^

v )

Of"tA,'a" joe "M'J!a*N'

1. lsiM4PM?'ci- l OF MANAGEMENT AND BUDGET, WASHINGTON, DC W3, a fd.CILsTV NAM 4 Hs DOCKET NU8flOER (21 68R NUMSER (G) PAGE (3) l vsa -

" $ '3* '  :

"'#.0 -)

Wolf Creek Generating Station o plolnlol4[8l2 9l0 ._,

0l 0l 6 ._

0[0 0l4 or 0l 5 TEXT I# neere apsce a regeme( ese edtheoner NAC ,onn JsH W (17)

MXF CMEB A10 C35tK3'1VE ACTIGEi 1

%e root cause of these events was the failure to have adequate prMwes i to govern de-energization of-inctividual 120 volt A.C. distribution centers. l System operating gvwdure SYS G331, "De-energization of 480 volt Class 1E Bus (es)," is utilized to de-energize the notor control centers supplying the -

120 volt A.C. distribution centers. When the 120 volt A.C. distribution -

centers were originally de-energized to allow the installation of taiporary power, this suce. lure a s utilized, and consequently, no unnecessary ESF actuations resulted. %is procedure identifies the actions to be taken to '

de-energize entire motor control centers to prevent unnecessary ESF actuations, but does not specify those actions which are specific to a ,

particular 120 volt A.C. distribution center. Upon conclusion of the 480 >

volt A.C. bus outage, the t-vary power supply was -left installed to the 1 120 volt' A.C. distribution centers. When subsequently pramvNg to renove '

the tarporary power supply, the anu.vslate instruments were not placed in' bypass and unnecessary ESF actuations resulted when the associated distribution center was de-energized. While SYS E 331 contained )

information relative to the distribution centars, it was not recognized that this information could be selectively applied to individual 120 volt A.C.

distribution centers. To preclude recurrence,la procedure for de-energizing aan.vgiate 120 volt A.C. distribution centers will be developed prior to ,

the next scheduled 120 volt A.C. distribution center dewanergization. '

Investigations were conducted to determine the reason that CGK04B was not restored to service along with SGK04B at 0300 CDT on April 16, 1990. ..It was determined that during the re-energization of the 480 volt A.C. notor control centers, the handswitch for CGK04B ms left in pull-to-lock because of a lack of clarity in system operating procedure SYS !G-131, ."Energization.

of 480 volt Class 1E Bus (es)". W e applicable procedural step states that CGK04B and SGK04B should be restored to service utilizing the aan.vgiate procedure. mis step was interpreted to mean that .CGK04B and SGK04B should 1

[ be restored concurrently. Because SGK04B was to renain out of service for unrelated activities, the Control Room operators left CGK04B out of service.

in accordance with their understanding of t M procedure. When SGK04B was >

restored to service on April 16, 1990, at 0300 CDT, it was not recognized that CGK04B required restoration also. A clarification to SYS G 331~has l been initiated to no longer require placement of CGK04B in pull-to-lock prior to de-energization of the associated 480 volt A.C. bus. A revision to SYS E131 has also been initiated to list restoration of CGK04B and'SGK04B.  !

as separate sign off steps to ensure personnel are aware that the um s ments T may be restored separately. %ese changes will be issued prior to June 30, ,

1990.  !

NRC Penn 344A (4891 i nr , < , .:.-..-..,_-- .

Net conM 3eeA U.S. NUCLE AA kt wkAT0JV COsdMISG10N APf'R0vt0 OM8 NO,31600104 4 KPints 4!30/92 LICENSEE EVENT REPORT (LER) ISa%^'A!!o*J'"8'"e"o"'!"a"fd,'

.0 fc t'A' ,*o'.".1%'!

• NX"A",'o',"I u'2nifJU!%i'le'Ul!E 'u"' "5EEfA TEXT CONTINUATION ^

0?"t#a"JoWa'#N*N n!"iC?"nil@ 0?d?

OF MANAGEMENT AND 9UDOtt, WASHINGTON,0C 20503 PkCILif y NAMt 11 DOCKET NUMttR 121 LER NUMetR 161 PAS 8131 YE*" n adI aYa Wolf Creek Generating Station o l5 l0 l0 j o l 4l8 l2 9 l 0 ,0 l0l6 -

0l0 0l 5 0F 0l5 flXT C# pure spees is enruwod, use sdeepnet NRC form 33Wat l1h JEIIITIGIRL IEWGESIS'IGt

• A previous similar occurrence of unnecessary ESF actuations which resulted fran a lack of gvcisdural guidance for de-energization of electrical equipnent is discussed in Licensee Event Report 87-049-00. In response to that event, a procedure e s developed for de-energizing safety related'4.16 i kilovolt division buses. However, prior to the events discussed in this report, it was believed that the gvcx. dure governing de-energization of the entire 480 volt Class 1E notor control center provided sufficient guidance I for de-energization of 120 volt A.C. distribution centers.

In each of the events discussed in this report, the plant was in a stable shutdown condition thereby the occurrence of these events-did not pose a- '

threat to the health and safety of the public or u.m p unise safe plant operation. ,

i l

l l

s NXC Form 365A 16401