ML19327B984

LER 89-017-00:on 891005,discovered That Number of Operable Logarithmic Power Level Instrumentation Channels Less than Required by Tech Specs.Caused by Personnel Error.Shift Supervisor & Senior Reactor Operator counseled.W/891106 Ltr

ML19327B984
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/06/1989
From:	Ewing E, Millar D ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN118902, LER-89-017-01, LER-89-17-1, NUDOCS 8911140339
Download: ML19327B984 (4)

Text

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, j Aikinses P wer & Ught Company

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, Little Rock An 72303 i Tel 501377 4000 t

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. November 6. 1989 B

2CAN118902 U. S. Nuclear Regulatory Commission ,

Document Control Desk Mail Station P1-137.

Washington, D. C. ~20555

SUBJECT:

Arhansas Nuclear One - Unit 2 Docl.et No. 50-368 License No. NPF-6 Licensee Event Report No. 50-368/89-017-00 1'

Gentlemen:

In accordance with 10CFR50.73(a)(2)(1)(B), attached is the subject report concerning a personnel error wnich resulted in less than the required Technical Specification Logarithmic Power Level Nuclear Instrumentation

~ channels operable.

Very truly yours, E. C. Ewing General Manager -

Technical Support and Assessment ECE: DM: sgw attechment cc: Regional Administrator Region IV U. S. Nuclear Regulatory Co.amission

,- 611 Ryan Plaza Drive Suite 1000 Arlington, TX 76011 ,

INP0 Records Center 1500 Circle 75 Parkway Atlanta, GA 30339-3064 pgp$$k$Nhkt* .

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8 Form 1062.01 A U.S. Nuclear Regulatory Cummission NRC Form 366 Approved OMB Nu. ?150-0104

-(9-83) Expires: 8/31/85 EVENT LICENSEE REP 0RT (L E R)

FACILITY NAME (1) Arkansas Nuclear one, Unit Two IDOCKET NUMBER (2) (PAGE (3) 10151010101 31 61 Bill 0Fl013 TITLE (4) Personnel Error Results in Less Than the Required Technica) Specification Logarithmic Power Level Nuclear Instrumentation Charnels Ope *able EVEN' OATE (5) i LER NUMBER (6) l RLPORT DATE (7) 1 OTHER FACILIT]ES INVOLVED (0)

I i l . I 15equentiall l Revision l l l l 1  ;

Month! Day lYear lYea" l l Nurger I l Number ]Monthi Day lYear l Facility Names IDocket Number (s) l I i I i i i i l 10151010101 I i i 1 11 01 01 51 81 91 81 91--I 01 11 71--I 01 01 Il 11 of 61 81 91 101610 0i01 I I

. OPERATING l lTH15 REPORT 15 ;UBMITTED PUR$UANT TO THE REQUIRF.MENTS OF 10 CFR 5 MODE (9) 1 51 (Check one or aiore of the followino) (11)

POWERI 1,,,1 20.402(b) l _l 20.405(c) l_t 50.73(a)(2)(iv) (_l 73.71(b)

. LEVEL) 1.,,,) 20.405(a)(1)(1) 1,,,,) 50.36(c)(1) l_l 50.73(a)(2)(v) 1 ,,,i 73.71(c)

(10) 1010101 l 20.405(a)(1)(11) 1 ,,1 50.36(c)(2) l_l 50.73(a)(2)(vii) l,,,,,l Other (Specify in 1.,,,1 20. 405(a)(1)(111) 1,JI 50.73(a)(2)(1) I,,,,,l 50.73;a)(2)(vlii)(A)l t.bstract below and I, I 50.73(a)(2)(v111)(B)] in Text NRC Form I ) 20.405(a)(1)(iv) l_t 50.73(a)(2)(ii) I f 50.73(a)(2)(x) i 366A) i I 20.405(a)(1)(v) l l 50.73(a)(2)(iii)

(IrENSEE CONTACT,FOR THIS LER (12) lArea l Dana Miller, Nuclear Safety and Licensing Specialist l Code l ,

1510111916!41-13111010 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN TH15 REPORT (13)

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',,PPLEMENI REPORT EXPECTED (la) 1 EXPECTE0 l Month! Day itear 1 SUBMIS$10N l l l l'l Ves (If yes, complete Expected Submission Date) lxl No 1 DATE (15) i I I I I i ABSTRACT (Limit to 1400 spaces, i.e., approximetely fifteen single-space typewritten lines) ('.6) 7 l.

