ENTERGY T F % i u · Lice'nsee Event Report 50-458/94-030 ---I ' December 29,1994...

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Entergy Operations. Inc.Rver Bend Station5485 U S. Highway 61.

-==~ ENTERGY T F % i u 75

(504) 336-6225FAX (504) 635-5068

!. JAMES J. FISICARo| D: rector

Nx! car Safety -/|

| December 29,1994

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U.S. Nuclear Regulatory CommissionDocument Control DeskMail Stop PI-37

| Washington, D.C. 20555;

SUBJECT: River Bend Station - Unit 1Docket No. 50-458,

l License No. NPF-47Licensee Event Report 50-458/94-030File Nos. G9.5, G9.25.1.3

RBG-41141RBF1-94-0151

Gentlemen:

In accordance with 10CFR50.73, enclosed is the subject report.

Sincerely,

S/

JJF/RMMEnclosure

M9501050269 941229 I

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{DR ADOCK 05000458 (PDR

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Lice'nsee Event Report 50-458/94-030 - --I

December 29,1994'

RBG-41141RBF1-94-0151Page 2 of 2'

cc: U.S. Nuclear Regulatory Commission611 Ryan Plaza Drive, Suite 400

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'' Arlington, TX 76011

NRC Sr. Resident Inspector )P.O. Box 1051 iSt. Francisville, LA 70775 j

INPO Records Center700 Galleria Parkway i

'Atlanta, GA 30339-3064i

Mr. C.R. Oberg |Public Utility Commission of Texas j7800 Shoal Creek Blvd., Suite 400 North .;

Austin, TX 78757 -

-iIouisiana Department of Environmental Quality ;

Radiation Protection Division |P.O. Box 82135 ;

Baton Rouge, LA 70884-2135 !A7TN: Administrator *

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ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS

LICENSEE EVENT REPORT (LER) EOu$YE"RYARE E E EuS 'TO"E'-

E1S"U's"NuCtESR REYULATORY"^ "' *

M W SHINGTDC 205554001. AND TO THE PAPERWORK REDUCTION PROJECT(31504104). OFFICE OF MANAGEMENT AND BUDGETWASHINGTON, DC 20503

7 ACIUTY NAME (1) DOCKET NUMBER (2) PAGE (3)

River Bend Station 05000-458 1 of 4TITLE (4)REACTOR SCRAM RESULTING FROM INADVERTENT MSIV ISOLATION DUE TO FAILURE TO FOLLOW TESTPROCEDURE

EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)MONTH DAY YEAR YEAR SEQUENhAL REVISION MONTH DAY YEAR F ACILITY NAME DOCKET NUMBER

NUMBER NUMBER N/A 05000F ACILITY NAME DOCKET NUMBER

12 04 94 94 030 00 12 29 94 N/A 05000OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF to CFR l(Check one or more (11)

MODE (9) 1 20 402(b) 20.405(c) X 50.73(a)(2)(iv) 73.71(b)POWER 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)

LEVEL (10) 100 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER

20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) D$C Fe* te t w no m

20.405(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B)20 405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12)NAME TELDHONE NUMBER (includ. Ar.a Code)T. W. Gates, Supervisor - Nuclear Licensing 504-381-4866

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)CAUSE SYST E M COMPONENT M ANUF ACTURER REl BLE CAUSE SY5 TEM COMP %ENT MANUF ACTURE R R R

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SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED M TH DAY YEAR |

YES X NO SUBMISSION_

tw >= compi.t. EXPECTED SUBMISSION DATE) DATE (15)ABSTRACT (tima to 14a0.pu i . . .pprommoi.iy is smai.-.pu.o typ nit.n im )lis

On December 4,1994 with the plant in Opemtional Condition 1 (Power Operation), a reactor scramoccurred when isolation logic was satisfied for a Main Steam Isolation Valve (MSIV) isolation. Thisisolation signal was the direct result of surveillance activities that were being performed prior to the event. |

| The mot cause of the event was that a pmcedural step requiring removal of a half MSIV isolation signalwas not performed as required. This action esulted in the failure to remove a half MSIV isolation'

signal on one test channel prior to proceeding to the next test channel where another half MSIV isolationsignal was generated. Corrective actions consisted of reinforcing management expectations regardingpersonal accountability and procedure compliance. A160, the procedure revision pmcess was modified to

| ensure that the appropriate verification requiremcats am considered during procedum revisions andreviews. The surveillance procedure was revised to incorporate the appropriate level of verification toI

ensure the MSIV isolation circuitry was restored before proceeding in the procedure. An evaluationdetermined that operator actions during the scram were appropriate and that safety systems functioned asdesigned.

