05000456/LER-1990-007

LER 90-007-00:on 900601,during Removal of Ohmmeter Probe, Operator Touched Probe to Exposed Terminal Point,Resulting in Automatic Start of Auxiliary Feedwater Pump 1A.Caused by Methodology Deficiency.Probes modified.W/900628 Ltr

ML20055D381
Person / Time
Site:	Braidwood
Issue date:	06/28/1990
From:	Lau P, Querio R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BW-90-0664, LER-90-007-04, NUDOCS 9007060250
Download: ML20055D381 (4)

LER-2090-007,

Event date:
Report date:
4562090007R00 - NRC Website

text

. . - . .

.: .. Commtnwocith Edison

• Brcid food Nucitar Power Stction Route #1, Box 84 Braceville, Illinois 60407 l Telephone 815/458 2801.

June 28,1990 BW/90-0664 U. S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Dear Sir:

The enclosed Licensee Event Report from Braidwood Generating Station is being transmitted to you in accordance with the requirements of 10CFR50.73(a)(2)(iv) which requires a 30-day written report.

This report is number 90-007-00; Docket No. 50-456.

Very truly yours, l

R. E. Querto jd>

Station Manager Braidwood Nuclear Station REQ /JDW/sjs (7126z)

Enclosure:

Licensee Event Report No. 90-007-00 cc: NRC Region 111 Administrator NRC Resident inspector INPO Record Center CECO Distribution List o

9007060250 900628 DR- ADOCK0500g{6 1

I l LICENSEE EVENT REPORT (LER) 7 Facility Name (1) Docket Number (2) _Eagt,(3)

Jtaica : _

J13LD1ola.lJ.lajL.13efjd3 Title (4) Inadverted $ tart of the 1A Auxillary f eedwater Pump due to TestingPethodohyDeficiency a

iranLDt1edi.) LER h'c.ithtf If.} .AtPott_D.a.teJ L 0tbar LasilititLiny.ohed_t61 .