On October 5,1989, while in Cold Shutdown Control Room Op9rators recognized that the r6 aber of

! operable Logarithsh. (Log) Power Level Instrumentation channels was less than required t y Technica.

l Specifications for the existing plant condition. Modifications were in progress on the in* Tt 7*

,er I.evel channels to replace :able conne:: tors between instruments and Control Room cabf nei Shift Supervisor author 12eri the work to be performed on these instru.aents, without rev J. % the Techr. . 41 Sr.,cificition requirements. At the time vf occurrence of this event, the fun;"ar performed b/ d.e Log Power instrumentation channels was to provice e means of monitoring reactor . ore reactivity aM annunciation of abnormal conditions. During the time period Log Power was inoperatle other Control Room instrumentatiot. including boron dilition monitors and stat tup nuclear instruwentation channels were available for monitoring core reactivity conditions. Therefore, there was no safAty significance I

as a result of this event. Initial training has been provided to Operations persennel and additional training will be provided on the simulator concerning this event. This event is considered operations ,

prohibited by Technical Specifications and is reportable per 10CFR50.73(a)(2)(1)(8).

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. b' Form 1062.01B

'NRC Fors 366A U.S. Nuclear Regulatory Coe W eion *

(9 43) Approved OfS No. 315# 0104 Expires: 8/31/85 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION FACILITY NAfE (1) (DOCKET NLDSER (2) l HLASER (6) l PAGE (3)'

l l l . glnequentiell IRevision]

. Arkansas Nuclear One, Unit Two l l Veer I Number l l dumber l '

10151010101 31 61 8I E! 9 --I 01 11 71--I 01 Ol01210F1013 TEXT (If more space is requFed, use additionai NwC Fem 36sA's) (17)

A. Plant Status i

At the time of occurMnce of this condition Arkansas Nuclear One, Unit 'fwo (ANO-2) was in plant Mode 5 (Cold Shutdown) in preparation for the seventh refueling cutage (2R7). Reactor r oclant Systes (RCS) [A8) pressure was at atmospheric and RCS temperature approxiaetely 90 deg ~es FahrenSeit.

8. Event Description Technical Specification 3.3.1.1 requires that a s1nious of two of the four Logarithmic (Log)

Power Level Nuclear Instrumentation channels, a part of the Resctor Protective System (RPS) (JC),

be operable while in Mode 5 (Cold Shutdown) whenever the Reac'.or Trip Circuit Greakers (TCBs) are open. On October 2,1989, while perfoming a modification which replaced the cable connectors on the cabling from each nuclear instrumentation detector to e.ch Log Power Level channel, two Log Power Level channels were removed from service. A third channel was removed free service on October 3, 1989. On October 4, 1989, the fourth Log Power Level channel was removed from service.

l The sans operating crew was involved each day during the removal of the Log Power Level channels l

free service. On October 5, 1989, at 0335 hours0.00388 days <br />0.0931 hours <br />5.539021e-4 weeks <br />1.274675e-4 months <br />, Operations personnel recoge12ed that Techaical Specifications required at least two channels to be operable in the existing plant condition. A reactor Shutdown Margin calculation was perforwed to satisfy the Action requirements of the e applicable Technical Specification. Actions nye initiated to restore tin instrumentation to an operable condition. At 0755 hours0.00874 days <br />0.21 hours <br />0.00125 weeks <br />2.872775e-4 months <br /> on October 5,1989, three of the Log Pour Level channels were returned to service, therefore, meeting the requirements of Technical $per fications for Cold Shutdown conditions. The fourth Log Power Level channel was restored to seevice at 1435 hohrs on October 5, 1989.

l C. Safety Significance The RPS consists of logic, switchgear and other equipment necessary to moniser selected Nuclear Steam Supply System conditions and to effect reliable and rapid reactor shi.toown (reactor trip) if any or a combination of the sonitored conditions reach a Lietting Safety Systee Setting. The syster functions are to protect the core, the fuel design limits, and RCS pressure boundary for Anticipated Operational Occurrences. Four seasurement channels, with electrical and ohysical esperation, are provided for each parameter used in the generation of trip signals. Ouring normal operation, with all four channels operable, a 2-out-of-4 r. Incidence logic of lika trip signals is

