ML20024G744

LER 91-003-00:on 910322,control Bldg Local Air Intake Radiation Monitor Control Power Circuit Deenergized, Resulting in Isolation of air-operated Dampers.Caused by Inadequate Work Plan.Work Plan revised.W/910422 Ltr

ML20024G744
Person / Time
Site:	River Bend
Issue date:	04/22/1991
From:	England L, Odell W GULF STATES UTILITIES CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-91-003, RBG-34-884, NUDOCS 9104290235
Download: ML20024G744 (4)

Text

. ..*

• 1.

GULF STATES UT1LITUES COMPANY w . w,w en con m.uteo. m o nuuma wmso 4,,

ANALDM494 $M D'Mid 346 18061 April 22,1991 RDG- 34,884 File !bs. G9.5, G9.25.1.3

- U. S. Nuclear RegulatoIy Oxanission I Docunent Control Ibsk -

Washington,~ D.C.- 20555 Gentleiren: 1 River Dend Station - Unit 1 I Docket No. 50-458  ;

Plonso ' find enclosed -Liceneoo Event Deport !b.91-003 for River Dend  !

Station' .. , Unit _.. 14 This report in_' being subnitted pursuant- to j 10 CIT (50.73. -

Sincerely, r \ /

-(

W.T. 'ocle 1 I Manager - Oversight  !

River Dend Nuclear Group k&

IAE/PDG/Gre/DCli/icM/pj

.$z$ OM .

cc: U.S. Nuclear Regulatory 01 mission

=611 Ryan Plaza Drive, Suite 1000

= Arlington, TX -76011 NRC Resident Inspector P.O.-Dox 1051 St. Francisvillei IA 70775 "i

' LINPO Records4 benter

'1100 Circle 75 Parkway Atlanta,_GA -30339-3064-Mr. C.R.' Oberg i-

.Public Utility Ccmnission of 'Ibxas 7800 Shoal Crook Blvd.,. Suite 400 North Austin, TX 78757

- r: n c n O r*

9104290235 910422 .

Z62.R

-POR-S ADOCK 05000458 ///

m __ POR

y;,m = u . ==a.. u n,t.,oa, co ...o. ,,,,,,, ,,,,,,,, , ,,,,,

......m,

! f (* ','i o '

UCENSEE EVENT REPOM (l.ER) .

.'?, i 0,f",'.','8".'Jt",*it,t?,",t ~ Ni"M'inW.' N.'i 09 M ape &OtutNT &ND DVDOt t.646H4NGTON DC 70603

.acitety e&M6ill DW s 4 I wute.t h 431 rapy a Rn$A _BmD STATIM 0l6lo1010M l5la 110Fl0 0 h' d **

Dsper Isolations and Autmutic Swap of Divisional Oantxol Building VentilatioVChj'.le:

Trains due to Inadequate Wark Plan t v0Nf 0418 Ill t e n huu.i n .., stront Da t t 17, OtnIn f Acattfill thyptytp i.e 6 04tes Day v vlam #% f *[*,,*Q po% f .i 47 184. 84C'6d'***l. DOC o l ? hvW.l k'l' ol6l010101 l 1

~ ~

0l3 42 9 1 9l1 0ld3 va.: . one is sv .nio eva v4=, to e d0 0l4 2l 2 9l1

..avi eus =ti e, i0 c a i ,c.. . ., . . ".., nie 0 is10 toioi 1 1 moos i., 1 . , , , ,

g ,,,,,n,,,,,,

a WI.t.ittnd .0 Mi., to 786.tunel 73 716 1 n., li 0 r o . .ni n.,

. . ..'.,ll _

. n.n.n..,

o, =, g,.,,, , ,

n ..in n.,

u n....no _

. n n n..n., m.,

34 ei,bl.llin,el 94 7 3!.tfll',' 48 7 h.llln elles 30 4 t.nln I .4 9li.ntilaist .013t.ittnel 6,CIN.4 8 CONT ACT POR fMit Lt h 1981