Month . Day Year Year jjj j/

/// Seque0tlal /jj/ Revision Month Day Year _Jacl11t v HAmtL _0.etlti_NahtIhl UL Juektl _ LLI JunktL 1 None ._013LOL010lJ l 1

~~~

0j_L 01 1 91_0_ 9l 0 0 1.0 l 7 _ _0_j_0 0 J }_jI _B 91 0 _0L5.LoJ_0J_01_1 I OPERAllNG LCh'LL'AI~'E-more the N ioyJD9}_{ll)

H0DE (9) 1

_ 20.402(b) ,.__ 20.405(c) .L 50.73(a)(2)(lv) _.,_ 73.71(b)

POWER _ 20.405(a)(1)(1) _ 50.36(c)(1) 50.73(a)(2)(v) __, 13.71(c)

LEVEL 20.405(a)(1)(ll) .__ 50.36(c)(2) _ 50.73(a)(2)(vil) _ Other (Specify l

_L] 0.) D___l ._9_0 _ .___

20,405(a)(1)(1ii) ___ 50.73(a)(2)(t) ._ 50.73(a)(2)(viii)(A) in Abstract mfm - ro *( " "" > - so '3( "z"" > - 5073( "2" "'"" 6' d '"

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/ / _ 20.405(a)(1)(v) _ 50.73(a)(2 Hill) ._ 50.73(a)(2)(x) Text)

LICEMSEL(QtilACT FOR THIS LEB 1J21 Name 1[LLEliONE_lNt91R AREA CODE 11All_(av.utiPESlootdinater Egtu2957 _ e LLil. 41JLeL-12LeLDL1 1 CQMPLETE O!(LLINE FOR EACtLCDtiEDMEN1_ FAILURE DL1[RIBED IN f tilSJ[EQRT (13)

CAUSE SYSTEH COMPONENT HANUFAC- REPORTABLE / CAUSE SY31EH COMPONENT MANUfAC. REPORTABLE l

_ _TURER TO NEED.$ _l#E[R TO NPRD$_ i

. J. JJ_I_ l i I I _ L l .L J _L.I._ l i i i i i I i _

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$UPPLEMENTAL REPORT EXPECTED (14) Expected tienth l D.ty_jltar i Submission Date (15) l l

-_ ]Yes H f.ye b somple.it E EE.CIED_SVDtt!S$10M.DAIE) X. l .M _._l I . ! L_L ABSTRACT (Limit to 1400 spaces, i.e. approximately fifteen single-space typewritten lines) (16) ,

1 l

On June I,1990 a Reactor Operator (RO) was performing a $ lave Relay Surveillance that tested the 1A Auxiliary Fe:dwater Pump (AT) Steam Generator low Low Level Auto Start Actuation Relay, K633. This relay was part of the l Solid State Protection System. As part of the restoration portion of the procedure the resistance across the rolcy contacts was measured to verify an open circuit prior to enabling the system. At 0927 the NSO measured the  !

r:;sistance across terminals 1 and 2 of relay K633 in accordance with the procedure. While maintaining one of the i ohmetsr probes on terminal 2 the HSO removed the probe from terminal 1. During the removal of the probe the N$0 l In:dvertently touched the probe to the exposed terminal point 13 on relay K633. This created a current path from  !

a p:rallel circuit through the ohmeter to the starting relay for the 1A AF pump. This resulted in the auto stcrt of the pump. The 1A AF pump control switch was immediately placed in the " pullout" position and the pump was secured. The cause of this event was a methodology deficiency which is considered a programatic d2ficisncy. Ohmeter probes have been modified to reduce the esposed metal surf aces to a small portion of the tip. Alternate locations for obtaining the readings will be used. Training will be provided, Previous corr ctive actions are not appilcable.

3036a(062190)/2

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tlLEN$LLIYENT _ REPORT f LER) TERII.QKIDfy61]QN f omJty19. .

FACIEliY NAM (1) DOCKET NVPSER (2) = ,1EfLHUtgER (6) Pegg&}_ '

Year g Sequential g Revision

l-I i.

11r 1Nektr la Haktt-o 0 LLLn_LoJJJaL513_9._Ln JJJJ1 - .0.Ln_ '

3fethatic .

JL2 JL JL3 TEX.i Energy Industry Identification System (fil$) codes are identified in the text as [XX} j A.. PLANT CONDITIONS PRIOR 10 EVENT:

Units' Braidwood 111 Event Date: June 1, 1990: Event ilme 0927; '

iModet .1 - Power Operation; Rx Power: "B%%I  !

<RCS (AB) Temperature / Pressure: NOT/NOP q

B. DESCRIPTION Of EVENT. i There were no systees or components inoperable at the beginning of the event which cor'tributed to the severity of tha event. A Nuclear station Operator (NS0) (Licensed Reactor Operator) was performing Braldwood Operating _

. Surveillance (BwCS 3.2.1-941 Unit One Quarterly Slave Relay Surveillance (Train A - K633)). The procedure tested

.the_1A Aunillary feedwater Pump (Af) (BA) $ team Generator Low Low tevel Auto Start Actuation Relay, K633, which

, w s an output function of the Solid State Protection System (SSP $) (JE). As part of the restoration portion of th> procedure the resistance across the relay contacts was measured to verify an open circuit prior _ to enabling .

the system.

1 .

At 0927 on June 1,1990 the NSO measured the resistance across terminals 'I and 2 of relay K633 in the Train A $$PS

' panel in accordance with the procedure. The value of the measurement indicated an open circuit. While