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3160-0104 '

p.m) EXPIRES 6/31/96

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River Bend Station 05000-458 94-030 2OF4|

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REPORTED CONDITION

On December 4,1994 with the plant in Operational Condition 1 (Power Operation), a reactor scram occunedwhen the isolation logic was satisfied for a Main Steam Isolation Valve (MSIV) (*ISV*) closure. Theisolation signal was the direct result of surveillance activities that were being performed in accordance withSTP-058-4501, " Containment and Drywell Manual Isolation Actuation Channel Functional Test." Duringthe STP performance, a procedure step requiring the test technician to request the operator to reset theisolation signal for a test channel (*CH*) was not perfonned. This resulted in the failure to reset a halfMSIV isolation signal on one test channel (Channel A) prior to proceeding to the next section of theprocedure (Channel B) where a second half MSIV isolation signal was generated. Initiation of the second,half MSIV isolation satisfied the system logic requirements for MSIV closure resulting in a subsequentreactor scram due to MSIV position. This report is submitted pursuant to 10CFR50.73 (a)(2)(iv).

INVESTIGATION

Surveillance STP-058-4501 performs a functional test of the Containment and Drywell manual isolation i

pushbuttons. These switches control several different isolation functions including the four channels ofMSIV isoMion iogic. The surveillance sequence performs the functional test on the first channel (ChannelA) prior to proceeding to the next sequential channel (Channels B, C and D). Both the At-The-Contn>ls(ATC) and Unit Operators perform the switch manipulations during the surveillance. The ATC operator wasthe primary interface with a Second Class I&C technician responsible for reading the procedure and operatorinterface. A Journeyman I&C technician was at the back panels and the Unit Operator was performing themanipulations which the ATC operator either could not perfonn (due to being outside the ATC area or werenormally under the cognizance of the Unit Operator).

Upon completion of the pre-requisites required to perform the test, the Channel A portion of the test wasinitiated. These steps consisted of 1) requesting the operator to bypass the Channel A Balance of Plant!

(BOP) isolation function for a test relay, 2) requesting the operator to arm the isolation switch (*HS*) andverifying the resulting annunciator, 3) requesting the operator to depress and hold the pushbutton to generatethe isolation signals and verifying the associated annunciator,4) verifying the IfOP isolation signals,5)requesting the operator to release the pushbutton, 6) requesting the operator to restore the bypassed BOPisolation function, 7) requesting the operator to disarm the isolation pushbutton, 8) verifying the BOP signalshad reset, 9) requesting the operator to reset the scaled-in half MSIV isolation signal, and 10) verifying allalanns cleared. The procedure then required an independent verification in accortlance with Attachment 2 ofthe STP which verified the ' vpassed BOP isolation had been restored and the isolation switch had beendisarmed.;

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 31504104ele 2) EXPlRES 6/31/96

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TEXT CONTINUATION u gegro pp gg1 M) OFF OF MANAGEMENT AND BUDGET,

NCLITY NAME (1) DOCKET NUMBER (2) LER NUMBER (d) PAGE (3)River Bend Station 05000-458 94-030 3OF4

iEKT (9 more spece on ooquvett. use nottilmnalocpes of NRC Ferm 306A)(17)