%Aug flil'HOht Nvw.6 8I Ahla COD 4 L. A. England, Director - Nuclear Licensing 5 1 04 a 8,1 j i 4l1 1 45 1 Co-a n o 6,~i . . i .e . Co-o =, . .it v. . .c . .. . i. , ,. . . .o. , ni, Aptl $ tlit M CO*870%841

" f, ,'n ,* C Avil 87 8tlM COMPONENT p hO p e I i i l I i l I i i I I i l i i 111 111 1 1 1I i 1 I

.v u...,u ...o., nn tn a n.,

oo~r- o., ....

vtSII,,.a ene.n $K9tCilO SVO.,ISSIQ4 p.Tft %Q l l l

...uC,,..x...,,...,.,.,...,,-.....,n.,

At 1055 on 3/22/91, during maintenance on the Division II control building local air intake radiation monitor 1RMS*RE13B, the Division II control power circuit was de-energized. This resulted in the de-energization of the Division II charcoal filter train suction dampers 1HVC*AOD19D and 1HVC*AOD19F, and isolation of the air operated dampers (AODs) to the Division II air handling units, 1HVC*AOD6B and 1HVC*AOD8B. Nota that dumpers I?D and 19F vers closed at the timo of the event. The isolations resulted in a trip of the Division II control building ventilation system / chiller and automatic swap to the Division I ventilation system / chiller. This report is submitted pursuant to 10CFR50.73 to document the engineered safety feature (ESP) actuations described above. The event occurred during the inaplementation of Modification Request (MR) 90-0007. This MR specified that the RM-80 mother board was to be removed from 1RMS*RE138. The root cause of this event-is that the maintenance planner overlooked the 115VAC control power to the RM-80 mother board and thus, the potential for the ESF actuations.

This event concerned ther engineering / maintenance planning interface and responsibility. As previously reported in LER 90-033, Revision 2, a task force evaluation of this issue was performed and the task force recommendations are undergoing management evaluation. Following management review, LER 90-033 will again be revised to provide GSU's

- final disposition of this issue.

NoC f rm att ifr498

gpa.o . ,

u . m,u.. .oom o,n u,....o~ , , , , , , , , , , , , _ ,

......e,-

LICENSEE EVENT REPORT (LER) ll7,$',W 2.","J'Mf?;'.,'o,jf"2.' .*'," %?,

TEXT CONTINU ATION W.l,T ',f,' ' '23'r$0 R'<'f '," , INT.' L'j @

7,',jt,.',a%"MNu.1'a.

o. -u omt *,'m?.2.%=,'2 u oc - 0? 't

,y ,u n ... n . ve " **

• a u ' u a mi,*.i a i., e.oi m

. .. Wm'- =,9 RWER BWD STATICt1 0l6l0l0l0l4l518 91 1 0l0 l 3 -

01 0 Ol 2 0F 0h nu . < -c,,,,m.m REPORTED CONDITION At 1055 on 3/22/91, during maintenance on the Division II control building local air intake radiation monitor 1RMS*RE138 (*RA*), the Division II control power circuit was de-energized. This resulted in the de-energitation of the Division II charcoal filter train suction dampers (*DMP*) lilVC*AOD19D and 111VC

• AOD19F, and isolation of the air operated dampers (*DMP*) (AODs) to the Division II air handling units, 11tVC* AOD6B and IllVC* AOD8B. Note that dampers 19D and 19F were closed at the time of the event. The isolations resulted in a trip of the Division II control building ventilation (*VI*) system / chiller and automatic swap to the Division I ventilation (*VI*) system / chiller.

This report la submitted pursuant to 10CPR50.73 to document the engineered safety feature (ESP) actuations described above.