' maintaining one of the chimmeter probes on terminal 2 the NSO removed the probe f rom terminal 1. During the removal of the probe the NSO inadvertently touched the probe to the exposed terminal point 13 on relay K633. This }

cr:ated a current path frein a parallel circuit through the ohnneter to the starting relay for the 1A AT pump.

This resulted in the. auto start of_ the pump. After verifying the auto start was not required, the IA Af pump control switch was immediately placed in the " pullout" position and the pump was secured.

The appropriate NRC notification via the ENS phone system was made at 1007 pursuant to 10CfR50.72(b)(2)(ll).

.This event is being reported pursuant to 10CFR50.73(a)(2)(iv) - any event or condition that resulted in manual or automatic actuation of any Engineered Safety feature, including the Reactor Protection System, l -C, CAUSE Of EVENT:.

The root cause of this event was a methodology deficiency. This is considered a programmatic deficiency. The procedure specified taking resistance readings on the relay terminal points 1 and 2. These terminal points are

~ located on the back side of a " dual deck" relay. The spacing between the front row terminal r31nts and the back row terminal points is 2 inches. The spacing between the terminal points on a row either back or f ront, is 3/4 of-an inch. The NSO was provided'wlth an ohnneter with probes that have 9/16 of an inch metal tips. Additionally th; N$0 was required to read a value from the ohmmeter while holding the probes on the terminal points. Due to' the physical layout of the panel the meter cannot be placed near the relay. As a result the NSO was required to. i h31d both a probe. and the ohnneter in one h.and the second probe in the other hand.

A rivlew of the task performance requirements was conducted by personnel tralned in Human Performance Enhancement System-(HPE$) event evaluation techniques. Based on the results of this review it has been concluded that the methodology for task performance places that NSO at a higher than acceptable risk level for creating an Intdvertent actuation such as the one that occurred in this event. The deficiency in the methodology for parforming the task created the event.

3036m(062190)/3

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• [ ' C' L I C ENSELEVENLRLt0RL11LRLICAlf 0HU NUMION rarm.RtL2A

.fACILI,TY NAME.(IL DOCKET NUMBER (2) ._1LR_lNtsIR (61 Page (3)

Year fj/j Sequential

// /j//

ff Revision UL - 11ektr U1 Uvettet 3raidwood_1 0 L5JJJJJJJ_41_513JJJ_ -

0JJJ 2 -

-0 l _ ct. _ol a _Q L a l_3 TEXI. Energy Industry Identification System (E!!5) codes are identified in the text as (XX) e D. SAFETY ANALYSIS:

'.This event had no effect on the safety of the plant or the public. All systems operated as designed. The safety function provided by the Auxillary Feedwater System was not required and was inappropriate for 4cxisting plant conditions. Discussions on redundant equipment are not appilcable. The AF initiation was n;lther desired or required. There are no reasonsble and credible alternative conditions that would have b2:n more severe.

E. CORRECTIVE ACTIONS:

~Th) 1A AF pump was imediately secured by placing the Control $ witch in the pull out position.

.0hmmeter probes that are used to obtain readings on back row terminal points of dual deck relays have been.

modified to reduce the exposed metal surfaces to a small portion of the probe tip. i l

A review will be conducted to identify the procedures that require readings obtained by placing probes on back: row contacts of dual deck relays. Alternate locations for obtaining the readings on the relays- ,  ;

id ntified by the review will be used if available. .This action will be tracked to completion by action item l 456-200-90-02201.

< ihis event will be covered in a training tailgate session for appropriate Operating Dept personnel. This f action item will be tracked to completion by action item 456-200-90-02202. i

F. ,PREVIOU$ OCCURRENCES:

j Thire was a previous occurance of an AF pump auto start during the performance of this procedure. -l LER No. DVR Number Title 50-457/88-006 20-2-88-018 Inadvertent Start of Unit 2 Auxiliary Feedwater Pump Due to personnel Error -j t

The corrective actions were implemented addressing both root and contributing causes. previous corrective ,

actions are not applicable to this event.

G. C0HP0tlENT FAltVRE DATA:

.}

This event was not the result of component failure, nor did any components fall as a result of this event. l I

3036m(062190)/4 n