Because the annunciators had reset after de-actuating and disarming the isolation switch, the I&C Technicianassumed that the half isolation signal had been reset by the operator and did not perform the step thatrequires him to request the operator to reset the signal. Following completion of Section 7.1 of theprocedure, " Outboard Isolation Manual Initiation Channel A," the team pmceeded to Section 7.2 of theprocedure, " Inboard Isolation Manual Initiation Channel B". The scram occurred when the isolation signalwas insened in Channel B. Neither section 7.1 nor 7.2 of the procedure contained a step to verify that allisolation signals had been cleared or that no isolation signals were present befom pmceeding to the nextchannel. In addition, the attachment used for independent verincation did not check the status of the MSIVisolation channel. No indication is available in the ATC area for the operators to use to determine the statusof the isolation circuitry. The operator did not recognize that the procedure had been changed significantlyfmm the last time it was performed and assumed the technician at the back panels would be checking theback panel indicatioris for the MSIV status lights (*IL*) and ammeters (*II*) to ensure the isolation signalswere reset. These checks were included only in the procedure's restoration section (Section 7.5) whichwould be performed after all channel functionals had been performed. The previous procedure mvisionincluded these steps after each section.

This procedure revision was performed as a result of the Technical SpeciHcation Surveillance Procedure i

review project. In the previous mvision, the status lights and ammeters wem veriGed in each section of theprocedure prior to proceeding to the next channel. These steps were marked to indicate they were requiredto satisfy Technical Specifications. The project determined that these steps (status lights and ammeters) werenot mquired to be checked by Technical Specifications and were deleted. The procedum mvision processfailed to identify the verincation function performed by these steps during the review and appmval process.

'In addition, neither the ATC operator who actually depressed the switch which insened the isolation signalnor the Unit Operator who should have reset the isolation signal followed up and ensumd that the signal wasremoved before pmceeding into the next section of the procedure. Since the operators had performed thisprocedum befom and were familiar with this STP, they each thought the isolation signal must have been msetsince the technician had proceeded to Channel B. Consequently, when the isolation switch was actuated, theisolation logic for the full MSIV isolation was completed. The MSIVs closed and a reactor scram occurmddue to MSIV position.

A review of recent River Bend Station Licensee Event Reports determined that no other similar events haveoccurred at RBS. However, there have been MSIV isolation events due to failed components and inadvenentgmunding/shoning of test leads.

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NRC FORM 36CA U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3160-0104tsm) EXPIRES 6/31/96

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LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE' ' " ^ "**TEXT CONTINUATION E ^S Nuc "Sa"n'$ "t T* "*"c'EEONEiETs T

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Riv:r Bend Station 05000-458 94-030 4OF4I

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ROOT CAUSE "

The mot cause of this event was that a procedural step requiring removal of a half MSIV isolation signal wasnot performed as requimd. A contributing cause was that steps to verify channel status had been removed

j during a previous revision.

CORRECTIVE ACTION

! To address the associated human perfonnance issues, individual counseling / discipline will be administered asdetermined necessary by department management. In addition, management expectations wem reinfo ced tosite personnel regarding personal accountability and procedure compliance through management meetingswhich discussed the specific issues and the overall philosophy of human performance impmvement.

In addition, procedum STP-058-4501 was revised to include verification of cimuit status lights (located in the,'

back panel) and ammeters for each channel prior to proceeding to the next channel. A review of similarmulti-divisional "high-risk" surveillance test procedures will be performed to determine if verificationbarriers are in place when needed. These type procedures will also be revised to include notification of theNuclear Control Operator, where appropriate, after work on each division is completed and prior topmceeding to the next step.

The procedure review and revision process will be enhanced by 1) revising the Technical Review checklistcontained in RBNP-0001, " Control and Use of RBS Procedures," to ensure that appropriate verifications areincluded as required by ADM-0076 " Verification Program" guidelines,2) revision of the pmcedum writer'sguide criteria to address human factors considerations and necessary barriers, and 3) provide additionaltraining for departmental Technical Reviewers on human factors considerations for station pmcedums. Inaddition, status indication of the MSIV isolation circuits will be provided inside the ATC area to improve thehuman factors considerations associated with this issue.

SAFETY ASSESSMFET

An evaluation determined that opemtor actions during the scram were appropriate and that safety systemsfunctioned as designed.

Note: Energy Industry Identification Codes are indicated in the text as (*XX*).

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