INVESTIGATION The event occurred during the implementation of Modification Request (MR) 90-0007. This modification was written to swap electronic components between rsdiation monitors (*RA*) 1RMS*RE13B and IRMS*RE14B in an effort to mitigate noise problems. This MR specified that the RM-80 mother board Las to be removed from 1RMS*RE13D. The design ESP actuation of the unit had been disabled by disconnecting the vendor wiring from the neutral side connection on the control interface junction box. Ilowever, the 115 VAC control power supplied by circuit 11tVCB14 was lef t connected. The circuit overload apparently resulted from the removal of the RM-80 mother board while the control power was still connected. Fuse (*FU*) 111VCB14-F2 failed, resulting in a loss of power to the components supplied by the control circuit and thus, the ESP actuations described above.

The root u use of this event is that the maintenance planner overlooked the 115VAC control power to the RM-80 mother board and thus, the potential for the ESP actuations. During the development of the work plan, lifting of the neutral lead was specified to defeat the design ESF actuation of 1RMS*RE13B, This is a standard practice when performing routine maintenance on the radiation monitors, and was a correct step in this case. Ilowever, the removal of the RM-80 mother board is non-routine maintenance and required the additional step of isolating the control power. A contributing factor to the event was that voltage monitoring was not performed to ensure that the mother board was noc powered prior to removal.

A review of previous reports has identified three similar events. LER 90-033 identified an isolation of the reactor water cleanup (RWCU) system during modifications to power supply wiring in a control room panel. LER 89-016 reported isolations of valves (*ISV*) 1 DER *AOV126 and IDFR*AOV101 during a modification in panel (*PL*) lill 3

• P 8 5 2 . An engineering analysis completed prior to the implementation of the I modification (to install an emergency operating procedure actuation switch) did not reveal the potential for relay 3B-2-11SCR04 to react NAC Poem 3&&A (6491

".".*.... v s wesian aiov6.,p, .co . g UCENBEE EVENT REPORT (LER) TEXT CONTINUATION .aao so owe =o sino .

8A8648 4 315 i

IaC648t186 880 til (KaCatt muesbI A tal 43Ae. m ga @ paggis,

"" " W l'  %'n:

RIVrR BmD STATION o p l010 l0 l41518 9 {l -

010 l 3 -

0l0 013 of 0 l3 eur . . m mu .o m before relay 3B-11SCB04 when the AC daisy chain neutral for the Division II BOP lost, of coolant accident (LOCA) initiation circuit was reestablished. LER 90-035 reported a loss of shutdown cooling when a cable (*CBL3 * ) was disconnected from control room panel (*PL*)

11113 -P 6 9 2 . The system engineer prepared a cable-effacts list for a modification. This was caused by the system engineer not recognizing that the removal of the cable would result in the isolation of valve IE12'MOVr009.

Each of these events concerned the engineering / maintenance planning interface and responsibility. As previously reported in LER 90-033, Revision 2, a task force evaluation of this issue was performed and the task force recommendations are undergoing management evaluation, rollowing management review, LER 90-033 will again be revised to provide GSU's final disposition of thir, issue.

CORRECTIVE ACTION The immediate corrective action was the lifting of the vendor wiring to the hot side of circuit 111VCD14. The work plan was revised to document correct removal and restoration of both the hot and neutral wiring.

Fuse llIVCB14-P2 was replaced. The control building ventilation system was restored to its pre-event line-up by operations personnel.

All instrumentation and controls (I&C) personnel will be instructed on the actuation interfaces which are typical of the ESP digital radiation monitoring system (DRMS) units, and emphasis will be placed on the fact that lifting the neutral lead alone is not sufficient for non-routine maintenance such ac mother board removal. In addition, the associated condition report will be added to required reading for all I6C personnel and I&C planners. These corrective actions will be completed by 5/3/91.

In addition, the maintenance planning department has an ongoing enhancement program which will strengthen the planning process. A lead planner position has been created with the responsibility to review every package after it has been planned and before it is issued to the field. This review is to ensure that the job plans are technically correct and that necessary precautions are in the packages.

EAFETY ASSESSMENT The ESP actuations all occurred per design. The control room ventilation system automatically shifted to its redundant standby train, as designed. Therefore, this event did not adversely affect the health and safety of the public. .

• " ~~ . v n. >.,. su .ii