/ required to generate a reacto: trip signal. Channel bypasses are provided to remove a channel from service for maintenance or testing. With a channel bypassed, the trip logic is converted to i a 2-out-of=3 basis of like trip signals. When the TCOs a~e cle; sed, the purpose of the High Log l- Power Level trip is to ensure the integrity of the fuel cladding and RCS pressure boundary in the I

event of an unplanned reactor criticality from a shutdown condition. When the TCBs are open, the l- Log Power Level channels are used for reactivity monitoring purpossa an.1 Control Rocs annereistion in the svent of an unplanned criticality. With four Log Power Level channels ir. operable, the capability to monitor reactor power level and the associated annunciation was not available with l-these ihstruments. However, two boron dilution sonitors and startup nuclear instrument: lion i channels were available to monitor core renctivity conditions during the time period the Log Power l instrumentation was inoperable. When in Mode 3, 4 and 5 with the TC8s open, and less than two Log c Power Level channels operable, one of the concerns is to ensure that adequate reactor Shutdown Margin exists. Although, a Shutdown Margin calculation was not performed within one hour of j <' removing the third Log Power Level channel, as required by Technical Specti1 cations, Shutdown Margin calculations were being perfomed once per twelve hours with no noted changes. Therefore,

!- the safety impact of this event is considered insignificant.

l O. Root Cause The root cause of this event was personnel error. Tre modifications to the nuclear instris entation l channels were being performed with a separate job order for each channel. Each job order was reviewed and ap,, roved by the Operatior.s Shift Supervisor prior to initiating the work. The Shift Supervisor who approved the job order, which iesulted in rendering the third channel of instrumentation inoperable on October 3, 1989, did not recognize that this activity would result in reducing, the number of operable channels to less than that required by Technical Specifications and cause entry into en Action Statement. This fact was also not recognized by a control Race tenior Reactor Operator who was infomed by Maintenance personnel that the channel was being removed free service 1

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, -e g s Form 1062.018

.NRC Fcre C46A U.S. Nuclear Regulatory Ceesission 1(9 83) Approved ODS No. 3160-C104 Expires: 8/31/86 LICENSEE E/Elff REPORT (LER) TEXT CONTINVATION

-k M TU W NAME (1) l DOCKET IRAGER (2) l 2R NL8tER (6) l PAGE (3) l l l lioquentiell IRevision!

Arkansas Nuclear One, Unit Two 1  % l Year i Number 1 I stueber l 10!$1010101 31;51 81 81 9 --I 01 11 71--I 01 Ol013IOF1013*

EXT (If more space is require (, use additional NRC Fors $66A's) (17) just prior to perforr.ing the modification. Additionally, the same errors occurred on October 4, 1989 when the fourth channel was allowed to be removed free service. Also, it we.s not recognized that Technical Specifications required at least one channel to be operable in the axisting plant condition.

Based on a detailed evaluation of the event, the following factors were e:onsidered to have contributed to the occurrence.

l e Control Rose personnel performed peradic conttoring (channel checks) of equipment required to be operable by the Technical Specifications. Following removal of the third and fourth nuclear instrumentation channels from service, it was noted on the monitoring log &, that the channel checks could not be performed due to the instruments being doenergized, ekwever, the n personnel did not refer to the applicable Technical Specification to ensure the requirements were ,

)

being met.

l e The job orders being used by reintenance personnel performing the work contai *d specif fe instructions requiring bypassing each channel prior to replacing the cable coi. sectors, however, these personnel did not consider bypassing the chantie'is to be required and therefors did not perfore this step. Additionally, there was no atteset safe to resolve this discrepancy prior to performing the work. Since the system is physics 11y oes4gned to prevent bypassing more than one ,

channel at a time, performance of the work activity without deviation free the job order l Ntruction would have prevented removal of more than one channel cf in;;.'usentation free service  ;

at one time. j E. Basis for Reportability Technical Specification 3.3.1.1 requirJs that a minious of two Log Power Level channels be operable in Cold shutdown.. - Since four channels were inoperable, this event is reportable under 10CFR60.73(a)(2)(1)(B), operation prohibited by Technical Specificctions.

F.. Corrective Actions The Operations Shif t Supervisor and the Control Room Senior Reactor Operator received counselling. ,

The Operations Shift Supervisor involved in this event has provided training to other Operations personnel to ensure each crew eneber is aware of the purpose of the performance of channel checks when in Cold Shutdown. Additionally, simulator training will be provided to Operations personnel to ensure each is made aware of the Technical Specifications associateJ with the Log Power Level  ;

channels. This training will be completed by March 1, 1990. The Superintendent of the maintenance personnel involved in this event will re-emphasize the importance ef complying with job ordce work instr

• actions to his personnel. Expected completion date of the re-esphesis is December 31, 1999.

G. Additional Information A similar event causad by personnel error whit:h resu'ted in the failure to eret a Technical Specification requirement to demonstrate nperab111ty of the redunJant valve ,.rior to initiating maintenance on a Low Pressure Irdection systes valve was reported in LEN 60-313/89-027-00.

Energy Industr/ Identification System (f!!$) code. are identified in the text as LXX3